End market applications for household polyethylene film pellets

Transcription

1 Summary report End market applications for household polyethylene film pellets A report investigating the potential end markets for post-consumer recyclate polyethylene derived from kerbside collected co-mingled film. Project code: WRAP IMT ISBN: [Add reference] Research date: June 2013 March 2014 Date: March 2014

2 WRAP s vision is a world where resources are used sustainably. We work with businesses, individuals and communities to help them reap the benefits of reducing waste, developing sustainable products and using resources in an efficient way. Find out more at Written by: Keith Freegard, Richard M c Carthy, Richard M c Kinlay and Liz Morrish Front cover photography: A variety of moulded products manufactured using post-consumer recyclate derived from household film waste While we have tried to make sure this report is accurate, we cannot accept responsibility or be held legally responsible for any loss or damage arising out of or in connection with this information being inaccurate, incomplete or misleading. This material is copyrighted. You can copy it free of charge as long as the material is accurate and not used in a misleading context. You must identify the source of the material and acknowledge our copyright. You must not use material to endorse or suggest we have endorsed a commercial product or service. For more details please see our terms and conditions on our website at

3 Executive summary This work focused on the identification of end market applications for Post-Consumer Recyclate (PCR) polyethylene film derived from UK kerbside co-mingled collection. Previous projects 1 have demonstrated that the same material was successfully used in the manufacture of refuse sacks. However, as the size of the refuse sack market is limited and black refuse sacks already contain recycled content, there is little scope to replace the use of virgin material in this application. In order to establish the collection and reprocessing of post-consumer polyethylene film in the UK, additional end markets for the PCR need to be identified. Five manufacturing trials were carried out to demonstrate the potential uses and end market applications for the material. These were: Manufacture of blown film dispatch bags and silage sheeting, from blends of PCR and virgin Low Density Polyethylene (LDPE) and Medium Density Polyethylene (MDPE) with British Polythene Industries (BPI); Production of injection moulded plaques made from blends of PCR and virgin Polypropylene (PP) using novel foaming technology with Coraltech Ltd; Manufacture of various rotational moulded items, including automotive parts, using blends of PCR and virgin MDPE with JSC Rotational Ltd; Manufacture of injection moulded nestable storage/ transport boxes with George Utz Ltd using a 50% PCR 50% virgin HDPE blend; and Manufacture of conventional foamed injection moulded parts with Hallam Plastics using a 50% PCR 50% virgin HDPE blend. The silage sheeting was produced at 17% PCR level to a satisfactory quality and it would be reasonable to assume that this could be increased to 20% without any significant production or quality issues being experienced. It has therefore been shown that the PCR can be successfully incorporated into thick gauged, heavy duty un-printed films to produce satisfactory products. The dispatch bags showed no significant reduction in mechanical properties when PCR was incorporated into a single layer of the film, however there is a noticeable reduction in print quality at low levels of PCR in the product. It will be important to understand if a slight reduction in appearance is acceptable by customers. The injection moulding trial using a novel foaming technique demonstrated that blends of PCR and PP can be made that could potentially be used in the production of items such as crates, boxes and pallets. Both the inclusion of PCR and foaming using the Coralfoam technology negatively affected some of the mechanical properties of the plaques and these factors should be taken into account if this technology were to be used. The PCR was also incorporated into several rotation moulded products of different shapes and sizes. It was demonstrated that the PCR could be used up to 100%; however, on some items the quality of the surface finishes was reduced and the stiffness of the PCR compared to virgin MDPE made larger sized products difficult to remove from the moulds. The PCR material does appear to be well suited to rotational moulding methods and can be used at lower concentrations (50% PCR or less) blended with virgin MDPE to overcome the above problems. Controlled 2 milling of the PCR to a suitable size (shown to be 500μm in this Controlling the temperature and rate of the PE milling process is vital to produce a high quality powder End market applications for household polyethylene film pellets 1

4 project) to produce a high quality powder is also desirable as this improves the surface finish of the moulded items. The injection moulding trial in which a storage/transport box was manufactured demonstrated that a 50/50 blend of the PCR and a virgin HDPE could be used to produce a box that was comparable to a box made from 100% virgin material in terms of aesthetics and functionality. This is a very promising result for the PCR as it highlights the potential to replace virgin HDPE and still manufacture products that meet final specifications. The trial carried out on the conventional foamed injection moulded part and injection moulded connectable turf tile gave similar results to the box manufacturing trial, in that there was little difference in a product made using a 50/50 PCR to virgin HDPE blend and a 100% virgin HDPE product. Once again this highlighted the potential for the PCR to be used as a virgin polymer replacement even in relatively complicated and demanding applications. It was, however, found that the market for this type of product is limited with a very low tonnage, and attention should probably be focused on the other markets identified. The results of this trial should be used to encourage moulders to incorporate this type of PCR into their products, most notably in the automotive industry Research into the potential size of the market for PCR for a selection of suitable products and the barriers of supplying the PCR in to these markets was undertaken. Table 1 shows estimated tonnages of PCR which could be supplied into various markets/products. Table 1 Potential estimated demand for PCR and likelihood of supply Market/product Heavy duty agricultural films and construction films Rotational moulded items (such as mannequins, storage tanks and bins) Estimated demand (tpa) 3 17,000 Automotive parts 15,700 Drainage and water piping 20,000 Pallets, boxes and crates 2,800 (assuming only black products are suitable) Undetermined, but could be in the region of 3,000 to 6,000 Total 58,500 to 61,500 Likelihood of supply High already uses recycled material and high demand for the products Medium to high is technically feasible but market is not used to using recycled material Medium recycled material can be used in non-critical parts although further trials to prove suitability are required Medium to high has not been tested in application but is likely to be feasible and product already uses recycled material High initial test with George Utz Ltd. show the PCR can be used to produce comparable products to virgin The most significant opportunity to replace virgin material is in the production of injection moulded pallets, crates and boxes. The injection moulded products represent a relatively 3 See Section 4 of the report for assumptions and calculations of the tonnages End market applications for household polyethylene film pellets 2

5 large potential tonnage (see estimates in Table 1) and the PCR could really make an impact in this market. Supply into the rotational moulding market is another great opportunity. The PCR was shown to mould well using this technique and a wide range of products could be made. Furthermore a high recycled content (75% PCR or higher) can be used in the products with no significant negative effect to functionality or aesthetics. Supply into the automotive market would be a great success and achievement. This market has demand for significant tonnages and is continuing to grow. Furthermore automotive parts require a good quality recyclate and if the PCR is shown to be used in this sector it would give others confidence in using the material. This supply route is more of a long term plan as the process of supplying recycled material into the automotive market can be lengthy. Further demonstration trials specifically moulding automotive parts would be needed. Supply into heavy duty films and drainage/water piping applications would mean a large potential demand and also as both currently use recycled material it would be technically feasible. Recycled material is currently sourced either from agricultural films (used in heavy duty films) and post-consumer jazz (coloured) HDPE rigid packaging (use in drainage pipes). The demand for these products is very high and manufacturers are seeking additional sources of PCR to increase production. In order to market the PCR it must ideally be displacing virgin polymer (as in the case of the pallet, box and crate manufacture) or at least be able to compete with recycled material from other sources, such as post-use agricultural films, films from commercial and industrial sources or post-consumer rigid jazz packaging. Two cost models have been presented which give the value for the PCR if it were to be marketed alongside other recycled material and the value for the PCR as a high grade virgin substitute. If the material is shown to have consistent properties that are desirable in a given application and is a high quality material (consistent and with known physical properties comparable with virgin PE) with low contamination levels (<0.5% solid contamination and a comparable level to virgin polymer), then it has the potential to be used in virgin replacement applications such as rotational moulding. If the extra effort through strict quality control and feedstock procurement is made then the PCR could be marketed for around 700 to 800 per tonne. It is also possible to supply the PCR into products that already have a recycled content, such as heavy duty films. These markets utilise significant tonnages and current demand for recycled material is high. In this market the PCR must compete with similar quality recycled material and a sensible market value would be in the region of 600 per tonne. The importance of quality control on any process making PCR from post-consumer film must be stressed, as with production of any recycled materials. Strict quality control and known properties of the recycled polymer will give customers confidence in the material and the product, which will in turn help increase the likelihood of supply into additional markets. It is desirable that further demonstration trials be carried out in moulding automotive parts as this could be a significant potential market which hasn t been thoroughly investigated in this report. The project has demonstrated that virgin polymer can be replaced to produce functional products such as dispatch bags with only a slight reduction in print quality. If this is determined to be acceptable as there is no negative effect on the functionality, then it could End market applications for household polyethylene film pellets 3

6 open up a large market for the PCR. Perception issues also need to be addressed; buyers, marketeers and consumers need to be educated to understand that the functional specification of these products can still be met with the inclusion of recycled plastics. It is feasible to have minimal impact on visual appearance by controlling the content of recyclate added. The opportunities for potential cost savings and support Corporate Social Responsibility initiatives within companies are significant. There is great potential for PCR derived from UK sourced post-consumer film. The evidence in this report shows there is a demand for the end product and if post-consumer film can be recycled in the UK there could be significant benefits. Not only would a high volume waste stream be diverted from landfill but also virgin polymer could be substituted by recycled material, leading to environmental and economic benefits for the whole supply chain. End market applications for household polyethylene film pellets 4

7 Contents 1 Introduction Properties of the PCR Manufacturing demonstration trials Film manufacture Dispatch bags Silage sheet Conclusion Injection moulding using novel foaming techniques Trial methodology Trial results and discussion Conclusion Rotational moulding Trial methodology Trial results and discussion Conclusion Injection moulding of storage/transport boxes Trial methodology Trial results and discussion Conclusion and recommendations Injection moulding of foamed part used in storage casings and injection moulded turf tile Foamed storage container Injection moulded turf tile Conclusions and recommendations Evaluation of end market opportunities Film manufacture Potential market size Barriers to adoption Rotational moulding Potential market size Barriers to adoption Automotive parts Potential market size Barriers to adoption Plastic water/drainage pipe Potential market size Barriers to adoption Plastic pallets, crates and boxes Potential market size Barriers to adoption Summary and conclusion of end markets Opportunities to amend the film recycling method Economic analysis Potential sales price Pricing model 1 supply into existing recycled markets Price model 2 supply into new applications Pricing models summary PCR production cost Routes to market for PCR Conclusion and recommendations Film manufacture demonstration trial End market applications for household polyethylene film pellets 5

8 8.2 Injection moulding using novel foaming technology demonstration trial Rotation moulding demonstration trial Injection moulding of storage boxes Injection moulding of foamed part used in storage casing and turf tile Market opportunity evaluation Economic analysis and potential for process simplification Closing comments List of Tables Table 1 Potential estimated demand for PCR and likelihood of supply... 2 Table 2 Physical properties of PCR Table 3 Composition of film blends made during the trial Table 4 Mechanical properties of dispatch bags Table 5 Mechanical properties of silage sheet Table 6 Blends used for Coraltech trial Table 7 Summary of effect of PCR content and foaming on mechanical properties Table 8 Products and blends made using rotation moulding at JSC Table 9 Recommended PCR content for products trialled at JSC Rotational Table 10 Physical properties of PCR/HDPE blend used in injection moulding trial Table 11 Blowing agents investigated in the trial Table 12 Potential market for PCR in rotational moulded applications Table 13 Potential recycled content of automotive parts Table 14 Summary of potential market demand for PCR Table 15 Virgin polymer prices Table 16 Cost model assumptions for film reprocessing plant List of Figures Figure 1 Dispatch bag blowing line Figure 2 Roll of film produced during the trial at BPI Figure 3 Example of lensing seen on inside of dispatch bag Figure 4 Comparison of print on virgin film (L) and film with 10% PCR in black layer (R).. 16 Figure 5 Comparison of print quality of bags with 20% (L) and 40% PCR (R) in the black layer Figure 6 Comparison of bags with different recycled content: virgin film, 10%, 20% and 40% PCR in the black layer samples Figure 7 Silage sheet Figure 8 Photograph of cross section of non-foamed plaque (top) and foamed plaque with smooth skin (bottom) Figure 9 Split of polymers used for injection moulding Figure 10 Blended feed material showing blowing agent, virgin PP and PCR Figure 11 Impact strength of virgin pallet grade PP and PCR blends, foamed and nonfoamed Figure 12 Comparison of impact strength for different PP grades Figure 13 Tensile strength of virgin pallet grade PP and PCR blends, foamed and nonfoamed Figure 14 Comparison of tensile strength for different PP grades Figure 15 Strain at ultimate tensile strength for virgin pallet grade PP and PCR blends, foamed and non-foamed End market applications for household polyethylene film pellets 6

9 Figure 16 Maximum strain for virgin pallet grade PP and PCR blends, foamed and nonfoamed Figure 17 Flexural strength for virgin pallet grade PP and PCR blends, foamed and nonfoamed Figure 18 One of two rotation moulding kilns at JSC Rotational Ltd Figure 19 Compounded and milled PCR (650µm) Figure 20 Products made during trials at JSC Rotational blended with white and black virgin MDPE Figure 21 Horse jumps made using different PCR concentrations Figure 22 Comparison between 100% PCR horse jumps moulded with material milled to 500μm (L) and 650μm (R) Figure 23 Close up comparison of the horse jumps Figure 24 Raised air intakes made with 25% PCR blended with black and white virgin MDPE Figure 25 Interior of hay feeder at various PCR contents Figure 26 Nestable storage/transport box Figure 27 Pellets made from the 50/50 PCR and virgin HDPE blend Figure 28 Injection moulding unit operated by George Utz Ltd Figure 29 Moulded boxes on production line Figure 30 Photograph showing shrinkage on the trim of the box Figure 31 Injection moulder operated by Hallam Plastics Figure 33 Comparison of foamed parts (external) Figure 34 Comparison of cross section of foamed parts Figure 35 Comparison of virgin and PCR sample Figure 35 Foamed structure of sample Figure 36 Terraturf turf tile made from 100% virgin HDPE Figure 37 Connectors on turf tile made with virgin HDPE Figure 38 Terraturf turf tile made from 50% PCR and 50% virgin HDPE Figure 39 Comparison of underside of turf tiles Figure 40 Connectors on turf tile made with 50% PCR Figure 41 Connected turf tiles Figure 37 Rotational moulding PE usage by product type Figure 37 Price fluctuations for HDPE between March 2011 and March Glossary BPI HDPE LDPE MDPE Mechanical properties MD MFI MRFs NIR PCR PE PP Physical properties TD British Polythene Industries High Density Polyethylene Low Density Polyethylene Medium Density Polyethylene Properties relating to the strength and stiffness of a material Machine Direction (direction in which the film is blown) Melt Flow Index measured in g/10 minutes Materials Recovery Facility Near-infrared Post-Consumer Recyclate Polyethylene Polypropylene All physical properties of a material including MFI, density and all mechanical properties Transverse direction (direction perpendicular to the machine direction) End market applications for household polyethylene film pellets 7

10 Acknowledgements Axion Consulting and WRAP would like to thank BPI, JSC Rotational Ltd, Coraltech along with FSG Tool and Die Ltd and GR8 Engineering, George Utz Ltd and Hallam Plastics for their participation in the project and assistance in the manufacturing trials. Axion would also like to thank Environmental Recycling Technologies, ICO Polymers, Micropol, and Huhtamaki UK for trial assistance, feedback on market research and sample testing. End market applications for household polyethylene film pellets 8

11 1 Introduction It is estimated that each year in the UK around 285,000 tonnes of waste Polyethylene (PE) film is generated 4 from consumer sources. Presently in the UK there is limited capacity to recycle waste PE film. This is due to the whole collection, sorting, processing and recycling sector being in its infancy. There is currently only a limited number of local authorities collecting post-consumer film, a lack of facilities sorting film from other dry recyclables, one dedicated post-consumer film reprocessing facility in the UK and a limited range of end markets for recycled PE film. A previous project conducted by WRAP 5 demonstrated the feasibility of separating postconsumer film from UK Material Recovery Facilities (MRFs), and showed it was possible to produce a high quality Post-Consumer Recyclate (PCR) capable of being used in the manufacture of refuse sacks. The refuse sacks produced from the PCR met product specifications, although there were some concerns over the odour of the material. Although the PCR was suitable for use in refuse sacks, this product already contains a significant proportion of recycled material, largely from recycled agricultural film. Introducing PCR from post-consumer film into the refuse sack market is technically feasible and it is a viable end market; however, in order to maximise the potential for reprocessing film additional end markets are required, particularly those that provide the opportunity to displace virgin polymer. As a result this project has been carried out to assess alternative end market applications, focusing on areas where virgin polymer could be replaced with recycled material. In order to give confidence to manufacturers and customers there is a need to demonstrate that PCR can be successfully incorporated into products. A series of demonstration trials were carried out investigating the effects of incorporating different concentrations of PCR into a range of products using various production techniques as follows: Film blow moulding of dispatch bags and silage sheeting carried out with British Polythene Industries (BPI) at its production site in Stevenston, Scotland; Injection moulding using novel foaming technology to produce test plaques with Coraltech Ltd at FSG Tool and Die Ltd at its site in Llantrisant, Mid Glamorgan; Rotational moulding to produce automotive parts, agricultural items and retail mannequins with JSC Rotational Ltd at its moulding facility in Worcester; Injection moulding of storage crates with George Utz Ltd at its moulding facility in Alfreton, Derbyshire; and Injection moulding of a foamed part (used in a storage casing) using conventional foaming technology with Hallam Plastics at its moulding facility in Langley Mill, Nottinghamshire. This report presents the results of these demonstration trials along with an end market assessment to quantify the potential usage of recycled PE derived from post-consumer film in the UK, suggesting the most suitable areas of uptake for the PCR. 4 Valpak PlasFlow 2017 Report (2013) 5 WRAP IMT , Processing trials for household film waste, End market applications for household polyethylene film pellets 9

12 2 Properties of the PCR The PCR used in the demonstration trials was material produced as part of an earlier WRAP project Processing trials for household film waste 6. The PCR was derived from UK sourced post-consumer film that was separated from kerbside collected co-mingled dry recyclables using Pellenc Selective Technologies near-infrared (NIR) technology and extruded into pellets at Régéfilms, then a leading film recycling company in France. The PCR was tested at Axion Polymers to measure the physical properties of the polymer. The testing was carried out following ISO standards and the results are presented in Table 2. Table 2 Physical properties of PCR MFI (g/10min) Impact Strength (kj/m 2 ) N.B. 8 Tensile Strength (MPa) 10 Elongation at yield (% of original length) 15.6 Elongation at break (% of original length) Moisture (% H 2 O) 0.21 Density (t/m 3 ) 0.95 These properties have been obtained from testing a relatively small quantity of PCR and if household film collection infrastructure was established across the UK these properties may vary slightly. The MFI will always be low as film can only be made from polymer with a low MFI (typically MFI <3 g/10 minutes is used). Comparing these properties with virgin HDPE or virgin LDPE is not feasible because there are many grades of HDPE and LDPE that have been specifically designed for certain applications. The physical properties of these different grades can vary a huge amount. The nature of the recycling process means that the resulting PCR s physical properties are a generic blend of all the individual constituent components in the sorted PE film packaging mix. The PCR had a green/grey colour that was inconsistent through the batch. This will limit the uses of the PCR to black or darker colours, or in applications where a consistent colour is not required. The PCR pellet also had an initial distinct odour which was not desirable. It is believed that this could be reduced or removed through using vacuum extrusion or 6 WRAP IMT , Processing trials for household film waste, 7 The MFI was measured several times by independent laboratories. The MFI varied largely, and this is most likely down to a fundamental issue that MFI measurements are done on very small quantities of material, and polymer behaviour can change greatly over small temperature intervals. A 5kg weight was used and 190 o C for all measurements 8 N.B. stands for No Break and means the sample did not break on impact. Instead the sample bent and absorbed energy through this. End market applications for household polyethylene film pellets 10

13 increasing the residence time in the extruder so shouldn t be considered an inherent problem or barrier to the PCR being used in manufactured products. As this material is derived from a variable feedstock, the physical properties may vary, depending largely on the blend of HDPE and LDPE within the original feedstock. Therefore in reality if this material were produced commercially, careful procurement of feedstock and blending and monitoring of the production batches would be required to give customers faith in the consistency of product. End market applications for household polyethylene film pellets 11

14 3 Manufacturing demonstration trials Five manufacturing demonstration trials were carried out to investigate using the PCR in different products using various moulding techniques. It is likely that to be used widely in industry the PCR will be blended with a virgin polymer for which the product has been designed for. Therefore many different blends of PCR and virgin polymer were investigated in most trials. 3.1 Film manufacture Following the success of the previous WRAP refuse sack manufacture trial 9 other blown film products that could use the PCR were also investigated. A production trial was carried out with BPI at its production site in Stevenston, Scotland. The trial looked at incorporating the PCR into two products; dispatch bags and silage sheeting Dispatch bags These are bags that are used by mail order companies and delivery companies to post goods to customers. The dispatch bags are a three layered film with outer, middle and inner layers. The inner layer makes up about 25% of the bag by weight and is where the PCR was used in this trial. It was used in the inner layer for two reasons: The inner layer is black and therefore the colour of the PCR would not be an issue; and The gels and contamination in the PCR can give a rough surface finish, which would probably not be printable. This should be less prominent when the PCR is used only on the inner layer. At the time of the project the dispatch bags made by BPI contain only virgin polymer and no recycled content, and so the opportunity to displace virgin material was available here. The reason why BPI do not currently utilise recycled material in the manufacture of this product is the high quality expected by the end customer. Previous experience with recycled polymers has led technical staff at BPI to conclude that any gels or contamination would likely prevent the film from meeting the required aesthetic standards for this product but the film may be fit for purpose in terms of the mechanical properties of the film if PCR is included at reasonable levels (around 20% PCR in total in the film) Trial methodology The trial took place at BPI Visqueen, in Stevenston, Scotland. This BPI site concentrates mainly on the production of heavy duty film such as agricultural films and construction films. The dispatch bag film is made using a film blowing line able to make three layered film. The film is blown using conventional technology; polymer is extruded through a ring shaped die and inflated to form a bubble. This bubble is then collapsed and the film cooled before being rolled up. Figure 1 shows the blowing line at BPI. 9 WRAP IMT , Processing trials for household film waste, End market applications for household polyethylene film pellets 12

15 Figure 1 Dispatch bag blowing line The blown film is split down the sides to produce two rolls of flat sheet which are later converted into dispatch bags off-line. Five different blends of film were made for the trial and the proportions of virgin and recycled material are shown in Table 3. Table 3 Composition of film blends made during the trial Sample number Composition of black layer PCR% content of whole bag PCR MDPE Masterbatch 0 0% 85% 15% 0.0% 1 10% 75% 15% 2.5% 2 20% 65% 15% 5.0% 3 40% 45% 15% 10.0% 4 70% 15% 15% 17.5% Masterbatch and the Medium Density Polyethylene (MDPE) were used to give the film its required stiffness. Because of this the maximum amount of the black layer that was PCR was 70%. In addition a desiccant was added to absorb excess moisture at 5% addition % addition means that 5% of the total mass of the layer of desiccant was added. For example if the layer had 10kg of material in there would be an additional 0.5kg of desiccant. End market applications for household polyethylene film pellets 13

16 Desiccant is not required when blowing film from virgin polymer and was used during the trial because of the inclusion of the PCR which has a higher moisture content. The materials were weighed and blended automatically and fed straight into the extruder. Each blend was processed for approximately 30 minutes to produce two rolls of film. Figure 2 shows a roll of film produced during the trial. Between each new blend a reject reel of film was made to purge the line of the previous material and avoid cross-contamination. Figure 2 Roll of film produced during the trial at BPI The 0% PCR film was made first after which the 70% PCR black layer film was made. The PCR content was then reduced with each subsequent blend to give the five different blends. Samples of the film were taken by BPI for physical properties testing and one roll of each blend was converted into dispatch bags and printed. By printing the bags any defects in the film caused by solid contamination would show up more prominently. Visual assessment of the film was undertaken by BPI during the processing to qualitatively assess the contamination level Results and discussion The PCR processed with some issues during the production of the dispatch bags. The blend with 70% PCR in the black layer caused problems with the film blowing process. Initially the bubble was formed but it was apparent there was a significant level of solid contamination in the film and lensing as a result of excess volatiles and moisture in the PCR pellets which formed small holes in the black layer of the film. Lensing is where gaps can be seen in the film, as shown Figure 3. End market applications for household polyethylene film pellets 14

17 Figure 3 Example of lensing seen on inside of dispatch bag 40% PCR in black layer These holes occasionally went through all three layers of the film and caused air to escape from the bubble, deflating it. This occurred several times and eventually the bubble collapsed. As a result it was not possible to produce a roll of film with a 70% PCR black layer. This demonstrated that even if customers were able to accept a reduction in aesthetic quality there were significant processing problems which would prevent this level of PCR being used. All the remaining blends (0-40% PCR in the black layer) were able to be processed with no issue. There were no other deflations or bubble collapses and rolls of film were successfully produced. An important property of the film is its visual appearance that must attain a high standard in order to meet customer requirements. This is the reason BPI do not currently use its own in-house recyclate in this product. As the film is thin any small pieces of solid contamination or gels, even when only in the inner layer, will become apparent on the outside white layer of the product. This produces a below standard product that would currently be likely to be rejected by the end customer, although it was not possible to obtain any formal feedback within the timescales for this project. A similar issue is present with lensing in the film which as well as resulting in processing implications has a negative effect on the aesthetics of the film. The gaps can be seen through the white outside layer and are also highlighted when the film is printed. Figure 4 shows the printed area of a bag with 0% PCR and one with 10% PCR in the black layer demonstrating the reduction in print quality as a result of the above factors. End market applications for household polyethylene film pellets 15

18 Figure 4 Comparison of print on virgin film (L) and film with 10% PCR in black layer (R) It can be seen that there are small defects on the printed area of the bag with just 10% PCR in the black layer. The print quality reduces further with increasing PCR content. Figure 5 shows dispatch bags made with 20% and 40% PCR in the black layer. There doesn t appear to be a significant difference between the print quality of the two bags although it is lower than the virgin or 10% PCR bags. Figure 5 Comparison of print quality of bags with 20% (L) and 40% PCR (R) in the black layer End market applications for household polyethylene film pellets 16

19 Figure 6 Comparison of bags with different recycled content: virgin film, 10%, 20% and 40% PCR in the black layer samples Although the film is considered to be good quality, it may not meet the exacting standards of marketing or purchasing departments even with as little as 10% PCR in the black layer. If attitudes and buying requirements were to change then it may be possible to include PCR in printed films in the future. Providing a slight reduction in appearance is acceptable by customers, using recycled material rather than virgin could potentially decrease production costs for the dispatch bag, although an economic assessment would be required to ascertain actual savings and confirm this. It is suggested that a survey should be conducted with the end recipients of the dispatch bags (ultimately customers receiving posted goods) to gather feedback on consumer attitudes towards packaging with recycled content. If it is shown that the end user accepts a reduction in print quality due to the use of recycled material it may give the customers ordering the dispatch bags confidence to include and accept recycled materials. It therefore should not be seen as an impossibility to include recycled content in printed films, and further research and development should be done to encourage customers to accept minor print defects if it enables the use of recycled material instead of virgin material Physical property testing As well as meeting the required standards visually the film must also have the required physical properties. In addition to having an impact on the appearance of the films, gels and lensing can also decrease the strength. Assessing the physical properties of the film is important, if the customer could accept the reduction in quality of the appearance, there would need to be reassurance that the bags would still be strong enough and fit for purpose. End market applications for household polyethylene film pellets 17

20 Table 4 shows the mechanical properties of the film as measured by BPI. BPI has commented that there is no standard specification for this product and each product is bespoke to meet its customers requirements. The table gives the mechanical properties of the film in the Machine Direction (MD) and in the Transverse Direction (TD). % PCR in black layer Table 4 Mechanical properties of dispatch bags 1% secant modulus (MPa) Stiffness (N/mm) Elongation at break (%) Ultimate tensile strength (MPa) Maximum load (N) Yield (MPa) Elmendorf tear strength (N) MD TD MD TD MD TD MD TD MD TD MD TD MD TD 0% % % % It can be seen that the mechanical properties of the film do not reduce significantly as PCR content is increased. Some properties such as stiffness and tear strength do show a downwards trend although this is likely to be within experimental error and natural variation Silage sheet In addition to trialling the production of dispatch bags BPI was able to run the material on a silage sheet product. This product is a thick gauge film (100μm) that comprises of three layers. To retain the strength of the film the PCR was added into one layer. Figure 7 shows the silage sheet product. Figure 7 Silage sheet Initially the PCR was added in at 80% to one of the layers. At this level it was not possible to sustain a bubble during blowing as gels in the PCR caused holes in the film. As a result End market applications for household polyethylene film pellets 18

21 the addition rate was reduced to 50% PCR in a single layer giving an overall PCR content of 17% for the silage sheet. At this level there were no processing issues and the film was produced successfully. Table 5 shows the mechanical properties of the standard BPI silage sheet and the trial sheet made with a total of 17% PCR. Table 5 Mechanical properties of silage sheet Standard film 17% PCR film 1% secant modulus (MPa) Stiffness (N/mm) Elongation at break (%) Ultimate tensile strength (MPa) Maximum load (N) Yield (MPa) Elmendorf tear strength (N) MD TD MD TD MD TD MD TD MD TD MD TD MD TD As with the dispatch bags there is no significant reduction of the physical properties which would prevent the film from functioning. There is a reduction of properties in the machine direction however in the transverse direction the properties increase slightly, although this could be down to experimental error and variation as it is not a significant difference. The success of the silage sheet production can be extrapolated to suggest that the PCR could be used in any thick gauge, unprinted heavy duty film such as building and construction films. The UK market for these films, including agricultural films is in the region of 85,000 tpa. Assuming a 20% addition of PCR this means a potential demand of 17,000 tpa for the recycled PE from post-consumer film. The PCR could be used by BPI and other film producers providing it is competitively priced (as discussed in the end market evaluation in Section 6) and the PCR is of a consistent quality. The PCR would have to be an equivalent quality to the material used in this project, with minimal contamination levels Conclusion The trials have demonstrated that it is technically feasible to incorporate PCR into printed film such as dispatch bags. The dispatch bags showed no significant reduction in mechanical properties when PCR was incorporated into a single layer of the film, however there is a noticeable reduction in print quality even at overall addition levels of 2.5% PCR in the product (10% PCR in the black layer). Currently it is believed by BPI that the products would not meet the visual standard that is expected from the buyer. The bags produced are fit for purpose; however, a change in attitude from the buyers would be required before PCR could be used in printed film products. If small reductions in print quality could be accepted then this would open up a significant market opportunity for PCR. It is strongly recommended that work be undertaken to establish end users opinions on reduction in print quality as a result of including recycled material. It may be the case that consumers are willing to buy/receive products in packaging that does not look visually perfect if this is as a result of the products having a recycled content. There could also End market applications for household polyethylene film pellets 19

22 potentially be a cost benefit to the manufacturer and customer, although this has not been established in this project. If this is found to be the case then it would open up a significant market opportunity for the PCR into printed film applications as technically it is feasible (no significant change in mechanical properties of the film) to include it in these products. The second trial carried out on the silage sheet product showed that film can be made with 17% overall PCR content to a satisfactory quality. Since there is no printing on the film and it is of a thicker gauge, contamination has less effect so this makes it an ideal product for the PCR. It was seen however that the PCR still contained too high a level of gels to be used in the silage sheet at a 27% 11 addition level. Gels are an inevitable part of reprocessing PE as they are formed when the polymer is heated and cooled. The level of gels can be reduced though the use of additives although the cost benefit of this would have to be assessed. However the PCR would still be suitable for use in heavy duty films such as silage sheet or damp-proof membrane at around a 20% addition rate. This could give a potential market demand in the region of 17,000 tpa of PCR. 3.2 Injection moulding using novel foaming techniques Injection moulding is widely used in the UK in the production of various items such as automotive parts, consumer packaging, crates, bins and many other items. It is an attractive moulding option as once a mould has been created it is relatively low cost to produce a large number of identical items. Coraltech Ltd is a UK firm that develops ways to maximise performance, value and efficiency of moulded polymers. The trials were carried out with technical assistance from GR8 Engineering at FSG Tool and Die Ltd in South Wales. This trial looked at producing test plaques made using the PCR and virgin polymer and foaming them using the Coralfoam technology. Coralfoam Core-Back technology is a process owned by Coraltech Ltd and has been licenced to vehicle manufacturers and packaging producers to manufacture stiffer and lighter articles in shorter cycle times. The technology uses carbon dioxide gas generated from chemical blowing agents, and through design of the mould and control of the process, produces foam mouldings with defined skins. Experience with carbon dioxide has also shown that the gas acts as a solvent and improves flow as well as improving mixing of dissimilar polymers. Figure 8 shows the cross section of a foamed and non-foamed plaque % PCR in the whole film is equivalent to 80% PCR in a single layer. End market applications for household polyethylene film pellets 20

23 Figure 8 Photograph of cross section of non-foamed plaque (top) and foamed plaque with smooth skin (bottom) This trial looked at blending the PCR with PP rather than substituting virgin PE. This is because PP is more commonly used in injection moulding applications than PE. It is not commonplace to blend PE and PP; however, the use of the blowing agent can aid in the mixing of the two polymers. This also demonstrates the versatility of the PCR. Figure 9 shows that 53% of material injection moulded is PP, and only 15% is PE. Furthermore the PE that is injection moulded is likely to be food contact closures such as bottle caps although some are articles such as crates and pallets. Figure 9 Split of polymers used for injection moulding 12 PVC 3% ABS/SAN 4% PA 3% PS 9% PE 15% Other 13% PP 53% Additionally, the characteristics of PE complement those of PP. PP is rigid yet brittle and PE is generally flexible and less brittle. By blending the two polymers interesting products can be made. Such injection moulded products that could potentially contain recycled PE would be automotive parts, crates, boxes and pallets. 12 Plasteurope.com, UK Injection Moulding, Applied Market Information data, End market applications for household polyethylene film pellets 21

24 3.2.1 Trial methodology There were a number of objectives to the trial carried out with Coraltech: To prove the PCR could be injection moulded without serious issues or damage to standard machinery; To produce several samples of plaques using different blends of PCR with different grades of PP; To compare the mechanical properties of plaques produced from various PCR and PP blends; To compare the mechanical properties of foamed and non-foamed samples; and To determine whether blends using PCR can be used as a viable alternative to virgin polymers in the production of materials via injection moulding, either using Coralfoam process or not. During the trial the PCR was blended with three different grades of PP to produce foamed and non-foamed plaques. The three grades of PP used were: A super stiff grade of virgin PP 13 ; A virgin PP used in pallet production 14 ; and A recycled PP derived from end of life vehicles 15. Each of these PP grades was used to produce individual blends with the PCR. The pallet grade virgin PP was used to create plaques with the greatest range of PCR blends, with the other two PP grades used on a limited number of blends. For each blend both foamed and non-foamed samples were produced. Table 6 shows the blends used to produce different test plaques. Table 6 Blends used for Coraltech trial Material blended %PCR included Super stiff virgin PP 50% Pallet grade virgin PP 0%, 10%, 20%, 30%, 50%, 75%, 90% Recycled PP 0%, 50% Each blend was created by weighing the appropriate ratios of materials, putting these into a bucket and hand mixing. This blended material was then placed into the hopper once the injection moulder had reached optimal conditions and the plaques were moulded. Figure 10 shows one of the feed blends produced for the trial. 13 A virgin PP no longer in a production. Had twice the stiffness of the pallet grade virgin PP 14 Borealis PP copolymer, product code BE375MO 15 Axion polymers, recycled PP, product code PP End market applications for household polyethylene film pellets 22

25 Figure 10 Blended feed material showing blowing agent, virgin PP and PCR The initial three plaques produced from each sample blend were discarded to account for any materials left in the injection moulder from previous blends. After this samples of subsequent plaques were taken. For the majority of samples a minimum of five non-foamed plaques and ten foamed plaques were produced. Any excess material was then purged from the injection moulding equipment and the process was repeated with a new blend. Following the trial at FSG Tool and Die, the plaques were transported to Axion s polymer laboratory for mechanical property testing. The flexural strength was measured by an external company, Huhtamaki UK Trial results and discussion There were no noticeable processing issues encountered when moulding the PCR. The moulding demonstrated that the material could be easily used on equipment designed for low MFI material. It is believed that the blowing agent (present in the foamed and nonfoamed samples) increased the MFI of the PCR and so including this could potentially allow it to be moulded on less specialised equipment. The operators who controlled the injection moulder during these trials were highly experienced and were able to give valuable feedback on the material. They commented that the quality of the plaques being produced, both foamed and non-foamed, was high and suggested that the PCR could easily be used in blends for manufacturers of injection moulding products, especially in the automotive industry. When mixed with white virgin PP the plaque had a green colour from the PCR as expected. When moulded with black recycled PP the overall colour was black and it is expected that Masterbatch would be added to give a consistent colour. This is standard procedure when processing recycled material with a varying or inconsistent colour. The mechanical property tests were mainly conducted at Axion s laboratory with the exception of the flexural strength test; conducted by Huhtamaki UK. Figure 11 shows the effect on impact strength of different proportions of PCR present and the effect of foaming the plaques. End market applications for household polyethylene film pellets 23

26 Figure 11 Impact strength of virgin pallet grade PP and PCR blends, foamed and nonfoamed Impact Strength, kj / m foamed non-foamed 0 0% 10% 20% 30% 50% 75% 90% %mass of PCR in blend It should be noted that none of the non-foamed samples broke upon impact. The foamed samples only broke at low PCR content (up to 30%). This was because of the PP present which breaks on impact whereas the PE yields; this could be a desirable property in products such as storage and transport boxes. The impact strength of the foamed plaque samples appears to remain fairly constant (within a range of 20 kj/m 2 ) regardless of the composition of the feed blend. The impact strength of the foamed samples is lower than non-foamed samples with the exception of blends with 30%, 75% and 90% PCR. This suggests that there isn t a strong correlation and it would be difficult to predict whether foaming would increase or decrease impact strength. This would depend on the impact strength of the non-foamed sample. Figure 12 shows a comparison between the impact strength of different foamed PP grades at 50% PCR content and a 100% PCR plaque. Interestingly the 50/50 virgin pallet grade PP, recycled PP and 100% PCR all had the same impact strength when foamed, suggesting the PCR properties dominated the blend. The super stiff PP however retained its strength more, showing that by altering the grade of virgin PP certain mechanical properties can be altered even when PCR is included and the material is foamed. End market applications for household polyethylene film pellets 24

27 Figure 12 Comparison of impact strength for different PP grades Impact strength kj/m 2 Ultimate Tensile Strength, MPa % PCR 50% super stiff virgin PP 50% PCR 50% pallet grade virgin PP 50% PCR 50% recycled PP 100% PCR 100% virgin Foamed plaque composition Figure 13 shows the tensile strength of the foamed and non-foamed plaques made from the virgin pallet grade PP and PCR. Figure 13 Tensile strength of virgin pallet grade PP and PCR blends, foamed and nonfoamed Foamed Non-foamed 5 0 0% 10% 20% 30% 50% 75% 90% mass% of PCR in blend There is a clear decrease in tensile strength as PCR content increases in the non-foamed samples. Again including additives or altering the virgin PP used could give a product with the desired mechanical properties although this could increase materials cost as modified polymers are generally more expensive. Once again there is little correlation in the mechanical properties of the foamed samples, although a general decrease can be seen. This suggests the foamed polymer structure is weaker. Figure 14 shows that by using a stiffer virgin PP originally the tensile strength can be increased, even when PCR is used and the material is foamed. End market applications for household polyethylene film pellets 25

28 Strain at Ultimate Tensile Strength, % of original length Tensile strength, MPa Figure 14 Comparison of tensile strength for different PP grades % PCR 50% super stiff virgin PP 50% PCR 50% pallet grade virgin PP Foamed plaque composition 50% PCR 50% recycled PP Figure 15 shows the strain at ultimate tensile strength. This shows that the higher the PCR content, the further the material will stretch before yielding. This could be a desirable property depending on the applications. Figure 15 Strain at ultimate tensile strength for virgin pallet grade PP and PCR blends, foamed and non-foamed 25% 20% 15% 10% Foamed Non-foamed 5% 0% 0% 10% 20% 30% 50% 75% 90% %mass of PCR in blend The testing also showed that by foaming the samples they stretched further before yielding. The foamed core most likely allows additional expansion. Figure 16 shows the maximum strain before the samples broke. There is little correlation to the data at PCR contents of less than 50%; however, above this point the maximum strain increases considerably. This suggests the PCR properties become dominant. End market applications for household polyethylene film pellets 26

29 Peak load (N) Maximum Strain, % of original length Figure 16 Maximum strain for virgin pallet grade PP and PCR blends, foamed and nonfoamed 500% 450% 400% 350% 300% 250% 200% 150% 100% 50% 0% 0% 10% 20% 30% 50% 75% 90% %mass of PCR in blend Foamed Non-foamed In some cases the foamed samples have a higher maximum strain, and in other samples it has a lower maximum strain. There doesn t appear to be an obvious explanation for this and if the maximum strain is a vital property then it must be kept in mind that foaming could potentially increase or decrease this property. The final mechanical property measured was the flexural strength, which demonstrates the stiffness of the material. Figure 17 shows the flexural strength as measured externally by Huhtamaki UK. Figure 17 Flexural strength for virgin pallet grade PP and PCR blends, foamed and nonfoamed Foamed Non-foamed % 20% 30% 50% 75% 90% %mass PCR in blend The results show a clear trend that as the PCR content is increased the flexural modulus decreases, showing stiffness is reduced. This is expected as PP is usually stiffer than PE. By foaming the plaques the flexural modulus increased slightly, showing increased stiffness. End market applications for household polyethylene film pellets 27

30 This would be a method of incorporating the PCR at low concentrations (20% or less) into a virgin PP product whilst retaining stiffness. Table 7 summarises the effect increasing PCR content and foaming had on the mechanical properties of the virgin pallet grade PP. Table 7 Summary of effect of PCR content and foaming on mechanical properties Mechanical property Effect of increasing PCR Effect of foaming content Impact strength Decrease from 0 to 30% PCR then samples didn t break at PCR contents above 30% Decreased at low PCR content (<50% PCR) and increased at high (75% and 90% PCR) Tensile strength Decrease Decrease Strain at ultimate tensile strength Increase Increase Maximum strain Increase No trend Flexural modulus Decrease Increase Conclusion The PCR was able to be injection moulded into foamed and non-foamed plaques successfully with no known problems. The testing showed that foaming the plaques could decrease the mechanical properties of a material, however through careful consideration and selection of the original polymer this could be overcome and a finished product with the same mechanical properties but more lightweight could potentially be made. The PCR reduced some of the mechanical properties of the virgin PP investigated such as tensile strength, although increased other properties such as strain at ultimate tensile strength and prevented samples from breaking on impact testing when using >30% PCR. As with the foaming using a complimentary virgin material to ensure the physical properties of the end product is in specification would be effective. The cost of the virgin material may increase although adding the PCR may decrease the overall cost. It can be concluded therefore that the PCR would be suitable for injection moulded applications, although careful consideration of the virgin material used to blend with the PCR would be needed. Foaming the material could also present benefits, but this must be treated in the same way as incorporating the PCR, with consideration to mechanical properties of the non-foamed material. 3.3 Rotational moulding Rotational moulding is a moulding technique predominantly used for producing large hollow products. A mould containing polymer powder is heated and rotated in a kiln to melt the polymer and evenly coat the mould. Once the mould is coated it is removed from the kiln and cooled. After cooling the mould can be opened and the product removed. Figure 18 shows a rotational kiln. End market applications for household polyethylene film pellets 28

31 Figure 18 One of two rotation moulding kilns at JSC Rotational Ltd Rotation moulded products include items such as animal feeders, water and oil storage tanks, leisure items such as canoes and automotive parts. PE is one of the key polymers used in rotational moulding so there is an opportunity to substitute some of the virgin PE used for PCR. JSC Rotational Ltd is a UK based moulding company who make a diverse range of products. The trial was carried out at its site in Worcester Trial methodology Rotational moulding requires the polymer to be in a powdered form and some additives are required to allow the material to be heated for extended periods of time without oxidising and to facilitate the removal of items from the mould. The PCR pellet was compounded with 0.25% antioxidant and 0.5% zinc stearate and then milled at Environmental Recycling Technology s (ERT) test centre in New Mills, Derbyshire. The material was milled with a 650μm screen. Figure 19 shows the milled PCR. End market applications for household polyethylene film pellets 29

32 Figure 19 Compounded and milled PCR (650µm) Once compounded and milled the material was transported to JSC. Five different product moulds were chosen for the trials. Table 8 details the products made within the trial, the mass of a single item and the PCR levels investigated. Table 8 Products and blends made using rotation moulding at JSC Product Mass per item (kg) PCR levels trialled Horse jump %, 50%, 75%, 100% Mannequin %, 75%, 100% Hay feeder 8 25%, 50%, 75% Air intake %, 30%, 40%, 50% Bin 4 50%, 100% The PCR was weighed out and blended with the appropriate mass of virgin MDPE. Both white and black virgin MDPE were used. The production of the horse jumps was used as a test run for the trial as they required the least amount of material to make, was a relatively simple shaped mould and allowed JSC Rotational to try the PCR material out and determine the optimum production variables to use for the other trials. Four PCR contents as shown in Table 8 were trialled. The moulded horse jumps were then inspected to determine which PCR contents would be suitable for the remaining products to be trialled. End market applications for household polyethylene film pellets 30

33 From these preliminary results, the blends to be trialled for the other products were decided upon. The mannequin, hay feeder and bin were simpler mould shapes and so were considered to be able to be produced using higher PCR levels. The air intake product had a higher level of detail and so was produced at a lower PCR content. Once each product was made at the specified PCR contents it was decided if any extra blends should be trialled. Only qualitative assessment was done on the moulded items. It is unusual to carry out properties testing on rotational moulded products and providing they can withstand a reasonable force and are aesthetically acceptable, they are likely to be accepted by the end customer Trial results and discussion The trial was conducted successfully with no major processing issues, with some minor issues being encountered when using the PCR at >50% in some products which will be discussed later in this section. Prior to the trial the trial host had some concerns about whether the PCR material would mould well due to its low MFI and the nature of recycled material. However, the PCR was used to manufacture products that were at satisfactory quality. Figure 20 shows examples of the different types of product created. End market applications for household polyethylene film pellets 31

34 Figure 20 Products made during trials at JSC Rotational blended with white and black virgin MDPE Horse Jumps % PCR Mannequins 50% PCR Hay feeder 50% PCR Raised air intake 25% PCR Bins % PCR It was noted that a pin-hole effect occurred in some of the products containing more than 50%. These are holes that go through the product and reduce the aesthetics of the moulded item. The higher the PCR content the more pin holes as is shown in Figure 21. End market applications for household polyethylene film pellets 32

35 Figure 21 Horse jumps made using different PCR concentrations The milled PCR was assessed by ICO Polymers who supply milled polymer to the rotational moulding industry. ICO Polymers commented that the milled PCR was fluffy and had a high moisture content, which would lead to the reduced quality surface finish. ICO Polymers milled a second sample of the compounded PCR at its test facility which was subsequently moulded into a horse jump after the main trial. The material was ground more finely and had noticeably finer and less fluffy characteristics. This in turn produced a horse jump that had a higher quality surface finish, although some pin-holes could still be seen. Figure 22 shows the horse jumps made using 100% PCR milled to 500μm and 650µm. End market applications for household polyethylene film pellets 33

36 Figure 22 Comparison between 100% PCR horse jumps moulded with material milled to 500μm (L) and 650μm (R) Figure 23 shows a close up comparison of the two horse jumps where it is apparent the sample made with the PCR milled to 500µm is a superior quality in terms of surface finish. Figure 23 Close up comparison of the horse jumps End market applications for household polyethylene film pellets 34

37 This shows it is important that the PCR is milled to a high quality to reduce pin-holes and increase the quality of the surface finish. The pin-hole effect was less noticeable on the more rounded mould of the mannequin and thus a higher PCR content would produce a satisfactory product. The raised air intake required a high level of detail for a rotational moulded item because of the presence of a company logo. Because of this a micro-pellet is added to aid the flow of the polymer in the mould as standard procedure. It appears that the micro-pellet significantly aided the flow of the PCR and virgin mix. Figure 24 shows that at 25% PCR the air intakes were an acceptable quality. Figure 24 Raised air intakes made with 25% PCR blended with black and white virgin MDPE It was also noted that the PCR was stiffer than the standard virgin MDPE used in rotational moulding. This is not a surprising result as the PCR is close to HDPE in characteristics 16 and so is a stiffer polymer. This stiffness was especially noticeable when moulding the large items such as the hay feeder and bins at PCR contents above 50%. The items were difficult to remove from the moulds when using 75% and 100% PCR. Furthermore the pin-hole effect was very noticeable in the bin and the surface quality of the interior of the hay feeder become rougher as PCR content was increased, as is shown in Figure Likely due to the high content of carrier bags in the input material End market applications for household polyethylene film pellets 35

38 Figure 25 Interior of hay feeder at various PCR contents 25% 50% 75% Conclusion Overall the PCR was used to successfully create satisfactory quality products. The level at which the PCR could be blended with virgin MDPE depends on the shape and size of the product. Table 9 gives the recommended PCR content for the products trialled that would lead to the production of an acceptable quality product for the end customer. Table 9 Recommended PCR content for products trialled at JSC Rotational Product Product characteristics Maximum PCR content Limiting attribute Horse jump Mannequin Air intake Hay feeder Bin Small with many corners Medium size with smooth body and few corners Small to medium size with a large amount of detail (micro-pellet used to improve flow of powder in mould) Large item with smooth corners Large item with smooth corners 50% (could be increased to >75% if PCR is milled to 500μm) 75% (could be increased to up to 100% if PCR is milled to 500μm) 25% (potentially could be increased with PCR milled to 500μm) 50% 50% Surface finish Surface finish (pinholes in base) Surface finish (reduction in clarity of logo) Stiffness making it difficult to remove from mould Stiffness making it difficult to remove from mould The PCR level of the smaller items is limited because of the surface finish requirements. The hay feeder and bin are unlikely to contain more than 50% PCR as the stiffness of the PCR leads to problems unmoulding the larger products. In conclusion the PCR could be used in variety of rotational moulded products. It is likely that as the material is being established within the sector it may be added at levels of 25% PCR, although in the future it may be possible to produce items with much higher PCR content. Rotational moulding appears to be a viable market for the PCR in which virgin MDPE could be replaced. End market applications for household polyethylene film pellets 36

39 3.4 Injection moulding of storage/transport boxes A moulding trial was conducted with George Utz Ltd at its moulding site in Alfreton, Derbyshire. The company is an international moulding business focusing on the production of injection moulded and thermoformed re-usable storage containers and pallets. The company make a large range of products and the product chosen for the trial was a nestable storage/transport box, as can be seen in Figure 26. Figure 26 Nestable storage/transport box George Utz Ltd currently uses HDPE and PP in its products with HDPE accounting for 25% of material usage. Some products already contain recycled material from commercial and industrial sources (C&I). The product moulded in this trial usually contains 25% recycled HDPE. The results from moulding this product could be used to determine whether other similar injection moulded products, such as larger or smaller boxes or pallets could be manufactured using the PCR Trial methodology The MFI of the PCR is too low for injection moulding. As the PCR was derived from postconsumer film packaging and a low MFI is required for film blowing, it is expected that the MFI of the PCR to always be low (in this project it was analysed at g/10 minutes). Injection moulding typically requires an MFI no lower than 6 g/10 minutes. For this reason the PCR was blended with virgin HDPE in order to increase the MFI. As only a limited quantity of PCR was available only one blend was produced in this trial. To blend the material, a mix of 50% PCR and 50% virgin HDPE was re-extruded into pellet. Figure 27 shows the pellet and a dog bone sample used for tensile testing. Although a higher PCR content could potentially be used, a 50/50 mix was chosen as it was unknown how the material would mould in the box and a more informed assessment of the PCR could be made if it was used at lower percentages. End market applications for household polyethylene film pellets 37

40 Figure 27 Pellets made from the 50/50 PCR and virgin HDPE blend Table 10 gives the physical properties of the 50/50 PCR/virgin HDPE blend used in the moulding trial. The MFI was higher than required although this was not an issue for the trial and less virgin material could be used in the blend. Table 10 Physical properties of PCR/HDPE blend used in injection moulding trial MFI (g/10min) 12.3 Impact Strength (kj/m 2 ) 5.1 Tensile Strength (MPa) 17 Elongation at yield (% of original length) 11.8 Elongation at break (% of original length) 498 Moisture (% H 2 O) 0.19 Density (t/m 3 ) 0.98 George Utz Ltd was supplied with 80 kg of the PCR blend for the moulding trial. Production staff ensured the injection moulding unit was purged and cleaned down to remove any remaining polymer from the previous production run prior to the trial commencing. The trial material was then fed into the unit and boxes were moulded. The first three boxes were discarded in order to avoid any potential cross contamination from the previous material. Figure 28 shows the injection moulding unit used to produce the boxes. End market applications for household polyethylene film pellets 38

41 Figure 28 Injection moulding unit operated by George Utz Ltd Operational staff were asked to comment on how well the material moulded compared to using virgin polymer alone. Once the samples had been moulded technical and commercial staff at were also asked for their opinions on the quality of the final product and whether it would be commercially attractive to customers. In addition an impact test was conducted on the boxes to determine if they would be fit for purpose. The test was to drop a 5 kg weight onto the box from a height of 1.5 m; if the box does not break upon impact then it passes the test and is deemed to be fit for purpose Trial results and discussion The moulding trial was carried out successfully, with no processing issues experienced. Figure 29 shows the boxes after moulding (note that the protruding part is the injection point which is cut off). Figure 29 Moulded boxes on production line End market applications for household polyethylene film pellets 39

42 The operators of the moulding unit commented that the PCR blend moulded very well and there was no difference in processing between the blend and a 100% virgin material. The staff were also happy with the finish of the boxes and there was no negative impact to the aesthetic properties. One property noted was that there was a slightly higher degree of shrinkage on the trim of the box. This was not a major concern as it is not a critical aspect of the product and through slightly changing the design of the mould this issue could be resolved. Figure 30 shows the shrinkage along the trim of the box. Figure 30 Photograph showing shrinkage on the trim of the box Some mild concern with the odour of the PCR was expressed. This was a problem encountered with a number of the trials conducted within this project, but should not be seen as a barrier to the development of end markets for recycled film. It is believed the odour could be reduced or removed at the initial reprocessing stage through optimisation of the de-gassing stage of the process. The moulded samples passed the impact testing with no signs of damage from the 5 kg weight; meaning the box is fit for purpose. In addition to this, staff commented that although the sample was as strong as its standard products, it had more flexibility, which could be a desirable property as it makes the product less brittle. Staff were impressed with the material and believe it could be used to substitute virgin polymer and increase production as it offers an alternative, more environmentally friendly product that could open up additional markets. Positive comments were also made in relation to the quality of the material and they would be prepared to consider an increase in PCR content up to 80% based on these initial tests. One other positive point to highlight is that the material could be used in a variety of other products such as storage boxes or reinforced pallets. George Utz Ltd estimated it could utilise between 600 and 1,200 tonnes per annum of the material (based on between 50 and 100 tonnes per month). As a virgin replacement the PCR could be commercially attractive at a cost of between 650 and 700 per tonne. This compares well with the value of the PCR estimated in Section 6.1 of this report Conclusion and recommendations The trial conducted with George Utz Ltd was very positive and promising. A 50/50 blend of the PCR and a virgin HDPE was shown to produce a storage/transport box that was comparable to a 100% virgin product. End market applications for household polyethylene film pellets 40

43 The company believe the PCR could be used as a virgin replacement and there would be a healthy market demand for use in similar products, such as other storage boxes and reinforced pallets. There could be a potential demand for 600 to 1,200 tpa, and potentially more, from George Utz Ltd alone. Although unable to comment on what the UK tonnage would be for other moulders, it was felt that it would be a very marketable product at 650 to 700 per tonne. It is recommended that this market be viewed as one of the strongest opportunities to supply the PCR into, as the tonnages are significant and it is an area for virgin polymer replacement. 3.5 Injection moulding of foamed part used in storage casings and injection moulded turf tile The fifth trial carried out was the moulding of two parts manufactured by Hallam Plastics, Nottinghamshire. The company contract mould products on behalf of customers and are not directly involved in the specification of material or mould. Hallam Plastics mould a wide range of products, primarily for medical equipment. Its HDPE usage is in the region of 250 to 700 tonnes per month which approximately 98% of the polymer used is virgin. It also produces structural foamed products. This is done by blending a blowing agent into the polymer pellet, and injecting these into a cavity. This process differs from the Coralfoam process (outlined in Section 3.2) for several reasons: The cycle time is much longer at around 5 minutes per item; The degree of foaming is lower; The mould is not moved back to give the smooth finish; and There is less impact on the physical properties as a result. The two products made for the trial were: An injection moulded foamed part of a storage container used to hold hazardous material; and An injection moulded connectable turf tile which is used to cover grass for events. This product is not foamed Foamed storage container The first product made in this trial was a foamed section of a storage casing assembly, used to house hazardous materials. This product is normally manufactured from 100% virgin HDPE and uses black masterbatch to colour it. The trial investigated the use of different blowing agents at different concentrations, and also looked at producing parts with and without masterbatch Trial methodology As with the moulding trial conducted with George Utz Ltd, a 50/50 blend of PCR and HDPE was used to increase the MFI of the material. Trials were restricted to a single blend due to the limited quantity of PCR available. The first aim of the trial was to determine which blowing agent was required and how much was needed to give the best foamed structure and achieve the highest quality surface finish. Technical staff at Hallam Plastics were able to determine the quality of the foamed structure by visually inspecting a cross section of the part. Different materials require different blowing agents at varying quantities to give the desired product quality. Once the optimum End market applications for household polyethylene film pellets 41

44 blowing agent and quantity was agreed a sample with black masterbatch was moulded to compare with the virgin product. Table 11 shows the blowing agents and black masterbatch used to produce the different samples (all samples used the PCR blend to make up the remaining mass). Approximately 10 kg was used for each sample. It was necessary to carry out these trials as different materials require different blowing agents at different concentrations. Table 11 Blowing agents investigated in the trial Sample % exothermic 17 % endothermic 18 number blowing agent blowing agent % black masterbatch 1 0.0% 1.6% 0.0% 2 0.0% 1.0% 0.0% 3 1.6% 0.0% 0.0% 4 0.0% 1.0% 2.0% Hallam Plastics was supplied with 100 kg of the blended PCR. The injection moulded unit was purged and cleaned to remove any residual polymer from the previous production run. Figure 31 shows the injection moulding unit. Figure 31 Injection moulder operated by Hallam Plastics The first sample was weighed out and blended, before being fed into the moulding unit. A small amount of the feed was used to purge the extruder before the injection moulding cycle was started. The parts were moulded and allowed to cool in the mould for approximately 5 minutes before being released. 17 Releases energy in the form of heat on reaction 18 Takes in energy in the form of heat on reaction End market applications for household polyethylene film pellets 42

45 Once released the samples were cooled further in a water bath for 30 minutes. The samples required a long cooling time due to the thickness of the parts. After cooling, the trial products were cut in half to inspect the cross sectional area and the quality of the foamed structure. All samples were labelled with the amount and type of foaming agent used. As with JSC, Hallam Plastics do not carry out specific property or strength testing, with the analysis undertaken being more qualitative Trial results and discussion The PCR blend was used to produce a variety of foamed parts with no processing issues experienced. The operating staff were pleased with the moulding process and felt it was comparable to moulding virgin material. All products made were believed to be fit for purpose and had the required strength. It was found that sample 2, which used 1% of the endothermic blowing agent, gave the best foamed structure in terms of bubble distribution and size, and surface finish with regard to blistering (small bubbles on the surface of the part). This is a qualitative visual assessment undertaken by the production staff at Hallam Plastics. Sample 3 which used 1.6% of the exothermic blowing agent gave the most uneven foamed structure and the surface was more blistered (although only slightly and this is difficult to tell from the photographs of the samples). Figure 32Error! Reference source not found. shows the surface finish of the different samples. Figure 32 Comparison of foamed parts (external) Sample 1 Sample 2 Sample 3 Figure 33 shows the cross section of the different samples produced. It can be seen that the foaming is more even and the bubbles are finer in sample 2, thus giving a better foamed structure. The structure of this sample was comparable to that observed when moulding virgin polymer. End market applications for household polyethylene film pellets 43

46 Figure 33 Comparison of cross section of foamed parts As sample 2 gave the closest match in physical appearance to the normal virgin polymer product, a further sample was manufactured under the same conditions, with 2% masterbatch was added to aid colour matching ( Sample 4 ). A sample of the case made with PCR and black masterbatch and a sample made with 100% virgin polymer are shown in Figure 34. End market applications for household polyethylene film pellets 44

47 Figure 34 Comparison of virgin and PCR sample Technical and commercial staff at Hallam Plastics commented that sample 4, made with black masterbatch and the optimum blowing agent, had reduced the aesthetics of the sample as there was a degree of blistering present on the surface. This could be due to residual moisture in the PCR pellet. Although the technical staff also observed that the foamed structure of sample 4 was equivalent to the product made from virgin polymer. Figure 35 shows the foamed structure of sample 4. Figure 35 Foamed structure of sample 4 19 It was also noted that the shrinkage rate of the sample made with the PCR was different from the virgin material. The PCR shrank to a lesser degree on cooling compared to the virgin sample, meaning the resulting size of the product was larger. This is not necessarily a 19 Structure is less clear in the black sample although was deemed to be equivalent to virgin. End market applications for household polyethylene film pellets 45

48 problem although a slightly different mould design would be required to produce exactly the same end product dimensions. In addition to the quality of the surface finish Hallam Plastics expressed some concerns over the colour and odour of the finished product. It is believed that the odour of the recycled pellet could be reduced significantly, and using different pigments could produce a product with the correct colour, so it is believed that it would be feasible to solve these issues for commercial production. Since Hallam Plastics is a trade moulder and do not mould its own products, it has to be particularly mindful of the exacting standards of the buyer and end customer. This is the same situation as was found with BPI when using the PCR in printed film (see Section 3.1). Buyer s attitudes should be challenged as the qualitative differences in aesthetics of the products from virgin are only very slight. There is also potential to offset these differences with environmental and cost saving benefits, although a cost benefit assessment would be required to truly establish this. Despite the concerns Hallam Plastics did comment it would be feasible to use this material in the product trialled. The tonnage of this product manufactured by Hallam Plastics is approximately 1 tpa; this tonnage is very low as it is a specialist product. The only other product it moulded that could use PCR was identified as a turf tile. The production rate of this product is between 0.5 and 0.75 tpa. Hallam Plastics felt the other non-medical products it currently manufactures would not be able to use the PCR due to the slight difference in final appearance achieved. Additionally, it would not be permissible to incorporate PCR into the medical equipment products it manufactures, which must be produced from virgin material Injection moulded turf tile The second product made in this trial was a connectable turf tile called Terraturf, used to cover areas of grass for events, made on behalf of Terraplas. This product is made from 100% virgin material and is a relatively complex mould due to the connectors on the tiles. Figure 36 shows a standard turf tile made from 100% virgin HDPE and Figure 37 shows the connectors which clip together. The connectors must be of a uniformed size and shape and have enough strength to hold the tiles together without breaking. Figure 36 Terraturf turf tile made from 100% virgin HDPE End market applications for household polyethylene film pellets 46

49 Figure 37 Connectors on turf tile made with virgin HDPE Trial methodology For the trial the tiles were manufactured from the 50/50 PCR/virgin HDPE blend used for the foamed parts and nestable storage containers. As with the previous trial the extruder was purged of any residual polymer and the trial material fed into the extruder. The turf tiles were then moulded following Hallam s standard operating procedures Trial results and discussion The PCR blend was used to successfully mould the turf tiles with no operation issues. Operational staff at Hallam were pleased with the way in which the material processed and commented that it was comparable to virgin material with respects to how it moulded. Figure 38 shows the turf tile made from 50% PCR. End market applications for household polyethylene film pellets 47

50 Figure 38 Terraturf turf tile made from 50% PCR and 50% virgin HDPE Technical and commercial staff at Hallam Plastics commented that the product was of a high quality and comparable to the product made with 100% virgin HDPE. Figure 39 shows the underside of the virgin and PCR samples. It can be seen that the underside is relatively complex and that the PCR sample and virgin sample are of a comparable standard. Figure 39 Comparison of underside of turf tiles End market applications for household polyethylene film pellets 48

51 Figure 40 shows the connectors on the sample made with 50% PCR. Once again the PCR sample is equivalent quality to the virgin sample and the connectors are able to function with no signs of decreased strength when compared to a virgin product. Figure 40 Connectors on turf tile made with 50% PCR Figure 41 shows the turf tiles made from the PCR connected to create a larger area. Figure 41 Connected turf tiles End market applications for household polyethylene film pellets 49

52 The owner of the mould was contacted by Hallam Plastic and was pleased with the quality of the moulded product and could see it being used in this application. The colour of the PCR was desirable in this instance, however it is uncertain whether this would be a consistent colour and so a decision should not be made on this basis. The tonnage of this material produced annually is low compared to other products investigated in the report and is in the region of one tonne per annum. The moulding trial demonstrated that a 50/50 blend of PCR and virgin HDPE can be used to produce a relatively demanding and complicated product, and this should be used as evidence to encourage the sector to consider using recycled PE from post-consumer household films in other equally demanding parts, for example automotive parts Conclusions and recommendations The trial has shown once again that the PCR can be used in a blend with virgin HDPE to produce products that are fit for purpose. The trial also shows that the PCR can be used in relatively complicated moulds such as the turf tile, which needs quality material to mould functioning connectors. It can be concluded, however, that the specialist products, such as those produced by Hallam Plastics, is not a market in which the usage of the PCR should be focused on. This is because the tonnages are very low when compared with the other products and markets investigated in this project and significant effort would be required to engage individual customers and convince them to use the PCR. Whilst it is thought that that this could be achievable, the overall reward would be small in comparison with the potential to influence other more attractive markets such as the automotive or printed films markets which could provide far greater tonnages. For this reason such specialist items have not been included in the end market analysis. This trial shows that the PCR can mould well without processing issues, which in itself is a positive result and further evidence for development work. End market applications for household polyethylene film pellets 50

53 4 Evaluation of end market opportunities With the completion of the series of demonstration trials the market opportunity can be investigated further for each type of production method, with some additional markets investigated such as automotive parts, plastic piping and plastic pallets and crates. The evaluation has been carried out primarily through talking with representatives from the polymer moulding industry and some desk based research. 4.1 Film manufacture Potential market size Although in the future it may be possible to include PCR in printed, thin gauge film the opportunity for the PCR in film applications at the present time is in the heavy duty, thick gauged film applications. It is estimated the UK production of agricultural films such as silage sheeting and crop cover is around 10,000 tpa 20. The production of building and construction films such as damp proof membrane is estimated to be in the region of 75,000 tpa 21. Film production in the BPI trial was successful at a 17% addition rate into a silage sheet product and it should be possible to include the PCR at 20% with further optimisation and trial work. Therefore in both product types there is a potential market demand for 17,000 tpa of PCR in film applications Barriers to adoption The demonstration trials showed that, currently, it would not be feasible to incorporate this PCR into thin gauged printed film products (such as the dispatch bags), as even very small levels of gels or contamination would impact the appearance of the film products. Without the customer accepting a decrease in aesthetic quality, this is unlikely to be seen as an end market at the current time, although it should not be discarded as a potential market in the future if buyer attitudes were to change. Further work into the attitudes of decreased print quality as a result of using recycled material should be carried out. There are however, film products that would be well suited to this type of material. These products include: Silage sheeting; Damp-proof membrane; and Other heavy duty industrial and construction films. The drawback of these film products is that they already contain some recycled material, and there is little or no scope to replace any virgin material, as it simply isn t used unless a clear product is needed. Despite this there is a growing shortage of quality recycled PE, from agricultural film and in-house recyclate sources, and there is a healthy demand for the above products. As a result there is a clear market opportunity for PCR from household sources in these applications. The trial carried out with BPI on the production of silage sheeting showed that the PCR could potentially be used at an addition rate of 20% with no adverse effects on the film quality. It 20 BPI estimations 21 BPI estimations End market applications for household polyethylene film pellets 51

54 can therefore be assumed that the PCR could be used in a large variety of similar, thick gauged heavy duty films. 4.2 Rotational moulding Rotational moulding is a growing industry in the UK and currently consumes 45,000 tonnes of PE annually. This includes LDPE, HDPE and MDPE, although the majority of PE used in rotational moulding is MDPE. Figure 42 shows how this tonnage is broken down into various product types. Figure 42 Rotational moulding PE usage by product type 22 Traffic 7% Leisure 4% Toys 5% Home / Garden 8% Transport 8% Others 9% Automotive 15% Food / Agriculture 27% Industrial 17% Potential market size As a result, the potential mass of PCR that could be consumed by rotational moulding applications is given in Table 12. Table 12 Potential market for PCR in rotational moulded applications Total mass of PE used in rotational moulding (including black and coloured products) (tpa) 45,000 % of rotational-moulded products that would be suitable for PCR addition (black products) 25% % addition of PCR 25% Total potential demand for PCR (tpa) 2,813 The potential tonnage is therefore relatively small in comparison to the likely amount of PCR from household sources that will become available in forthcoming years. However it is possible that some products could contain more than 25% PCR, although it is likely the market would want to gradually introduce this new material. The mannequin is a particularly interesting application where film from front of store collections could be used in a product seen by consumers to encourage recycling. 22 Data provided by JSC Rotational End market applications for household polyethylene film pellets 52

55 This limited size of the rotational moulding market is a combination of rotational moulding typically being used to make small production quantities, the items having a long life and the limited number of products which are not brightly coloured. If customers were made aware of the possibility of including recycled material in their product which is usually a bright colour, it may be possible to convince them to include the PCR and market a product that utilises the unique colour of the PCR. This would then increase the potential market demand, but this requires further research and analysis Barriers to adoption The market opportunities for the PCR are limited by its colour, meaning it would most likely only be used in black products. JSC Rotational estimate that 25% of PE used in rotational moulding is black. This accounts for the fact that many products, such as toys and leisure items are brightly coloured, whereas industrial or agricultural products are more likely to be black or darker in colour. Specific rotational moulded products, including those produced during the trial, that would be most likely to include this PCR would be: Retail mannequins; Bins (wheelie bins, shop bins, street bins, etc); Automotive parts; Agricultural products, such as animal feeders; and Storage products (including water storage or garden storage). Currently recycled material is rarely used in rotational moulding as recycled HDPE from rigid post-consumer packaging which is readily available is not suitable due to its stiffness. Other recycled PE grades are not as readily available or cost effective. Concerns were given from one rotational moulding firm that the PCR would have too low a MFI to be used effectively. It was seen during the demonstration trial at JSC Rotational that the PCR did not melt and flow as easily as the virgin material; however at addition rates of around 25% and in simpler shaped moulds the PCR was used successfully to produce acceptable products so this does not appear to be a real barrier. 4.3 Automotive parts Potential market size The automotive industry is a significant market sector in the UK. Approximately 1.45 million cars were manufactured in the UK in Approximately 15% of a car by mass is made from plastic 24 and the weight of a car is approximately 1 tonne. This means that there is estimated to be 217,000 tpa of plastic used in the UK automotive sector. Plastic usage in the automotive sector is increasing and is set to continue increasing as manufacturers look for light weighting opportunities. 23 OICA, 2012 production statistics 24 e-xstream Engineering, DIGIMAT for Automotive, November 2012, BPF presentation End market applications for household polyethylene film pellets 53

56 Various plastics are used in automotive applications, with one of the major ones being PP. PP is used in cars for applications such as: 25 Exterior parts bumpers, body panels and external trims; Interior parts dashboards, door claddings and internal trims; and Under the bonnet fuel tanks, air intakes, batter cases, wires and cables. Table 13 gives the usage of plastic in each part of the car. Some assumptions have been made as to the amount of each area which could utilise recycled material. This is based on areas that need to have high quality finish (such as interior parts), or areas that would need specific grade material, such as under the bonnet components where performance is vital, and PCR may not be appropriate to use. Examples of exterior components that may be able to take recycled content would be body panels and bumpers. Initially it would be most likely the PCR would be used in under the bonnet components as these are not seen by the customers and aesthetics are less important, with vehicle manufacturers being more willing to include recycled content in this category of parts. Table 13 Potential recycled content of automotive parts Area Proportion of plastic in car Estimated % able to use recycled % addition of PCR Exterior 45% 40% 30% Interior 20% 20% 20% Under the bonnet 30% 20% 10% Other 5% 30% 30% Using these assumptions there could be a potential market of 15,700 tpa for supply into automotive plastics. This is a significant tonnage and supply into this market should be investigated further Barriers to adoption The automotive sector is moving towards an increased usage of plastic. Some of the parts require specific grades of polymer and a high degree of engineering, in which recycled content would be difficult to include. Automotive parts can be seen as a high end application where quality is important. However there is a great opportunity to include recycled content in automotive plastics. Not all parts are precision engineered and require a specialist grade of polymer. A significant tonnage of material is required for automotive parts and the use of recycled material can have a positive effect on lowering the overall carbon footprint of a manufacturing process. One barrier may be that PP is primarily used in components where PCR would be suitable. It has been shown in this project that the PE PCR can be injection moulded with PP. This does require a moulding unit that has additional mixing capabilities so there may be a need to upgrade equipment. For the automotive sector to adopt the use of the recycled material it would take a substantial amount of time and development, and is very unlikely to be a quick solution. However once the PCR has been introduced then the fact it can be used in a high end application such as automotive parts will give other potential end markets more confidence to use the material. 25 Borealis, lightweight vehicle polymer uses. End market applications for household polyethylene film pellets 54

57 4.4 Plastic water/drainage pipe Underground water pipes and drainage pipes represents a significant use of HDPE in the UK. These products are made by extruding the polymer through a ring die continuously to produce the length of pipe Potential market size Through the market research it was found that one manufacturer produced 10,000 tpa of water piping products, and estimated the UK market capacity was in the region of 100,000 tpa. If the PCR from post-consumer film was found to be suitable then a potentially huge market could open up. It is likely the PCR would still not replace 100% of the current recyclate used and would be used at an addition of around 20%. This would be done to reduce the impact of the variable nature of PCR from film, which is largely an unknown mixture of LDPE and HDPE. In time after the PCR has become more established it may be possible to increase the usage. At a 20% addition this could still give a potential market demand in the region of 20,000 tpa, a significant tonnage Barriers to adoption The pipes present a good opportunity to use the PCR. These pipes are black in colour and do not need to be aesthetically pleasing. However this product is currently made from 100% recycled HDPE. Therefore although this product would be entirely suited to use the PCR, there is no opportunity to replace virgin material but it might be possible to swap the use of different sources of recycled material. One manufacturer of water piping products, contacted during the market research, used recycled jazz HDPE derived from bottles from MRFs. Recycled material from this source should be a high quality recyclate with relatively consistent physical properties as it is primarily from one product type (consumer detergent/cleaning products). It is possible that the PCR investigated in this project could replace this potentially higher quality and more consistent HDPE which could then be used in more demanding applications, such as closed loop manufacture of packaging. 4.5 Plastic pallets, crates and boxes The trial conducted with George Utz Ltd was very encouraging and a strong opportunity to replace virgin HDPE with PCR was established Potential market size Estimating the potential market for these products is difficult due to the large product range and high number of moulding companies that exist. Utz believed it could initially be able to accept 50 to 100 tonnes per month, representing between 600 and 1,200 tonnes per annum. Potentially, it would be possible to increase this if there was a substantial demand for the products from customers. There are approximately 1,200 injection moulders in the UK 26 at the time of writing. It can therefore be assumed that there would be a substantial demand for the PCR in this sector if it had suitable physical properties. If five equivalent sized moulders with similar products were willing to buy the material, this could represent a demand of 3,000 to 6,000 tpa. 26 British Plastics Federation, End market applications for household polyethylene film pellets 55

58 4.5.2 Barriers to adoption The main barrier to adoption of PCR in this sector is the large number of manufacturers in the UK. There is a large number of individual injection moulders who produce these types of products and it may be difficult to engage with a significant proportion of them. Although it may require significant effort to supply PCR into this market, the fact there is a large number of moulders may also be beneficial. It means there are many different companies to engage with and it would be likely that some of them would value the opportunity to use such a material. If the PCR can be used initially even by a small number of moulders, it will gain the PCR a reputation and some familiarity in the sector, which would build confidence in the material and encourage others to use the material. Technically it would be feasible to include the PCR into PP or PE products as has been demonstrated in this project. It may however mean using a stronger grade of virgin material to account for the slight decrease in mechanical properties seen when incorporating the PCR in to products. Furthermore the injection moulding units would have to have sufficient mixing capabilities to blend the PCR with the virgin material. Some recycled polymer is currently used in this type of product, depending on the required finish. If a product is coloured or white then it limits the ability to use recycled content. This also applies to the PCR investigated in this project, although George Utz Ltd did not see this as a major barrier. Potential in this market is very large and it represents a real opportunity to replace virgin material with PCR material. This is an excellent market opportunity for PCR to be supplied into and in the long term could provide a significant outlet for PCR material. 4.6 Summary and conclusion of end markets There is substantial potential demand in non-virgin replacement applications, in which there is a demand for additional volumes of products, or where the PCR could potentially replace an existing higher quality source of recycled material (for example HDPE rigid packaging), which could subsequently be moved up the value chain in to higher value end applications. There is also potential to directly replace virgin HDPE, as was found during the injection moulding box product trial and the rotational moulding trial. Through the market research it has been found that in some markets directly replacing virgin is challenging. This is for the following reasons: Products that use virgin material do so because the quality is superior to recycled material. This was seen with the dispatch bags that even at low PCR content the material couldn t currently meet customer s particularly high printing quality requirements; Products may require specific properties from the polymer such as a high MFI or high impact strength; and Products that can use recycled material tend to already do so rather than using virgin. Although the above points are valid, they should be seen as a challenge rather than a barrier. Supplying recycled material into products that currently use virgin material is on the whole technically feasible as demonstrated with the printed film manufacturing trial. It is strongly suggested that potential consumers and purchasers of converted polymer be surveyed to determine their attitudes towards the quality and recycled content issues. It may be found that a slight reduction in non-critical quality (i.e. a product is still fit for End market applications for household polyethylene film pellets 56

59 purpose although may have reduced aesthetic properties) is acceptable if it is known that the product has a recycled content, with the benefits this can provide. Using recycled material instead of virgin material has significant benefits, economically and environmentally which have been demonstrated in a large number of industries and sectors, most notably the PET and HDPE food grade bottles sector. If a similar solution can be found for post-consumer film then this would not only reduce virgin polymer usage but also divert a proportion of a currently vast waste stream in the UK from landfill. Table 14 summarises the potential market demand for the products and markets investigated in this project. Table 14 Summary of potential market demand for PCR Market/product Heavy duty agricultural films and construction films Rotational moulded items (such as mannequins, storage tanks and bins) Estimated demand (tpa) 27 17,000 2,800 Automotive parts 15,700 Drainage and water piping 20,000 Pallets, boxes and crates Undetermined, but could be in the region of 3,000 to 6,000 Likelihood of supply High already uses recycled material and high demand for the products Medium is technically feasible but market it not used to using recycled material Medium recycled material can be used in non-critical parts although further trials to prove suitability is required Medium to high has not been tested in application but is likely to be feasible and product already uses recycled material High initial test with George Utz Ltd showed the PCR can be used to produce comparable products to virgin Total 58,500 to 61,500 Providing the product is priced competitively there is a large existing market in which the PCR can be used as shown above. In order to break into markets such as printed films there is likely to need to be a significant change in attitude from the customers to allow a slightly lower quality printing on the film. Supply into the automotive parts market warrants further investigation on a considerable scale as it presents a substantial market opportunity for PCR. The quantities estimated above should not be seen as a maximum. Rather it is the quantity that there is likely to be a demand for at the present time in products that are receptive to the inclusion of recycled material. It is possible there is a larger potential demand, and once placed on the market a high quality PCR would be used in many different applications. The rate of acceptance in the market will accelerate as soon as the early adopters are seen to gain commercial advantages from its use and the volumes of recycled grades become more widely and consistently available. 27 See above sections for calculations and assumptions used End market applications for household polyethylene film pellets 57

60 5 Opportunities to amend the film recycling method The PCR used in this project was derived from kerbside collected, co-mingled dry recyclables in the UK and was separated using several NIR sorters, cleaned using a hot wash and extruded. Further detail can be found in the previous WRAP report Processing Trials for Household Film Waste 28. Through conducting these manufacturing demonstration trials it is possible to determine if the PCR had been over or under processed. If the material was a higher quality than was demanded by the applications trialled, then there may have been scope to simplify the processing of the film to still give a satisfactory end product. There does not however appear to be any applications that could use a reduced quality pellet, other than those already known such as panel products such as hoardings and boards. The products investigated in these demonstration trials required the quality of the pellet to be as it was. It can therefore be concluded there is little scope to reduce film processing costs and technologies such as those investigated in the previous WRAP report are needed. The pellet did have two issues that may be avoided by adopting additional processing stages. These were the odour of the pellet and the excess moisture. It may be possible to remove the odour during the extrusion stage if additional de-gassing was allowed. This would also most likely remove the excess moisture from the material. It was seen there was little odour in the rotational moulded items because of the increased cooking time driving off the volatiles, which is strong evidence that odour can be removed. A desiccant could also be used to reduce moisture levels although the cost for this would need to be reflected in the purchase cost of the PCR End market applications for household polyethylene film pellets 58

61 6 Economic analysis 6.1 Potential sales price A study has been carried out to determine a potential sales price for the PCR based on Axion s experience and knowledge of the polymer sector and feedback from the trial partners and additional moulders contacted during the project. The analysis assumes that a process has been established to produce a PCR to the same standard as that investigated in this report and that supply and quality of material are consistent. In order to estimate a realistic sales price for the PCR, it is necessary to understand the virgin polymer market. Table 15 shows virgin polymer prices for various PE and PP grades from between March 2011 and March Table 15 Virgin polymer prices 29 March 2011 March 2012 March 2013 March 2014 HDPE injection moulding 1,262 1,323 1,341 1,210 HDPE film 1,228 1,248 1,264 1,136 LDPE injection moulding 1,418 1,335 1,315 1,202 LDPE film 1,410 1,315 1,324 1,231 PP injection moulding (homopolymer) 1,371 1,285 1,264 1,223 Figure 43 shows how the sales price of virgin injection moulding grade HDPE varied month by month between March 2011 and March There are some significant changes in price, with the price decreasing by over 300 per tonne between March 2012 and July 2012, confirming that polymer prices are somewhat unstable and influenced by factors such as oil price and polymer supply and demand. 29 Plastics Information Europe, accessed April 2014 End market applications for household polyethylene film pellets 59

62 HDPE injection moulding grade ( /tonne) Figure 43 Price fluctuations for HDPE between March 2011 and March Mar-14 Nov-13 Aug-13 May-13 Jan-13 Oct-12 Jul-12 Apr-12 Dec-11 Sep-11 Jun-11 Feb-11 It should be noted that large consumers of polymers would likely benefit from a discount on these prices due to large order volumes, therefore the prices presented above are likely higher than most buyers would pay. To calculate the value of a recycled material there are two pricing models to consider. These pricing models have been based on feedback from moulders and also on Axion s experience of the recycled polymer market. The prices presented are therefore indicative of what should and could be achieved as opposed to suggesting an exact price at which the PCR should be placed on the market. It should be remembered also that the price of virgin polymer, and therefore recycled polymer, can fluctuate with changes in oil price and polymer supply and demand Pricing model 1 supply into existing recycled markets The first model is regarding the use of large quantities of recycled material that is being used as a virgin polymer substitute. A good example of this is the heavy duty films market where the specific grade of a material is not critical and there is a degree of flexibility on what the product can be manufactured from. In this market price is all important. If the wholesale virgin price is 1, per tonne for injection moulding HDPE, assuming a 20% discount on the listed price for a high volume supply, it is likely there would be an off-specification 32 product supplied by the polymer 30 Plastics Information Europe, accessed April Note that all price values given are approximate and apply only to the time of writing 32 off-specification polymers are products made by polymer producers that do not meet the specification they require. This is then sold at a discounted price and can be in the region of 20% cheaper than on-specification virgin polymer End market applications for household polyethylene film pellets 60

63 producer which would be in the region of 800 per tonne. Therefore in order for the recycled material to be competitive it must have a sales price of 600 per tonne as this still demonstrates a saving on an off-specification material and would encourage usage. Although it is true that the PCR could be sold for more and still represent a saving, this value concurs with what many of the companies contacted for the market research felt the PCR could be sold for. Above this cost there are other recycled materials on the market which moulders could purchase for less and could be used to manufacture a product to the required standards. This is the lowest value scenario however it is also the most likely area to first establish the use of this PCR, as volumes are high and quality is not critical. This model is still dependent on the virgin material price, and so the value of the recycled material would still fluctuate Price model 2 supply into new applications This model considers supplying the PCR into markets dominated by the use of virgin polymer. If it can be shown that the recycled polymer has properties that match the need of the product, then the polymer consumers would be willing to pay a higher premium for the recycled material. This is also true if there is seen to be a marketing advantage that may increase sales or value of a given product, thus allowing for a higher price of the recycled material. A good example of this is rotational moulded products, which through this project has been identified as a market for virgin replacement. As this is dominated by virgin material currently, a small saving in polymer cost would be beneficial to the moulder. These types of markets would be lower volume than those in model 1, and so initially there would be less of a discount on the virgin price. Once again assuming a virgin price of 1,000 per tonne, a recycled material could be sold for approximately 70 to 80% 33 of this price, giving a sales value of between 700 and 800 per tonne, significantly higher than in model 1. This then brings the value of the PCR in line with off-specification polymers. This cost fits in well with the price suggested by one of the moulding companies that participated in the trials that would be economically viable for the PCR. For rotational moulding, it was suggested by one of the moulders that a market value of 1,000 per tonne for the milled PCR would represent a cost saving for the moulder. It would cost up to 200 per tonne 34 to produce a 500µm milled powder from a pellet (although it is possible the cost would be lower which could be established after carrying out processing trials). This would bring the PCR up to 900 to 1,000 per tonne and thus still present a significant saving from purchasing milled virgin material. As with model 1 there would still be the price fluctuation trend following current virgin polymer prices. The model does give a higher value to the PCR but the markets are more limited than selling the PCR into existing recycled markets and more effort would be needed to establish a market presence. The PCR would also need to be shown to have consistent properties which may be challenging when the material is derived from a mixed postconsumer source. 33 Based on Axion Polymers experience of supplying recycled polymer 34 This cost depends heavily on quantity of material. Quotes were obtained from Micropol and ICO polymers who offer toll milling based on processing 100 to 200 tonnes per month of PE pellet End market applications for household polyethylene film pellets 61

64 6.1.3 Pricing models summary Both cost models have advantages and disadvantages. In terms of this project looking to replace virgin material model 2 is applicable, however due to the limitations of the market it is far more likely that model 1 will be adopted first. Therefore initially, until the PCR is well established and its properties and uses proven, a sensible market value would be in the region of 500 to 600 per tonne. 6.2 PCR production cost In order for the production of PCR from post-consumer film to be successful an end market must exist and the value of the PCR should give a reasonable profit margin for the reprocessor. For this reason a basic economic study has been carried out to calculate the cost of producing the PCR to determine if the exercise is profitable or not. A model has been developed in Excel to estimate the production cost for the PCR and therefore give the potential margin. Table 16 gives the cost and other assumptions used in the model. These values are based on several years of Axion s experience in designing, building and carrying out economic analysis on various recycling facilities. Table 16 Cost model assumptions for film reprocessing plant Feed rate (tpa) 20,000 Cost of feed (delivered) ( /t) 75 PCR pellet yield 65% Waste disposal cost ( /year) ,000 Operating cost ( /year) 2.7 million Plant capital cost ( ) 5.5 million Capital cost depreciation period (years) 10 The feed is assumed to be >93% PE film and could have a value of 75 per tonne, as estimated in previous WRAP report on household film reprocessing 36. However, some upgrades to existing MRFs in the UK would be required to produce this feed. A yield of 65% has been assumed although this is somewhat conservative. This allows for loss of moisture and loss of mass though contamination removal and loss during extrusion. It has been assumed only one NIR is required as the feed material would already have a high purity. Using the above assumptions 37 sales price can be calculated to be around per tonne of finished pellet product. This calculation shows that selling the pellet at 600 per tonne, as estimated in price model 1 (the lower price estimation), would give a good margin. This shows that the processing of household film waste could lead to a sustainable, profitable business. 35 This assumes 10% of the feed is removed as waste and is landfilled at 100 per tonne and the remaining 25% is moisture and dirt that is removed at 40 per tonne 36 WRAP IMT , Processing trials for household film waste, 37 Prices and costs used in this modelling exercise were based on assumptions, for the purposes of developing a broad view of commercial viability. Actual costs at any given time in the market may vary and are likely to fluctuate. End market applications for household polyethylene film pellets 62

65 7 Routes to market for PCR From this study two clearly defined markets for the PCR have been identified: Supply into high volume products already using recycled PE with capacity to increase production, specifically heavy duty films, plastic pipes; pallets and crates; and Supply into applications where virgin polymer can be substituted, specifically rotational moulded products, injection moulded pallets, crates and boxes and potentially automotive parts. It is suggested that if post-consumer film can be processed to give an equivalent PCR as investigated in this project, potentially with additional de-gassing to reduce odour and moisture, then it would be a very marketable material. The PCR would need to be produced to a high standard (the same as investigated in this report) with consistent supply and quality. The most significant opportunities to replace virgin material are in the production of injection moulded pallets, crates and boxes and rotational moulded products. The injection moulded products could represent the highest tonnage of the two and should be targeted initially. The demonstration trial carried out at JSC Rotational provides strong evidence for the PCRs suitability which should be noted by the sector. The opportunity for supply into automotive parts should also be investigated if evidence can be given that the PCR is of sufficient quality. From the research conducted in this report it is apparent that the area in which the PCR could have the most impact in terms of tonnages is into the products already using a recycled material. This is because it is technically feasible to supply to this market, as products already using recycled material can deal with the additional contamination, gels and less well defined physical properties. This may be a more stable market for the PCR but is not one in which virgin is replaced. This market should be developed alongside the injection moulded pallets, crates and boxes market. It is vital that any film processing facility has a robust, rigorous testing of the PCR to measure the physical properties of each batch. This will give potential customers confidence they will be able to process the material. It may also be possible to include additives to give the customers exactly what they require, such as a higher impact strength or higher MFI. End market applications for household polyethylene film pellets 63

66 8 Conclusion and recommendations The key conclusions and recommendations to the sector that can be drawn from this project are given in the below sections. 8.1 Film manufacture demonstration trial The conclusions from the dispatch bag and silage sheeting manufacture trial with BPI are: Thin gauge printed film (dispatch bags) was successfully manufactured with an overall PCR content of 17.5%; Above this PCR content the film was unable to be blown as the contamination, gels and lensing in the PCR created holes; Thick gauged film (silage sheeting) was able to be blown with 17% PCR. At a higher PCR content of 27% PCR the film could not be blown due to the contamination, gels and lensing; The printed film showed a noticeable reduction in print quality when low levels of PCR were included; and Neither film types showed a significant reduction in mechanical strength; both would be fit for purpose if PCR was incorporated at around 17 20%. As a result of the trial the following recommendations are made: Obtain feedback from dispatch bag customers with regard to their attitudes towards a reduction in aesthetics as a result of using recycled material; and Obtain feedback from end receivers or users of printed film with regards to their attitudes towards a reduction in aesthetics as a result of using recycled material. 8.2 Injection moulding using novel foaming technology demonstration trial The demonstration trial carried out with Coraltech gave the following conclusions: The PCR can be successfully injection moulded despite a low MFI; The PCR can be blended with PP to produce a composite material; Incorporating PCR into the PP reduced the impact and tensile strength and stiffness although increased strain at maximum tensile strength; Foaming the PP/PCR blends had an inconsistent impact on the mechanical properties, with some being reduced and other being increased; Foaming can reduce the overall density and potentially increase efficiency of raw material usage; and Care must be taken to select the right grade of virgin or recycled polymer used with the PCR to ensure the moulded item has the correct properties. Injection moulding is used in a large number of applications that require further demonstration trials. Key products include automotive parts and pallets, boxes and crates. It is strongly recommended that trials in moulding these components using the PCR be undertaken to establish and demonstrate technical feasibility. 8.3 Rotation moulding demonstration trial The following conclusions can be drawn from the rotational moulding trial with JSC Rotational: The PCR is especially suitable for use in rotation moulding as contamination and gels are not as critical in product quality; Several products of different shapes and sizes were moulded using a blend of the PCR and MDPE; PCR was used to produce a satisfactory quality automotive part at levels of 25% PCR; End market applications for household polyethylene film pellets 64

67 High PCR contents of up to 100% PCR can be used in moderate sized products (i.e. horse jumps and mannequins) providing the PCR is milled to a good quality powder; and Larger items such as the horse feeder and bins would be restricted to 50% PCR as above this the stiffness of the PCR prevents efficient un-moulding. Rotational moulding presents an exciting opportunity for the PCR, particularly where products can be made that convey a strong message to the consumer such as the shop/retail mannequin. 8.4 Injection moulding of storage boxes The PCR is well suited for use in the injection moulding of storage/transport boxes; A 50/50 blend of PCR and virgin HDPE was used to manufacture boxes that were equivalent quality to those made from virgin material; There could be a large demand for the PCR in this market; and The PCR would also be suitable in other similar injection moulded items such as pallets and different sized boxes or crates. 8.5 Injection moulding of foamed part used in storage casing and turf tile For the foamed storage casing part, the 50/50 blend of PCR and HDPE were successfully foamed using 1% endothermic blowing agent. The moulding process was comparable to moulding carried out with 100% virgin material with no processing issues. All products were believed to be fit for purpose; The surface finish was slightly below the standard of that produced when using 100% virgin material for the foamed part; The 50/50 blend was also used to produce a high quality turf tile with functioning connectors that was an equivalent quality to a tile made with 100% virgin HDPE; The turf tile is a relatively complicated and demanding mould and the successful trial shows that the PCR could potentially be used in other demanding applications such as automotive parts; and The tonnages of the specialist products made by Hallam Plastics that could use the PCR are very low and it is not advised to actively pursue this market over others investigated in this report. 8.6 Market opportunity evaluation A study was undertaken to determine potential market demand for the PCR and barriers to its adoption. There are many opportunities to use the PCR with an estimated total demand in the region of 60,000 tpa; The four main opportunities to supply high tonnages of the PCR are into heavy duty films, drainage/water piping products, automotive parts and pallets/crates/boxes; Rotational moulding presents an exciting opportunity where the PCR can be used to directly replace virgin material and manufacture products with strong consumer environmental messages (i.e. retail/shop mannequins). The market demand is however significantly lower; The use of PCR in products that already use recycled material can displace higher quality recycled PE (for example derived from jazz HDPE bottles or agricultural films) which could then be used in closed loop applications to give maximum environmental benefit. Demand for these products is also high and production could be increased if an additional source of recyclate were available; Supply into virgin replacement markets would have a positive benefit on reducing product carbon footprints and diverting material from landfill; End market applications for household polyethylene film pellets 65

68 Supply into injection moulded pallets, crates and boxes as well as into rotational moulding should be focused on as in these markets virgin material can be displaced and there is a significant potential volume opportunity; In addition to these markets supply into heavy duty films and drainage/water piping should be developed, as although it is not possible to displace virgin material there is still a large demand for high quality recyclate; There is a huge opportunity to supply PCR into automotive products although this is a longer term opportunity, with further testing and development being required before this market would open up significantly; and Supply into printed film applications is not currently feasible due to quality concerns although the issue could potentially be addressed by working with buyers and consumers. The study carried out shows there are several opportunities for PCR usage. Some opportunities, like the heavy duty film market, could readily accept the material in the near future. The following recommendations have been made to maximise the potential market for the PCR: A programme of moulding trials of automotive parts should be carried out to demonstrate technical feasibility in the sector; and Consumer/buyer surveys should be conducted to establish true attitudes towards acceptable printed film appearance when including recycled material. 8.7 Economic analysis and potential for process simplification A high level economic analysis was undertaken to determine the cost of producing PCR and potential values of the end product. In addition the potential to simplify the processing of post-consumer film to reduce costs was considered. The following conclusions can be drawn from this study: Two pricing models have been presented: supply into markets using other sources of recycled material giving the PCR a value of 600 per tonne or supply as a virgin replacement which would give a higher value of 700 to 800 per tonne; It would cost approximately per tonne to produce finished PCR pellet which would give a sensible profit margin if valued at 600 to 800 per tonne; and There does not appear to be any potential to simplify the reprocessing of post-consumer film as this may result in an inferior quality PCR. The potential route to market for the PCR was also investigated and the following conclusions can be drawn: Initial supply should be focused on the injection moulded pallet, crate and box market as there is a potentially high demand and a strong opportunity to displace the use of virgin polymer; Supply into rotational moulding would also be feasible in the short term but additional effort may be required to convince an industry currently using virgin material to start using recycled material; Supply into the heavy duty films and drainage/water pipe market should be developed alongside the pallets, crate and box market as there is a very large potential demand from this sector and the industry is already used to working with recycled materials; and Supply into the automotive market should be seen as a feasible longer term goal. 8.8 Closing comments This project has demonstrated it is technically feasible to incorporate PCR derived from postconsumer film into a variety of products made using a number of different manufacturing techniques. There has been an overall positive reception from moulding companies and End market applications for household polyethylene film pellets 66

69 there is on the whole a willingness from the industry to increase (or start) the usage of recycled material, for its proven benefits in reducing environmental impact and costs. It is worth noting that any PCR derived from household post-consumer film waste placed on the market would have to be of an equivalent quality to that investigated in the report and the quality and supply would have to be consistent for the results of this project to be applicable. There is a significant potential demand for a PCR of the same quality investigated in this project. Reprocessing and supplying the PCR into UK manufacturing markets would not only potentially reduce the use of virgin polymer but also divert a large waste stream from landfill. End market applications for household polyethylene film pellets 67

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