FINAL TECHNICAL REPORT

Transcription

1 FINAL TECHNICAL REPORT The MASTALMOND project aims to develop new masterbatches, or colour concentrates, based on natural waste (almond shell) on biodegradable thermoplastic matrixes, replacing mineral and synthetic fibres commonly used. These lignocellulosic fibres are easy to process, provide lightness while maintaining suitable levels of hardness and stiffness in accordance with industry standards, which makes them particularly interesting in the field of non-structural composites, both from the economic point of view and due to their lower environmental impact. The concentrates developed will cover technical requirements for two traditional industries, such as the toy and auxiliary furniture. To achieve this overall objective the following specific objectives are aimed: - Physical and chemical analysis of the almond shell to be added into plastic matrixes. - Process of incorporation and dispersion of almond shell into biodegradable polymers. - Addition of organic and inorganic pigments to the polymer-almond shell compounds. - Definition of the specifications and design of the final demonstrators. - Optimisation of the process of incorporation of the masterbatches obtained to biodegradable plastics to meet the technical specifications set by the application sectors involved. - Design of prototype parts and validation, as well as optimisation of the injection process. Figure 1 LIFE MASTALMOND masterbatches achieved within the project development The key deliverables and outputs obtained are: - New processes to obtain masterbatches with the optimum incorporation and dispersion of milled almond shell in a high concentration in biodegradable polymers new formulations of biodegradable masterbatches with almond shell have been developed for injection moulding processes containing organic and inorganic pigments. - Biodegradable prototype demonstrator of the toy and auxiliary furniture sectors with different colours, containing almond shell in their formulation: parts of a ride-on toy, a sandbox, chairs, desk accessories, waste bins - Optimisation of the injection moulding process of biodegradable materials (with PLA and blends of PLA with a starch derivative) with the new masterbatches.

2 - Technical validation according to the applicable European legislation of the masterbatches and demonstrators obtained. The new masterbatches change the appearance but not their properties. - Environmental Validation of PLA-based masterbatches and demonstrators. The new biopolymer masterbatch has a 50 % reduced dependence on non-renewable fossil fuels compared to a conventional one; however, during its manufacturing a higher amount of electricity is consumed. Recommendations for reducing energy consumption by up to 80 % were proposed. Figure 2 Test specimens and platelet injected with MASTALMOND masterbatches The technical tasks performed are: ACTION A1: State of the art: current situation regarding the use of organic materials in plastic matrixes. The partners of the project have performed previous research about the state of the art concerning almond shell. The demonstrators to be developed were defined: furniture and office furniture pieces and toy parts (a sandbox and a ride-on toy). The factors that may affect the final properties of the moulded specimens were studied. Besides, a search for biodegradable polymer matrixes with their main features was conducted in order to define what matrixes may be similar to polymeric materials that are currently used in the toy industry and auxiliary furniture sector. A search for literature about different treatments for almond shell has been conducted in order to improve compatibility between fibre and matrix and the high moisture content of the fiber. After the search for literature about the different treatments that can be applied to almond shell to improve compatibility between fiber and polymer matrix, we have studied and characterised the almond shell modified with different surface treatments, both physical and chemical. These treatments can produce surface changes such as the increase of the surface energy, bonds or crosslinks between chains through surfaces or the introduction of radicals and reactive functional groups which can help increase the filler-matrix adhesion. Corona discharge treatments, alkaline treatments (NaOH) at different concentrations and temperature and maleic anhydride were selected to work with during Action B1. Under this action, we have been performed a legislative search that all those materials must meet, as well as the final demonstrators, so that they do not pose a risk to the user. Moreover, we have studied Ecolabelling for furniture, with the aim of analysing how results could be incorporated into the certification system; besides, we have carried out a report of the factors to consider and the methodology for the life-cycle assessment (LCA) and calculation of energy efficiency in both the production of masterbatches and the injected demonstrators.

3 ACTION B1: Establishment of specifications: We have defined the following requirements for the shell, materials, processes and products to be developed: - We have selected six varieties of almond, to study whether the type of shell affects the mechanical properties of the moulded parts: LARGUETA, DESMAYO ROJO, GUARA, MARCONA, COMUNA, MOLLAR and a MIXTURE of these varieties. Action B.2 includes a study of the influence of the type of variety in the mechanical properties of the moulded parts. - Size of almond shell: we agreed to study a range of shell particle size between 0.1 and 0.7 mm, which are sizes that were obtained either by grinding large fragments at the premises of the partners supplied by different suppliers, or by sifting in a controlled manner the shell already crushed by suppliers. - We conducted a search for different biodegradable polymer matrixes, such as two kinds of polylactic acid (PLA), polyhydroxyalkanoates (PHA), polycaprolactone (PCL) and combinations of PLA with starch and PCL + starch (potato starch), depending on the properties we want to obtain for the final demonstrator. - Study of % of the masterbatch in injection specimens: we defined the addition of the masterbatch in the injection of parts at 4 and 8 % by weight for the further characterisation of mechanical properties (tension, bending, hardness, Charpy impact). - Study of different surface treatments, both chemical and physical, in order to check whether there has been an improvement of the adhesion in the fibre-matrix interface and of the drying conditions. - Study of a sweep of colours in order to check what colours can better behave and be displayed in biodegradable polymer matrixes with almond shell. The study of colour for masterbatches was very important because brown almond shell interferes with many other colours. Initially, we made a selection of pigments to allow us to work with biodegradable polymers PLA, PCL, starch derivatives and PHA. Later, those who could meet the standards of compostability according to DIN EN Requirements for packaging recoverable through composting and biodegradation. Test scheme and evaluation criteria for the final acceptance of packaging. The best results were obtained using pigments of blue, green and white / beige, as they presented colorimetric properties more compatible with almond shell colour. Although pink was chosen for the final toy demonstrator, which was also compatible but somewhat lower than the other pigments, due to the impact that this colour has on the world of children. ACTION B2: Implementation of the process to obtain new masterbatches: We studied the effect of type, size and supplier of almond shell on the mechanical properties of the masterbatch and different biodegradable polymers, and we obtained up to 33 formulations of biodegradable masterbatches with almond shell with PLA, PHA, PCL base and mixtures of these materials. The main findings were: - After the study of different types of shell depending on the variety of almond, we concluded that the mixture of varieties gives similar mechanical properties to these parts than those given by most of the varieties separately. Because of this fact and given that suppliers usually provide

4 shell as a mixture, we used along the project mixed varieties. This study was published in the journal Waste and Biomass Valorization (June 2015, Volume 6, Issue 3, pp ). - We found that a range of shell particle size between 0.3 and 0.5 mm was most suitable for processing by extrusion of the masterbatch and for the injection moulding of parts, due to the size of the nozzles through which the plastic material flows; larger shell particle sizes gave some problems during the extrusion of the masterbatch, such as clogging of the nozzle, accumulation of particles in the nozzle and their degradation after increasing the residence time. - By adding the almond shell as a filler, the most affected mechanical property of the injected parts is impact resistance. The material becomes slightly more fragile when shell particles are larger and with the introduction of 8 % masterbatch versus 4 % in the injected part. The remaining mechanical properties do not appreciably vary with the percentage of masterbatch. - Shell particles smaller than 3 mm provide better mechanical properties and a more homogeneous aspect. Larger particles provide an interesting appearance. - The almond shell supplied by different providers presents a similar behaviour in all masterbatches; then it is possible to work with the most convenient supplier depending on prices and availability. - We have chemically treated almond shell using compatibilising agents in order to improve fibre-matrix bonding, since there is a small improvement in their mechanical properties. From the preliminary injection tests conducted, we decided to work with PLA and PLA or PCL combinations + starch derivatives due to their injection behaviour during the processing of final demonstrators. For this reason, masterbatches were developed based on PLA, PLA + starch derivative and PCL + starch derivative for scaling up and use in the injection of demonstrators in Action B.3, which are compatible with these biodegradable materials selected for injection. Then the colours to be processed were decided after performing a colorimetric sweep and noting that almonds provide a reddish colour to the parts and the smaller sizes of almond have a more pronounced effect on colour variation than those particle sizes which are larger; we chose pink, beige and green, due to the target users for which the final demonstrator is intended. The biodegradable polymer matrix of PLA with starch derivatives keeps the properties of impact resistance and flexibility somewhat over the rest, regardless of its colour. Furthermore, a prototype extruder was also developed, with the aim of obtaining biodegradable masterbatches, a challenge we have achieved after performing an extensive study of configurations of spindles, modification of parts of the extruder, changes in process parameters, etc. ACTION B3: Development of demonstrators: toy and furniture parts including new masterbatches in their composition: We performed a review of the regulations and requirements of each sector. In the case of furniture, we selected: a complete office chair and some auxiliary furniture (pen holders, pen trays, rubbish bins and bin complements); in the case of toys: a sandbox and hubcaps and battery parts of a ride-on vehicle. For both sectors, we considered large parts and smaller parts.

5 In the case of auxiliary furniture, we initially found some difficulties when processing biodegradable polymers before adding the newly-developed masterbatches, mainly at the stage of demoulding of the largest parts of two of the demonstrators, the office chair and the rubbish bin, the material becomes more brittle when it quickly cools. Tests were performed on other smaller moulds for other expected demonstrators for office equipment, such as pen holders, pen trays and bin complements. In these products, the problems we found were minor but we still had to tune the injection process with the biodegradable material and then the injection process was optimised by adding 4 % of the coloured masterbatches with almond shell developed in action B.2. In the case of the toy sector, during the injection process we experienced similar problems than those had with auxiliary furniture. Large parts, such as the sandbox, require on the one hand greater fluidity of the material, and on the other hand tempering the mould so that the workpiece is properly filled. Other smaller demonstrators (hubcaps and battery parts of a ride-on toy) were developed and once the process was optimised more parts were injected with PLA incorporating 4 % of PLA + 30 % almond shell masterbatch (with different dyes) and parts of PLA + starch derivative material with 4 % PLA + starch derivative with 30 % almond shell masterbatch (with different dyes). In all cases, we carried out the design and development / modification of parts and injection moulds for these products in order to complete the optimisation of the different processes. During processing, working pressure has increased, as well as energy waste in consequence, which is why new injection parameters were sought to optimise the cycle time. Biodegradable prototype demonstrators have been obtained for toys and auxiliary furniture which include new almond shell masterbatches in different rates and in different colours. Figure 3 Toy sector demonstrators

6 Figure 4 Auxiliary furniture demonstrator ACTION B4: Evaluation of results: During this action we have determined and compiled the regulations and legislation involved in the final demonstrators containing the new masterbatches with almond shell in a biodegradable polymer matrix when they are injected into parts of a toy or a chair and/or other similar accessories. The relevant safety and quality tests have been conducted, and the samples meet the requirements as expected. ACTION C1: Monitoring the impact of the project through indicators: We have compiled information for the life-cycle assessment (LCA) to be performed by companies: amount of material used, energy required for grinding almond shell, energy consumption associated with the production of masterbatch to consider whether it is significant or not, the failure rate in companies, and data about the transport of materials (means of transport and kilometres). We have developed LCA (life-cycle assessment) studies of products, in order to compare environmentally formulations based on conventional and biodegradable polymers (in this case polypropylene, which is the material currently used in toys and furniture products similar to the demonstrator developed). In conclusion, we have seen a considerable reduction in the impact of the carbon footprint and the impact of the depletion of fossil fuels with the new biopolymer masterbatch compared to the conventional polyethylene masterbatch. However, when the biodegradable polymers are processed, the values of the carbon footprint and the depletion of fossil fuels both during the manufacture of masterbatches by extrusion and during the injection of a ride-on toy part and the rubbish bin have increased, because a larger amount of electricity is consumed in the process mainly due to lower fluidity of the material, which requires more processing time and temperature, thereby increasing the energy required.

7 We have performed an energy audit with on-site measurements of both the manufacturing process by extruding the masterbatch, and the injection of plastic parts using the relevant masterbatch. In this case, we have monitored the energy consumption of processes of extrusion of masterbatches and injection of demonstrator parts in order to compare the energy efficiency of each of the processes, varying the composition of materials (traditional (PP) vs biodegradable materials). For this purpose, we made a comparative study of energy efficiency between the extrusion process for obtaining traditional and biodegradable masterbatches and the injection process with traditional and biodegradable materials for obtaining two types of parts (for ride-on toys and bin complements). As conclusion of these measurements, it has been possible to glimpse the potential for improvement in the industrial processes studied (extrusion and injection). All this has allowed us to define a series of actions that can be implemented to improve the energy efficiency of these production processes (extrusion and injection) and thus make them more sustainable. The use of other more fluid biodegradable matrixes lead to injection cycles 25 % shorter and energy improvements of %, as we have checked by measuring injection cycles of the formulations of moulded parts with PLA + starch + 4 % masterbatch PLA + starch with almond shell. Summary of Dissemination Tasks ACTION D1: Dissemination and information. We have performed all the activities included in the Communication Plan, as well as other additional actions that reinforce and enhance their impact. We have made 2 different types of brochures, one informative and one more commercial, and a leaflet with the most relevant results of the project. These have been disseminated in 3 international conferences which we have attended in order to present the results of the project and a training event at the University of Las Palmas de Gran Canaria. The project has been published in 9 AIJU newsletters. Besides, we have published 8 Mastalmond newsletters, published on the website of the project and sent by to all the contacts in the Mastalmond contact list (140). We have designed and printed a poster and a roll-up banner in Spanish and English, shown in 14 industrial fairs and 4 national events. ACTION E1. Networking. The consortium has organised three events for important networking actions, including an international event: Event MASTALMOND: Challenges of the creative industry; bio-materials customised products. We have participated in five actions of business to business of great interest in Europe. In addition, we have selected and contacted 32 LIFE11 projects and 48 LIFE13 projects for networking actions. Long-term benefits. This proposal has allowed the launching of a new process and products aimed to improve / optimise the management and sustainable use of natural resources and waste, improving the recovery and recycling of waste, in this case from the agricultural sector which is one of the priority areas of the VI Environment Action Programme. The results can be implemented in the plastics processing industry anywhere in Europe, and not just in the studied sectors but also in any other plastic industries, without incurring in expensive infrastructure investments. Life11 ENV/ES/ MASTALMOND