Packing Design for Canned Fruit KTH 2009-03-06, Department of Solid Mechanics Design project in SE2127 Packaging Materials, 2009 Frida Schildauer, 820429-1986 Pedro Soler, 841216-A419
Introduction One very common product that comes in tin cans is the fruit cocktail. Fruit in tinned cans is a product that exists all over the world and if a successful alternative packing is developed and implemented in the market this could means major differences from a environmental aspect as well as how the packing is used. In the development of the new packing design for canned fruit special focus has been put on the environment and add the packing extra values. Requirement from the instructions for the project is also that focus should be on product flow, protection and runability properties, even though the all functions of the of the packing system should be considered. It is also important to point out that this is not a detailed analysis of a new the packing design, but a simple and qualitative first suggestion. The Design of the Packing The Design The background to the esthetical design is to find an extra value that the packing can offer. The main though was the function to use it as a packing from where the fruit could be eaten directly or from where it could be served and placed on the table. With this is also created the possibility to bring and eat your desert everywhere, without worrying about bringing an extra plate. In figure 1 a schematical photos of a first model of the suggested packing solution can be seen. Figure 1 A schematical set of photos of the suggested packing design Materials A systematical sketch of the suggested material build up can be seen in figure 2. PaperBoard + Coating - Korsnäs light 270g/m2 Adhesive/Moisture barrier Low-density Polyethylene (LDPE) Aluminium foil for high resistance to gas transportation, ex. Oxidation Adhesive/Moisture barrier Low-density Polyethylene (LDPE) Fig 2 The layer of the material used for the packing.
For barrier and also adhesive coating is LDPE chosen, this because for its low cost and properties as a good moisture barrier and good heat sealibility. [1] It is also approved for food contact and is today the coating used to give for example the milk boxes their barrier properties. LDPE is also used as adhesive between the aluminum and paper board layer. Stiffness analysis for a maximum product flow showed that among the paperboards offered by Korsnäs the best solution was Korsnäs light 270g/m2. Technical speciation for Korsnäs Light is found as appendix 1. Functions of the Packing System Product flow The pallet used for transportation is most likely the Euro pallet with dimensions 800mm. 1200mm. 144mm. From a brief investigation made is seems that the volume of a can with about 400g canned fruit is 496 000 mm2. The dimensions used for the rectangular box which will be the primary packing are width 55.5 mm, length 74 mm and height 121 mm. If a secondary packaging in form of a tray with corrugated board with thickness 5 mm is used, then the dimensions for it are 232mm of width, 380mm of length and 50 mm. of height. This solution above the pallet results in a layer of 5x2 secondary packaging and this gives a under hang of 20 mm on all four sides. To complete this process the under hang will be useful to use plastic wrapping. Finally in the top will be put a ply and straps tighten the packaging on the pallet. Backwards to give an optimum volume use of the tertiary (transportation) there will be 8 layers, totally will be 150 primary packaging in each layer and finally 1200 units in the pallet. Figure 3 Dimensions of a euro pallet This means that the total weight of the load in the pallet will be 480 kg. and adding the pallet weight as 15kg. (average weight for Euro Pallets having an approximately load capacity of 750 kg) is finally 495 kg. The total height for the tertiary packaging (load + pallet) will be:
TH = Top ply thickness + layers*(product height + sec. packaging thickness) + pallet height TH = 5 + 8 *( 121 + 5 ) + 144 = 1157 mm. For big load transportations will be considered the 20 ft. ISO container. In this, there is one designed possibility to order the pallets and with the calculated height for this tertiary packaging the total quantity is 30. Then the total load in the container will be 14850 kg. and the 20 ft. container has a maximum load capacity of 21600 kg, so it is perfect. Dimensions of the 20 ft. ISO container is seen in figure 4. Finally are used 330.94 m³ inside the container, a 93.19% of his capacity. Figure 4 Inner dimensions of a 20 ft. standard container Protection The content has very high percentage of moisture, so the good properties as a moister barrier of polyethylene (PE) is very important as well as its sealing properties. The aluminum layer keeps the light out of the box to maintain to keep the freshness of the fruits. The PP and Aluminum foil can be considered not to contribute to the stiffness and other mechanical properties of the box. With Korsnäs Optipack with the simplification to use a box A6020 the requirement for load caring properties was 214 N. The suggested design for the canned fruit is assumed to have higher load caring properties, but no better offer of packing was given with the programs suggested. The requirement of load caring properties 214 N is probably higher that the actual requirement on the box. The Korsnäs 270 Light gave a BCR calculated to 224 for the suggested design and dimensions, which is good enogh and also offers a small buffer. Runnability The carton board from Korsnäs is well know and well functioning material, which has developed for running smoothly in the packing industry. The stiffness needed in the transportation is fulfilled. The coating on the out side is manufactured to have good printing properties.
Figure 5 Type of packing of similar type already on the market. The carton board will first printed, then creased and cut. After wards folded and glued and the side corners, there after filled with the fruit and finally sealed on top and folding to get its final shape of a box. If the figure 1 of the suggested design is seen this will be easier to understand. Environment Environmentally friendly processes are to be used in manufacturing and a minimum of environmental hazardous substances must be prioritized when selecting adhesives to be used. As the packing is a food packing the substances used are strongly restricted. One problem with using aluminum foil inside the packages is that its recycling properties are affected. If the aluminum layer could be avoided, recycling of the packing would be possible, as it is today possible to reuse the milk cartons with PE coating. Packages reuse is not applicable for a paper packing of this type, due to obvious reason of the type of packing. Energy re-use is the remaining possibly. One environmentally concern is the aluminum foil inside the box. It needs to be considered of it might be good enough with only LDPE layers, or other plastic as barrier. This will lead to positive effects regarding the possibility to recycling of the paper. Barrier with higher demands on barrier properties than PE can offer can be replaced with PP. Properties in some types of PP like Borpact BC914TF allows resistance to low temperatures, stiffness and heat resistance, offering a very good component to use with paperboard in the construction of a packaging s composite [2] This will lead to positive effects regarding the possibility to recycling of the paper. Recycled paper may not be used in food packing in this type, because the content of the paper is not known [1] Communication Communication of packing is divided in two parts; information needed in the transport and distribution and information. This should not be cause of any problems because standard tertiary and secondary packing are used. One problem with the suggested packing is where to put the information needed for the end consumer. The information needed to fit on the packing is declaration of content, how to prepare the fruit, last date for consumption and barcode. Important in this special case is also how to use the packing and how to present the possibilities with the new type of packing. Suggestion on a graphical design is seen in figure 6.
Figure 6 Suggestion on the graphical design. Conclusion/Problems / Further investigations needed I the estimations done in this investigation are correct, the suggested packing could be a alternative to the existing alternative to the tinned cans for the packing of fruit cocktail. Stress concentrations in corners due to the extreme folding of 180 degrees will probably be a major problem if the suggested design is investigated further. It is also important to investigate further if it is possible to use a barrier without an aluminum foil. Referenses 1. Course compendium for SE2127, Fabrication of Paper and Paperboard, s 223-224 2. Iides The Plastic Web, http://www.ides.com/grades/ds/e90163.htm, 2009-03-05
Appendix 1- Technical Specification Korsnäs light