G.R. Wilkes, D. You, J. Kim, A. Kim, C. Park
Amylum Systems,
United States
Summary:
ADVANCED POLYPROPYLENE FOAM EXTRUSION TECHNOLOGY AND ITS POTENTIAL APPLICATIONS Gary Wilkes1, David You1, John Kim1, Andrew Kim1, Ardom Lin1 and Chul Park1 ,2 1 Amylum Systems Inc. 2 Department of Mechanical and Industrial Engineering, University of Toronto, Canada Polypropylene(PP) is regarded as a recyclable commodity polymer which is also considered as a safe plastic for microwave-heating food container applications. The Food Packaging industry has been challenged since the early 1990s to find a more recyclable replacement material for polystyrene (PS) foam, often called Styrofoam®, that does significantly increase the cost of the various product offerings. While based on required properties polypropylene was identified as a possible candidate material, particularly for hot foods and beverages, the process to make low density, lightweight product required an expensive grade called High Melt Strength Polypropylene. Amylum Systems has developed and commercialized the breakthrough technology on PP foam extrusion in which expensive high-melt-strength PP content is minimized at only 30 to 40% by adopting very unique feed screw and die channel design. On top of price competitiveness from minimized material cost, the non-crosslinked PP foam sheet of Amylum features fine cell structure and excellent thermoformability to produce various shapes of food containers. The high-quality foamed PP could be manufactured via accumulated expertise and know-hows of two co-founders (professor Chul Park, University of Toronto and Mr. Ardom Lin, Reach Plastic in Taiwan) on material recipe and foam extrusion process variables. The surface of PP foam food containers made by the Amylum process does not become hot even after microwave heating, which significantly reduces the risk of heat burn injury. This advantage is critically important for consumer safety because most of ready-made food items are supposed to be heated in a microwave oven. Consumers can even hold PP foam instant noodle bowls filled with boiling hot water with their bare hands. When PP foam containers are used as delivery food containers, the food quality can be well preserved for much longer time because of excellent thermal insulation property. Since PS foam packaging is phasing out around the world, PP foam containers will become the only solution boasting both thermal insulation function and recyclability. Non-crosslinked PP foam material is also very promising as recyclable light-weight automotive parts and building materials due to noise shielding and thermal insulation effect. For instance, existing headliner material in cabin room is made of crosslinked non-recyclable polyurethane (PU) foam, so there is no denying that recyclable PP foam headliner is much more ecofriendly and innovative automotive part. Potential PP foam material market size is believed enormous, because there are many more applications waiting for environmentally friendly alternative to polystyrene foam; insulated disposable cup, to-go-box, meat/fish tray, fruit protective tray, egg carton, sign/graphic display board, etc. As PS ban is expected to accelerate after PP foam products spreads around the globe, new paradigm of PP foam material as a perfect substitute is expected to begin soon via Amylum’s unprecedented foam extrusion technology.