Thermoforming flexible plastic foam shells

Abstract From the Canadian patent

of Disclosure, An improved method and apparatus for rapidly forming plastic foam shells from a flexible foam sheet. The foam sheet is i??er mittently passed through a radiaent heating unit and is rapidly heated on both sides to 130-250°F to soften the foam. The heated foam sheet is immediately passed through a forming die unit in which the foam sheet is deformed partly into the die cavity by withdrawal of air from the cavity and a die plug, descends and final forms a shell while rapidly cooling the foam shell to below its plastic deformation temperature. By this forming method and apparatus. ethylene-containing foam shells having a depth 10-25 times the foam sheet initial thickness are …