Biodegradable expanded foam material
First Claim
1. A method for preparing a foamed material, comprising:
- combining a starch-graft copolymer having at least 15% of a monomeric resin grafted to a first starch with a second starch to make a mixture, said starch graft copolymer having a glass transition temperature below about 390 degrees F;
adding liquid and/or vaporous water to bring the water content of the mixture to between 10 and 50 percent;
conditioning the wetted mixture at elevated temperature; and
expanding the mixture.
2 Assignments
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Accused Products
Abstract
Expanded foam materials having a high degree of biodegradability are prepared by combining a starch-graft copolymer (SGC) with grain based starch containing materials and 15-25% water and expanding the mixture either with or without blowing agents. The mixture of SGC and grain based material is directly expanded at elevated temperature with an extruder or other expansion means. The product may be customized for particular applications by manipulating the particular grafted monomer, manipulating the ratio of SGC to grain based material and/or by the addition of nucleators, blowing agents, plasticizers or other additives, and/or by varying moisture content and the conditions of expansion.
92 Citations
6 Claims
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1. A method for preparing a foamed material, comprising:
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combining a starch-graft copolymer having at least 15% of a monomeric resin grafted to a first starch with a second starch to make a mixture, said starch graft copolymer having a glass transition temperature below about 390 degrees F; adding liquid and/or vaporous water to bring the water content of the mixture to between 10 and 50 percent; conditioning the wetted mixture at elevated temperature; and expanding the mixture. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification