Inventors:
William C. Decker - Cary NC
William A. Wittosch - Warwick NY
Assignee:
International Paper Company - Purchase NY
International Classification:
B32B 326
B32B 514
Abstract:
A compostable, biodegradable foam core board has a facing sheet adhered to a foam core sheet made of a foamable biodegradable material selected from a polyvinyl alcohol polymer, a starch-based thermoplastic polymer, a polylactic acid polymer, and other foamable, biodegradable polymers having structural rigidity when foamed. The foam core sheet has selected structural properties including a foam core weight in a preferred range of 30 to 50 lbs/msf, a foam density in a preferred range of 1. 5 to 9 lbs/ft. sup. 3, and a foam cell size in a preferred range of 0. 30 to 0. 70 mm. In one example, the foam core material is composed of a mixture of a polyvinyl alcohol polymer and high-melt-index polystyrene as a structural polymer additive. In another preferred example, the foam core material contains a blend of destructurized starch, polyethylene, polyvinyl alcohol, polyvinyl acetate, and glycerol as a plasticizer.