| 摘要 |
Biodegradable free fill expanded polyurethane foam packing materials are formed by pumping liquid starch or sugar, diisocyanate, polyols and a catalyst into a mixing head. The mixture is released from an exit port in the mixing chamber as a sticky material. At predetermied intervals air blasts chop the sticky material mass from the exit port. The material beings expanding as it drops through a curing chamber against upward warm air currents. When the materials expand to full size and dry to a non-tacky surface, the materials are released from the chamber and collected for use as packing materials. The materials have a bionutrient starch or sugar content of about 40% or more, making them readily biodegradable by microbes. The polyurethane components are broken down into very small sizes and convert to urea, making the products highly suitable for disposal in landfills and as soil amendment and fertilizers.
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