Pellet based tooling and process for biodegradable component

Abstract

An example starch-based material for forming a biodegradable component includes a mixture of a starch and an expansion additive. The starch has an amylose content of less than about 70% by weight. The expansion additive enhances the expansion and physical properties of the starch. A method of preparing a starch-based material is also disclosed and an alternate starch-based material for forming a biodegradable component is also disclosed.

What is claimed is: 
     
         1 . A starch-based material for forming a biodegradable component, comprising:
 a mixture of a starch having an amylose content of less than about 70% by weight and unexpanded heat-expandable thermoplastic microspheres.   
     
     
         2 . The starch-based material of  claim 1 , wherein the unexpanded heat-expandable thermoplastic microspheres comprise between about 0.5% and 10% by weight of the mixture. 
     
     
         3 . The starch-based material of  claim 2 , wherein the heat-expandable thermoplastic microspheres comprise between about 1% and 5% by weight of the mixture. 
     
     
         4 . The starch-based material of  claim 1 , wherein the unexpanded heat-expandable thermoplastic microspheres are between about 45 and 120 microns in diameter. 
     
     
         5 . The starch-based material of  claim 1 , further comprising an additive including at least one of an etherification additive, latex, peat, and glycerol. 
     
     
         6 . The starch-based material of  claim 5 , wherein the additive comprises more of the starch-based material by weight than the unexpanded heat-expandable thermoplastic microspheres. 
     
     
         7 . The starch-based material of  claim 1 , wherein the amylose content is between about 20% and 30% by weight. 
     
     
         8 . The starch-based material of  claim 1 , wherein the unexpanded heat-expandable thermoplastic microspheres comprise a high elongation copolymer of acrylic. 
     
     
         9 . The starch-based material of  claim 1 , further comprises expanded heat-expandable thermoplastic micro spheres. 
     
     
         10 . A method of preparing a biodegradable material, the method comprising:
 mixing unexpanded heat-expandable thermoplastic microspheres with a starch to form a biodegradable material mixture, the unexpanded heat-expandable thermoplastic microspheres enhancing the physical and expansion properties of the starch, and the starch having an amylose content of less than about 70% by weight.   
     
     
         11 . The method of  claim 10 , further comprising forming the biodegradable material into a biodegradable component. 
     
     
         12 . The method of  claim 10 , wherein the forming includes extruding the biodegradable material through a die, dividing the extruded biodegradable material to form a plurality of biodegradable pellets, applying a binding agent onto the plurality of pellets, and compressing the biodegradable pellets with the binding agent in a mold to form a biodegradable component corresponding to a geometry of the mold. 
     
     
         13 . The method of  claim 12 , wherein the extrusion causes the unexpanded heat-expandable thermoplastic microspheres to expand. 
     
     
         14 . The method of  claim 10 , further comprising expanding a portion of the unexpanded heat-expandable thermoplastic microspheres prior to the mixing. 
     
     
         15 . The method of  claim 10 , further comprising mixing an additive including at least one of an etherification additive, latex, peat, and glycerol with the unexpanded heat-expandable thermoplastic microspheres and the starch. 
     
     
         16 . The method of  claim 15 , wherein more of the additive than the unexpanded heat-expandable thermoplastic microspheres by weight is mixed with the starch during the mixing. 
     
     
         17 . The method of  claim 10 , wherein the unexpanded heat-expandable thermoplastic microspheres comprise between about 1% and 5% by weight of the mixture. 
     
     
         18 . The method of  claim 10 , wherein the amylose content is between about 20% and 30% by weight. 
     
     
         19 . The method of  claim 10 , wherein the unexpanded heat-expandable thermoplastic microspheres comprise a high elongation copolymer of acrylic. 
     
     
         20 . The method of  claim 10 , further comprising mixing expanded heat-expandable thermoplastic microspheres with the unexpanded heat-expandable thermoplastic microspheres and the starch.