Polymer-wood composites and additive systems therefor

摘要

The present invention provides a method of forming a polymer-wood composite structure and additive systems for use therein. The method of the invention includes extruding a heated mixture that includes from about 20% to about 80% by weight of a thermoplastic polymer, from about 20% to about 80% by weight of a cellulosic filler material, and from about 0.1% to about 10% by weight of an additive system. The additive system according the invention includes a blend of from about 10% to about 90% by weight of a nonionic compatibilizer having an HLB value of from about 9 to about 19 and from about 10% to about 90% by weight of a lubricant. Use of the method and additive system according to the invention facilitates the production of highly filled polymer-wood composite structures at a very high output rate while maintaining commercially acceptable surface appearance. Moreover, the method and additive system according to the invention facilitate the reprocessing of scrap material generated during the production of polymer-wood composite structures without degrading the surface appearance of the polymer-wood composite structures.