MULTILAYER PLASTIC BOTTLES WITH MINERAL FILLER AND FOAMED LAYER FOR IMPROVED RECYCLABILITY

摘要

Plastic containers exhibiting reduced plastic resin usage, while maintaining a specific gravity of below 1.0, so as to allow their quick and easy separation using floatation techniques during recycling. Within a layer or portion some of the plastic resin of the container body may be replaced with an inorganic mineral filler material, while within another layer or portion of the plastic container, the plastic material (e.g., polyethylene, polypropylene) may be foamed. The fraction of mineral filler material that may be included within the polyethylene may thus be increased beyond that previously possible while maintaining the specific gravity below 1.0, by also foaming a layer or portion of the polymeric material, so as to create voids therein. This allows significantly less resin material to be employed, while maintaining strength characteristics of the plastic container so as to be at least comparable to existing plastic containers not including such mineral filler materials.

主权项

1. A method of forming a blow-molded plastic article, the method comprising:
(a) providing a polymeric material for a parison, the polymeric material comprising a polyolefin; (b) conveying the polymeric material in a downstream direction in an extruder; (c) introducing a mineral filler material into the extruder to be mixed with at least a portion of the polymeric material; and (d) introducing a foaming agent into the extruder to form a mixture of foaming agent and the polymeric material; and (e) subjecting the mixture of foaming agent and polymeric material to blow-molding conditions to form a cellular foamed blow-molded article; and (f) wherein the specific gravity of the blow-molded article is greater than 0.90 and below 1.0.