Extrusion method and apparatus for recycling waste plastics and construction materials therefrom
AssigneePolymerix, Inc.
InventorsWolfgang A. Mack, Peter J. Canterino
Life of this patent
Estimating the term…
Abstract
An extrudable composition comprised of waste polyolefins and an alkali metal bicarbonate salt/solid, saturated fatty acid foaming agent system, and a method for extruding such extrudable composition wherein the fatty acid/bicarbonate foaming agent system foams the waste polyolefins during the extrusion to produce end products which have qualities closely simulating natural lumber suitable for use as construction materials.
Claims27
An extrudable composition for making construction material, comprising a dry blend of:
- at least 50%, based of total weight of said composition, of a used polyolefinic material derived from residential, commercial, or industrial waste;
- about 0.1 to 1.5%, based on the total weight of said composition, of an alkali metal bicarbonate;
- and
- in a molar ratio of about 1:1 to 2:1 with respect to said bicarbonate, a saturated fatty acid which is a solid at room temperature, the amount of said alkali metal bicarbonate and said fatty acid being sufficient to form, upon extrusion, a foamed construction material having a specific gravity of 0.4 to 0.9;
- and
- about 2 to 50% of a reinforcing material.
A foam composition having a specific gravity of 0.4 to 0.9 formed by a continuous extrusion process in the presence of a saturated fatty acid and an alkali metal bicarbonate in a molar ratio of from 1:1 to 2:1 and suitable for use as a substitute for construction lumber, comprising:
- at least 50%, based on total weight of said composition, of a used polyolefinic material derived from residential, commercial, or industrial waste;
- and
- an anionic salt of an alkali metal carboxylate of a saturated fatty acid;
- and
- about 2 to 50% of a reinforcing material.
A method of making a composite foam extruded product which simulates lumber comprising the steps of:
- continuously supplying to an extruder used polyolefinic material derived from residential, commercial, or industrial waste;
- blending with said polyolefinic material an alkali metal bicarbonate and a saturated fatty acid which is a solid at room temperature, said bicarbonate being at a concentration of about 0.1 to 1.5% of total weight of said blend and said fatty acid being in a molar ratio of from about 1:1 to 2:1 with respect to said bicarbonate and about 2 to 50% of a reinforcing material;
- extruding a melt of said blend through a profile die;
- forming a foaming agent and a lubricant for said blend by the in situ reaction of said bicarbonate and said fatty acid;
- feeding the lubricated blend from said die into a sizing zone wherein the blend is foamed to substantially its final cross-section;
- cooling the thus-foamed material in said sizing zone so as to rigidify the foamed material;
- and
- forcing and pulling the rigidified material through and from said sizing zone.
Dependencies are inferred from the claim text.