Plastic stonewashing stone and method
OwnerJerry L. Grigsby, Jr.inventor
Life of this patent
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Abstract
A porous and abrasive plastic stone is disclosed for use in a stonewashing process to commercially age garments or fabric. The plastic stone replaces the pumice stone that is typically used in the stonewashing process. A method for manufacturing the stone includes mixing plastic material with a gas-producing agent within a plastic extruder. This produces a plurality of cells or voids in the plastic as gas expands during the cooling of the plastic. The cells along the periphery of the plastic material are ruptured by the gas to form an abrasive surface comparable to that of pumice and yield a plastic stone with a desired density.
Claims15
A method of manufacturing a plastic stone useful for abrading fabric, comprising the steps of:
- combining a plastic material and a gas-producing agent to form a mixture of plastic material and gas-producing agent;
- heating the mixture of plastic material and gas-producing agent within a pressurized chamber of an extruder to form voids of gas within said heated plastic material from said gas-producing agent;
- extruding the heated plastic material from the pressurized chamber to ambient pressure;
- cooling said plastic material so that said voids within said plastic material achieve a density of from 20 lbs./1 cu. ft. to 50 lbs/cu. ft. for said plastic material, said voids of gas further rupturing an external surface of at least some of said voids to form an abrasive exterior surface on said plastic stone;
- and
- adjusting the quantity of said gas-producing agent to create peaks and valleys on said abrasive exterior surface of said plastic stone wherein the distance between said peaks and said valleys is, in an average range from less than 0.25 mm to about 6 mm.
An artificial stone having a density greater than about 20 lbs./cu. ft., said artificial stone having a plastic material content greater than 75% of the total content by weight of said artificial stone, said artificial stone having voids therein such that said artificial stone has a porosity from 20% to 40%, at least some of said voids having a broken outer surface forming jagged edges and forming a broken exterior surface of said artificial stone.
Dependencies are inferred from the claim text.