Method of reconstituting mica
First Claim
1. In a method of making reconstituted mica sheet including the steps of blending mica and polyester, forming the mixture into a layer, and subjecting the layer to heat and pressure for bonding the layer into sheet form, the improvement comprising providing dry ground mica having a particle size in the range of from about 200 mesh to about 14 mesh;
- providing ground thermoplastic polyester having a particle size of less than about 60 mesh;
proportioning the mixture to have from about 90 to about 50% mica by weight of the mixture;
forming the layer to have a thickness in the range of from about 1/8 inch to about 3/4 inch;
bonding the layer into a sheet having a thickness in the range of from about 1/64 inch to about 3/34 inch; and
maintaining the ground mica and ground polyester free from water during the steps of blending while producing the mixture, forming the layer and subjecting the layer to heat and pressure.
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Abstract
A method of making reconstituted mica sheet in which dry ground mica is blended together with dry ground thermoplastic polyester to produce a dry powder mixture having no more than about 90% mica by weight of mixture, the dry powder mixture is formed into a layer, and the layer of dry powder is subjected to heat and pressure for softening the polyester and bonding the mica into sheet form. The mica used preferably is scrap mica and the polyester used preferably is scrap polyethylene terephthlate, ground to have particle size distributions as set forth in detail hereinafter.
4 Citations
7 Claims
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1. In a method of making reconstituted mica sheet including the steps of blending mica and polyester, forming the mixture into a layer, and subjecting the layer to heat and pressure for bonding the layer into sheet form, the improvement comprising providing dry ground mica having a particle size in the range of from about 200 mesh to about 14 mesh;
- providing ground thermoplastic polyester having a particle size of less than about 60 mesh;
proportioning the mixture to have from about 90 to about 50% mica by weight of the mixture;
forming the layer to have a thickness in the range of from about 1/8 inch to about 3/4 inch;
bonding the layer into a sheet having a thickness in the range of from about 1/64 inch to about 3/34 inch; and
maintaining the ground mica and ground polyester free from water during the steps of blending while producing the mixture, forming the layer and subjecting the layer to heat and pressure. - View Dependent Claims (2, 3, 4, 5, 6)
- providing ground thermoplastic polyester having a particle size of less than about 60 mesh;
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7. In a method of making reconstituted mica sheet including the steps of blending mica and polyester together while producing a mixture of mica and polyester, forming the mixture into a layer, and subjecting the layer to heat and pressure for bonding the layer into sheet form, the improvement comprising providing dry ground mica having a particle size in the range of from about 200 mesh to about 14 mesh;
- providing ground polymerized polyethylene terephthlate having a particle size of less than about 60 mesh;
proportioning the mixture to consist of about 75% mica and about 25% polyethylene terephthlate by weight of mixture;
forming the layer to have a thickness in the range of from about 1/8 inch to about 3/4 inch;
bonding the layer into a sheet having a thickness in the range of from about 1/64 inch to about 3/34 inch; and
maintaining the mica and polyethylene terephthlate free from water during the steps of blending while producing the mixture, forming the layer and subjecting the layer to heat and pressure.
- providing ground polymerized polyethylene terephthlate having a particle size of less than about 60 mesh;
Specification