Plastic articles having isotropic properties and methods of making same

Claim 1

THE METHOD OF PRODUCING WARP-FREE PLASTIC ARTICLES HAVING ISOTROPIC AND BALANCED PROPERTIES COMPRISING THE STEPS OF (A) INTRODUCING SUBSTANTIALLY EQUAL QUANTITIES OF A FLOWABLE MATERIAL CURABLE TO A SOLID RESIN INTO TWO IDENTICAL LEVELED SHALLOW OPEN MOLDS HAVING MOLD BOTTOMS, WHICH CONFORM TO THE DESIRED EXTERIOR SURFACE FINISHES OF THE ARTICLE, SAID BOTTOMS HAVING UPSTANDING GASKETS ATTACHED THERETO, SAID MOLDS HAVING A COMBINED TOTAL DEPTH DETERMINED BY THE COMBINED HEIGHT OF THE GASKETS THAT CORRESPONDS TO THE THICKNESS OF THE ARTICLE, SAID QUANTITIES BEING SUCH THAT THE SAID MATERIAL PARTIALLY FILLS SAID MOLDS, PERMITTING SAID QUANTITIES OF SAID MATERIAL TO CURE UNTIL SET (B) TILTING BOTH MOLDS TO A VERTICAL POSITION AND JOINING THE MOLDS SO THAT THE MOLD GASKETS POSITIONED THEREBETWEEN COME INTO CLOSE CONTACT FORMING A CLOSED MOLD WITH A LEAK-PROOF CAVITY LIMITED BY THE TWO SET INNER SURFACES AND THE CORRESPONDING GASKETS, SECURING THE CLOSED MOLD IN THE VERTICAL POSITION, AND ALIGNING THE MOLDS SO THAT THE OUTER SURFACES OF THE TWO FIRST SET LAYERS THAT FORM THE TWO FINISHED SURFACES OF THE ARTICLE ARE MUTUALLY PARALLEL (C) INTRODUCING INTO SAID CAVITY, BY MEANS OF AN OPENING THAT HAS PREVIOUSLY BEEN PROVIDED IN AT LEAST ONE SECTION OF THE CLOSED MOLD MATERIAL INCLUDING SUFFICIENT FLOWABLE MATERIAL CURABLE TO A SOLID RESIN TO COMPLETELY FILL THE CAVITY, PERMITTING THE AIR TO ESCAPE THROUGH AN UPPERMOST SLOT AND THE MATERIAL IN THE CAVITY TO CURE AND SELF-BOND TO THE ADJACENT LAYERS UNTIL SET, THEREBY FORMING A BALANCED ARTICLE OF EQUAL STRESS AND ISOTROPIC WITH TWO FINISHED PLASTIC SURFACES.

Claim 2

THE METHOD OF PRODUCING WARP-FREE PLASTIC ARTICLES HAVING ISOTROPIC AND BALANCED PROPERTIES COMPRISING THE STEPS OF (A) INTRODUCING SUBSTANTIALLY EQUAL QUANTITIES OF A FLOWABLE MATERIAL CURABLE TO A SOLID RESIN INTO TWO IDENTICAL LEVELED SHALLOW OPEN MOLDS HAVING MOLD BOTTOMS, WHICH CONFORM TO THE DESIRED EXTERIOR SURFACE FINISHES OF THE ARTICLE, SAID BOTTOMS HAVING UPSTANDING GASKETS ATTACHED THERETO, SAID MOLDS HAVING A COMBINED TOTAL DEPTH DETERMINED BY THE COMBINED HEIGHT OF THE GASKETS THAT CORRESPONDS TO THE THICKNESS OF THE ARTICLE, SAID QUANTITIES BEING SUCH THAT THE SAID MATERIAL PARTIALLY FILLS SAID MOLDS, PERMITTING SAID QUANTITIES OF SAID MATERIAL TO CURE UNTIL SET (B) TILTING BOTH MOLDS TO A VERTICAL POSITION AND JOINING THE MOLDS SO THAT THE MOLD GASKETS POSITIONED THEREBETWEEN COME INTO CLOSE CONTACT FORMING A CLOSED MOLD WITH A LEAK-PROOF CAVITY LIMITED BY THE TWO SET INNER SURFACES AND THE CORRESPONDING GASKETS, SECURING THE CLOSED MOLD IN THE VERTICAL POSITION, AND ALIGNING THE MOLDS SO THAT THE OUTER SURFACES OF THE TWO FIRST SET LAYERS THAT FORM THE TWO FINISHED SURFACES OF THE ARTICLE ARE MUTUALLY PARALLEL (C) INTRODUCING INTO SAID CAVITY, BY MEANS OF AN OPENING THAT HAS PREVIOUSLY BEEN PROVIDED IN AT LEAST ONE SECTION OF THE CLOSED MOLD MATERIAL INCLUDING SUFFICIENT FLOWABLE MATERIAL CURABLE TO A SOLID RESIN TO COMPLETELY FILL THE CAVITY, PERMITTING THE AIR TO ESCAPE THROUGH AN UPPERMOST SLOT AND THE MATERIAL IN THE CAVITY TO CURE AND SELF-BOND TO THE ADJACENT LAYERS UNTIL SET, THEREBY FORMING A BALANCED ARTICLE OF EQUAL STRESS AND ISOTROPIC WITH TWO FINISHED PLASTIC SURFACES.