Process for producing plastic articles

Claim 1

IN MAKING, WITHIN A MOLD, AN ARTICLE INCLUDING POLYVINYL CHLORIDE AND MIGRATORY PLASTICIZER THEREFOR AND PROTECTING THE ARTICLE AGAINST EXUDATION OF PLASTICIZER FROM THE OUTER SURFACE OF THE ARTICLE, THE PROCESS WHICH COMPRISES COATING THE INTERIOR OF THE MOLD WITH AN UNPLASTICIZED SEALING FILM ABOUT 0.00005-0.001 INCH THICK OF THERMOSPLASTIC MATERIAL THAT IS SOLUBLE IN THE SAID PLASTICIZER AND THAT, WITHOUT BECOMING TACKY, TOLERATES THE SAID PLASTICIZER IN PROPORTION THEREOF IN EXCESS OF THE PROPORTION TOLERATED BY THE POLYVINYL CHLORIDE AND THAT IS OF INTRINSIC VICOSITY AT LEAST 0.8 I CYCLOHEXANONE AT 20* C., MOLDING AGAINST THE SEALING FILM A MIXTURE OF THE SAID POLYVINYL CHROLIDE AND MIGRATORY PLASTICIZER THEREFOR, HEATING THE WHOLE TO A TEMPERATURE OF FLUIDIZING THE SAID MIXTURE AND SOFTENING THE SURFACE UNION OF THE SEALING FILM TO THE RESULTING PLASTICIZED POLYVINYL CHLORIDE PLASTIC, AND THEN COOLING THE PRODUCT BEFORE THE SAID PLASTICIZER PENETRATES THROUGH THE SEALING FILM, THE PLASTICIZED POLYVINYL CHLORIDE PLASTIC AFTER THE COOLING HAVING AN INTRINSIC VICOSITY SUBSTANTIALLY LESS THAN THAT OF THE MATERIAL OF THE FILM.