Process and apparatus for molding hollow articles from synthetic thermoplastic materials

Claim 1

THE PROCESS OF PRODUCING A SHAPED HOLLOW ARTICLE, WHICH COMPRISES PROVIDING A HOLLOW MOLD THAT IS OPEN AT ONE END AND HAS AN INTERNAL SURFACE OF THE CONFIGURATION OF THE ARTICLE TO BE PRODUCED, PROVIDING A THERMOPLASTIC RESIN MATERIAL THAT WILL FORM A FILM UNDER THE INFLUENCE OF HEAT IN A MESURED QUANTITY CORRESPONDING TO THE DESIRED WEIGHT OF SAID ARTICLE, AND WHILE SUPPORTING THE MOLD WITH ITS OPEN END FACING DOWNWARD AND HEATING IT TO A TEMPERATURE SUFFICIENT TO FUSE SAID MATERIAL ON SAID INTERNAL SURFACE, SPRAYING PARTICLES OF SAID MATERIAL SUBSTANTIALLY EVENLY TO SAID SURFACE, ADHERING TO SAID SURFACE AND FUSING TOGETHER THEREUPON BY THE HEAT OF SAID SURFACE SOME OF THE SPRAY PARTICLES AS THEY IMPINGE UPON SAID SURFACE IN THE SPRAY, FLOWING THROUGH SAID OPEN END AND COLLECTING BELOW THE MOLD THE SPRAY PARTICLES NOT ADHERED TO SAID SURFACE, AND CONTINUALLY RE-SPRAYING SAID NON-ADHERED PARTICLES TO SAID SURFACE, UNTIL SUBSTANTIALLY ALL OF SAID QUANTITY HAS BEEN ADHERED TO AND FUSED INTO A LAYER COVERING SAID SURFACE.