Process for molding hollow thermoplastic articles and resulting articles

Claim 1

A PROCESS FOR MOLDING A HOLLOW ARTICLE FROM A THERMOPLASTIC MATERIAL COMPRISING THE STEPS OF DEPOSITING A MEASURED AMOUNT OF SAID THERMOPLASTIC MATERIAL IN A HOLLOW METAL MOLD HAVING SIDE AND BOTTOM WALLS, ROTATING SAID MOLD ABOUT A HORIZONTAL AXIS WHILE SIMULTANEOUSLY HEATING SAID MOLD AND MAINTAINING SAID AXIS IN HORIZONTAL ATTITUDE UNTIL A LAYER OF PARTIALLY FUSED MATERIAL IS FORMED AGAINST THE SIDE WALL THEREOF, PIVOTING SAID MOLD TO AN ATTITUDE WHICH IS INCLINED WITH RESPECT TO THE HORIZONTAL AND HEATING THE MOLD IN THE LATTER SAID ATTITUDE FOR AN ADDITIONAL PERIOD OF TIME UNTIL A LAYER OF PARTIALLY FUSED MATERIAL IS FORMED AGAINST THE BOTTOM WALL AND DURING WHICH ADDITIONAL PERIOD OF TIME SAID LAYER OF PARTIALLY FUSED MATERIAL PREVIOUSLY FORMED AGAINST THE SIDE WALL IS PERMITTED TO CONTINUE TO FURTER FUSE BY THE CONTINUED APPLICATION OF HEAT, RETURNING THE MOLD TO HORIZONTAL ATTITUDE FOR AN ADDITIONAL PERIOD OF TIME TO FORM AN ADDITIONAL LAYER OF PARTIALLY FUSED MATERIAL ON THE PREVEOUSLY FORMED LAYER OF PARTIALLY HEATING OF SAID MOLD UNTIL AT LEAST SUBSTANTIALLY ALL OF THE MATERIAL IS FUSED, THERE BEING DWELL PERIODS AT THE HORIZONTAL AND INCLINED ATTITUDES WHICH ARE SUCH DURATION THAT INTERFACIAL BONDS ARE FORMED WHICH AR INSUFFICIENTLY COMPLETE TO FORM A HOMOGENEOUS MASS, COOLING THE MOLD, AND REMOVING THE THUSLY MOLDED ARTICLE FROM THE MOLD WHEREBY A LAMINATED ARTICLE IS FORMED ENTIRELY FROM SAID MEASURED AMOUNT AND FROM THE SAID MATERIAL.