Method for forming wedge shaped edge

Abstract

Abstract TO MAKE A MAT OF FOAM OR SPONGE ELASTOMER, A VINYL OR THERMOPLASTIC FILM IS SUPERPOSED ON A FOAM OR SPONGE LAYER WHICH IS PLACED ON A PLATEN AND A DIE IS BROUGH DOWN AGAINST THE SAME. THE DIE IS HEATED BY MEANS OF AN INTERNAL ELECTRICAL RESISTANCE OR STEAM OR THE LIKE AND CAUSES THE UPPER SURFACE SECTION OF THE FOAM OR SPONGE LAYER TO FUSE AND BOND TO THE FILM. THE DIE HAS EDGE PORTIONS CAPABLE OF PROVIDING A WEDGE SHAPED PERIPHERAL EDGE ON THE RESULTING MAT AND A HIGH FREQUENCY ENERGY IS PASSED THROUGH THE RESULTING MAT PARTICULARLY AT THE PERIPHERAL EDGE THEREOF IN ORDER TO CONTROL THE SHAPE OR PROFILE OF THE EDGE, THE DIE IS PROVIDED WITH CHANNELS OR GROOVES CAPABLE OF IMPRESSING RIDGES INTO THE UPPER SURFACE OF THE MAT AND USE IS MADE OF THESE GROOVES TO PERMIT THE EVACUATION OF AIR FROM BETWEEN THE FILM AND THE SPONGE OR FOAM LAYER BY OPERATING THE DIE IN SEQUENTIAL PRESSURE STAGES IN THE FIRST STAGE OF WHICH A RELATIVELY LOW PRESSURE IS EMPLOYED.

Inventors

• 👤 J Ballard

Bibliographic Details