Method of making picture-type phonograph records

Abstract

Abstract A DISC OF CARDBOARD OR PAPERBOARD HAVING A THICKNESS IN A PREDETERMINED RANGE IS PRINTED ON BOTH SIDES WITH PICTURE, PRINTING, ETC. SUCH PAPERBOARD DISC IS SANDWICHED BETWEEN TWO CORRESPONDING SHEETS OF TRANSPARENT THERMOPLASTIC SYNTHETIC RESIN. THE SYNTHETIC RESIN IS PREHEATED TO A PREDETERMINED TEMPERATURE, AND THE INDICATED SANDWICH IS PALCED BETWEEN THE MATRIX ELEMENTS OR "STAMPERS" OF A RECORD PRESS OR MOLD. THE THICKNESSES OF THE RESIN SHEETS, AND THE DEPTH OF THE MOLD CAVITY, ARE CORRELATED TO THE THICKNESS OF THE PAPERBOARD AND OTHER FACTORS IN SUCH MANNER THAT VERY LITTLE RADIAL-OUTWARD FLOW OF PLASTIC RESULTS WHEN HEAT AND PRESSURE ARE APPLIED BY THE MOLD OR PRESS. THE METHOD FURTHER COMPRISES EMPLOYING RIM MEANS AT THE MATRIX EDGES TO CREATE EFFECTIVE SEALS BETWEEN THE PERINHERAL EDGES OF THE PLASTIC SHEETS, AND TO EFFECT RADIALINWARD FLOW OF PLASTIC FROM THE RIM MEANS IN ORDER TO AID IN FILLING VOID ADJACENT THE PERIPHERAL EDGE OF THE PAPERBOARD DISC. THE HEAT AND PRESSURE EMPLOYED IN THE MOLDING OPERATION ARE PREFERABLY HIGHER THAN CONVENTIONALLY EMPLOYED TO MAKE RECORDS NOT OF THE PICTURE TYPE.

Inventors

• 👤 Joe Rock
• 👤 Harold F Dague

Bibliographic Details