Manufacture of blanks for recording discs utilizing coextrusion and blanks and records made thereby.

摘要

It been found that a layered recording disc having an inexpensive core layer and high quality recording groove-accepting outer layers can be made in a relatively simple manner through an application of the technique known as coextrusion, wherein a common die, e.g. a coextrusion die (10) having a die orifice (11) for a plurality of streams (13,23 and 33) provides a multilayer coextrudate (60) having a plurality of layers (64,74 and 84). The coextrudate (60) can be cut into segments (60a) with a suitable cutting means (20). The coextrudate segments can be substantially of record thickness with a circular periphery. Alternatively, coextrudate segments (60b) can be much thicker than a record and much smaller in surface area. In either case, segments can be compression molded into discs (100) having the desired profile and/or grooves.