Shape memory polymer configurative tooling

Abstract

Cornerstone Research Group, Inc. (CRG) has developed processes to make molds for casting and mandrels for filament winding composite parts from novel shape memory polymers (SMPs). For external molding, the SMP tooling system is capable of being thermally formed into a precise negative image of a master part, cooled, and made to retain the new shape. For filament winding mandrels, internal SMP mandrels can be used and easily extracted after curing. CRG has developed the ability to fabricate SMP materials from a wide range of polymer systems. Veriflex, the trademark name for CRG's shape memory polymer resin systems, functions on thermal activation customizable from -20°F to 520°F. These materials can withstand the elevated temperatures that are needed to cure composite parts without deformation and offer a gentle, simple demolding process. After the composite part has cured, the mold is raised above the Tg, which allows it to retract to its memory shape. SMP tooling processes provide the opportunity to mitigate the drawbacks of traditional fabrication techniques for advanced composite parts. This tooling system also possesses versatility in size variations, including being capable of micro (nanometers) to macro (meters) replication.