MUPET™ Composite Tooling
CTD developed Multiple Use Precision Extractable Tooling (MUPET™) for use in fabricating complex composite structures in a single manufacturing operation. The patent-pending MUPET™ system is based on CTD’s TEMBO® Shape Memory Polymer (SMP) technology. This tooling provides composite manufacturers with the capability to manufacture net-shape forms that have no joints, require no secondary bonding operations, weigh and cost less to fabricate due to reductions in material mass and the number of manufacturing steps. These highly efficient composite structures can be fabricated in a single manufacturing operation.
Improved efficiency is realized by the use of stiffeners with ‘C’ and ‘I’ cross-sections that increase the stiffness and strength with little or no gain in mass. These structures result in areas that trap mold tooling after cure. MUPET™ is designed to mold these structures that trap the tooling and reduce the volume of the tool to allow its removal from the trapped volume.
MUPET™ utilizes rigid, epoxy-based, shape-memory polymer foams, developed by CTD, that can be used as molds to form the composite. The TEMBO® foam is stiff enough to support lay-up loads, even from automated tape placement. Once the composite lay-up is complete, the MUPET™ tool is pressurized to consolidate the composite during cure. The foam tool is then removed by exercising the shape memory behavior of the foam. After cure, a vacuum is applied to the still-warm SMP foam, which rapidly reduces its volume to allow for easy extraction of the tool from trapped regions. Once the tool is removed, the vacuum is released and the SMP foam returns to its original shape in seconds.
The SMP foam can be machined to produce net-shape, high-precision tools that can produce subtle and discrete details, such as ply drops, into the composite. CTD has used MUPET™ to demonstrate the fabrication of lighter weight, more structurally efficient composite panels. These included a panel representative of an aircraft fuselage, bulkhead, or access panel such as a door for landing gear in collaboration with Boeing. CTD has also demonstrated the fabrication of a high-precision, thermally stable composite structure for use on a high-frequency antenna reflector for NASA. Furthermore, CTD has received considerable interest from the automotive industry for the use of MUPET™ in rapid cycle composite manufacturing processes.