Tooling to match composite production

Advanced composites have dominated consumer and production products, and therefore, proper tooling is necessary for them. The challenge is to match as nearly as possible the coefficient of thermal expansion (CTE) of materials used for tooling (molds and mandrels) with that of the composites used for parts. Invar 36, a cast iron with 36% nickel, offers a minimal CTE, and was invented for applications that might best be described as delicate, like sensitive measuring devices, watch springs, clock pendulums, and such. HexPly prepregs are epoxy-resin formulations reinforced with glass and carbon fibers and supplied to customers on large rolls. ATK is working with an industry collaboration team to design a break-down and composite layup mandrel to meet requirements for the largest composite parts. Remmele Engineering is developing its Invalite hybrid tooling system for advanced composites as an alternative to all-Invar or all-composite tool.