CompositesWorld
Issue link: https://cw.epubxp.com/i/891910
NOVEMBER 2017 30 CompositesWorld Reconfigurable tooling: Revolutionizing composites manufacturing Shape-changing molds eliminate tooling for large 3D panels while automated assembly fixtures go modular, using metrology to reduce cost and shimming. » Although composites offer many benefits, the historically high costs and long cycle times required for manufacturing components from complex, fiber-reinforced materials have been and remain a challenge. Application of automation and digital technology to fabrication processes have yielded some spectacular cost-cutting success stories. Among them are automated fiber and tape placement, high-pres- sure resin transfer molding (HP-RTM) and, most recently, fast robotic processing of preforms. e latter has promised to eliminate a longstanding bottleneck in the production of complex 3D parts (see Learn More, p. 37). Production of the mold tooling as well as the jigs and fixtures required for machining and assembling large composite structures, however, remain expensive and time-consuming production steps. In new commercial aircraft programs, for example, estimates are that these account for one-third of total nonrecurring costs. Toolmaking's outsized and continuing contribution to part cost, in terms of time (notably, lead time) and money, can be traced largely to the fact that tools, historically, have been shape dependent. at is, a mold or a part fixture has had to precisely mirror — with carefully calculated allowances for shrinkage and differ- ences in material coefficients of thermal expansion — the desired dimensions and geometry of the finished part. If a single dimension, or the radius of a curve, for example, in a part's design were to change, then in many cases an entirely new tool or fixture might have to be constructed. One of the current toolmaking trends is a move away from shape-dependence in tooling and fixture design toward designs that are modular, reconfigurable and, therefore, adaptable to changes in a part's design, and also flexible enough to use in forming multiple parts of different, but similar design. Shape independence Producing the mold tools (e.g., lower left) and the fixtures (e.g., upper right) for assembly and machining of demolded parts is an expensive proposition. To reduce cost, toolmakers are devising ways to make tools and fixtures less shape-dependent. Source | Curve Works/ADAPA Source | Prodtex By Ginger Gardiner / Senior Editor