A new layup-molding process developed by General Magnaplate Corp., Linden, N.J., reduces the time required to make layup molds (toolfaces) for large, contour-shaped, complex reinforced composites. The result is significantly faster tooling delivery and lower costs.
The patented, robotically controlled process, called CMPT (custom moldmaking process technology), is a dense, multidirectional, metal-weaving technique that eliminates the need to machine heavy ingots or castings for layup toolfaces. CMPT cuts the time it takes to manufacture complex reinforced composite molds from between six and 12 months to just six weeks. It also reduces costs by one-third. Toolfaces can be made from any alloy -- aluminum to zinc -- including high-nickel Invar and stainless steel, and can also be treated with a permanent-release agent.
In the past, tooling that wasn't machined from billets or castings typically had stress problems from voids and iron-oxide contamination. But a CMPT toolface, equivalent to a Grade 2 casting, is reportedly more dense and contains fewer oxide voids than those produced by other methods. High-temperature tooling for long or short production runs is possible for cures up to 750°, and compaction pressures to 1,500 psi. According to the company, CMPT toolfaces have all the properties of solid-metal tools without the high cost, extra weight, and lengthy finishing time. A 5-ft2, 3-ft-thick Invar billet weighing 3,500 lb, for instance, generally takes four months to process, and can cost about $20,000 before it's ready for CNC machining. But a 5-ft2 CMPT toolface with a 3-ft contour weighs just 400 lb and takes about seven days to make, reducing costs by as much as 60%.
CMPT-produced toolfaces can be created with built-in piezo electronics programmed to monitor voids, intralayer damage, temperature, and rate controls, as well as surface positioning of the layup.