When MAG Industrial Automation Systems (Hebron, Ky., USA) announced in September the development of the Continuous Laminating Line for automotive composites applications, many eyebrows were raised about the system — particularly the material developed in conjunction with the machinery. CompositesWorld caught up with Dan Allman, director of MAG's Automotive Composites Business Unit, and learned more about the laminating line and resin system it employs.
Allman, who has extensive experience with automotive composites thanks to his work with some of the Detroit-based automakers, says he'd seen examples in Europe of creative application of composites in automotive structures and joined MAG with the hope of developing tape-laying or fiber-placement technology for automotive manufacturing. Given automotive's demand for high-volume part processing, Allman and MAG recognized that material input rates needed to be evolved and improved. In particular, prepreg composites required maturation to meet high-volume manufacturing rates.
A few years ago, says Allman, MAG formed technology partnerships with resin and glass suppliers with the goal of developing a relatively inexpensive composite prepreg that requires little or no heat cure, is room temperature stable, has a long shelf life and requires compaction about a third that of traditional prepregs. What MAG wound up with, after several iterations of material development and testing, was a glass-based thermoset prepreg that costs about $1.75/lb to $2.50/lb, has strength characteristics that rival steel and sheet molding compound (SMC) and cures in 55 to 60 seconds under moderate heat at 1 to 2 mm (0.04 to 0.08 inch) thicknesses. It has "nearly infinite" shelf life, says Allman. MAG cannot yet release the identity of the resin and fiber suppliers; further, Allman says MAG will hold exclusive rights to the material.
In the meantime, MAG began work on the hardware that would process this prepreg. The Continuous Laminating Line is the result. It features a series of roller modules, each of which applies a layer of prepreg that is lap-spliced to the suceeding layer. An inline cutting head at the end of the line creates the charge, which is formed via match metal die or vacuum forming.
Potential applications for this technology, says Allman, include high-strength, thin-walled (1 to 2 mm) structures, like underbody structures, roof reinforcements and firewalls. Several automotive OEMs have expressed interest in the technology, MAG reports, including one customer looking at a hybrid steel/composite structure with Class A surface. A proof-of-concept structure is being developed this month to convert an existing non-composite part to composite using the MAG system. Look for news on results of this effort in the next few weeks.
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