Faster cure of thermoset pipe and tubing, minus the oven

An industrial curing oven is a cumbersome piece of equipment on a busy shop floor — and if you can do without it, while saving energy and improving part characteristics in the process, why wouldn’t you?

If you’re a manufacturer of thermoset filament wound pipe, maybe now you can.

A new super thermal conductive mandrel technology developed by Acrolab Ltd. is designed to cure filament wound pipe and tube sections through induction heating, without the need for curing ovens.

Trademarked the “Isomandrel”, the new mandrel design consists of an internal process within the mandrel that enhances thermal conductivity and thermal reactivity. It sounds simple: A long, cylindrical-shaped bar of metal heated uniformly to up to 500F by an induction coil, the process permits heat to be applied in a localized concentration that’s then rapidly and homogeneously redistributed over the complete mandrel working surface. The heating can occur while the assembly is in the winding cycle, after the winding cycle — while the mandrel is one the winding machine — or on a separate rotating fixture within the manufacturing cell. Once completed, the mandrel is allowed to cool and the pipe section is removed.

CONTROLLING THE HEAT

How is this an improvement over traditional approaches? “Hollow composite tube or pipe sections are typically made by winding the material around a hollow mandrel which is then placed in a convection curing oven,” said Joseph Ouellete, Acrolab’s president. “The challenge has always been to produce the fastest cure of the resin/ fibre composite matrix using the least energy applied in the most uniform fashion. The Isomandrel method cures these resin fibres quickly from the inside out without the oven by using high watt density energy generated by the induction heating system and applied directly to the Isomandrel, which then heats the composite matrix directly.” The result is a very rapid cure time, he continued, with a lower energy requirement and a significantly more uniform cure.

“We’re basically introducing an entirely new methodology for manufacturing fibre-reinforced plastic pipe,” added Peter McCormick, Acrolab’s technical sales manager. “It not only reduces production time from as much as four hours down to less than one hour, but also produces a much better product.”

AID FOR AUTO PARTS MAKERS

Over two years in the making, the technology was developed by Acrolab in conjunction with several U.S. firms, including Ameritherm and Chino Works America Inc., and was introduced at the American Composites Manufacturers Association show in Las Vegas in February. Recognition has been quick to follow, with the Isomandrel being selected as a finalist for the worldwide 2010 JEC Process Innovation Award. According to Ouellette, Acrolab and Ameritherm are currently coordinating the development of a fully integrated software and hardware station to provide the controlled power and recipe requirements to integrate with the Isomandrel units.

For plastics processors, Acrolab’s CEO John Hodgins said, the potential manufacturing implications are huge. “The Isomandrel technology can be a valuable new tool for lightweighting component processing of any tubular structure or reinforcement, such as drive shafts, seating structures, front end modules and door reinforcements,” he explained. “For the right auto parts suppliers, it can be a game-changer, giving them a real advantage over their competition.”

Acrolab Ltd. (Windsor, Ont.);

www.acrolab.com;519-944-5900