CHICAGO (July 18, 11:45 a.m. EDT) — Plastics, famous for their insulative abilities, are beginning to replace metals in heat-conducting applications.
At least three companies at NPE 2000 featured thermally conductive polymers. One of the firms, Peregrine Industries Inc., is making its debut in the plastics industry with its new polymer. Cool Polymers Inc. and LNP Engineering Plastics also featured their new materials at the trade show.
Peregrine got into plastics indirectly while trying to solve corrosion problems for metal parts in swimming pool heaters, according to Chief Executive Officer Merrill Yarborough. It developed a plastic compound that transferred heat efficiently while resisting corrosive materials like chlorine and acids common in swimming pool water.
Now the company is getting inquiries for the polymer´s use in electronics, automotive and other industries, Merrill said in a telephone interview from Peregrine´s office in Deerfield Beach, Fla.
Electronics engineers rapidly are embracing thermally conductive plastics because they can absorb heat about as well as most metals and can be molded into intricate shapes and act as structural components as well.
Cool Polymers of Warwick, R.I., said it has molded a million parts out of CoolPoly for electronics, medical, automotive, lighting and industrial equipment. Jim Miller, the firm´s product manager, said CoolPoly offers thermal conductivities of up to 100 watts per meter-degree Kelvin, or 100 to 500 times the conductivity of standard polymers.
In an interview at NPE, Miller said his firm´s material is a spin-off from stealth bomber technology. Cool Polymers and other firms have cut the costs of the pioneering materials that sold for $500 a pound to a tenth or less of what the U.S. aerospace industry paid for the first thermal plastics.
Miller said the new generation of plastics can be useful in components where heat build-up can degrade a conventional plastic. By spreading the heat load throughout the component, no one area gets overheated.
Suppliers, understandably, are reluctant to divulge their recipes for thermal polymers. Yarborough said his company´s products are based on liquid crystal polymers. Miller said CoolPoly contains ceramics and metals. LNP´s Konduit materials are available in a range of resins with ceramics or carbon fibers.
Although most early applications of thermal polymers relate to miniaturization, design freedom and lightweighting, LNP has announced an application that shows how much potential the new materials have.
LNP´s Konduit is used to encapsulate an electric motor for an undersea remotely operated vehicle. The plastic housing radiates heat from the motor to prevent overheating and burnout. And it does so while withstanding pressures of up to 10,000 psi at depths of 20,000 feet.
"The only way for an electric motor to work in this type of undersea environment is to encapsulate it in a very strong plastic that has a very high thermal conductivity," said Griffith Neal, founder of Encap Technologies, a consulting firm in San Francisco that helped develop the undersea vehicle made by Alstrom GEC of Davis, Calif.
"In 7,500-watt motors like these, the wire will actually melt if the packaging material does not dissipate the heat," Neal explained.
LNP officials said their entry into thermally conductive polymers was a natural extension of its compounding expertise.
Cool Polymers was formed early this year as a subsidiary of ChipCoolers Inc., a private firm in Warwick that specializes in thermal cooling products for electronics. Cool Polymers sells material and does molding too.
Peregrine´s core business has been heat transfer products for air conditioners and swimming pool heaters. The 5-year-old company, listed on Nasdaq, has a plant in Montgomery, Ala.