Thermally conductive polymers delete the heat

The conventional plastic shown on the left can't spread or dissipate heat, resulting in a localized hot spot. Conversely, the thermally conductive plastic, CoolPoly, (on the right) uniformly spreads heat, giving a more isothermal profile across the part. CoolPoly also dissipates the thermal energy to its surroundings, lowering maximum part temperature. Designers at Apple Computer, Cupertino, Calif., realized, after the initial design was completed, that they needed a heat spreader to dissipate heat from the video processor in the PowerBook computer. But space was extremely limited. The unique design of the heat spreader was possible because the thermally conductive plastic was injection moldable. To make a metal or ceramic part to fit in the available volume and meet all component clearance requirements was impossible. A new family of polymers from Cool Polymers Inc., Warwick, R.I., can replace metal, ceramics, and conventional plastics for heat-sensitive applications. The polymer family, called CoolPoly, is said to be 100 to 500 times more thermally conductive than standard plastics. Conventional, nonthermally conductive polymers tend to experience localized heating that can degrade the polymer and lead to part failure. But the addition of nonmetallic fillers in commodity and engineering thermoplastics such as ABS, nylon, liquid-crystal polymers (LCP), and polyetheretherketone (PEEK) makes uniform heat dissipation possible. Parts made from the CoolPoly polymers are also 40 to 50% lighter than equivalent aluminum and components. They can be processed similar to most engineering thermoplastics and find use in a wide range of applications including computers, automotive, electronics, motors, heating and cooling systems, housings, gaskets, and lighting. CoolPoly composites have low coefficients of thermal expansions (CTEs), low mold shrinkage, and lower operating temperatures, that will help add life to components and devices that use them. This combination of properties produces parts that meet tight design tolerances with little distortion. According to