LanXess is expanding its Durethan Thermally Conductive polyamide range for thermal management in miniature electrical and electronic devices, as demand for thermally conductive thermoplastics grows across many industries.
Christof Boden, application developer at LanXess, said: “The compounds are specifically designed with additional properties depending on their area of use which benefit the respective applications. This includes, for example, a high level of flame retardancy, excellent mechanical behavior, outstanding resistance to thermal aging, or high reflectivity.”
He added: “Because of their high content of thermally conductive particles, the compounds have a comparably high density, which means they feel good to the touch and can be used to create components with a perceived quality similar to those made of metal.”
Lanxess TC polyamide 6 chart
One highlight of the thermally conductive line is a new Polyamide 6 that combines excellent thermal conductivity with high reflectivity, flame retardancy, and tracking resistance. Its thermal conductivity is direction-dependent due to the mineral filler particles and equals 2.5 watts per meter-kelvin in the direction of melt flow (Nanoflash method). The trial product is halogen-free flame retardant and achieves the best classification of V-0 (0.75 millimeters) in testing pursuant to the United States’ UL 94 (Underwriter Laboratories Inc.) standard for safety of flammability of plastic materials. The results of glow wire testing pursuant to IEC 60695-2-12/13 are also impressive, with the compound achieving the best possible classification (0.75 millimeters) in the GWFI (Glow Wire Flammability Index) test, at 960 °C. With a CTI (Comparative Tracking Index, IEC 60112) value of 600 volts, the compound also exhibits particularly high tracking resistance. Despite the significant concentration of thermally conductive particles, the compound can be processed just as well as polyamide 6 types with high contents of glass fibres and exhibits a similarly low level of tool abrasion. The compound’s areas of application range from heat sinks and support profiles for LED lights to LED cooling fins for automotive headlamps to housings and cell holders for battery systems.
The TC product line also includes two easy-flowing polyamide 6 compounds filled with a special thermally conductive mineral that comprises 65 and 75 percent of the compound’s weight, respectively. Durethan BTC65H3.0EF and BTC75H3.0EF have a thermal conductivity of 1.3 and 1.7 watts per meter-kelvin, respectively, in the direction of flow. Their thermal conductivity is also almost entirely isotropic, meaning they dissipate heat nearly equally in all directions. Both compounds offer an excellent price-performance ratio. “We view them as alternatives to polyamide 6 types that contain boron nitride or aluminum oxide as the thermally conductive filler. This is because they dissipate heat similarly well as aluminum oxide systems, for example,” says Boden. These compounds also have better mechanical properties than polyamides with boron nitride additives.