For this purpose, Lanxess has developed a wide range of laser-weldable polyamides and polybutylene terephthalates (PBT) Durethan LT and Pocan LT (Laser Transparency) and has expanded its range to include three new compounds.
Pocan B3233XHRLT (currently Pocan TP155-002) is a new, 30-percent-glass-fiber-reinforced PBT compound that exhibits good laser transparency and an excellent resistance in a hot and humid environment. Materials like these are almost unprecedented on the market because standard additives for hydrolysis stabilization generally cause the laser transparency of PBT to deteriorate significantly. The outstanding hydrolysis resistance of the trial product from the latest Pocan HR generation has been demonstrated in the SAE/USCAR-2 Rev. 6 long-term tests of the American Society of Automotive Engineers (SAE). Most flame retardants also diminish the laser transparency of thermoplastics, which is why PBT, polyamide 6 and polyamide 66 compounds with good laser-weldability and high flame-retardant properties are rarely seen on the market. They are, however, needed for components in battery systems for electric vehicles. The material can be safely processed within a stable process window and leaves hardly any deposits in the tool. Its high tracking resistance of 600 V (CTI A, Comparative Tracking Index, IEC 60112) makes it ideal in components for high-voltage batteries and plugs. The third new material for laser welding is Pocan TP150-002. The 30-percent-glass-fiber-reinforced PBT compound is optimized for extremely high laser transparency. It exhibits a transmission of 13 percent, which is around double the transparency of most other laser-transparent PBT product types (measured with a LPKF TMG-3 at 980 nm and a test specimen thickness of 2 mm).
Lanxess AG – www.lanxess.com