High-voltage components are usually exposed to significant and repetitive temperature fluctuations, which normally lead to strong discoloration in conventional polyamides (PAs). In contrast, polybutylene terephthalate (PBT) largely guarantees color stability, especially for the in-demand orange color (RAL 2003) desired by automakers, with no apparent color fluctuations or yellowing during heat aging. With its latest offering, however, BASF is expanding its portfolio of flame-retardant engineering plastics for the e-mobility market and meeting color stability requirements with a PA 66 resin — Ultramid A3U44G6 DC OR (PA66-GF30 FR).
"High-voltage components are usually exposed to significant temperature fluctuations, leading to strong discoloration in conventional polyamides. Our newly developed Ultramid A3U44G6 DC OR closes the innovation gap in terms of color stability and mechanical strength," explained Tina Weller, Product Development. For the first time, the new grade meets all the criteria of color stability and heat-aging resistance and, thus, also enables long-lasting color coding, which is safety-relevant in the sensitive area of high voltages. Color stability has been confirmed after 1000 h at up to 130°C in tests.
In addition to color consistency, Ultramid A3U44G6 DC OR possesses high electrical insulation, characterized by a CTI of 600. The use of tailor-made pigments while simultaneously dispensing with halide-containing flame retardants also counteracts electrocorrosion, which was previously difficult to contain, especially in humid and warm environments.
"During development, we focused on the elimination of halides such as iodide and bromide, thus setting the course for a durable product without contact corrosion," explained Michael Roth, Product Development.
With a very low total halide content — less than 50 ppm — the PA66 achieves fire protection class UL94 V0 at 0.4 mm. Furthermore, the product is equipped with a special organic heat stabilization package to meet technical market requirements.