Lexan HF4010SR resin from Sabic is a polycarbonate (PC) material that can make it possible for customers to develop complex headlight bezels with enhanced aesthetics. Sabic has also added new grades to its existing Lexan XHT resin line, which can offer improved flow at high temperatures compared to other high-heat polycarbonate materials available today.
Low draft angle is important because it enables greater styling freedom as well as a larger optical surface. LexanHF4010SR resin helps processors achieve draft angles between 0.5 and 1.0 degrees lower than the recommended draft angle for PC tools (typically between 3 and 5 degrees).
SABIC’s new materials targeting forward lighting parts come at a time when the complexity of these applications continues to increase. Current high-end LED headlamps weigh close to six kilograms with up to 200 components, thanks to the additional functionality they incorporate. Automakers are also striving to create highly distinctive lighting parts to help differentiate and increase the appeal of their vehicles.
Sabic has engineered the new Lexan resin to address customers seeking to produce complex headlamp bezels with enhanced styling, but at a lighter weight and at a lower overall system cost.
“These new offerings are examples of how we listen to our automotive lighting customers, stay in touch with their emerging needs, and propose materials they can consider to meet the challenges in front of them,” said Scott Fallon, global leader of SABIC’s Automotive business.
When designing injection-molded parts, a low draft angle is important because it enables greater styling freedom as well as a larger optical surface. However, the lower this angle, the more problems arise with parts sticking in the mold, creating scuff marks and potentially even resulting in a part with cosmetic defects.
To help the industry meet this challenge, Sabic has developed Lexan HF4010SR resin. This material can enable customers to target draft angles between 0.5 and 1.0 degrees lower than the recommended draft angle for PC tools (typically between 3 and 5 degrees).
Bezels that are injection molded in Lexan HF4010SR can be directly metallized (no need for priming) and gloss and reflectivity performance under high temperature environments are both very good. The material has a unique wide processing window and high flow. Parts perform in environments requiring a maximum constant use temperature of up to 130°C.
According to market feedback, the increased styling capability made reachable with Lexan HF4010SR can provide designers with new freedom to imagine and produce shapes with greater complexity, and integrate more features and functionality into each individual component. In addition, the production of headlamps with fewer bezels can be possible, which could then potentially lead to important weight and cost reductions. Potential cost savings up to $2 per vehicle can be achieved by avoiding the use of complex tools, potentially enabling faster molding, part integration and weight-out.
LEDs are relatively cold light sources, but LED headlamps can still generate considerable amounts of heat. already has an extensive portfolio of XHT (extra high temperature) grades of Lexan resin, with heat deflection temperatures (HDTs) of up to 183°C (under a load of 0.45 MPa). But many high-heat PCs still have problems with flow (for example, weaknesses are knit lines or limited flowability in comparison to regular PC) and these materials cost more than ‘standard’ PC.
To help customers address this issue, Sabic has added new grades to its existing Lexan high flow XHT portfolio: Lexan XHT1171, XHT2171 and XHT3171. These grades provide particularly high flow for high temperature PC resins – supporting customers looking at producing high quality parts, and can be considered as a drop-in alternative to standard PC.
A recent molding study carried out by Sabic indicated that a bezel molded in Lexan XHT2171, for example, could weigh 37 percent less than a bezel in a rival PBT material, thanks to possible reductions in wall thickness and the lower density. Lexan XHT2171 resin can potentially enable cost savings of up to 40 percent per bezel, by avoiding the use of complex tools, potentially enabling faster molding and part integration as well as reducing weight.
To support the launch of these new resins, Sabic will display simple and complex demonstrator parts at its exhibit space (no. 6) at this year’s International Symposium on Automotive Lighting (ISAL) conference in Darmstadt, Germany from September 25-27. Sabic will also provide insights from processing studies performed under extreme conditions (thin-wall molding / parts with draft angles beyond standard design rules) from its global automotive test center in Bergen op Zoom, The Netherlands.