Celanese XAP technology helps automakers meet low-emission standards

CELANESE Corporation announced that its proprietary XAP low-emission technology for Hostaform acetal copolymer (POM) is helping automakers achieve their global engineering emission standards for molded parts located in a vehicle’s interior.

Driven by international legislation, air quality in automobiles is receiving renewed focus. Hostaform is an ideal engineered material for automotive interiors, which has led one of the world’s largest automakers to identify Celanese’s Hostaform as the preferred material in a specification standard for POM. Hostaform UV270Z XAP2 meets OEM performance requirements for automotive cockpit applications with a combination of high flow, UV stability, colourability, scratch resistance, and impact strength.

One automotive interior application for the use of this Celanese engineered material is speaker grills. Hostaform UV270Z XAP2 can be injection moulded in one shot, and then snap-fitted or ultrasonically inserted in the support element. One recent set of front and rear door speaker grills posed specific challenges since they required a perfect fusion of function and form to ensure excellent sound transmission, as well as aesthetics.

The grill pattern design, with its small and thin pattern and small and tight holes, pushed the material and processing envelope.The engineered material needed a high-flow characteristic because the small design created significant sheer and molding issues.

Another challenge involved colour matching. The Celanese colour technology team needed to adapt the formulation to match interior colours without losing any of the low-emission properties. Formulating a colour-matched material to meet the OEM colour approval process required numerous formulation iterations and moulding trials. Colourants were specifically selected to match each colour. All colours were approved with the first submission in plaque form to the design studio. The challenge came in translating a solid moulded plaque to a speaker grill with hundreds of holes on the appearance surface. Offsets to the official master were developed in the laboratory and trialed in the actual part until part appearance approval was achieved.

The latest XAP2 technology of low-emission Hostaform POM products from Celanese is an excellent material for parts in the passenger compartment of the vehicle. Components such as door modules or seatbelt pre-tensioning systems increasingly call for low-emission materials. Other potential applications include head rests and lumbar support, fastening solutions in the door area and trim for door elements, instrument panels and center consoles.