Acrylonitrile styrene acrylate (ASA)

Acrylic styrene acrylonitrile (ASA) is a transparent thermoplastic with superior resistance to weathering. It provides a lasting paint-free finish and high-gloss appearance. Similar to acrylonitrile butadiene styrene (ABS), and used in the same type of applications, ASA is the material of choice for parts that will be exposed to sunlight, rain and general weathering. It is available in a wide range of saturated colours. Unlike ABS, and most other plastics, even light colours are resistant to colour change and degradation in UV.

ASA is compatible with many other plastics and blended to combine its resistance to weathering with their mechanical and physical properties. For example, it is blended with polymethyl methacrylate, acrylic, (ASA/PMMA), to enhance scratch resistance and produce parts with very high visual quality; and with polycarbonate (PC/ASA) to provide a tough engineering plastic for injection moulded enclosures.

As well as alloys, it is utilised in two-shot injection moulding, and co-extrusion, to provide a clear and glossy weather-resistant surface layer on compatible plastics. However, it is not particularly resistant to scratching and abrasion. This is where the combination with acrylic helps.