ASA (Acrylonitrile-Acrylate-Styrene copolymer) is a weather-resistant modified general-purpose engineering plastic that replaces ABS's butadiene with acrylate rubber. It retains acrylonitrile's chemical resistance and styrene's rigidity and processability, while offering excellent UV and weather resistance. With a slightly higher density than AS, it is the preferred weather-resistant material for outdoor products, automotive exterior parts, and building materials. ASA density is primarily influenced by rubber phase content, polymerization process, and filler modification. Virgin material density is stable, with a significant increase after reinforcement. Accurate density is critical for ensuring long-term dimensional stability of outdoor products.

• Virgin ASA: 1.05–1.09 g/cm³, typical value 1.07 g/cm³. It features exceptional weather resistance, UV resistance without yellowing, and impact resistance, with moderate density suitable for outdoor signage, automotive exterior parts, and building profiles.

• Glass Fiber Reinforced ASA: 1.22–1.38 g/cm³. Density increases with glass fiber content, primarily enhancing heat resistance, rigidity, and creep resistance for outdoor structural parts and load-bearing automotive exteriors.

• Flame-Retardant ASA: 1.06–1.11 g/cm³. Modified with flame-retardant systems, density rises slightly, providing V-0 level flame retardancy for outdoor electronic device enclosures and charging pile accessories.

• Impact-Modified ASA: 1.04–1.08 g/cm³. Adjusting acrylate rubber content slightly reduces density, primarily strengthening low-temperature impact resistance for outdoor products in cold regions.