Styrene Acrylonitrile (SAN) is mainly used unreinforced for products that must be transparent but also chemically resistant. Typical applications include cigarette lighters, battery casings and transparent parts for domestic appliances. SAN reinforced with glass fibre possesses an enormous rigidity at temperatures up to approximately 80°C, but this is at the expense of its impact resistance. The maximum permissible temperature is 85°C, with transient outliers of up to 95°C. Frequent temperature variations do not have an adverse effect.
SAN flows excellently and shrinks hardly at all during injection-moulding, thus making it suitable for precision parts with tight tolerances. Moving parts made of SAN – lubricated with graphite – are regularly used in water meters, for example. The material has an amorphous structure and high impact resistance and hardness at temperatures up to 80°C. The absorption of moisture is extremely low, i.e. 0.1% at 23°C/50% RH and 0.2% when saturated in water. Moisture has hardly any effect on the dimensions and mechanical properties.
Resistance to chemicals like diluted acids, bases, oils, greases and aliphatic hydrocarbons is good, but the same cannot be said of aromatic hydrocarbons, esters, ketones and concentrated acids. Chlorine salts can cause stress cracks.
UV radiation degrades the mechanical properties and causes yellowing. Therefore, black and special UV-stabilised types are recommended for outdoor applications.