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Engineering Plastic

SAN

SAN (styrene-acrylonitrile) is a transparent, rigid copolymer that improves on polystyrene with better stiffness, heat resistance, and chemical resistance, reaching about 72 MPa tensile. It is clearer and stiffer than ABS but, lacking ABS's rubber phase, stays brittle with only about 3% elongation.

How SAN machines

Rated 3/5. It cuts to a clean, clear finish but its brittleness invites edge chipping, so use sharp tools, light cuts, and firm support. Cutting heat can craze the transparent surface. SAN is predominantly molded; machining is mainly for prototypes and secondary features.

Manufacturing & processing

Injection molded and extruded with good flow and excellent clarity. It bonds with solvents and adhesives and takes a glossy finish. Its 80 C service ceiling exceeds plain PS, and its acrylonitrile content gives it better resistance to oils, greases, and chemicals than polystyrene.

Typical applications

Clear housewares such as tumblers, mixing-bowl lids, and food containers; cosmetic packaging; battery cases; instrument lenses; and appliance components. It is chosen where rigid transparency and chemical resistance are needed at low cost and modest impact demands.

When to choose it

Choose SAN over PS when you need better clarity, stiffness, and chemical or grease resistance but can still tolerate brittleness. Choose ABS or PC/ABS instead when impact resistance matters, accepting reduced clarity. For glass-clear, scratch-resistant parts, acrylic or PC may serve better.

Suitable surface finishes

Common finishes for SAN: bead blasting, powder coating. Use the finish selector →

FAQ

How is SAN different from ABS?
ABS is essentially SAN with a dispersed rubber phase added for impact toughness, which makes ABS opaque and far less brittle. SAN keeps the clear, rigid, chemically resistant styrene-acrylonitrile matrix without the rubber, so it is transparent and stiffer but cracks more easily under impact.
Is SAN suitable for food contact?
In appropriate grades, yes. Its clarity, rigidity, and good resistance to oils, greases, and many chemicals make it common for tumblers, food containers, and bowl lids. As always, verify the specific grade carries the relevant food-contact certification for your region before specifying it.
Why choose SAN over plain polystyrene?
The acrylonitrile content gives SAN noticeably higher stiffness, heat resistance to about 80 C, and much better resistance to oils, greases, and chemicals than PS, plus comparable or better clarity. If PS is too soft, heat-sensitive, or chemically vulnerable for your clear part, SAN is the natural upgrade.

Property values are typical/nominal for early guidance and vary by temper, grade, supplier and heat treatment. Confirm critical specs against a certified datasheet or with an mfgiq engineer.