Polystyrene (PS)

PS is a versatile plastic that can be rigid or foamed. Pure polystyrene is a colorless, hard plastic with limited flexibility, and has a relatively low melting point. Typical applications include protective packaging, food service packaging, bottles, and food containers.

Characteristics:

• Clarity – mostly colored opaque (can be clear)
• Versatility – can be rigid or foamed
• Strength – significant stiffness in both foamed and rigid forms
• Excellent moisture barrier for short shelf-life products
• Low thermal conductivity and exceptional insulation properties in foamed form
• Ease of forming – medium soft (some cracking)
• Longer heat cycle
• Some shrink issues
• High yield

Common Forms:

• Disposable food containers like hinged takeout containers (clamshells), meat and poultry containers, and rigid food containers
• Food service applications: cups, plates, bowls, and cutlery
• Compact disc jackets
• Egg cartons
• Aspirin bottles