Plastic Types
ABS
This material is a terpolymer of acrylonitrile, butadiene, and styrene. Usual compositions are about half styrene with the balance divided between butadiene and acrylonitrile.
Characteristics
- High or low gloss
- A variety of surface textures available
- Good impact resistance with toughness and rigidity
- Paints and metal coatings have excellent adhesion to ABS
- Easily processed by conventional thermoplastic methods
- Light-weight, strong, less brittle than styrene
- Easily bondable
- Limited solvent resistance
- Low dielectric strength
- Limited outdoor weatherability unless protected
- Good chemical resistance
- Available in fire retardant and conductive grades
Typical Applications
One of the most commonly used thermoformable plastics, ABS offers an excellent combination of physical and cosmetic characteristics. Custom colors and pre-textured sheet make secondary painting or finishing unnecessary in many applications. When an injection molded look is desired and female pressure forming tooling is used, ABS will support a variety of interior and exterior finishes that give designers and engineers maximum flexibility. ABS is available in UL flame rated, conductive, anti-static, and food grades. For utility applications, excellent grades of reprocessed material are available. Among its many applications, ABS is commonly used for electronics housings, computer bezels, doors, side panels, automotive trim, custom cases, refrigerator liners, musical instrument cases, luggage, and enclosures.
Acrylic
Most acrylics are polymers of methyl methacrylate (PMMA) with methyl, ethyl, or butyl acrylate added to modify properties. Impact-modified acrylics are used as a cap stock for HIPS, ABS, PVC, PC, and other acrylics and may be co-extruded or applied as a laminate during extrusion.
Characteristics
- Good optical clarity
- Good weatherability and resistance to sunlight
- Poor impact strength unless modified
- Good dimensional stability and low shrinkage
- Good abrasion resistance high gloss (or controlled gloss)
- Limited solvent resistance; attacked especially by ketones, esters, chlorocarbons, aromatic hydrocarbons, and freons
Typical Applications
Lenses, automotive trim, household items, light fixtures, signs, spas; impact-modified versions are used in RV components, shutters, bathtubs, wall panels, roofing components.
Polycarbonate
Polycarbonate is formed by reaction of bisphenol A and phosgene.
Characteristics
- Optical clarity
- High impact strength
- Ignition-resistant
- Subject to stress cracking
- High heat deflection temperature
- Fair solvent resistance
- High gloss
Typical Applications
Windows, helmets, instrument cases, mechanical goods, glasses, compact disks, glazing material.
Polyesters
These materials are typically prepared by the condensation of alkylene glycols and phthalic acid or a combination of ethylene glycol and terephthalic acid. These polymers are common in film and fiber form. A number of structure variations are possible in the form of copolymers such as polyethyleneterephthalate (PETG). Thermoplastic polyesters include PBT, recycled PET, and alloys.
Characteristics
- Tough and rigid resins
- Excellent dimensional stability
- Attacked by acids and bases
- Limited solvent resistance
- High gloss
- Low outgassing
- Clean room compatible
- Easily sterilized
Typical Applications
Film and fiber, food and medical trays, soft drink bottles, displays, clothing, wire insulation, sailboat sails.
Polyethylene
Polyethylene is a thermoplastic resin which is manufactured from the polymerization of ethylene monomer. This thermoplastic is available in a range of densities and molecular weights depending on the production process and copolomer (alpha olefin) used. Polyethylene lends itself to a variety of thermoplastic processing methods.
Characteristics
- Excellent impact resistance over wide temperature range
- Moisture resistance
- Good environmental stress cracking resistance (ESCR)
- Limited weatherability (w/o modification)
- High thermal expansion and secondary shrinkage
- Limited ability to bond and paint
- Good chemical resistance
Typical Applications
For thermoforming applications, best used where durability, toughness, and price are more important than cosmetics. Tote boxes, pallets, agricultural products, truck bed liners, reusable material handling packaging, ATV fenders and body panels, battery boxes, etc. Available in black and white as standard colors. Custom colors available with 2,500 pound extrusion minimum. For utility products, an excellent, random gray, 100% post manufacturing reprocessed grade offers very good price/performance characteristics.
Polypropylene
Polypropylene is produced by the polymerization of propylene monomer with or without co-monomers.
Characteristics
- Excellent moisture resistance
- Excellent chemical resistance
- High heat resistance
- Limited weatherability (w/o modification)
- High gloss
- Attacked by chlorinated solvents and aromatics
- Limited ability to bond and paint
- Limited thermoformability
Typical Applications
Not as shock resistant as polyethylene, but less subject to secondary shrinkage and the cosmetic problems it can present, polypropylene is frequently used in manufacturing industrial parts for fluid processing, lab applications, automotive and electrical hardware, packaging material, stadium seats, and battery cases.
Polystyrene
Polystyrene is a thermoplastic resin which is manufactured from the polymerization of styrene monomer. There are two basic grades, crystal or unmodified general purpose polystyrene and impact or rubber modified polystyrene. The crystal polystyrenes possess high rigidity, gloss, and transparency (clarity) but have limited impact or toughness properties. Impact grades are generally opaque but have improved impact resistance and environmental stress crack resistance due to rubber modification.
Characteristics
- Excellent processability
- Good dimensional stability
- High gloss
- Limited solvent resistance
Typical Applications
Food and medical packaging, housewares, toys, audio/video cassettes, electronic housings, furniture, expanded foam articles, cutlery, advertising displays, back-lit signs, tub surrounds, refrigerator liners.