Polyethylene (PE) Plastics
Polyethylene plastic is characterized by toughness, near-zero moisture absorption, excellent chemical resistance, excellent electrical chemical resistance, excellent electrical insulating properties, low coefficient of friction, and ease of processing. Polyethylene plastics are classified by density and the primary differences are in rigidity, heat resistance, chemical resistance, and ability to sustain loads. In general, as density increases, hardness, heat resistance, stiffness, and resistance to permeability increase. Low-density polyethylene plastics are quite flexible, with high impact strength and relatively low heat resistance.
Traditional markets for LDPE are in packaging films, extrusion coating of paper, wire and cable coating, injection molding, and pipe and tubing.
Polypropylene (PP) Plastics
The polyolefin has turned out to be the most versatile of the plastic family, accounting for the continuing rapid increase in its use. Polypropylenes have better resistance to heat and resist more chemicals than do other thermoplastic plastics of the same cost. Also, polypropylenes have negligible water absorption and excellent electrical properties, and they are easy to process. Like other polyolefins, polypropylene plastics have excellent resistance to water and to water solutions, such as salt and acid solutions that are destructive to metals. They are also resistant to organic solvents and alkalis.
Apllications: .The greatest commercial uses for homopolymer PP are in fibers and filaments. PP plastic is also made into unoriented and oriented films for packaging and is injection-molded into caps and closures, appliance components, and auto parts.
Polystyrene (PS) Plastics
General purpose of polystyrene is the low-cost member of the plastics family. Properties of the amorphous polymer include hardness, rigidity, optical clarity, dimensional stability, and excellent processibility.
HIPS and EPS - High-impact polystyrene, is generally recognized as the best styrenic material for load bearing applications. Typical applications include food packaging (cups, lids, take-out containers), house wares, office products, and video and audio cassettes.
SAN - Acrylonitrile are copolymers that are transparent, amorphous materials with higher heat and chemical resistance than crystal polystyrene plastic. SAN is injection molded into such products as dishwasher-safe housewares, refrigerator shelves, medical devices, oven caps, connectors for PVC tubing, and lenses.
SB - Styrene-Butadiene are block plastic copolymers that combine transparency and high impact strength. Packaging is a major market in items such as cups, lids, trays, and clamshells for the fast-food industry.
Polyvinyl Chloride (PVC) Plastics
Polyvinyl chloride is one of the world's most widely used plastics. Its acceptance comes from the plastics versatility - it can be utilized in rigid compound or blended with plasticizers to produce flexible plastic grades.
Applications: Almost three-quarters of rigid PVC plastic produced goes into building and construction applications. Most is processed via extrusion into products such as pipe, siding, and window profiles. Packaging is another major market for PVC plastic. Rigid grades are blown into bottles and made into sheet for thermoforming boxes and blister packs. Flexible compounds are made into food wrap. Other markets for PVC plastics include wire and cable coating, flooring, garden hose, and toys.
ABS Plastic (Acrylonitrile - Butadiene - Styrene)
ABS plastic is an easily machined, tough, low cost rigid thermoplastic plastic with high impact strength, ideal for turning, drilling, milling, sawing, die-cutting, shearing.
ABS plastics are composed of acrylonitrile, butadiene, and styrene in varying proportions, combined by a variety of methods including graft copolymerization and physical blending. ABS plastics provide a balanced combination of mechanical toughness, wide temperature range, good dimensional stability, chemical resistance, electrical insulating properties, and ease of fabrication. ABS plastics are produced in a wide range of grades including medium and high-impact, heat-resistant, plateable fire-retardant, and both low and high gloss varieties. ABS plastics are available as compounds for injection molding, blow molding, extrusion, and calendaring, as sheet for thermoforming or cold forming, and in expandable grades for foam molding.
Applications. ABS applications are extremely broad, falling between commodity plastics and the engineering resins. ABS fills the property re1quirement for many parts at a reasonable price.
PA - Nylon Plastics (Polyamide)
The nylon family of plastics are identified by the number of carbon atoms in the monomers. Where two monomers are involved, the polymer will carry two numbers (e.g. nylon 6 / 6). Crystalline nylons have high tensile strength, flex modulus, impact strength, and abrasive resistance. Several different types of plastic nylon are on the market, the two most widely used being nylon 6 and 6 / 6. General purpose nylon molding materials are available for extrusion, injection molding, blow molding, rotational molding, and (for nylon 6 materials) casting or anionic polymerization. Nylon sheet and film are also marketed.
Polyester (PET) Plastics
The unsaturated polyesters are extremely versatile in terms of the forms in which they are used. Polyester resins can be formulated to be brittle and hard, tough and resilient, or soft and flexible. In combination with reinforcements such as glass fibers, they offer outstanding strength, a high strength-to-weight ratio, chemical resistance, and other excellent mechanical properties. The two dominate materials in this plastics family are polyethylene terphthalate (PET) and polybutylene terephthalate (PBT). The thermoplastic polyesters are similar in properties to types 6 and 6/6 nylons, but have lower water absorption and higher dimensional stability than the nylons.
PET - Polyethylene terephthalate is a water-white polymer and is made into fibers, films and sheets, and blow-molding and thermoformed containers for soft drinks and foods. Glass reinforced PET compounds can be injection-molded into parts for automotive, electrical/electronic, and other industrial and consumer products.