Engineering plastic
Encyclopedia
Engineering plastics are a group of plastic
materials that exhibit superior mechanical and thermal properties in a wide range of conditions over and above more commonly used commodity plastics
. The term usually refers to thermoplastic
materials rather than thermosetting ones. Engineering plastics are used for parts rather than containers and packaging.
Examples of engineering plastics include:
as they are traded and used in great quantities. Examples are polystyrene
(PS), polyvinyl chloride
(PVC), polypropylene
(PP) and polyethylene
(PE).
Typical applications for commodity plastics are high production volume products such as ‘polythene’ bags (made from polyethylene), vacuum-formed food packaging (low density polyethylene), disposable drinking cups (high-impact polystyrene) and window frames/wire insulation (PVC).
Engineering thermoplastics are sold in much lower quantities and are thus more expensive per unit weight. Despite this, they are widely used in everyday products. For example ABS is used to manufacture car bumpers, dashboard trim and Lego
bricks, polycarbonate is used in motorcycle helmets and polyamides (nylons) are used for skis and ski boots.
Typically, an engineering plastic is chosen for its range of enhanced physical properties e.g. polycarbonate is highly impact resistant and polyamides are highly resistant to abrasion. In these types of applications, designers are looking for plastics that can replace traditional engineering materials such as wood or metal. The advantage gained is the inherent ‘formability’ (ease of manufacture) of plastics as opposed to metal-working or fabrication.
Other properties exhibited by various grades of engineering plastics include high heat resistance, mechanical strength, rigidity, chemical stability and flame retardency.
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
materials that exhibit superior mechanical and thermal properties in a wide range of conditions over and above more commonly used commodity plastics
Commodity plastics
Commodity plastics are plastics that are used in high volume and wide range of applications, such as film for packaging, photographic and magnetic tape, beverage and trash containers and a variety of household products where mechanical properties and service environments are not critical. Such...
. The term usually refers to thermoplastic
Thermoplastic
Thermoplastic, also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently...
materials rather than thermosetting ones. Engineering plastics are used for parts rather than containers and packaging.
Examples of engineering plastics include:
- Acrylonitrile butadiene styreneAcrylonitrile butadiene styreneAcrylonitrile butadiene styrene is a common thermoplastic. Its melting point is approximately 105 °C ....
(ABS) - Polycarbonates (PC)
- PolyamidePolyamideA polyamide is a polymer containing monomers of amides joined by peptide bonds. They can occur both naturally and artificially, examples being proteins, such as wool and silk, and can be made artificially through step-growth polymerization or solid-phase synthesis, examples being nylons, aramids,...
s (PA) - Polybutylene terephthalatePolybutylene terephthalatePolybutylene terephthalate is a thermoplastic engineering polymer, that is used as an insulator in the electrical and electronics industries. It is a thermoplastic crystalline polymer, and a type of polyester...
(PBT) - Polyethylene terephthalatePolyethylene terephthalatePolyethylene terephthalate , commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination...
(PET) - Polyphenylene oxide (PPO)
- Polysulphone (PSU)
- Polyetherketone (PEK)
- Polyetheretherketone (PEEK)
- PolyimidePolyimidePolyimide is a polymer of imide monomers. The structure of imide is as shown. Polyimides have been in mass production since 1955...
s - Polyphenylene sulfidePoly(p-phenylene sulfide)Polyphenylene sulfide is an organic polymer consisting of aromatic rings linked with sulfides. Synthetic fiber and textiles derived from this polymer are known to resist chemical and thermal attack. PPS is used to make filter fabric for coal boilers, papermaking felts, electrical insulation,...
(PPS) - Polyoxymethylene plastic (POM)
Commodity plastics
The more commonly used thermoplastic materials are known as commodity plasticsCommodity plastics
Commodity plastics are plastics that are used in high volume and wide range of applications, such as film for packaging, photographic and magnetic tape, beverage and trash containers and a variety of household products where mechanical properties and service environments are not critical. Such...
as they are traded and used in great quantities. Examples are polystyrene
Polystyrene
Polystyrene ) also known as Thermocole, abbreviated following ISO Standard PS, is an aromatic polymer made from the monomer styrene, a liquid hydrocarbon that is manufactured from petroleum by the chemical industry...
(PS), polyvinyl chloride
Polyvinyl chloride
Polyvinyl chloride, commonly abbreviated PVC, is a thermoplastic polymer. It is a vinyl polymer constructed of repeating vinyl groups having one hydrogen replaced by chloride. Polyvinyl chloride is the third most widely produced plastic, after polyethylene and polypropylene. PVC is widely used in...
(PVC), polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
(PP) and polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
(PE).
Typical applications for commodity plastics are high production volume products such as ‘polythene’ bags (made from polyethylene), vacuum-formed food packaging (low density polyethylene), disposable drinking cups (high-impact polystyrene) and window frames/wire insulation (PVC).
Engineering plastics
INTRODUCTIONEngineering thermoplastics are sold in much lower quantities and are thus more expensive per unit weight. Despite this, they are widely used in everyday products. For example ABS is used to manufacture car bumpers, dashboard trim and Lego
Lego
Lego is a line of construction toys manufactured by the Lego Group, a privately held company based in Billund, Denmark. The company's flagship product, Lego, consists of colorful interlocking plastic bricks and an accompanying array of gears, minifigures and various other parts...
bricks, polycarbonate is used in motorcycle helmets and polyamides (nylons) are used for skis and ski boots.
Typically, an engineering plastic is chosen for its range of enhanced physical properties e.g. polycarbonate is highly impact resistant and polyamides are highly resistant to abrasion. In these types of applications, designers are looking for plastics that can replace traditional engineering materials such as wood or metal. The advantage gained is the inherent ‘formability’ (ease of manufacture) of plastics as opposed to metal-working or fabrication.
Other properties exhibited by various grades of engineering plastics include high heat resistance, mechanical strength, rigidity, chemical stability and flame retardency.