Polimeros

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Engineering plastics
Engineering thermoplastics are sold in much lower quantities and are thus more expensive per unit weight. Despite this, theyare 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 usedfor 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 toabrasion. 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.
Engineering plastics are a group of plastic materials that exhibit superior mechanical and thermal properties in a wide range of conditions over andabove 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 andpackaging.
Examples of engineering plastics include:
* Acrylonitrile butadiene styrene (ABS)
* Polycarbonates (PC)
* Polyamides (PA)
* Polybutylene terephthalate (PBT)
* Polyethyleneterephthalate (PET)
* Polyphenylene oxide (PPO)
* Polysulphone (PSU)
* Polyetherketone (PEK)
* Polyetheretherketone (PEEK)
* Polyimides
* Polyphenylene sulfide (PPS)
*Polyoxymethylene plastic (POM)

These materials are developed from giant organic molecules, generally replace othermetal materials usually with excellent results, as general benefits of plastics are....