High performance thermoplastics materials for demanding applications. These tend to be more expensive and less widely applied than commodity thermoplastics and include thermoplastics such as acetal polyamides, polycarbonate and thermoplastic polyesters.
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.