Engineering plastics are plastic materials that exhibit good mechanical and thermal properties. The term engineering plastics usually refers to thermoplastic materials rather than thermoset plastics.
Pacific West Corporation can facilitate a wide range of engineering plastic needs – cut to size, machined and/or fabricated to different specifications and requirements.
Examples of engineering plastics include:
- Higher grades of polyethylene
Engineering plastics are widely used in everyday products and often substitute for metals in various applications. For example ABS is used to manufacture car bumpers, dashboard trim and Lego bricks, polycarbonate is used in motorcycle visors and nylons are used for skis and ski boots.
Engineering plastics are typically selected for their diversity of enhanced physical properties e.g. polycarbonate is highly impact resistant and nylons are highly resistant to abrasion.
To select the right engineering plastic, the following factors are considered:
- Tensile strength – the ability of a material to resist breaking under tensile stress is an important property. Although some plastics have lower tensile strength than commonly used metals, their density is lower, thus ensuring that its strength to weight ratio is far better than the metal equivalent.
- Compression strength – is the stress that a material can withstand under pressure. With engineering plastics, there is generally no ultimate yield, as plastics will slowly deform as compared to metal which can suddenly fail. Due to the elastic nature of plastics, the stress factor on the material is less than that of metal.
- Temperature – engineering plastics can operate at continuous temperatures of 100-120°C, with short term allowable operating temperatures of up to 240°C. If higher temperature performance is required, there are some engineering plastics which will operate continuously up to 310 and even 500°C for short periods.
- Thermal expansion – the amount of contraction and expansion of materials due to temperature change. Plastics are affected more than metals to temperature change, but this can be overcome with clever design. For example, for long wear strips, incorporating scarf cuts – a 45 degree cut – will allow for thermal expansion.