Engineering plastics are a group of materials that have better areas of thermal resistance, impact, chemical resistance, or mechanical strength than the more widely used commodity plastics like acrylic.
Being more expensive, engineering plastics are produced in lower quantities and tend to be used for smaller objects or low-volume applications (such as mechanical parts), rather than for bulk and high-volume ends (like containers and packaging). These materials are generally used in applications that require design and/or engineering to produce parts for a specific purpose or result.
Engineering plastics have gradually replaced traditional engineering materials such as wood or metal in many applications. Besides equalling or surpassing them in weight/strength and other properties, engineering plastics are much easier to manufacture, especially in complicated shapes.