Thermoplastics - from PP to PEEK

Thermoplastics - the absolute leader among injection molding materials. For more than 100 years, thousands of clever minds have been developing and improving this group of materials every day. During this time, an impressive arsenal of plastics has come together. These differ from each other in special properties, resistance and price. Thermoplastics can be roughly divided into the following groups:

Standard plastics

The most commonly used thermoplastic group. Due to their low price and yet excellent properties, these plastics are used for over two thirds of all plastic applications. Most of the time, even these basic plastics can mechanically outperform 3D printed parts when injection molded.

This group includes among others:

  • Polyethylene (PE)
  • Polypropylene (PP)
  • Polystyrene (PS)
  • Polyethyleneterephthalate (PET)
  • Acrylonitrile butadiene styrene copolymer (ABS)

Technical plastics

More demanding applications often require better mechanical properties and stability. This class of plastics come at a slightly higher price, but are still very cheap compared to metals and other alternatives of a similar performance. Engineering plastics include, among others:

  • Polyoxymethylene (POM)
  • Polymethyl methacrylate (PMMA)
  • Polyamide (PA)
  • Polycarbonate (PC)
  • Polybutylene terephthalate (PBT)

High performance plastics

If nothing else will hold or extreme properties are required, only high-performance plastics will help. They come at hefty prices, but prove their value for the corresponding applications. High-performance plastics include:

+ Liquid Crystal Polymer (LCP) - Extremely unreactive, high strength and resistance to fire

+ Polyetheretherketone (PEEK) - Extreme temperature, strength and chemical resistance

+ Polysulfone (PSU) - High stiffness and highest temperature stability

Thermoplastics in additive manufacturing

Only very few of the plastics described here can be processed in 3D printing processes. An exception is the FDM / FFF process. With filament-based processes however, major compromises in the surface quality and mechanical strength of the components must be expected.

Rapid Injection Molding as alternative

Injection molding is the only way to meet the high demands on the material and the surface quality. And if only a small batch size is required, Injex's «Additive Tooling» process is a very fast and cost effective way to produce injection molding prototypes and small series.