Within the field of metal additive manufacturing, metals such as titanium with excellent tensile strength and low density are ideal for light-weighting applications, and as such demand for these materials continues to increase.
The trend in polymer additive manufacturing is that thermoplastics with a high Young’s modulus, thermal resistivity or tensile strength are increasingly attractive. Although the use of these materials has been tempered to date, the issue is this the inability of most additive manufacturing hardware systems to reliably print such high temperature, functional polymers. For instance, Fused Filament Fabrication (FFF) has been limited by nozzle temperature and the temperature of the build plate and envelope.
PEEK and ULTEM are two high temperature functional thermoplastics that offer high thermal resistivity up to 350 °C for short time frames, chemical resistance and wear characteristics, and low density. These characteristics make PEEK and ULTEM ideal for application in the aerospace industries due to their light-weighting potential.
For example, noncritical legacy parts formerly made from aluminum may no longer be in production. In this case reverse engineering and additively manufacturing a component with a strong, lightweight material such as ULTEM becomes an ideal cost-effective solution to creating a one-off component.
PEEK offers even higher thermal resistivity than ULTEM, in addition to reduced hygroscopicity and higher tensile strength as well as being bioinert. As such, PEEK is also suitable for application to the aerospace industry, but because of its biocompatibility, has now seen application as coatings for custom orthopaedic implants.
Until now, a combination of price and technical barriers has reduced the appetite for these thermoplastics. In terms of price, ULTEM is manufactured exclusively by Sabic and users have little choice but to accept the market value. PEEK, however, is manufactured by a range of formulators, so end users can shop around for the best deal. However, even with greater consumer choice, PEEK filaments cost upwards of $700-1000 per kg.
Nonetheless, the technical barriers that once precluded the use of these high temperature thermoplastics on Fused Filament Fabrication printers are being addressed. Previously the preserve of the Stratasys Fortus line, ULTEM and PEEK can now be reliably extruded on a range of new printers that have been commercialized since 2015. Of these, the INTAMSYS Funmat HT stands above the rest with an affordable price point of $5,000 per printer. With new printers coming to market over the next year, the benefits of ULTEM and PEEK look set to be enjoyed by a much broader audience than before.
IDTechEx discusses more in its report: 3D Printing Materials 2018-2028: Technology and Market Analysis.