There are polymers, and then there are superpolymers.
Superpolymers are so-named because they exhibit exceptional characteristics in specific areas, such as mechanical or chemical. These might include tensile strength, flexural strength, chemical resistance, a high strength-to-weight ratio or a desirable FST (flame, smoke, and toxicity) rating. In any case, the point is, these materials are the very best at what they do. They are superior to other polymers.
The 3DGence F420 is capable of manufacturing high-performance functional parts using a range of polymers that in some applications can replace machined metal parts. Key to this ability is a series of three interchangeable print modules which are designed for low, standard and high-temp materials.
Imaged above: Module M500.
These modules are the Module M280, which reaches a temperature up to 280°C, the Module M360, which reaches a temperature up to 360°C, and the Module M500, which reaches a temperature up to 500°C.
By swapping out these extruder modules, you can print a wide variety of polymers with different mechanical properties. These materials are split into commodity filaments (ABS, ASA, PLA, PP), advanced filaments (PA, PET, PC, PA-CF), and the high performance filaments we’ll take a closer look at today (PEEK, PEKK and ULTEM).
PEEK, PEKK and ULTEM
PEEK, PEKK and ULTEM are categorised by 3DGence as high-performance 3D printing filaments. They are engineering-grade materials used in aerospace, automotive, electrical, medical and other demanding industries.
PEEK and PEKK are semi-crystalline in structure. This means they contain both disordered amorphous and crystalline ordered regions. This gives them very specific mechanical properties. It also makes them quite difficult to print, requiring an extremely high extrusion temperature and bed temperature. ULTEM, on the other hand, is an amorphous resin hybrid. It is easier to print as a result at a lower temp.
The INDUSTRY F420 3D printer is one of only a handful of 3D printers capable of printing these materials, and it is the first of its type to print ULTEM, which has very specific engineering applications.
This is because of their respective high melting points. The standard extruders on FDM printers cannot reach the high temperatures needed to melt the plastics, nor do standard FDM printers usually have a heated print chamber or a heated build plate that can reach the temperatures required for a stable print platform (up to 180°C).
PEEK (polyether ether ketone) is an organic thermoplastic polymer. It is exceptionally robust, especially under stress. The processing conditions used to make PEEK vary so no two PEEK products from two companies are the same.
3DGence’s PEEK is manufactured to demonstrate the most desirable mechanical properties possible from printer extrusion. It has a tensile strength of 105 Mpa, whereas most other PEEKs sit between 90 to 105 Mpa. It has a flexural strength of 130 Mpa, whereas most other PEEKs sit anywhere between 110 and 120 Mpa.
With the correct infill and structure, it’s possible to 3D print parts using PEEK that are an effective replacement for machined metal parts. You can fabricate snap-fits, casings, bearings, piston parts, pumps, HPLC columns and compressor plate valves. PEEK is also suitable for fabricating medical instrument parts, dental implants, electrical connectors and manifolds in performance critical applications.
To print PEEK with the 3DGence F420, you need to use the Module M500. The Module M500 also supports ESM-10, a soluble support material, allowing you to print complex parts from PEEK with overhangs and interesting geometries.
PEKK (polyetheretherketone) is not to be confused with PEEK. Although the two materials are similar in their structure, they are quite different in practical application. For starters, PEKK is easier to print with better layer adhesion and dimensional accuracy. This is because it melts at a lower temperature and is slower to crystallise.
As a result of this slower crystallisation, PEKK demonstrates far greater compression strength than PEEK. It has 8% elongation at break versus 30% with PEEK and a tensile modulus of 2,850 Mpa versus 4,100 Mpa. This means PEKK is a much more flexible material, so it tends to lend itself better to certain applications. It also offers exceptionally good resistance to hydrolysis (chemical breakdown) in hot water.
As with PEEK, with the correct infill and structure, it’s possible to 3D print parts from PEKK that are an effective replacement for machined metal parts – and particularly in applications that are underwater. PEKK is easily machined itself and because of its resistance to hydrolysis, it’s widely used in the marine sector. Potential applications include pistons, seals, bearings, washers, braking components, casings and valves.
To print PEEK with the 3DGence F420, you need to use the Module M500. As with PEEK, PEKK can be combined with ESM-10, a soluble support material, allowing you to print complex parts with overhangs and intricate geometries.
Unlike PEEK and PEKK which are semi-crystalline materials, ULTEM AM9085F is a high-performance polyetherimide resin-blend. It has comparably low resistance to heat and lower dimensional stability, but it is much easier to print and extrudes at a lower temperature. It has an exceptionally high heat resistance and mechanical strength with low toxicity, making it highly suited to mechanical applications.
ULTEM AM9085 is a particularly popular material in the marine, aerospace and oil and drilling sectors because it has desirable flame, smoke and toxicity ratings. In other words, it doesn’t flame or smoke even at extremely high temperatures. It also has an extremely high strength-to-weight ratio which is very similar to PEKK.
Another desirable characteristic of ULTEM AM9085 is its ability to withstand repeated autoclave cycles. It has very specific physical characteristics to achieve this, which PEEK and PEKK do not possess. For example, it will retain 100% of its tensile strength after 1,000 cycles in a steam autoclave above 134°C.
To print ULTEM with the 3DGence F420, you need to use the Module M360. The Module M360 is also capable of printing polycarbonate (PC) and ESM-10, the same soluble support material you can use with PEEK and PEKK.
If you found this article useful, be sure to read our 3DGence INDUSTRY F420 guide. You can also find out more about 3DGence’s print modules here and more about 3DGence’s filaments here (including those discussed in this article).
All images in this article are credited to 3DGence.