PEEK (polyetheretherketone) plastic raw material is an aromatic crystalline thermoplastic polymer material, with a melting point of more than 300 °C, high mechanical strength, high temperature resistance, impact resistance, flame retardant, acid and alkali resistance, hydrolysis resistance, wear resistance, fatigue resistance, radiation resistance and good electrical properties. These have good prospects in industry, military, medical, and motorsport. For 3D printing technology, we can use SLS or FDM to achieve. Although the cost of SLS is high, it is very in line with the requirements of high-end manufacturing, and the limitations of the molding process are relatively small. On the positive side, we will learn about the specific application of PEEK through some cases.
Take an SLS commercial PEEK model in Germany as a reference. They pointed out that due to software limitations, German companies can only use one PEEK material, which is quite restrictive for research institutions or users. Their research is also aimed at exploring and open path to material for Russia and other companies. Based on the current existing funding and material base, a conceptual sketch is roughly envisaged, the main structure of which is as follows:
Performance parameter requirements:
1. Molding size: 500X500X300mm
2. It can sinter a variety of PEEK materials
3. The preheated powder layer is heated to 385 degrees Celsius and the accuracy is ±2 degrees
4. Nitrogen protection concentration 99.8%
5. Accuracy± 10μm
6. The silo body can be kept slowly cooled as a whole
7. Laser sintering methods can be Gaussian transform, inverse Gaussian transform, etc
8. The fuselage, galvanometer and other components should be heat-resistant.
After several rounds of discussion and revision, the final design and prototype were finally met.
Analysis: From this drawing, it can be seen that although all the organs are complete, because it is a prototype, the electrical protection and modular concept have not been strengthened for the time being, and the heat insulation layer and heat insulation board drawn in red circle are to protect other electrical parts.
Analysis: We see that the innovative point is the use of servo motor-controlled threaded screw rods to control the lifting of the platform, replacing the belt control of the platform lifting method of some traditional enterprises. This is also the mainstream choice of similar equipment such as TPM3d in China, which uses double-sided scraper powder spreading to improve the efficiency of working speed.
Double-sided squeegee back-and-forth reduces print strokes, saving time.
The optical path diagram principle and sintering method
Some equipment is purchased from the current mainstream mature products, so the performance is relatively conservative. The 80W laser source is available in Gaussian, Top-had, and reverse Gaussian sintering methods, which provide a variety of options for sintering crystalline phases.
A SLS printer is being installed and tested
PEEK test part printed on a prototype
Eventually, the parts were tested and performed as follows:
The researchers said that although the performance of other existing manufacturers on the market is still not up to the same level, this is due to the fact that the equipment of the current researchers' test projects is not complete enough, but this attempt has successfully proved the reliability of some new structures and the feasibility of multi-thermal field settings, providing a good test platform for the next stage of continuous improvement and debugging. At present, TPM3D's high-temperature SLS laser sintering models, such as S320HT, have also broken through these technical difficulties, can basically meet the above design requirements, and have preliminarily manufactured their own PEEK prints.
PEEK personalized parts printed by TPM3D
