The most difficult filament to print is PEEK, a high-performance thermoplastic that requires very high temperatures and special equipment to print successfully. PEEK is known for its excellent mechanical, thermal, and chemical properties, but it also poses many challenges for 3D printing. In this article, we will explore why PEEK is so hard to print, what are the benefits and applications of PEEK, and how to overcome some of the common problems associated with PEEK printing.
PEEK has a very high melting point of around 343°C, which means it needs a very hot extruder and a heated chamber to prevent warping and cracking. Most desktop 3D printers cannot reach such high temperatures, and even industrial 3D printers need special modifications and calibration to print PEEK.
PEEK is very sensitive to moisture and oxygen, which can degrade its quality and performance. PEEK filament needs to be stored in a dry and sealed environment, and printed in a controlled atmosphere with minimal oxygen exposure. This adds to the complexity and cost of PEEK printing.
PEEK is very expensive, costing hundreds of dollars per kilogram. This makes PEEK printing a risky and costly endeavor, as any mistake or failure can result in a significant waste of material and money. PEEK printing also requires a lot of trial and error to find the optimal settings and parameters for each printer and model.
Despite its difficulties, PEEK is a very desirable material for 3D printing because of its outstanding properties and advantages. Some of the benefits and applications of PEEK are:
PEEK has a very high strength-to-weight ratio, making it ideal for lightweight and durable parts. PEEK can withstand high stresses and strains without breaking or deforming, and it has a high fatigue resistance and impact toughness.
PEEK has a very high thermal stability, meaning it can operate in extreme temperatures without losing its properties or functionality. PEEK can resist temperatures up to 260°C, and it has a low thermal expansion coefficient and a high heat deflection temperature.
PEEK has a very high chemical resistance, meaning it can resist corrosion and degradation from a wide range of acids, bases, solvents, and fuels. PEEK can also resist radiation and UV exposure, making it suitable for harsh environments and long-term applications.
PEEK has a very high biocompatibility, meaning it is safe and compatible with the human body. PEEK does not cause any adverse reactions or inflammation, and it has a low bacterial adhesion and infection rate. PEEK is widely used for medical implants, devices, and instruments, such as spinal fusion, dental implants, surgical tools, and catheters.
PEEK has a very high electrical insulation, meaning it can prevent the flow of electric current and protect against electric shocks and sparks. PEEK also has a low dielectric constant and a high dielectric strength, making it suitable for high-frequency and high-voltage applications. PEEK is used for electrical connectors, wires, cables, and sensors.
How to overcome some of the common problems associated with PEEK printing?
PEEK printing is not impossible, but it requires a lot of preparation, expertise, and patience. Here are some tips and tricks to overcome some of the common problems associated with PEEK printing:
Use a 3D printer that is designed or modified for high-temperature printing, with a nozzle that can reach at least 350°C, a heated bed that can reach at least 120°C, and a heated chamber that can maintain at least 80°C. Make sure the printer is well calibrated and leveled, and the extruder is clean and free of any residue or contamination.
Use a high-quality PEEK filament that is dry and sealed, and store it in a desiccant box or a vacuum bag. Use a filament dryer or a heated spool holder to keep the filament dry and warm during printing. Avoid exposing the filament to air or moisture for more than a few minutes.
Use a suitable build plate and adhesive for PEEK printing, such as PEI, glass, or aluminum with a glue stick, hairspray, or Kapton tape. Make sure the build plate is clean and flat, and the nozzle is close enough to the build plate to ensure good adhesion. Adjust the bed leveling and the first layer height and width accordingly.
Use a suitable print settings and parameters for PEEK printing, such as a nozzle temperature of 360-400°C, a bed temperature of 120-140°C, a chamber temperature of 80-120°C, a print speed of 10-30 mm/s, a layer height of 0.1-0.2 mm, and a fan speed of 0-20%. Experiment with different settings and parameters to find the best results for your printer and model.
Use a suitable post-processing method for PEEK printing, such as annealing, polishing, or coating. Annealing can improve the crystallinity and the mechanical properties of PEEK, but it can also cause warping and shrinking. Polishing can improve the surface quality and the aesthetics of PEEK, but it can also remove some material and alter the dimensions. Coating can improve the protection and the functionality of PEEK, but it can also add some weight and cost.
PEEK is the most difficult filament to print, but it is also one of the most valuable and versatile materials for 3D printing. PEEK printing requires a lot of knowledge, skill, and equipment, but it can also offer a lot of benefits and applications. PEEK printing is not for everyone, but it is definitely worth a try for those who are looking for a challenge and a reward.
