Insulators in Laser Cutting Heads: Teflon, Peek, Ceramic, PPS, & Vespel

There are several different materials commonly used as electrical insulators on the cutting heads of CO2 and Fiber lasers. Teflon, Peek, PPS, ceramic, and Vespel are the most popular among these insulators. How do you choose between these if you have the option? Details about specific temperature resistance and strength vary depending on who manufactures the material and what grade of material is used. Below, you will find an overview of the advantages and disadvantages of each material from the perspective of an experienced technician who has rebuilt many Mazak cutting heads.

Teflon® (PTFE)

Teflon is a brand name of PTFE (polytetrafluoroethylene). Teflon is such a well-known name that many refer to any type of PTFE as Teflon. PTFE is a very low-cost insulator. This material is flexible, which makes it more durable in case of a collision of the cutting head. It has a temperature resistance of up to 500 °F. This is low when compared to some of the other insulators. This property makes PTFE a poor choice if you have a high-temperature application, such as cutting thick mild steel or a material that is reflective like stainless steel or aluminum. In low-temperature applications, PTFE is a great choice because it is otherwise durable and holds up well if you have a minor collision with the nozzle tip. View our selection here.

Peek

Peek is the shortened name for a type of plastic called polyetheretherketone. It is a type of plastic with an operating temperature resistance of up to about 500 °F, making this material another poor choice for high-temperature applications. However, Peek is a harder material than PTFE with a much higher tensile strength. Peek is not flexible and holds its shape better than PTFE as temperatures rise to the useful limit. Peek is generally a little more expensive than PTFE. Peek is a popular alternative for PTFE because it is stronger and more heat resistant. Even though the melting point is near the same, Peek still seems to hold up better than PTFE. Peek is great for applications that require a harder material that won’t flex or change shape with heat. That being said, it is still not a great choice for applications that have sustained temperatures higher than 500 °F. View our selection of Peek products here. 

Ceramic

Ceramic is the most useful insulator for high-temperature applications. The price of ceramic is generally high. It can withstand 1500-2000 °F, possibly higher for larger insulators. After prolonged exposure to high temperatures, ceramic will become brittle and crack easier. The smaller or thinner the insulator, the easier it will be affected by temperature. Ceramic also has a high compression strength, so it will hold other parts together tightly without flexing. The disadvantage to ceramic is that it has low tensile strength and because it doesn’t flex, it will crack if there is a collision. In comparison, PTFE and Peek have some flex so they won’t crack. However, PTFE and Peek can still be damaged if the crash is bad enough; they will usually squish and lose their shape. View our selection of ceramic insulators here. 

PPS

Polyphenylene sulfide (PPS) is often simply called resin. This is a type of plastic that has been used as a replacement for Peek in some of the newer Mazak cutting heads. The main reason it has become popular is because of its lower cost. Peek has a slightly higher temperature resistance, is more flexible, and has a higher tensile strength, while PPS has a higher compressive strength. Peek is the better option, but there aren’t many instances where both materials are available as the same insulator in a cutting head. When an insulator is called “Plastic”, it could mean Peek or PPS. View our selection of PPS insulators here. 

Vespel®

Vespel is an expensive, high-performance type of plastic made by the company DuPont. It has properties that make it well-suited for aerospace and semiconductor manufacturing, but as it is used on the cutting head of a laser, we are mostly impressed by its superior temperature resistance. Vespel has a temperature resistance of up to about 500 °F continuously and up to 900 °F intermittently, making it the preferred plastic for higher-temperature applications. It also has low friction and superior wear performance, making it better for applications that have moving parts. If Vespel is an option, it is the best and likely most expensive option. View our Vespel selection here. 

Conclusion

Teflon (PTFE), Peek, PPS, ceramic, and Vespel are among the most popular materials used as electrical insulators on the cutting heads of CO2 and Fiber lasers. Each material varies in temperature resistance, tensile strength, compression strength, cost, hardness, and damage resistance in case of a crash. Details about specific temperatures and strengths will vary depending on the manufacturer and the grade of material used. In the graph below, you will find an overview of the properties of each material graded on a scale of 1-5 based on our technician’s experience as well as technical specifications. View MG Laser’s selection of insulators here.