PAI material - Polyamide-imide

Torlon® PAI is recognized around the world as being the highest performing thermoplastic material that is melt processable. Stock shapes made by Ensinger are known as TECAPAI polyamide-imide grades.

 

Ensinger produces PAI plastic via both extrusion and compression moulding processes. These shapes are designed for machining, and are manufactured in plates and rods using Solvay Torlon® pellets or powder depending on the manufacturing process. Polyamide-imides are amorphous thermoplastic high performance polymers that are characterized among other things by high thermal stability, good chemical resistance and superior wear properties with temperature capabilities up to 275°C.

 

Parts manufactured from Torlon plastic will exhibit high levels of tensile and compression strength that ensure good mechanical loading capability. Additionally Torlon material provides elevated levels of toughness and rigidity.  The mechanical rigidity coupled with low thermal expansion characteristics and thermal stability help to provide dimensionally stable finished components. Other favorable Torlon properties include high tensile and compressive strength.  Modifications of the PAI polymer are also possible with such materials as glass or carbon fibers, to increase strength and stiffness, or PTFE and other lubricants to reduce friction and increase bearing properties, even in dry running situations.  Torlon material will exhibit elevated levels of moisture absorption which can induce dimensional changes.  Torlon is also sensitive to saturated steam exposure.  Torlon PAI plastic offers an excellent balance of mechanical, electrical, chemical, thermal and tribological properties and will perform well in demanding applications with severe environments at elevated temperatures.  

 

This makes TECAPAI an outstanding bearing and seal material at elevated temperatures. In addition, PAI polymer also offers superior compressive strength and higher hardness characteristics that are critical in many bearing and seal applications which typically demand a high level of wear performance. TECAPAI polyamide-imide excels at low and high temperature bearing and seal applications, while PEEK should have a performance edge within a broader range of chemical exposure.

Among other Torlon material properties, PAI polyamide-imide can also offer superior toughness or impact strength.  PAI has a much higher heat deflection temperature than PEEK and hence retains higher strength and stiffness at elevated temperature. With PAI having superior stiffness and a lower coefficient of thermal expansion, this means that PAI has the advantage of better dimensional stability at elevated temperatures. However, PAI does absorb moisture, therefore, this also needs to be considered relative to the potential limitations a lack of humidity control could present with regard to dimensional stability. PEEK could end up being the preferable choice in some dimensionally critical situations. PAI has higher tensile and compressive strength in the unreinforced extruded grade which has advantages in some applications.

 

Both PAI and PEEK offer an excellent combination of properties. PAI may have an edge in tribological performance, strength, thermal stability, and toughness, while PEEK should have a slight advantage with chemical resistance, and is a more ductile material in the extruded unfilled grade. Torlon PAI is proven performer in tough applications.   

 

Similar to most engineering plastics, TECAPAI polyamide-imide stock shapes are likely to be machined into a finished part.  Typically, this will be done by computer numeric control (CNC) machining, a process that is widely used to manufacture polymer components.  When machining polyamide-imide materials, it is important to note that carbide tooling can be used for short-run applications. Alternatively, polycrystalline diamond (PCD) tooling should be considered for long-run applications, precision tolerance requirements, or anytime reinforced PAI material grades are being utilized. Non-aromatic, water soluble coolants should be used to optimize surface finish as well as extend tooling life.  

 

Note that when machining extruded grades of Torlon PAI, the machined component can be re-curred after machining if maximum wear resistance and chemical resistance are desired.   

 

Semiconductor industry: test sockets, electrical connectors and insulators

Aerospace: fasteners, insulators and other components

Oil and Gas: natural gas compressor components, pump components and labyrinth seals

General industrial: bearing and wear components and components that require high strength and stiffness