PAI material - Polyamide-imide

TECAPAI Ensinger Plastics made from Solvay’s Torlon®

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 molding 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.  
 

Torlon® PAI is a registered trademark of the Solvay Group.

PAI MATERIAL PROPERTIES AND SPECIFICATIONS

  • Outstanding tribological and wear performance
  • Excellent strength and stiffness at elevated temperature
  • High tensile strength
  • High compression strength
  • Exceptional heat deflection temperature
  • Excellent coefficient of thermal expansion
  • Very good impact strength
  • Superb thermal stability
  • Good machinability
  • Strong chemical resistance

MANUFACTURED TORLON PAI MATERIALS

Polyamide-imide plastics are manufactured by Ensinger under the tradename TECAPAI using Torlon® PAI polymer. The Ensinger TECAPAI family of high temperature plastics offers polyamide-imide shapes in several modifications. PAI rods and plates are made with two different processing techniques including extrusion and compression molding.  Extrusion offers the advantage of producing shapes that exhibit physical properties close to injection molding.  Compression molded PAI shapes can be produced with minimum order quantity as low as one piece.  

Extruded plates and rods

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TECAPAI CM XP403 green

TECAPAI CM XP403 is a unreinforced compression molded Torlon PAI plastic. It has excellent physical properties …
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TECAPAI CM XP730 black

TECAPAI CM XP730 black is a compression molded 30% carbon fiber reinforced polyamide-imide with excellent physical properties.

torlon vs peek? 

When customers ask us about Torlon vs PEEK, they would like to understand performance differences between PAI and PEEK. While both Torlon PAI and PEEK are excellent bearing materials, PAI material  may be the better performer depending on the application. When comparing the bearing grades of these materials,  Torlon PAI may be a better solution for close tolerance seals or bearings that are exposed to temperatures over 150°C (302°F).  The stiffness of PEEK decreases over 150°C and the thermal expansion rate increases.  In contrast, Torlon PAI maintains strength and stiffness 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.   
 

machining torlon

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.  
TECAPAI CM XP530 black-green is a compression molded grade that contains glass fibers, and is often used in precision machining applications. This Torlon plastic has compared favorably to competitor materials in test socket applications where precision and micro-machining are required.
 
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.   
 

Typical pai applications

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