Insulation Tubing

FP liner as PTFE alternative: production and application

PBT (polybutylene terephthalate) is a thermoplastic from the polyester group with properties comparable to semi-crystalline polyethylene terephthalate (PET). GREMCO manufactures the thermoplastic fluorinated polymer alloy FP (Fluorinated Engineering Polymer) based on the PBT base polymer, whereby the PBT is upgraded by the incorporation of fluorinated additives. Thanks to these fillers, the resulting FP liners are of significantly higher quality and performance than standard PBT pipes. Thus, they are specifically designed for use as control cable liners.

Manufacturing and properties of FP liners

Our FP liners are manufactured by specialized extrusion. Hereby, the raw material in the form of plastic pallets is fed into a hot extruder, which presses it into shape under pressure and heat. The FP liner is then cooled in a cold water bath, where it is drawn to the desired size.  Thanks to state-of-the-art production equipment with the latest continuous in-line laser measurement, GREMCO is able to maintain dimensional tolerances of 0.05 mm on inner and outer bores. The resulting line of FITCO® FP liners offer a variety of significant performance advantages:

• Improved consistency and dimensional stability
• Reduced wear and abrasion
• Adequate temperature resistance
• Improved long-term durability
• Optimized sliding behavior

Application of FP liners

Thanks to their optimized properties, the PBT-based FITCO® liners are ideal for a wide range of applications in the automotive sector. The excellent consistency, abrasion resistance, and long-term durability of the products, combined with their optimized sliding behavior, enable them to be used on an automatic, manual transmission, clutch, radiator, trunk, and door lock cables. Furthermore, thanks to a continuous temperature resistance of up to 150°C (302°F), light-duty applications are sometimes possible in the engine compartment and hood areas, especially since the threshold value for the temperature resistance of most automotive control cable linings can be located at 120°C. For special applications, GREMCO also offers FP liners with an irregular surface on the inner diameter, also known as corrugated liners. This leads to a reduction of friction on the inner surface.

FP- as an PTFE alternative?

Due to the largely congruent areas of application of PTFE liners and fluorinated polymer products, a comparison of the product groups is appropriate. In terms of stability and resistance, these plastics can be classified as almost equivalent. Both materials also exhibit comparable frictional behavior. In the areas of sliding behavior and temperature resistance, PTFE liners prove to be superior. They are therefore to be preferred, particularly in temperature-intensive application contexts. FP liners, on the other hand, are characterized by a tighter dimensional tolerance (0.05 mm to 0.08 mm), easier processability, and significantly lower costs. Consequently, the latter can be used as a cost-effective alternative to PTFE liners in applications with lower temperature requirements.