Heat protection, Heat-shrink Tubing FITCOTUBE®

Dual-walled PTFE/FEP heat shrink tubing

A unique GREMCO product is the dual-walled PTFE/FEP shrink tubing. This is a special, dual-layer shrink tubing consisting of the semi-crystalline fluorocarbon polymer polytetrafluoroethylene (PTFE) and the copolymer tetrafluoroethylene-hexafluoropropylene (FEP). In this way, the unique properties of the materials are combined in one product and complement each other reciprocally. Furthermore, heating the dual-walled PTFE/FEP shrink sleeve triggers a melting process of the FEP, while PTFE is shrinking. Thus, a liquid-tight encapsulation of critical components and parts can be ensured, which can easily withstand strong mechanical abuse in aggressive chemical environments. Furthermore, it also operates at high temperatures.

Versions of dual-walled high-temperature shrinkable tubing

Two different versions of dual-walled heat shrinkable tubing can be differentiated in the GREMCO product range. These are:

• Standard dual-walled PTFE/FEP shrink tubing.
• Dual-walled FEP/EFEP shrink tubing

PTFE/FEP heat shrink tubing

In dual-walled PTFE/FEP shrink tubing, the outer PTFE tube surrounds the internal FEP layer. The PTFE cover, which also provides excellent corrosion resistance, has a minimum shrink temperature in the range of 350°C (662°F). The maximum continuous service temperature of the shrink tubing is 210°C (410°F). In addition to the high-temperature resistance, this product provides moisture-proof sealing, high chemical resistance, and is also a flame retardant.

In accordance with the above-mentioned properties, the main area of application for dual-walled PTFE/FEP shrink tubing is in high-temperature line connections of primarily hot/cold wire connections. The dual-walled heat shrinkable tubing is also used for encapsulation of temperature sensors in high-temperature applications such as electric motors, transformers for frequency converters, and in the battery compartment of electric vehicles. Further applications are common in medical technology as well as in the aerospace industry.

Dual-walled FEP/EFEP shrink tubing

Dual-walled FEP/EFEP shrink tubing consists of an outer shrinkable FEP sleeve with an inner EFEP layer. EFEP is a terpolymer that differs from pure FEP containing additive ethylene resulting in a lower melt temperature. In terms of properties and applications, these are largely similar to those of classic dual-walled shrink tubing. In contrastFEP/EFEP shrink tubing is primarily used in temperature-sensitive applications in which damage would occur as a result of excessively high processing temperatures. Accordingly, this is only 215 °C (419 °F), while the maximum continuous operating temperature is set at 150 °C (302 °F). The main mechanical and chemical properties are very similar to the classic dual-walled PTFE/FEP shrink tubing.