Victrex Peek polymer protects engine harnesses

Citation

(1998), "Victrex Peek polymer protects engine harnesses", Aircraft Engineering and Aerospace Technology, Vol. 70 No. 4. https://doi.org/10.1108/aeat.1998.12770dad.017

Victrex Peek polymer protects engine harnesses

Victrex Peek polymer protects engine harnesses

Keywords Electrical wires, Protection, Victrex

When US electrical harness producer, Rohr Inc., of San Diego, wanted a high temperature overbraiding for their electrical wire harnesses, they chose one made with Victrex Peek polymer monofilament (Plate 6). It provides the thermal and chafe protection needed for long-term exposures to engine environments.

Plate 6 Electrical wire harness from Rohr Inc.

According to group engineer John Anderson, "Our electrical wire harnesses are used in the very high temperature environments of commercial aircraft engines, such as those used on the Airbus A330, A319, A320 and A321 aircraft. They are also installed on the McDonnell Douglas MD11 aircraft. We chose the Peek polymer monofilament because it provides excellent mechanical protection in temperatures as high as 260°C".

The fact that monofilament can be braided is a definite advantage when additional temperature performance is required. Says Anderson, "In some areas where the temperature requirements exceed 260°C, we splice stainless steel into the overbraiding process and get protection in the 315°C range. The braided nature of the oversleeve makes this possible".

Equally important is the chafe protection afforded by the Peek polymer monofilament. "Aircraft engines are very high vibration environments. If a wire bundle touches anything within the engine, there is a potential for it to be sliced right through. It is essential that a harness remains isolated and protected. The overbraiding acts as chafe protection for the wire harness", explains Anderson.

Prior to choosing the Victrex Peek polymer, Rohr tested a variety of different materials. "We wanted mechanical properties in the 260°C range that were suitable for overbraiding," says Anderson. "None of the other materials came close. We liked the Peek polymer because it has excellent tribological properties. It also has a very low coefficient of friction. This was a requirement in case the harnesses would rub against anything in the engine compartment. Any rubbing or chafing could start abrading the harness or the equipment in the engine.

"We are very pleased with the Peek polymer monofilament. It provides a final outer layer braided over all the wires. We consider it one of the essential features of our harnesses. Not only does it provide thermal and chafe protection, it can also extend the life of the harness."

For further information contact Victrex plc. Tel: +44 (0) 1253 861321; Fax: +44 (0) 1253 861152; E-mail: awalker@victrex.com