Monday, May 28, 2018
Publication Date: 02/1/2011
Archive >  February 2011 Issue >  Electronic Mfg. Products > 

RTP Custom Compounds: Watertight Wiring Harnesses
Overmolded chemical/moisture-resistant wiring harness.
Winona, MN — RTP Company recently partnered with Maxi-Seal to develop the new "Defender" commercial wiring harness system, which offers an unprecedented 10-year warranty against leakage and corrosion. The product was developed to fill a need for a new modular wiring harness for the underside of long-haul semi-trailer trucks.

As the connection point for cabling that delivers power from the truck cab back to the trailer, wiring harnesses are exposed to grimy exhaust and road particulate combined with spraying water, caustic de-icing solutions, and other chemical agents. Given this type of environment, a watertight seal, in addition to chemical and corrosion resistance, were essential design requirements. However, the initial prototypes, which used existing materials, were disappointing due to unacceptable moisture penetration.

The two materials at the heart of the device were the issue — at the connection point a rigid housing needed to bond with a flexible thermoplastic elastomer (TPE) overmold and create a watertight seal. The custom engineered materials included an RTP 1000 Series polybutylene terephthalate (PBT) compound reinforced with glass fiber for the rigid housing, and an RTP 1500 Series polyester thermoplastic elastomer (TEEE) compound for the flexible overmold, which forms a watertight seal. Both compounds provided the necessary chemical and corrosion resistance while bonding so well together that the harness has successfully endured field tests on a fleet of 20 trucks driven 1.6 million miles.

The innovative wiring harness design has allowed Maxi-Seal to beat out competitors to win all the wire harness business for the national truck fleet that had first expressed the need — an extremely large order in the industry.

Contact RTP Company, 580 East Front Street, Winona, MN 55987 800-433-4787 or 507-454-6900 fax: 507-454-2041 E-mail: Web:

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