Exceptional Conduct

FOR TRELLEBORG SEALING SOLUTIONS,

helping its customers adapt to emerging market trends is key to its success. “With new eMobility, Internet of Things and sensing applications being developed, we saw an opportunity to provide high specification electrically-conductive materials to manufacturers, not just making products safer, more reliable or smaller, but enabling entirely new designs,” says Soeren Roepstorff, Development Manager at the Trelleborg Sealing Solutions facility in Helsingør, Denmark.

Though the idea of conductive seals and bearings has existed for some time, material options have been limited. “Conductive elastomers are available, but these are primarilyonly for static applications. There are also electrically conductive injection molded plastics, however, these lack the required flexibility for effective operation and closed-grooveinstallation,” says Soeren. “Turcon® MC1 and MC2 have been engineered from the start for the kinds of products that these existing materials can’t be used for – seals and bearings with complex geometries for dynamic applications.”

Development and testing

The new Turcon® MC1 and MC2 were developed in Helsingør - home to all Turcon® materials and a facility that has decades of experience in polytetrafluoroethylene (PTFE) development and compounding. Inherently, PTFE is an excellent insulator,but with carefully considered additives, the conductivity can be raised without sacrificing the material properties that make it so useful.

Research and development worked to test both amounts and types of fillers, until a suitable formulation that permitted conductivity was found. “Once we were happy with the initial compound produced, we had to construct a custom, dedicated test rig to prove the material’s performance under real-life conditions,” says Soeren.

A Turcon® Slydring® design was chosen for testing the two new materials and another seal made from Turcon® T29 was used as a control. Turcon® MC1 and MC2 demonstrated negligibledry contact resistance even with low contact pressure and when running in oil. The resistance shown was low and conductivity was high - marking the tests a success.

Turcon® MC1 and Turcon® MC2 differ though, in that they have been specifically developed for electrical conductivity in dynamic sealing applications and therefore sealing performance is optimized in these situations.

Enhancing application performance

“These new materials can offer a reliable connection between two moving parts; something that was not possible before,” says Soeren.

This makes the material useful for important and innovative applications includ ing safely dissipating static in the event an airplane gets struck by lightning, grounding currents in electric motors and permitting signals to transmit through components without circuitry.

“Making use of Turcon® MC1 and MC2 opens the door for manufacturers to really take advantage of all the benefits of PTFE in new ways,” finishes Soeren.

Ideal for eMobility

Turcon® MC1 and Turcon® MC2, as the first electrically conductive Polytetrafluoroethylene (PTFE) based materials for use in spring-loaded and elastomerenergized seals, enable us to guarantee important properties such as, thermal and electrical conductivity, as well as electromagnetic shielding.

The Turcon® materials are an optimum solution for the e-Motor battery, meeting the new and unique sealing challenges it poses. The materials need to withstand the high temperatures typically found in the e-Motor, as well as the battery’s fluids.

Fluid compatibility is particularly complex in the e-motor as a fully charged battery has a different chemical cocktail to an empty one. The Turcon® materials are specifically engineered to cope with this issue.