A manufacturer of luxury vehicles identified undesirable cabin noise and a vibration in the shifter. Both defects are unacceptable in the luxury automotive market. The manufacturer traced the cabin noise and the vibration to a linear solenoid for transmission selector lever locking. As the solenoid opened and closed a vibration could be felt by the driver on the shifter and a noise was generated which could be heard by passengers in the cabin. An initial attempt to eliminate the problem involved the application of EPDM to the solenoid moving parts. Testing by the manufacturer determined the EPDM material was unable to damp and was degrading under the high engine temperatures and repetitive opening and closing.
To prevent the cabin noise and shifter vibration the manufacturer needed a material that could damp and maintain its properties under repetitive opening and closing conditions in a high temperature environment. The manufacturer gathered a variety of materials including Rogers‘ PORON® 79, PORON® 92 and Rogers’ BISCO® BF-2000. The manufacturer performed a Q Factor test on the materials to determine the rate at which each material damped oscillation. Rogers’ PORON® 92 and PORON® 79 were the top performing materials. Rogers’ BISCO® BF-2000 was the next best performing material. While Rogers PORON materials were excellent damping materials the BISCO® BF-2000 was selected for its ability to maintain properties at well above 120 C (248 F). The BISCO® BF-2000 was also subjected to a 7000 hour test of repetitive opening and closing in 120 C (248 F) heating. After passing the aging test, BISCO® BF-2000 was purchased and a ring was applied to the moving parts on the solenoid.
Rogers’ BISCO® BF-2000 was selected for its ability to damp as the solenoid opened and closed in extreme heat. Applying a ring of BISCO® BF-2000 to the moving parts on the solenoid eliminated the shifter vibration and the cabin noise, providing the smooth and noise free ride that luxury car owners expect.