Effects of Aging on PVC-based Instrument Panel Skin for Passenger Airbag Deployment Analysis

Plasticized polyvinyl chloride (PVC) has many applications in automotive industry including electrical harnesses, door handles, seat and head rest covers, and instrument panel (IP) and other interior trim. In IP applications, the PVC skin plays a critical role in passenger airbag deployment (PAB) by tearing along the scored edge of the PAB door and allowing the door to open and the airbag to inflate to protect the occupant. As part of the IP, the PVC skin may be exposed to elevated temperatures and ultraviolet (UV) radiation during the years of the vehicle life cycle which can affect the PVC material properties over time and potentially influence the kinematics of the airbag deployment. Chemical and thermal aging of plasticized PVC materials have been studied in the past, yet no information is found how the aging affects mechanical properties at high rates of loading typical for airbag deployment events. This paper compares mechanical properties of the virgin PVC-based IP skin material with the same material after it has been exposed to 110C for 400h. Both, virgin and aged materials, were tested at three temperatures, viz. -30C, 23C and 85C and at four strain rates ranging from 0.01/s to 100/s. Finally, effects of the aged material on the PAB deployment simulation are discussed.