A STATISTICAL ANALYSIS OF ELASTOMERIC SEAL DEGRADATION IN A PNEUMATIC CYLINDER WITH VARIATION OF TEMPERATURE

Pneumatic Cylinders are one of major mechanical components which are widely used in various industries such as automobile production line and semiconductor inspection device due to its low contamination and low maintenance cost. Most of existing studies on pneumatic cylinders have focused on their performance improvement such as operating sliding friction measurement, contact stress minimization, appropriate dynamic response, and etc. This research carried out life tests of pneumatic cylinders and the concerned failure mechanism was the degradation of pneumatic polyurethane seal since leakage caused by seal degradation occurs very frequently. The considered operating parameter was environmental temperature. To assess operating temperature as an acceleration parameter, the lifetime of a pneumatic cylinder was tested at high temperature and the degradation mechanism and characteristics of sealing surface were analyzed by statistical Weibull analysis method as well as by surface analysis using pyrolysis gas chromatography. Ultimately this research will help the life prediction of other pneumatic reciprocating machines.