Evaluation research of MWCNT / elastomer nanocomposites and cellulation model for Valve sealing components

摘要

This introduces our trial in applying MWCNT nanocomposite elastomer to rubber liners of butterfly valves. Obviously butterfly valves need extended durability, reduced operating torque and improved chemical resistance rubber liners. Through repeated researches, we could verify higher performance of this elastomer in (a) frictional coefficient, (b) chlorine resistance and (c) tear strength, than conventional carbon black (or CB) composite elastomer. Tests reported here were all done on sheeted test pieces.(a) Frictional coefficient was found 40% to 50% lower. A butterfly valve of concentric drive design 90° opens or closes a metal disc in contact with a rubber liner, to release or shut off the line fluid. Here, frictional coefficient between the disc and the rubber liner considerably affects valve operating torque. Therefore, the operating torque is lower, the better, when sealing performance is sufficiently maintained.(b) Some test pieces proved better by more than 50% on chlorine resistance. It is usual that chlorine content in potable water usually deteriorates rubber material. Use of FKM could be a chemical solution, but a problem is its impractically high cost.(c) Some test pieces were also found 50% to 100% better on tear strength.Further study is needed to find the best design of material mix for MWCNT composite elastomer to ultimately solve this problem, and the problem of chlorine content as well.