Technical Paper
Use of Thermosets/Thermoplastics in General Motors 4.3 Liter Vortec V6 Valve Cover I - Crush Testing and Simulation
1996-02-01
960147
This paper summarizes crush test results of General Motors 4.3 liter Vortec V6 valve cover currently made at Joh, a division of Gecamex Technologies Inc., through injection-compression of 25% glass reinforced epoxy vinyl ester by Cytec Industries Inc. The test consisted of displacing the middle of three central bolts to 15% of cover's height, disregarding gasket and grommet which simulates worst cover conditions. One of the production molds was modified at Build-A-Mold ltd. to allow injection of thermoplastics from four suppliers, DuPont, BASF, GE Plastics and DSM Engineering Plastics. These were crush tested in a similar manner to production covers, Dry As Molded and after moisture conditioning to 50% Relative Humidity. While thermoset covers exhibited progressive cracking, covers made out of glass reinforced nylons sustained compression whereas polyethylene terephthalate covers cracked prematurely.
