| 摘要 |
Transfer molding of polypropylene, polyvinylidene fluoride, FEP fluorocarbon resin or PFA fluorocarbon resin to produce a lining for a 6'' tee pipe fitting is accomplished isothermally by applying pressure of the order of 200 psi to the material while the material, the charge holding chamber and the tee mold are secured in a fixture in an oven. Transfer is performed at a stabilized resin temperature of the order of 375 DEG F. for polypropylene, 450 DEG F. for polyvinylidene fluoride, and 640 DEG F. for FEP and PFA resins over a relatively long time interval. Pressure is removed, the mold assembly is transferred to a press outside the oven, pressure of the order of 700 psi is reapplied to the material, and the mold is force cooled progressively from a remote point back toward the gate which is located in the fitting opposite the stack section thereof. |
