Calculating Torque -Plastic Injected Part
Can anyone provide me the formula or assistance in calculating torque(in/lb) required to start initail rotation of a cylindrical steel core in a plastic injected mold for part ejection. The core is a threaded core material S7 or H-13. The molded plastic is PE or PP. The Diameter of part is approx 5 inches. Threaded surface width is 1.5 inches. Part thickness is about .200 inches. I want to eject molded part by rotating core in opposite direction of thread to push out part off core/cavity. I am attempting to apply a 1 hydrualic motor with chain drive to demold two parts. If I get any help in this calculation I would appreciate it.