I have a blow mold and mold hanger setup.
Can SW help me determine the pressure it will take to open/crack the mold hangers open?
I know the closing force of the hanger perpendicular to the split line.
I can not use the blow pressure because of exhaust vents and leaks.
I'm triing to determine the maximum pressure we can apply to the product during it's forming process.
Tom,
If I'm understanding you correctly, this is a tough problem to solve. You apply a certain pressure to the inside of your part, but you don't actually know what the real pressure applied to the part is because of vents and leaks in the system. I suppose you could fix that part of the problem by adding a pressure sensor in or very near the mold in the pressure line. But then you need to figure out how much force actually gets applied to your mold halves. To do that you need to accurately model the behavior of the plastic in your part. You are going to have large displacements and high temperatures, and most likely a fairly good variation in temperature across the part and during the expansion of your part. Just finding a good material model at the molding temperatures is going to be hard.
I would think that there exists a program for blow molding that is equivalent to Moldflow for injection molding. Probably not inexpensive, but trying to work this out on your own will involve a massive investment in time and testing.
Jerry Steiger