posted February 18, 2007 01:14 PM            

some clamping issues with new tools coming into the shop. Tools designed for

a standard tpo, but have been changed to a different matetrial. Originally trialed

at 750tn per cavity but now will not even hold at 1800tn with new material

material supplier says clamping force should be 3-5tn per sq/in. We are only

using 1000psi of max. substained injection pressure. The part is .90 thick,

13" wide, and 42" long. Runner depth is .375 usings extremely large fan gates.

Actually 3 gates are .500 wide and center gates are 4" wide.

The material is a newly engineered grade tpo, with ground up reprocessed

tires. I would appreciate if someone could help me with an actaual engineering

equation for determing clamp force for new molds.

Thanks