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THE HISTORY OF INJECTION SCREW DESIGN BY: R. F. DRAY R. B. GREGORY AND K. STROBLE THIS HISTORICAL REPRESENTATION IS GENERATED FROM THE ACTUAL PATENTS. IN TECHNOLOGY ADVANCES THAT WERE NOT PATENTED, THE INFORMATION SHOWN WAS GIVEN BY PEOPLE WHO WERE DIRECTLY INVOLVED AT THE TIME. THE DESCRIPTIONS SHO...

Testing a new non-return valve design Robert F. Dray, Mark Blevins, and Scott Knoop Robert Dray Sr. is owner of R. Dray Mfg. Inc. in Dallas, TX. Mark Blevins is manager of molding systems, at Van Dorn Demag, Demag Plastics Group, in Strongsville, OH. Scott Knoop, no longer at Van Dorn Demag, was tit...

THE ALL PURPOSE VALVE (APV) Ideally a Non-return valve s function is to close after the screw plasticizes a selected amount of resin (shot size) so that this plasticized resin can be forced (injected) into the mold. The intent of this paper is to describe how the most widely used non-return valve ty...