Hot runner micromolding solution

Polyshot Corp. (West Henrietta, NY) has developed a turnkey, quick-change, all-in-one hot runner molding system for Nissei's HM7, a tabletop micromolding press. The system consists of two major components that bolt directly to the machine platens. No machine modifications are required for installation.

The fixed half of the system has a hot runner assembly that bolts directly onto the HM7's fixed platen. It houses a P-Multi-8 Polyshot multitip hot runner system designed for direct part injection. The Multitip operates on one zone of control and has a tip-to-tip center distance of .75 inch. This assembly also features mounting holes and guide pins that allow interchangeable cavity inserts to be bolted to it.

The system's other major component is an ejector housing that bolts directly to the HM7's moving platen and allows interchangeable cavity inserts to be slid in and out of it. The inserts are retained with two socket head cap screws, or optional thumb retainers. Several different ejection systems can be used, including sleeve, standard pin, or stripper plate types.

Both halves of the system include a feature that automatically connects the waterline circuits in the mold cavities upon installation. Cooling inlet and outlet holes are drilled into the mold cavities at predetermined positions. When the cavities are installed, these holes mate with O-ringed seals in the system, which feed water to each cavity. This approach makes cavity changes quick and easy. There are no hoses or fittings to connect. The entire system is constructed of hardened and ground stainless steel for long life. It is designed to process unfilled resins with processing temperatures of less than 580F.