Injection molding (June 01, 2004)

Molding metal parts requires precise process control

Small, precise, high-volume parts are the best candidates for metal injection molding, says Anthony DiBattista, sales and process engineering manager for Boy Machines Inc. Boy was molding a stainless steel part on a vertical injection press at Plast-Ex in May. Using a compounded PowderFlo material from RTP Co., the parts were molded on a general-purpose 35 AVV vertical press equipped with Boy’s Procan CT controller.

DiBattista notes that cycle time and tool design are similar to injection molding, so the switch to metal injection molding is not a huge leap for plastic molders.

“The biggest problem is that part quality issues may not surface until the debinding and sintering steps are complete,” says DiBattista. To counteract this, he suggests precise process monitoring is needed.

As well, he notes that precise barrel heat is needed to mold metal parts.

The PowderFlo metal injection molding process, patented by Latitude Manufacturing Technologies, uses an aqueous/agar binder system which simplifies post-molding operations. Air drying is sufficient for the de-binding phase, which is then followed by a sintering step.

Boy Machines Inc. 610-363-9121

Tunnel gates for larger parts

I-mold has broadened its line of Exaflow tunnel gate inserts to include inserts for larger parts. “One-hundred gram to 150 g parts was our previous limit. The new models can handle up to 1000 g,” says Andy Walker, managing director of I-mold GmbH. Exaflow tunnel gate inserts allow the gate mark to be below the surface on cold runner parts.

One benefit of using tunnel gate inserts is that they are replaceable when worn.

DMS Diemould Service Co. (Canada) Ltd. 519-253-2431