50 ways to cut your injection molding cycle time.

Time is money. Opportunities to save some of both are often overlooked. Try out these tips from experts who spend their time trimming the fat off molding cycles.

What molder doesn't want to reduce cycle times? No, not the kind of shortcuts that sacrifice part quality. We're talking about cycle-time

With that challenge in mind, take a look at the following collection of time-and cost-saving tips. It was put together with the help of technical-service professionals and auxiliary-equipment vendors who spend much of their time coming up with the kind of cycle-time strategies that can help your process fly.

Their recommendations are organized by topic areas: the mold, the press, the material, and the auxiliaries, among others. When looking for savings, keep in mind this rule of thumb: injection molding cycle times are 5% injection, 80% cooling, and 15% ejection.

Much of what the experts offer is common sense, pure and simple. But there's probably a nugget or two of gold here for even the most experienced molders. Anyone can occasionally overlook some of the basics.

Keep in mind that most of these tips work' best as part of a comprehensive strategy. "You can never really separate the contributing factors of cycle time. They are always related," explains Blair Souder, manager of injection molding at GE Plastics' Polymer Process Development Center in Pittsfield, Mass.

In fact, some of the items here don't have much of a direct influence on cycle time - but their indirect influence can be helpful or harmful. To take a commonly cited example, some molders compensate for improperly dried resin by adding excess heat to the process, which in turn extends cycle times. Or consider screw selection: Rich Lair, product support manager at Hoechst Technical Polymers in Summit, N.J., points out that molders may try to overcome poor mixing by increasing barrel heat or backpressure, both of which can needlessly lengthen cycle times. "Many molders stick with the general-purpose screw all the time, but they may need to choose the right screw for a given application," says Lair.