Xaloy Inc. is offering a novel option for injection molding systems that it claims can improve part quality and reduce costs.
The ICU system overcomes inherent limitations of reciprocating-screw machine designs in melt-temperature control and mixing, shot-size accuracy, machine wear and cycle time, according to Hartmut Jahnke, vice president of technology.
Xaloy is offering ICU, based on a patented design by inventor Robert Dray, as a retrofit kit for standard injection presses and as a component package for machinery builders. The price range for a typical 14-ounce-shot press is $17,000-$22,000.
Dray said at a June 26 news conference at NPE in Chicago that injection molding lacks the technological sophistication of the extrusion industry. A reciprocating screw cannot ensure constant viscosity, the correct temperature or consistent part weight, he said. Yet the technology has been standard since the 1950s, when reciprocating screws replaced plunger injection systems.
ICU uses an extruder with a nonreciprocating screw, a separate ram to inject the material into the mold and an injection control unit that works like a shutoff nozzle to control flow and injection sequencing. Packing and hold pressure are generated by the control unit's hydraulic system. ICU allows operating an injection press at lower temperatures and pressures because the fixed-screw extruder can deliver a better-mixed, lower-temperature melt at higher throughput rates by exploiting advanced screw designs originally designed for extruders. Process temperatures are typically 50Ã¸-100Ã¸ F lower in the ICU setup.
ICU eliminates the reciprocating screw's nonreturn valve at its tip and related problems with wear and accuracy.
In an ICU retrofit, an existing injection molding machine's hydraulic injection cylinder powers the injection ram, which is fitted to the existing machine's injection barrel. The existing screw drive assembly can be used for the ICU extruder, or a new electric screw drive motor could be installed for energy savings.
Xaloy's Melt King barrier screw for extrusion and Melt Optimizer barrier screw for injection molding are based on another of Dray's patented designs.