Trend Watch: What to Look for in Injection Molding

Trends to look for in injection molding this year include enhancements to injection mold speed and quality, process control and advancements to the elimination of machine downtime.

Speed
From all-electric presses, improved clamp and screw designs, new stack molds, faster preheating of composite organosheets, and variotherm molding, look for exhibitors to demonstrate how they are testing the limits of dry cycles.

Injection-machine designers will likely be introducing all-electric presses that can compete with accumulator-assisted hydraulics in high-speed packaging and cap molding. Other suppliers may showcase dedicated systems for caps or PET preforms, using closer integration of the machine and mold to overlap motions and get the absolute most out of the cycle time.

Improved clamp designs as well as screw designs have also been appearing in the industry’s search for speed, along with tools like rotating “cube” type stack molds that permit cooling to occur in one or two of the four faces.

Faster preheating of composite organosheets is an emerging technology in specialty molding for industries like automotive, computers, and electronics. Rapid heat/cool, or variotherm, molding enhances both speed and part quality.

Quality
Recent developments in molding processing-control software increase speed and quality as well, by automatically adjusting injection parameters for changes in material viscosity; finding the minimum necessary clamp force to avoid over-stressing parts and molds; and determining the appropriate coolant flow in mold circuits to achieve optimal heat removal without overdoing the cooling and wasting energy.

In micromolding, special two-stage systems featuring a fixed plasticating screw and reciprocating screw or plunger are designed for enhanced quality as well. These systems claim to eliminate the nonreturn valve so that shot size is volumetrically certain and repeatable.

Process Control
Look for new developments to be on display in injection molding process control, specifically focused on accurate monitoring and control of melt temperature in the barrel and of mold cooling in individual flow circuits.

Elimination of Downtime
Machine builders always aspire to keeping machines running with the least possible downtime, so look for advancements in remote service capability and predictive maintenance. New approaches to “condition monitoring” with on-machine sensors for vibration, torque, temperature, and other variables are striving to all but eliminate unplanned downtime. Ways are also being developed to monitor the health of ballscrews, electrical systems, clamps, injection units, and more, and to measure screw/barrel wear without pulling out the screw.