Reduced cycle time, minimized rejects and increased process reliability are significant competitive advantages in injection molding. To gain these advantages, companies rely increasingly on high-precision injection molding machines - often in combination with appropriate process monitoring systems. But an important factor that is often overlooked is mold temperature control.
To maintain high rates of repeatability -- even over long periods -- it is necessary to keep the key manufacturing parameters constant. Modern injection molding machines offer processors the option of monitoring and documenting a wide variety of process parameters. However, there is generally not a lot of information available about the current temperature status in the current process. This is all the more surprising since the temperature exerts a strong influence on the product quality, as well as being at the source of a range of malfunctions and influencing factors (Fig.1). Therefore, it is understandable that, according to a study, an average of 24% of rejects can be attributed to defects in mold temperature control .
To eliminate these influences, the flow rates through the individual heating/cooling circuits and the supply and return temperature should be measured, monitored and, if necessary, corrected. However, the manual flow meters that are widely used for this purpose are often not up to the job. For that reason, ENGEL has developed and launched a cooling water distribution system with electronic sensor, which can be integrated into the machine control.