Adaptive Process Control system

Improving process stability and component quality with APC

In injection molding production, process stability plays a critical role with respect to the quality of the manufactured components. This is why injection molding machines must operate with a very high repeatability rate over a long production time period. In real-world applications, however, various external factors can, under certain circumstances, negatively influence a process that starts off with stable configurations. These factors range from viscosity fluctuations of the material and the influences of ambient conditions, all the way to effects caused by wear. The injection molding machine does continue to operate with typical precision, but is unable to compensate for the fluctuations from outside the process. This leads to quality defects and, ultimately, production waste. "We can eliminate these problems to a large extent with our Adaptive Process Control system. The new machine function is integrated into the MC6 machine control system and analyzes the current process state in each injection process. As a result, the injection molding machine alone is capable of keeping the configured process and the end product quality stable, even if the viscosity of the material or the flow resistance in the mold change due to external factors," explains Dr. Reinhard Schiffers, Head of Machine Technology at KraussMaffei. These changes are registered by recording specific key parameters of the machine. Through clever evaluation of this process data, the machine can respond to the current process state within the specified limits. To do so, the Adaptive Process Control system adjusts the changeover point and the holding pressure profile to the current melt viscosity and current flow resistance in the mold. This makes it possible to compensate for deviations in the same shot.

Spatial proximity for close collaboration and efficient processes

"We are very satisfied with the work we accomplished with KraussMaffei. This project involved close collaboration between our two companies that proved to be fruitful for both parties," adds Burghart. "Our insights and wishes were successively applied to the development of the new machine function. Everything went off without a hitch."