Will it someday be possible to optimize an injection molding machine for processing and quality production? David Kazmer said the answer is yes, but the technology still faces some limitations.
Kazmer, a professor at the University of Massachusetts at Lowell, presented a technical paper May 2 during the Society of Plastics Engineers Antec conference in Boston. Kazmer recently became associate dean of the College of Engineering at the university.
Kazmer detailed a research project at UMass Lowell to test setting up an injection press over the Internet. A design of experiments looked at 46 process variables. Researchers showed the machine's response across 942 cycles.
The team ran six validation tests. Kazmer said these included looking at the impact of variables in the material and determining if the controller could change the process to handle high- or low-viscosity material. Another test studied cycle-time minimization.
Continued improvements in more-powerful machine controllers means “the concept of online optimization is getting closer,” Kazmer said. “Eventually we will see online optimization, I'm sure of that.”
One big challenge is how to measure dimensions of molded parts — something that still needs to be done physically, not in the virtual online world. Kazmer noted that computer simulation programs can measure parts, but he said they can have long-term variability.
Measuring quality is time-consuming, making it difficult to do online, he said.
Another problem is a lot of molders are not willing to run the 942 cycles needed to prove out the process.