German scientists say they have developed a way of automating the polishing work required by injection molds, now done exclusively by hand.
The researchers at the Fraunhofer Institute for Laser Technology in Aachen, Germany, said polishing injection molds is time-consuming and requires concentration since any blemish can render a mold useless. Up to now it has been impossible to use machines for such work because they cannot get into the curved shapes.
But the researchers, led by Edgar Willenborg, say they found a way to accomplish the task using laser technology.
“The laser beam melts the surface to a depth of about 50 to 100 micrometers,” said Willenborg. “Surface tension ensures the liquid metal flows evenly and solidifies smoothly.”
As in conventional grinding and polishing, the process is repeated with increasing degrees of fineness, he explained.
Willenborg said although laser polishing does not achieve the same surface smoothness as perfect hand polishing, he still sees considerable market potential for the system, especially for molds used in making standard plastic parts.
But the high-end levels of smoothness will remain the domain of skilled hand polishers, he said.
Examples of laser polishing will be presented next month in Frankfurt, Germany, during the Euromold trade show.
