Glue dispensing
LEM’s core products include a number of ski goggle models. The application dispenses glue on a specific area of the foam padding to be glued to the frame of the goggles. As a result of a production parameter adjustment, the padding now protrudes by about two millimeters outside the frame: the glue has to applied only to the part that comes into contact with the frame. “Manually, it was impossible to perform this operation with the necessary repeatability, on an identical trajectory and at a constant rate,” explains Stefano Lodigiani. “So we installed a UR5 equipped with a dispenser fed from a tank, which distributes the glue on the padding along a trajectory that is always identical and at a constant rate. We have obtained a consistent, higher-quality product. Moreover, since this stage is performed on a mezzanine floor inside our plant, the automation had to meet specific weight and footprint conditions, given that the layout was already fairly full and the mezzanine could not be overloaded. The UR5 weighs less than 20 kg, we carried it easily up the stairs and installed it without difficulty.”
Tending of injection molding machines
The third and final application developed by LEM is tending of a injection molding machine. The machine molds the frames of ski goggles. A UR10 cobot places the male molds inside the machine, removes them when the cycle has been completed, and places them in a transfer area where the operator separates the mold from the finished frame. The cobot is fitted with a 4-point pick-up unit. With two points it picks up two empty male molds and places them in the machine; at the same time, the other two points remove the other two molds with the molded frame. The operator separates them and a new cycle begins.
“In this application, the cobot meets two main needs” explains Stefano Lodigiani. “It improves the ergonomics of the molding station (the molds weigh about 1 kg each, so the operator is required to handle about 4 kg of material every 60/70”) and optimizes the rate of production. Cycle time is fundamental in plastic molding to guarantee product quality: the cobot ensures that the application proceeds at a constant rate and pressure.”