Sometimes you want to collaborate; other times, you want to keep things close to home. Mold builder and in-mold labeling (IML) automation specialist Müller (Conthey, Switzerland) did some of both on the recent SKET cup project that PlasticsToday reported on last month. The company is demonstrating its expertise at Fakuma in Friedrichshafen, Germany, this week, where it carved out a niche at the expansive Arburg stand.
To recap, the SKET cup is said to set a new standard in the injection molding of polypropylene (PP) packaging by reducing the amount of PP by as much as 50% compared with conventional products. Developed by Uniplast, part of the Knauer Group (Dettingen, Germany) and a leader in PP packaging for dairy products, with the collaboration of Müller, the SKET cup walls are only 0.22 mm thick, allowing the aforementioned reduction in material usage. The 0.7-mm-thick lip of the cup must be maintained at that thickness, however, and without defects. "It's important to produce lips without sink marks to ensure proper sealing," Müller told PlasticsToday from the Arburg stand. Spiral grooves in the cup walls assist in flow and ensure that the PP reaches the 0.7-mm-thick sealing rim quickly enough to completely fill out the cup.
Müller worked closely with the engineering department of the Knauer Group on the SKET project and, notably, developed and implemented the pilot cell equipped with a Multiflex IML robot, which it is running at Fakuma. The system was developed specifically for the pilot phase, so that all injection molded IML products could be tested on the same system. The system's flexibility and speed is such, however, that it can be used for small batch production.