Visually appealing and functional surfaces are in greater demand than ever in automotive, household appliances and now increasingly in medical technology. The In Mold Decoration process (IMD) and its implementation of a decorated film using the mold, from which the layers of paint are transfered onto the plastic part, offers an efficient and attractive option for finishing. "Options for multi-cavity molds were previously limited to continuous designs and flat components. Single-image designs with precise positioning were not possible," explains Jochen Mitzler, Manager of Market Intelligence and Product Management at KraussMaffei. The IMD production cell with a PX 320 points reveals the future. In cycle times of approximately 40 seconds, two differently designed products (total weight of 136 grams) were created from Plexiglas made by Evonik during the Comptence Forum. One had an anti-reflective scratch-resistant surface, such as is used for touch applications, and another had precisely positioned operating symbols. "The IMD SI DUO film feed by Leonhard Kurz makes this possible for the first time by aligning two film webs independent of each other on the basis of fiducial markers. It is precise to the hundredth of a millimeter," Mitzler said.
"Using the new large PX and the IMD SI DUO film feed, plastic processors can increase their output through multi-cavity molds and gain more flexibility for their production."
The servomotor-controlled positioning unit is integrated into the injection molding machine, in this case into the PX 320, which is the heart of the manufacturing cell. With this, KraussMaffei expands the clamping force range of its all-electric machine series to 3,200 kN. Electric machines are particularly well suited for complex processes such as these due to their speed and precision and because after the injection molding, additional fully automated finishing steps follow This way, sprue cutting and the removal of flakes, which can develop during the IMD process, were done in a laser cell from the partner Datatronik and were automatically transported to a waste bin. A conveyor with integrated UV lamps completed the curing of the scratch-resistant layer. The entire cell is very compact because industrial robots operate with elaborate gripper technology in extremely compact areas. This allows for installation of an optional complete cleanroom hood so that IMD production can be done in a clean environment. A flow box by Max Petek Reinraumtechnik did this at the Competence Forum.