Laptop covers are molded in an IML process with previously unachievable thicknesses of less than 1 mm in a collaboration of European and Chinese companies.
Engel (Schwartberg, Austria) showed the technology at a recent symposium on an injection-compression mold by Inmold Technologies (Suzhou, China). The laptop has a coated polycarbonate (PC) foil covering and a PC carrier.
The approach includes a process tweak to avoid the high reject rates often experienced with in-mold labeling (IML) despite use of a clean room. In an effort to improve the foil
cleaning technology, brushes supplied by Wandres (Buchenbach-Wagensteig, Germany) are moved immediately adjacent to the mold. Cleanroom technology is supplied by Max Petek Reinraumtechnik (Radolfzell, Germany).
“The trend in consumer electronics products is towards customization. The design is becoming an important differentiating feature”, says Heinz Rasinger, head of the Engel Teletronics Business Unit. “The challenge for the manufacturer now is to create premium, individually decorated surfaces while at the same time reducing the component size and weight.”
Bayer MaterialScience (Leverkusen,Germany) provoded the polycarbonate and hardcoat foils for the demonstration.
Engel has experience in producing thin wall covers with good surface quality. The front covers for the Amazon Kindle eReader are molded on Engel injection molding machines using Variothermal technology. During the technology symposium, a single cavity mold by RocTool (Le Bourget du Lac, France) was used on an all-electric e-motion 940/200 T machine. “This application shows the optimum performance that can currently be achieved using inductive-variothermal mold temperature control,” says Rasinger. “The matte gray surface is just as demanding as designs using glossy piano black.” The surface is free from sink marks and flow lines, although the wall thickness varies across the component. The thinnest point is just 0.4 mm.