Jun 4 2007
More and more manufacturers of bathroom appliances and fashionable body care accessories are discovering the advantages of Film Insert Molding (FIM). This process can be used to produce attractive surface finishes on three-dimensionally formed plastic films. A good example is the HQ 7140 electric shaver from Philips. The front and back are made of the polycarbonate blend film (PC+PBT) Bayfol® CR 1-4 from Bayer MaterialScience AG. The film is printed on the back with a decorative honeycomb surface using the screen-printing process. “Our glossy, highly transparent film enhances the brilliance of the decoration. Apart from its good chemical resistance and processing properties, this was a major reason for choosing it,” explained Georgios Tziovaras, a FIM expert at Bayer MaterialScience. He expects even greater use to be made of FIM technology in future for the design of particularly stylish decorative finishes on hair dryer, curling wand and toothbrush handles, front panels for washing machines and tumble dryers and control panels for TV sets and radios. “Stylish cosmetic packaging is another particularly attractive field of application,” he said.
The production of the easy-grip parts of the shaver housing begins with printing the design on the back of the 175-micrometer-thick PC blend film, then shaping it and cutting it. In Europe, this is carried out by the Finnish films specialists Audel Oy headquartered in Oulunsalo. At Philips, this component is then back-injected with a thermoplastic in an injection molding tool and reinforced. Because the decoration is on the inside of the film, it is well protected from external mechanical influences, which means that the printing inks retain their brilliance and color over a long period. Bayfol® CR 1-4 is cold-formed under gentle conditions by the high-pressure forming process (HPF). Compared with thermoforming, this ensures higher positional accuracy of the decorative honeycomb surface. The film is also very resistant to typical “shaving chemicals” such as shaving foam, soap and water, aftershave balm and lotion. Consequently, the outside of the waterproof shaver, which can be simply washed under the tap, remains attractive and looks as good as new for a long time.