It’s a match made in plastic injection molding heaven: IMD (In-Mold Decoration) and PUR technology. That’s right; in this process called IMD PUR, plastic parts are decorated during injection molding through in-mold decorating and then covered with PUR (polyurethane) within the same clamping unit. This produces beautifully complex designs under a crystal clear, high-gloss surface. PUR layer thicknesses of between 0.3 and 15 millimeters can be created that evince a noticeable 3-D effect. Besides a glossy glass appearance, the PUR coating also provides a high level of scratch-and-dent protection. The plastic part decoration remains intact even when exposed to scratches or hard object impact, and the PUR topcoat is self-healing when scratched.
IMD coating and mold technology have advanced greatly
The production and PUR flooding of injection molded parts in a single machine pass is a well-established manufacturing process. What’s new is in combining this with the IMD process. Many manufacturers have developed IMD coatings that adhere perfectly to the PUR topcoat. Mold manufacturers, too, have also precisely tailored the mold technology to the process. So it seems the secret to success is linking a specialist mold-maker with a plastic injection molding company that has extensive history in thin-layer and process technology. Thanks to the comprehensive research-and-development work undertaken by both parties, it’s now possible to perform injection molding, IMD coating, and PUR coating in a single clamping unit. Furthermore, the tailored formulations of the IMD and PUR layers, as well as process-optimized molds, significantly reduce cycle times.
The IMD PUR process combines the advantages of the IMD and PUR technologies. Plastic parts decorated by means of IMD PUR exhibit the high surface quality, depth effect, and glassy appearance of PUR coatings. At the same time, IMD PUR offers the great design freedom that is characteristic of IMD technology, with the ability to perform design changeovers both quickly and efficiently.