Low-temperature polyurethane system applies clearcoats to automotive parts on the double


Bayer MaterialScience (Leverkusen, Germany) says that it has developed a unique technology for coating plastic parts on automobiles at low temperatures. Bumpers, mirror housings, spoilers, tailgates and roof modules can reportedly be finished with an outer clearcoat at an energy- and cost-efficient temperature of just 80°C. The process is much faster than existing ones.
Although curing is as much as 30 percent faster than with proven two-component polyurethane coatings, appearance is still very good according to Bayer MaterialScience. In the medium term, this technology will reportedly offer the possibility of coating plastic, composite and metal automotive parts together for the first time.

A new car needs to look good and convey a sense of aesthetics and value. The clearcoat is responsible for the external appearance. It is the last layer to be applied to the body, and gives the vehicle its high-gloss finish. Two-component coatings formulated with polyurethane (PUR) raw materials from Bayer MaterialScience have proved invaluable for this. Along with their outstanding appearance, they also boast excellent resistance to weathering, chemicals and impact.

Although many bodywork parts are still made from sheet steel, plastics are increasingly used for add-on automotive parts. They are one way of reducing fuel consumption and CO2 emissions. To ensure that the coated plastic parts look just as good as the coated metal, they are coated in exactly the same way, but at a lower temperature.

However, when using conventional, uncatalyzed coating technology, plastic parts generally need several days to dry completely after being coated with two-component polyurethane coatings. This leads to delays in further processing and requires special measures for storing the coated parts.

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