Pittsburgh, Philadelphia - According to Bayer MaterialScience, selecting the right waterborne coating for direct-to-metal (DTM) applications is complicated by necessary surface treatment, application requirements, cost of the coating and desired performance properties.
No one coating can overcome all of these challenges, says BMS, adding that water-borne polyurethane coatings nevertheless provide an excellent starting point to meet the performance requirements of today's industrial markets.
Two Bayer MaterialScience llc researchers, Dr Raymond Stewart, senior R&D scientist and Margaret Kendi, associate research scientist, Coatings, Adhesives and Specialties, have studied waterborne polyurethane coatings for DTM industrial coatings.
They found that a single coat of a PUD is as effective as multiple coats of commercially available coatings and that the waterborne urethane has low volatile organic compound (VOC) levels. "The study succeeded in confirming that waterborne urethane coatings based on polyurethane dispersions have superior performance properties over commercially available coatings," said Stewart.
The presentation, "Waterborne Polyurethane Coatings for Direct-to-Metal Industrial Coatings - Challenges and Successes," was given as part of the Innovations in Industrial Liquid & Powder Coatings Session of Track B: Industrial Coatings II, at the North American Industrial (NAI) Coatings Show, held recently in Indianapolis, Indiana. NAI, the largest industrial coatings conference in North America, provides a technical programme and exhibits focused exclusively on industrial and protective coatings.
During his presentation, Stewart compared the different formulations of polyurethane dispersions (PUDs) for ambient or low-temperature cure with the benchmark formula, a commercially available latex emulsion coating. Stewart also discussed the advantages of each formulation with an emphasis on resin evaluation protocols for best utilisation of time and other scarce resources.