![]() These gases form bubbles in the film that move to the coating-air interface, driven by buoyancy forces or surface-tension-driven flow. The most common cause of pinholes is the release of volatile materials or trapped air from the drying film after application. The effect can be seen in Figure 1, which shows the cured surface of a black, solvent-based, automotive OEM basecoat where the coating film thickness increases from left to right. They are also frequently seen in oven-cured coatings when the defect may not appear until the coating is baked. Pinholes are a problem for both water-based and solvent-based coatings although the cause of the defect may be different. Pinholing has been described as “the formation of minute holes in the wet film of a coating material that form during application and drying, due to air or gas bubbles in the wet film that burst, giving rise to small craters that fail to coalesce before the film has set.” 1 These tiny defects disrupt the surface appearance, especially in high gloss formulations, and reduce the protective properties of the finished coating. This new additive shows comparable pinhole elimination compared with hydrocarbon-based defoamers, but without compromising formulation compatibility or final coating appearance. ![]() This paper describes a new additive that combines both deaeration of microfoam and modified surface drying for pinhole elimination. Hydrocarbon-based defoamers help eliminate the foam and pinholes in these formulations, but their limited compatibility results in lower gloss, poor leveling and surface appearance. Pinholes also occur in baked coatings, as the trapped vapor regains mobility when the coating softens under heating, before crosslinking hardens the film, preventing flow back into the voids. Pinholes are often caused by air or solvent vapor release from the film when the coating is too viscous to flow back and repair the holes. Pinholes are a problem for formulators developing fast-drying, water-based coatings, especially in coatings cured at high temperature and applied at high wet film thickness. Apart from this, we are able to deliver the products on time and safely at client premises with the help of our well-connected distribution network.By Jim Reader, Jos van Oosterwijk, Caixuan Xu, Ye Dai, Ruediger Mertsch, Shauna McAuliffe, and Jianchang Tang, Evonik Corporation ![]() With the help of our high-quality products, we have the huge client base. Moreover, to increased productivity and greater revenues, we believe in quality instead of quantity. To achieve our organizational goals, our professionals are working hard and close coordination with each other. Also, we hired a group of talented and experienced personals. With the help of our sophisticated infrastructure facility, we are prepared our products as per the well-defined norms. Moreover, we are providing these products in various packaging options to choose from. All our products are composed under the supervision of our domain experts. Our offered assortments are prepared by taking high-quality ingredients that are sourced from the certified vendor of the market. ![]() We are offering a complete range of OEM Coating Paint and Protective Coating Paint. From 2016, we "Novus Paints" are one of the renowned manufacturers and service provider of the highly effective array of Coating Paints and painting services.
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