One of the fastest growing segments in the custom powder coating industry is the use of water based polyurethane dispersion, commonly known as PUD. Technological innovations made the PUDs more attractive in many industrial applications. They contain lower amount of VOCs (volatile organic compounds) and harmful air pollutants.
A reliable dispersion can be formulated as air dried or baked coatings both for flexible and rigid substrates, including plastics, paper, fabric, ceramics, and more. PUDs are used in beautiful art inks as well as in adhesives providing excellent heat resistance, bonding strength and quick curing time. The major drawback, however, is its relatively higher price. But the benefits it provides are all worth it. To better understand polyurethane and its dispersion when it comes to custom powder coating, it’s best to learn the processes involved.
Creation of Prepolymer
The ingredients used to form the prepolymer, the water dispersibility enhancing compounds and active hydrogen compounds, are combined. This blend of polyurethane prepolymer is then dispersed in aqueous medium.
Dispersion in Water
Dispersion of prepolymer blend in water can be done in any method but the approach of making the substance free of surfactants, when necessary, is very desirable. It makes the custom powder coating less sensitive to water, will have better film formation, and reduce attack of bacteria.
Polymer Neutralization
In cases where surfactants or water-dispersibility enhancing compounds are used, neutralizing agents would be necessary to convert carboxyl groups into carboxylate anions.
Chain Extension
While aqueous polyurethane dispersion can already be used, it can still be processed more into chain extension. This is an option to convert the the prepolymer particles into something more complex as polyurethanes.
Teff-Line is a surface coating specialist with the technical expertise in custom powder coating, combined with excellent customer service. We always ensure that any type of industrial coating we provide undergoes the best dispersion process and technique for achieving the highest quality for your special requirements.