Polyurethane paint for a durable and high-gloss finish
A polyurethane paint (PU paint) is a hard-wearing, highly-resistant coating used in industrial and architectural coating systems for steelwork, concrete, wood, and other substrates. It is a reaction polymer, a combination of a polyol resin and an isocyanate hardener or curing agent. Essentially, a polyurethane coating is a liquid plastic which dries to form a paint-like film on a substrate. The properties of a polyurethane can be manipulated by the types of isocyanates and polyols which are used to make it, and so it can be modified to suit a wide range of projects. Polyurethane paint provides durability, resistance to chemicals, water, abrasion, and temperature, as well as an attractive glossy finish.
In this article we outline the benefits of a polyurethane coating, as well as the applications and industries that rely on it. We also look at the different types of polyurethane paint and where best to apply them.
Why to choose a polyurethane paint (aka PU coating)
The physical properties of polyurethane paint are greatly influenced by the choice of base components, with different formulations strengthening certain qualities over others. It is this versatility which is one of the main strengths of PU paint, meaning it can be made to purpose for any number of applications. Some of its other strengths are:
- Quick drying and easy to apply – Polyurethane paint is fast curing, meaning less downtime and associated losses. Like an epoxy it is easy to apply, but polyurethane has faster return-to-service times than epoxy.
- Weather resistance and UV stability – Polyurethane can withstand harsh environments, from underground to offshore, as well as being stable when exposed UV radiation and having thermal stability across a range of temperatures.
- Water and chemical resistance – Resistance to water, steam, moisture, and most chemicals means that polyurethane is a waterproof barrier, preventing corrosion of the substrate.
- Extreme durability – When cured, polyurethane forms a hard, durable surface which provides protection from mechanical abrasion, stains and scratches.
- Attractive finish – Whether high gloss, semi gloss, or matt, polyurethane coatings provide a flawless finish which resists colour fade.
Note that polyurethane paint is not the best option for industrial heavy duty areas due to the fact that it lacks epoxy’s durability and the extreme chemical resistance of phenolic coatings. Polyurethane is also sensitive for humidity especially during the application phase.
Polyurethane coating: Industrial, architectural, and automotive
Because of their extreme versatility, polyurethane paints have applications across the coatings industry. There are polyurethanes formulated for the architectural, industrial, automotive, and marine coating markets. With that breadth of application in mind, we have listed some of the most common uses of polyurethane paints and what properties they bring to each.
1. PU paint for pipes and tanks
Tanks and pipes present a particular problem for protective coating. The substrate needs protection both from the external environment and from the possibly corrosive contents it is storing. As well as that, they need to protect the contents and the local environment from contamination. For this task polyurethane is used in storage and process tanks, reservoirs, wastewater treatment tanks, secondary containment, water pipe lining and oil and gas pipelines. Polyurethane’s excellent ability to withstand exposure to chemicals, high temperatures, harsh environments including salt water, wind, sand, wet soil and more, as well as being UV stable make it the perfect candidate.
Example product: International Interdur 8860 (AkzoNobel). A two component acrylic polyurethane coating giving excellent durability and long term recoatability with a high gloss finish.
2. Anti-corrosion coatings
PU paint for metal provides a waterproof barrier between the substrate and the environment. When combined with its UV stability and its ability to withstand harsh weather and environmental conditions, this makes polyurethane an excellent anti corrosion coating. Polyurethane is often applied over epoxy coating, as an anti-corrosion system to provide the best possible protection against all kinds of corrosion.
Example product: International Interthane 1026 (AkzoNobel). A two component, high build, acrylic polyurethane primer/finish providing anti-corrosion barrier protection and long term recoatability.
3. Automotive coatings
The automotive coatings industry covers everything from a vehicle’s colour coat to underbody protection and internal plastic coatings. Polyurethane paint’s abrasion and weathering resistance is used for the protective undercoating on a car, and most vehicles have a polyurethane clear coat which seals and protects the colour. The soft touch coatings that make a dashboard, armrest, or steering wheel feel soft and luxurious are polyurethanes. Polyurethane is applied mostly as an OEM coating in the paint shop, but underbody coatings are often part of vehicular refinish coating.
4. Architectural polyurethane coatings
Polyurethane is a popular protective coating for the architectural industry. They can be used for steelwork, panelling, infrastructure, as a clear topcoat, a vibrant colour, or as a varnish (polyurethane paint for wood is one of the most popular wood floor coating choices). PU paint is used as a finish on wood flooring, a topcoat to an epoxy cement flooring, and its resistance to chemicals makes it ideal for coating surfaces in laboratories, hospitals, leisure centres with pools and spas, and more.
Example product: Coo-Var P101 2 Pack Polyurethane Varnish. A clear aliphatic polyurethane coating which provides a hard wearing protective coating for wooden floors, inside or outside.
Where to find polyurethane paint suppliers in the UK
Polyurethane paints are available in the UK for every segment of the market. Companies and brands such as BASF, Coo-Var, International (AkzoNobel), Rust-Oleum, Teamac, and PPG all have products in the UK. If you would like more information about polyurethane, or have a more specific need for your project, use the search box above and follow the links. If you need polyurethane coating for a project, our experts are here to help! Let us, in cooperation with our coating partners, connect you with a coating solution. Take advantage of our 100% free quote service by clicking on the “Request a Quote” button below.