Derived from step-growth polymerization, polyurea is an elastomer created by combining isocyanate-reactive elements with a synthetic resin. The result is a reaction of both elements to create a polymerization called polyurea.
There is also a hybrid coating that involves polyurea being blended into polyurethane. The result is a product that offers the advantages of polyurea but without the high cost of the product.
There have been different formulations of polyurea that emphasize different attributes ranging from moisture resistance, fire resistance, pigmentation or color, and how long it takes to set.
Because this product offers some unique advantages, it is quite popular in terms of a protective coating. However, there are also limitations to polyurea as well. What follows is an examination of the pros and cons that polyurea provides for the user.
Benefits of Polyurea Coatings
There are numerous advantages to polyurea, even if the cost of the product may be daunting depending on its availability. In fact, no coating system is equivalent to polyurea in all aspects.
This is because the product is quite durable, long-lasting, and versatile. But it is true that it requires a specific type of surface for it to work at its best such as the following.
It can protect such surfaces in terms of impact, scratch, and premature gaining. Plus, it can resist the salts, chemicals, and oils that may damage such surfaces.
You can apply polyurea to boats to prevent them from deteriorating. Some of the main advantages include the following.
- The fast curing time, scratch, chemical, and abrasion resistance
- Resistant to environmental conditions
- Long-lasting, can be applied at various temperatures, and heat resistant
- Bonds quite well with concrete, steel, and wood
- Low viscosity and high tensile strength
All these factors make polyurea quite desirable for many different applications. It can not only resist heat but water immersion as well.
The sheer variety of advantages makes polyurea one of the most versatile products of its type on the market. However, despite all the benefits, polyurea does have its limitations.
Limitations of Polyurea Coatings
Because the coating can dry quickly, often in under five minutes, it may not fully bond or adhere to the surface. This means that the surface must be prepared with the product properly applied evenly. Otherwise, it is quite possible that it will not stick to the surface properly.
Polyurea is vulnerable to UV or ultraviolet radiation in terms of chalking and changes in color which means that for surfaces exposed to sunlight, an aliphatic polyurea blend must be used.
If the polyurea is to be applied using a hot spray, then special spray equipment must be used. Plus, the person who is doing the spraying must be specially trained to perform this task.
This is not something that a first-timer can do when applying polyurea to a surface properly.
Polyurea Coating Usage & Applications
You will find polyurea used in several industries and areas, including the following.
For at least three decades, the automotive industry has used polyurea for coating its products. This is because of the mechanical properties of polyurea and that it is impact resistant.
In addition to the automotive industry, areas that include the handling of materials, such as construction and mining, have used polyurea to coat their equipment.
For example, coal and metallic ore can scratch surfaces, so polyurea is used on equipment that transports such items. You’ll find polyurea on trucks, large commercial vehicles, and equipment used to haul various materials.
b) Pipes & Irrigation Systems:
Because polyurea is resistant to scratching and corrosion, it is used in pipes, pumps, and irrigation systems.
This reduces erosion, corrosion, and cavitation. The application of polyurea also improves the output of pumps, can be used for repairing canals, and offers protection against leaks.
c) Defense & Security:
Because polyurea can absorb explosive energy, is quite durable, and can set quickly, it is often used for linings and coatings to protect military and security equipment.
Also, because polyurea can contract and expand without rupturing, it is often used to create a moisture-tight seal that works in different temperature ranges.
It is also resistant to abrasions, dents, and scratches as well. It is why polyurea is used for truck liners, coating military structures, and other items that may be exposed to bomb blasts and explosions.
Hospitals are locations where viruses and bacteria present a danger to the inside. Coating the walls and floors with polyurea minimizes the risk of secondary infections in patients and limits the spread of diseases.
Polyurea can help maintain sterile conditions inside operating rooms, neonatal, and intensive care units.
In addition, polyurea is used to cover steel, concrete bridges, and other construction materials. It can prevent concrete from cracking and allow moisture to penetrate the surface. This makes the polyurea quite versatile and useful when used on different types of surfaces.
Best Application Methods for Polyurea Coating
There are currently four types of application processes used to coat polyurea. These include:
High-Pressure Hot Spray: This method preps the surface, mixes the component parts of polyurea, and coats the surface quickly.
The surface must be cleaned of contaminants, and the pressure spray can be difficult to control. The temperature will reach 176 degrees F, but it does provide a fast method of application.
Warm Spray Coating: This is the same type of application as the hot spray, but the temperature range is considerably lower.
The volume of the coating is medium with the formulators to ensure a low viscosity level. Thus, the temperature is kept below 140 degrees F.
Low-Pressure Cold Spray: The formulators must be of low viscosity, but the temperature must be that of the ambient surroundings. For small jobs such as repairing surfaces, this is the preferred method.
In addition, there is the brush or roller method, where the polyurea is directly applied to small surface areas, such as the inside of a small pipe for example.
Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.