Polyurea coatings have revolutionized the protective coatings industry with their exceptional durability and versatility. These protective coatings have found applications in various industries, ranging from construction and automotive to mining and petrochemical. In this blog post, we will explore the science behind polyurea coatings, including their molecular composition, application, and the benefits they offer. By understanding the underlying science, we can appreciate the unique properties and advantages of these Polyurea protective coatings.
The History of Polyurea Coatings
Polyurea coatings were initially developed in the late 20th century. Their early applications were primarily in the automotive and construction industries, where they demonstrated superior performance compared to traditional coatings. Over the years, advancements in technology and formulation have further enhanced the properties and application possibilities of polyurea protective coatings.
The Science Behind Polyurea
Polyurea is a type of coating formed through the reaction of isocyanate compounds with resin (amine) blends. This reaction results in a fast and highly crosslinked polymer network. These components are combined and applied using specialized equipment to ensure the optimal reaction.
The distinctive characteristic of polyurea protective coatings lies in their extremely fast reaction, gel, and cure times. Unlike other coatings that may take hours to gel or days to cure, polyurea protective coatings can gel within seconds or minutes, depending on the formulation. This rapid reaction is due to the specific chemistry of the isocyanate compounds and resin blends used.
Benefits of Polyurea Protective Coatings vs. Other Coatings
Polyurea protective coatings offer several advantages over other commonly used coatings.
- Exceptional Durability: Polyurea coatings are highly durable, capable of withstanding extreme conditions, including impacts, abrasion, and harsh chemicals. They provide long-lasting protection to surfaces, reducing the need for frequent repairs and replacements.
- Fast Application and Quick Cure Time: Polyurea coatings cure rapidly, allowing for faster project completion and reduced downtime compared to other coatings. The quick cure time enables a more efficient workflow, leading to increased productivity.
- Elongation and Tensile Strength: Polyurea coatings exhibit high elongation and tensile strength, allowing them to withstand significant deformation without cracking or breaking. They remain intact even in environments where temperature fluctuations or structural shifts occur.
- Tear and Abrasion Resistance: These coatings offer exceptional resistance to tears and abrasion, making them suitable for high-traffic areas and applications where mechanical stresses are prevalent.
- Environmentally Friendly: Unlike some coatings that contain solvents and volatile organic compounds (VOCs), polyurea coatings are virtually solvent and VOC-free, contributing to a safer and healthier working environment.
- Chemical and Corrosion Resistance: Polyurea coatings exhibit exceptional resistance to a wide range of chemicals, including acids, solvents, and alkalis. This makes them ideal for environments exposed to corrosive substances, such as chemical processing plants or wastewater treatment facilities.
- Waterproof and Moisture Barrier: Polyurea coatings form a seamless and impermeable layer, effectively protecting surfaces from water infiltration and moisture damage. They are widely used in applications where water resistance is critical.
- Versatile Application and Compatibility: Polyurea coatings can be applied to various substrates, including concrete, metal, wood, and even geotextiles. They adhere well to different surfaces, providing a versatile solution for a wide range of industries and applications.
- UV Stability and Colour Retention: Some polyurea coatings are aliphatic – UV stable – resisting colour fading and degradation when exposed to sunlight. This UV stability ensures long-lasting aesthetics and reduces the need for frequent repainting or maintenance.
- Reduced Maintenance and Longevity: With their exceptional durability and resistance to wear, polyurea coatings require minimal maintenance over their lifespan. They offer a cost-effective solution by reducing the frequency of repairs and replacements, saving time and resources.
Polyurea Coatings Application
Before applying polyurea protective coatings, proper surface preparation is essential to ensure optimal adhesion and performance. This typically involves cleaning the surface, removing contaminants, and repairing any damaged areas. The surface should be dry and free from dust, oil, grease, and loose particles.
A specialized plural component spray system is utilized for polyurea application. This system consists of:
- A Feed System: To deliver the isocyanate and resin from their respective drums to the proportioner. You need to ensure the proper pump is selected to meet the viscosity and storage temperature of the chemicals as the wrong pump may not deliver the chemicals at the right pressure or flow rate to the proportioner causing issues. Agitation is required on the resin side to avoid any sedimentation of material like color pigments or fillers.
- Proportioning and Heating System (Reactor): To meter the chemicals at the right mixing ratios, produce and maintain the required operating pressure, achieve enough temperature rise to heat the chemicals to the application temperature, and deliver the desired flow rate at the required pressure.
- Heated Hose: Utilized to maintain the temperature of the material after exiting the reactor and travelling to the application gun.
- Impingement Mix Gun (Air or Mechanical Purge): Due to the rapid reaction time of polyurea impingement guns are utilized in their application.
- Air Purge Gun: With the air purge model a metal mixing chamber is housed inside the gun with two orifices each with a valve that will open or close the fluid flow to the mixing chamber. When the trigger is pressed the orifices open and the two components flow into the mixing chamber, combine, react, and exit out of the nozzle of the gun as polyurea. When the trigger is released fluid flow is closed off and pressurized air flows through the orifices cleaning out the mixing chamber.
- Mechanical Purge Gun: With the mechanical purge model a needle is used to open and close the two orifices of the mixing module. When the gun is de-triggered and fluid flow is stopped the needle will push out all of the mixed material.
Different polyurea formulations are available, each designed for specific applications and performance requirements. Following the manufacturer’s specifications ensures optimal results.
Choose IMC/Nukote Canada for Exceptional Polyurea Coatings
Polyurea protective coatings are a game-changer, ensuring long-lasting performance and protection for critical infrastructures and assets. They also offer exceptional durability, fast curing times, chemical resistance, and versatility in various industries. You can trust IMC/Nukote Canada for all your coating needs to ensure the best product is used for your project. Get in touch with us today for fully engineered solutions for asset protection.
