Comparing Industrial Coating Cure Methods:

What is curing and why is it important in coating selection and formulation?

Curing methods and rates can have a big impact on coating selection and formulation. “Curing,” as it relates to industrial coatings, is the chemical process of a coating bonding to a substrate and becoming fully hardened for use. Factors like application method, environment/climate, cost, substrate, desired finish, throughput, and end-use of the product all come into play when determining the desired curing method. Different industrial coatings perform better or worse depending on the desired (or required) curing method, so it’s important to consider curing method in the coating selection process.

Following is a comparison of common industrial coating curing methods:

Heat Curing

Oven Baking: Coated objects are placed in ovens where heat is applied at a controlled temperature for a specific duration. This method is effective for solvent-based coatings, water-based coatings, and powder coatings. Chemistries of baked coatings include alkyds, acrylics, and polyesters that are blended with melamine. They can also be phenolics and epoxies that are cured with high temperatures.

Infrared Curing: Infrared radiation is used to heat the painted surface directly, accelerating curing. It's faster than oven baking and often used for heat-sensitive substrates.?

Heat Lamps: Heat lamps emit focused heat onto the painted surface, speeding up curing.? This method is commonly used for localized curing or touch-ups.

Air Drying

Natural Air Drying: Painted objects are left to dry in ambient air, allowing solvents and water to evaporate and the paint film to cure. This method is slower but suitable for many coatings and conditions. Chemistries of coatings suitable for air drying can vary from solvent-based and water-based alkyds, acrylics, hydrocarbons, lacquers, and epoxy esters. ???

Forced Air Drying: Fans or blowers are used to accelerate air circulation around painted objects, expediting solvent and water evaporation. ?In some cases, customers use low-temperature heat when circulating the air to further speed up the cure. ?This method is more efficient than natural air drying.

Chemical Curing

Catalyzed Curing: Some paints contain chemical catalysts or hardeners that initiate curing when different products are mixed during or prior to the coating application process. This method provides rapid curing and excellent coating durability for both primer and topcoat finishes. Typical chemistries of catalyzed coatings are epoxies and urethanes.

UV Curing: Ultraviolet (UV) radiation is used to initiate photochemical reactions in certain coatings, leading to immediate curing. UV curing is precise and energy-efficient but requires UV-curable chemistries and proper coating application.

Electron Beam (EB) Curing

Electron beams are used to initiate polymerization reactions in certain coatings, resulting in rapid curing. EB curing offers high-speed curing without heat and is suitable for heat-sensitive substrates.

Moisture Curing

Moisture-curable coatings use atmospheric moisture to initiate curing reactions. They are often used for outdoor applications or in humid environments where moisture is readily available.

Dual-Cure Systems

Combining methods: Some advanced systems combine two or more curing methods to leverage their advantages. For example, combining UV curing with heat or moisture curing can enhance curing speed and performance.

Finding the Best Coating

Each industrial coating curing method has its advantages and limitations, and the selection of which method to use depends on specific OEM requirements, goals, and application constraints. The technicians and scientists at Sheboygan Paint Company are experienced in working with customers to formulate an industrial coating that fits their precise requirements for curing and other coating characteristics. Contact us at 800.773.7801 to discuss how we can meet your industrial coating needs.