What Does Force Curing Mean?
Force curing is method that increases the rate of a coating's or resin’s curing by increasing the temperature of the curing process. Depending on the material at hand, increasing the temperature generally will produce the desired reduction of cure time. Different methods are available to achieve force curing, including:
- Air movement
- Convection heating
- Infrared (IR) heating
- Accelerator additives
Most industrial force curing equipment takes the form of an oven, but portable devices are also available for convenience. Among the methods, IR heating provides several advantages over convection heating, such as the ability to cure from the inside out, requires less floor space, is better for the environment and typically has the fastest cure times.
Force curing, referring to the curing process, should not be confused with force drying, which involves the removal of solvent from a liquid coating.
Corrosionpedia Explains Force Curing
The process of curing can be hastened because chemical reactions are central to the curing process. As molecules in the reaction receive more energy from sources like heat, they are more likely to react, which may increase the rate of the resin polymerization. Thus, while the chemical reactions may occur at room temperature, they can be forced to occur more often with heat.
Convection ovens provide the heat through the air and transfer heat to the outermost layer of the coating first before transferring heat sequentially to deeper parts of the coating. As such, convection heating will speed up curing at the surface first. IR heating’s advantage over convection is due to the way it heats. IR radiation penetrates deeper into the coating, adding energy to molecules more consistently throughout the depth. The even heating offers a more rapid force cure.
While it may sound ideal to force cure all coatings or resins, care should be taken to understand the curing properties of a given material. Some resins may perform poorly when subjected to temperatures greater than specified, possibly creating negative overcure effects.