The technology of infrared curing for powder coated parts
The infrared oven is an Industrial oven that is gaining increased popularity because of shorter curing cycles and the potential for minimized space requirements. However, before replacing the conventional convection oven for curing, it is important to learn the basics of infrared curing because the decision will not simply rely on being able to save production space. Unlike the technology used in convection ovens that heats air in order to transmit energy to a part, infrared energy in the form of radiation will be absorbed directly by the powder coating. When the equipment is perfectly matched to the application either absorption or transmission may become the primary method to achieve a cure. However, infrared curing has its limitations because it is based on line of sight meaning that energy will travel in a straight line that will be absorbed by sections of the part that are facing the source. In some cases, infrared ovens may provide some degree of convection heating which will help in achieving a cure.
Benefits provided by infrared curing
Because powders respond well to fast heat up rates, infrared curing can provide the benefits of better appearance. For example if the powders used are high gloss coatings, the results after curing will be higher in gloss. On the other hand, if low gloss coatings will be used, they tend to respond in a similar way to produce a gloss that is even lower. In order to overcome this issue, a good option will be trial runs to avoid predicting the results particularly since many products tend to have higher value when the aesthetics are enhanced by a high gloss coat. Another advantage provided by rapid part surface heating in the infrared oven is better powder flow and less chances for dust or dirt defects since there is minimal air flow that can deposit dust particles to the coated part.
The use of convection ovens for powder curing is not only slow but costly particularly for large parts since curing depends on the bulk temperature of the part. Large volumes of air need to be heated and exhausted from the Industrial oven so as to effectively dry and cure the parts. Curing is typically energy intensive since high temperature is required on the convection ovens to cure a part. This is issue may not be present if thin-walled or small parts will be cured since the process will be relatively quick. In infrared curing, the rapid heating process will minimize the energy used.