How powder coating is cured in the Industrial convection oven
In the Industrial convection oven, heated air is circulated through an enclosed space where it provides the right temperature. Powder coated parts are then carried into this enclosed space so that they can absorb heat for a specified amount of time. Heat from the Industrial convection oven will cause the powder to melt, flow and coat the parts. The key to the technology of convection ovens is its efficiency in heating air and circulating it around the parts without disturbing powder coating on the surface of the substrates. The burner combustion air can be used to directly heat the part without the need for a heat exchanger. A circulation fan with associated ductwork is used in the distribution of heated combustion air around the coated parts. Any byproducts of combustion and powder cure are exhausted from the oven chamber. Most of the byproducts of curing are moisture but it also includes carbon monoxide which must be exhausted to prevent oven fouling or the tar-like streaks on its walls.
The combination of Industrial convention oven with infrared energy
There are curing ovens that combine the best qualities of the Industrial convection oven and infrared technology to process a variable mix of parts. In the combination oven, the infrared part gels or sets powder coating so that it can accelerate the cure ahead of the convection soak portion that will complete the cure. Infrared energy prevents powder loss by setting the finish before it can be disturbed by air turbulence during convection. This will also prevent cross contamination in facilities that use more than one color of powder coating. Total energy usage is also reduced as well as cycle time. The process of heating in the convection oven makes use of high volumes of circulating air that heat-soak the part inside and out. Through infrared energy, only the product surface and powder coating are heated to a temperature level where convection is very effective.
Infrared energy on the Industrial convection oven allows coated parts to reach the required temperature 37% faster than if convection oven is used alone. Energy is reduced by approximately 26% which can be very substantial for industrial customers. The combination oven also eliminates the need for multiple recipes because a variety of sized products in different thicknesses and weights can be cured within the oven. This will improve throughput and it ensures that parts are evenly cured without any over-curing or under-curing. All quality specifications will be met even for large geometrical parts.