Powder Coating Oven Selection – A Complete Guide
As all powder coaters know, your powder coating oven is one of the most important and often times most expensive equipment investments you make in your powder coating process. Given how critical your powder coating oven is and the variety of options available, it is important to understand the types of powder coating ovens that are offered, the benefits and drawbacks of each, and reasons why prices may differ between powder coating ovens. This guide will cover the details of powder coating ovens to help you make the best selection for your powder coating business needs.
Types of Powder Coating Curing Ovens
There are a variety of ovens commonly used for powder coating curing. The two main groups of powder ovens include infrared curing and convection curing. The main difference between these two ovens is how the coating is cured.
Convection Powder Coating Ovens
A convection oven relies on convection heat to elevate the temperature of the entire oven area which is transferred through the air and increases the temperature of the product surface. With a convection oven curing occurs from the outside of the powder coating in. Due to this outside in curing, convection ovens will typically be slower to cure a powder coating than their infrared oven counterparts. While they are not as fast, they are generally less expensive to initially purchase compared to an infrared oven. Within a convection oven you have electric and gas-powered convection powder coating ovens. Between the two gas convection ovens are not as expensive to operate but having sufficient gas available can be problematic for some. Electric ovens tend to have smaller variation in temperature control and being offered in class A or Class B designs can have a lower initial cost to purchase. Will cover class A and Class B shortly. Electric ovens due to a lower initial cost and lower quality options being available are often a common choice for a hobbyist or home powder coating application.
Infrared Powder Coating Ovens
Infrared powder coating ovens cure a product by radiant heat meaning that heat is transferred directly to the product surface resulting in the powder coating heating from the inside out to cure. Due to the way heat is transferred, infrared powder coating ovens cure powder coating much quicker than convection powder coating ovens. However, they are also significantly more expensive and have some limitations with curing what the infrared waves can easily reach or see. Infrared ovens are great when high production is needed and when parts are relatively flat and uniform in shape, other applications can work but will typically require testing to ensure infrared will perform well.
Powder Coating Oven Classifications and Design Standards
After reviewing whether an infrared or convection and whether an electric or gas powder coating oven is of interest the next consideration to determine whether a class A or class B oven will be considered. The primary difference between the two is that a Class A oven is built to more stringent safety requirements than a class B oven and is required if there will be potential for an explosion of combustibles or volatile substances. For powder coating, class b ovens are usually allowed, if any other curing will be done like with liquid coatings class a is critical. Whichever route you decide, you want to verify with your local authority to ensure they are ok with a class b over a class a oven as they will have to approve any equipment you decide on.
Powder Coating Oven Design Standards
Powder coating ovens have a variety of safety standards they should meet. NFPA 86 is the most complete powder coating oven code to reference other important classifications include UL listed and FM certifications. Other common things to consider about a powder coating ovens design include:
– The gauge steel used – Heavier gauge steel offers greater durability and longevity of use; a quality oven will have 16 – 20 gauge construction with channels for connecting being 18 gauge or thicker steel
– The insulation provided – insulation improves the operating efficiency of the powder coating oven; a good minimum is 4-6 pounds of insulation
– Ovens should have ductwork to remove hazardous build up and ductwork to recirculate air through the oven to ensure uniform heating of products (with convection style ovens)
– Include all pertinent safety features including but not limited to explosion relief panels, flame failure detectors, motorized gas valves, and more (in compliance with NFPA 86)
Ultimately the thicker the steel gauge used, the more insulation provided, the higher the efficiency of the gas burner, and the more precise the controls, the greater quality a powder coating oven will provide but this will also create higher costs.
By knowing the types of powder coating ovens available, the benefits and draw backs of each, safety standards, and design differences you can better determine if a particular powder coating oven is the right type and will perform well for your powder coating needs.