Infrared vs Convection Ovens for Paint Curing
When it comes to accelerating product dry time of powder or liquid coated products heat and infrared are the two primary ways to accelerate the dry time of the product. Each method has its benefits and drawbacks and can be right for you depending on your needs. Our goal is to uncover the Pros and Cons of Infrared and Convection ovens so you can make a good choice about which might be right for your product needs.
Infrared Ovens Pros
- Lower Energy Consumption – In most situations an infrared oven will be a higher efficiency oven. This is due to the nature of how an infrared oven cures a coating. Infrared ovens utilize infrared waves to accelerate drying of the coating alone. Unlike convection ovens that require the heat to elevate the temperature of the product and the coating to enable the product to cure. The end result of this difference is that an infrared oven will be more energy efficient
- Potentially Faster Cure Times – Since an infrared oven doesn’t require the product surface to be heated before curing of the coating starts and it immediately starts curing the whole thickness of the coating from the start, infrared can be a faster way of curing a coating.
- Cost savings on operation – since an infrared will typically use less energy it will usually have lower operating costs.
- Smaller in overall size in comparison to equivalent convection oven
- Will not elevate product surface temperature – If your product will change shape due to temperature elevation infrared does not elevate the surface temperature of the product which makes it an ideal choice for substrates that are sensitive to temperature elevations like plastics
- Greater Control over curing – Infrared ovens can change the wavelengths of energy used to alter the rate at which a product is cured. A convection oven on the other hand only has the temperature and movement of air to change the curing process
Infrared Oven Cons
- Infrared ovens require line of sight to cure a product – What this means practically is that infrared ovens will not typically do as well with objects that have a lot of recessed or protruding areas (objects that are significantly different than flat). The infrared oven has to have its infrared waves directly come in contact with the coating surface to be cured.
- Limitations with Certain Coatings – If a coating is excessively reflective in nature it will sometimes not cure well using Infrared technology. This is because rather than the infrared waves penetrating the coating and curing throughout the coating, it will cure only the top of the coating or will not cure well at all.
- Slower cure times depending on product surface – With the product surface reflectivity is a good thing because it causes more exposure from a single infrared wave
Convection Oven Pros
- Lower Initial Cost – Typically a convection oven will have a lower initial purchase price over a Infrared Oven. Additionally, there are a lot of quality used convection ovens on the market that can be found at a lower price
- No limitations on Part Shape – Convection ovens do not have any limitations on the shape of the product. Unlike infrared ovens that depend on energy waves to cure the product, Convection ovens heat the entire surrounding air which allows for curing of any recesses in the product surface.
- Less Coating Limitations – Unlike Infrared Ovens a Convection paint oven will cure a greater variety of coatings.
Convection Oven Cons
- Not Suitable for All Substrates – A convection oven will heat the product surface making it less ideal for products that high temperatures (above 200F) will alter the products surface
- Potentially Higher operating costs – Due to having to heat the ambient air before curing starts and due to the way heat is generated, Convection ovens have higher running costs. This will usually depend on the prevailing costs of the method heat is generated (electric or natural gas)
- Higher Maintenance Costs –
- Larger Floor Space Required – If a convection oven is the same size inside as an infrared oven it will require a larger overall footprint which can be important if shop floor space is at a premium
Combination Infrared and Convection Ovens
Pros
- Fastest cure time – By combining infrared and heat elevation you will be able to achieve the fastest cure times
- Best Curing of High Film Thickness Builds – By utilizing both infrared waves and heat you can cure high film builds most effectively
Cons
- Highest maintenance required – You have to properly maintain both a convection and infrared oven
- Highest initial cost
Alternatives
- If you want to cure a coating but it doesn’t need high temperatures (above 200 degrees) you can incorporate a bake feature into your paint booth. To learn more about baking in a paint booth you can read about it here.
Steps to Take
- An infrared or convection oven is a large expense . To best know whether one is right for you we recommend having your intended product and coating tested in both options to best know which will perform right for you. If you want further assistance evaluating a infrared vs convection based oven let us know and we can help you determine if one is right for your production needs.
Summary
- Infrared ovens are ideal if you have a relatively uniform product surface without recesses and want to minimize operating costs. Infrared ovens are also ideal if you have a product substrate that cannot be heated without changing the product surface. There can be limitations with certain coatings and surfaces so you should have someone cure your coating and product to make sure it will work for you.
- Convection ovens will work with the most coatings, work well with surfaces that are uneven, and have fewer limitations on product substrates.They typically will have higher operating costs than an infrared oven. They are also can be slower in curing than an infrared oven.