Combination Oven

ETAC helps evaluate and test combination oven (combo oven) technology applications that can benefit your business.

• About Combo Ovens
• How Combo Oven Technology Can Benefit Your Business
• Send a question to an ETAC combo oven expert. ETAC experts will answer combo oven questions every Tuesday, or if you can't wait contact us now.

About Combo Ovens

Combination or "combo" ovens use infrared (IR) heating in combination with convective heating for ideal curing. Natural gas-fired convection ovens that circulate hot air to heat the parts and coatings are widely used for drying and coating during manufacturing processes. However, manufacturers often use combo ovens to achieve greater production speed when converting from solvent-based to powder coatings. In its coatings laboratory, ETAC offers a state-of-the-art natural gas-fired combination convection and catalytic IR oven to demonstrate the benefits of the synergy of these two technologies. The IR provides a rapid rise in temperature of the product and the convection holds the temperature evenly and uniformly.

Convection ovens alone, with their low temperature and large volumes of re-circulating air, often prevent users from realizing the benefit of the higher throughputs offered by converting to powder coating. Just bringing the work piece up to the curing temperature may take twice as long in a convection oven compared to using a combo oven. Because of the slow, uniform heating in these convection ovens, the entire part will be raised to the curing temperature, which is a waste of heating energy. These drawbacks largely negate two of the greatest advantages of powder coating-greater productivity and lower energy costs.

An additional problem is that the high air movement in the convection oven may dislodge some of the powder from the part before it has the opportunity to properly cure. This can lead to a non-uniform coating thickness on the work piece or cross-contamination of work piece finishes.

The ideal curing oven has a combination of infrared and convective heating to accommodate variations in work piece geometry and coating thickness. These requirements can be met using a combo oven.

How Combo Oven Technology Can Benefit Your Business
When compared to convection ovens alone, combination ovens offer the following advantages:

• Higher energy efficiency—from 15 percent to 20 percent energy savings.
• Low environmental impact—greatly reduced NOx and CO produced by the catalytic heaters.
• Increased productivity—from 20 percent to 45 percent.
• Well suited to curing powder coatings. Catalytic IR heaters produce most of their energy as long wave radiation, matching the absorption characteristics of many coatings.
• Improved finish quality with uniform coating thickness, fewer rejects.
• Reduced floor space—15 percent to 30 percent reduction.
• Can be fully automated—full support for programmable logic controllers or other plant automation.
• Increased operating flexibility—a wide range of work piece geometries can be properly cured.

Gas Technology Institute (GTI) and PECO Energy, an Exelon Corporation, provided funding for the combo oven. Radiant Energy Systems, Inc. also offers technical support and assistance.

To learn more about how combo oven technology can benefit your business, contact us.