What is Burnoff?

Why use a Burnoff process

If your company produces a product that is painted electro-statically or powder coated, or rewinds electric motors, or rebuilds automotive engines and parts, or produces plastic products, you may find yourself with the task of using a burn-off oven.
Heat cleaning ovens, commonly known as burn-off ovens, are used to remove organic materials such as varnish, paint, oil and plastic from metal parts, allowing them to be reused. Burn-off ovens have been used for years in the motor rewind industry and in all industries where products are painted electro-statically or powder coated.

They are gaining acceptance in the automotive parts rebuilding industry and more recently in the plastics industry as the most economical method of cleaning metal parts. The emissions from burn-off ovens are quite low and the small amount of ash generated can usually go in the trash. With burn-off ovens environmental impact is minimized and operator safety is maximized.

Before Burnoff (Restoring the American LaFrance)

After Burnoff (all paint removed)

After Painting, Reassembly for Museum

Applications

Heat cleaning ovens, commonly known as burn-off ovens, are used to remove organic materials such as varnish, paint, oil and plastic from metal parts, allowing them to be reused. Burn-off ovens have been used for years in the motor rewind industry and in all industries where products are painted electro-statically or powder coated.

They are gaining acceptance in the automotive parts rebuilding industry and more recently in the plastics industry as the most economical method of cleaning metal parts. The emissions from burn-off ovens are quite low and the small amount of ash generated can usually go in the trash. With burn-off ovens environmental impact is minimized and operator safety is maximized.

The hooks and racks, or fixtures, that carry parts through a coating line accumulate over spray and lose the conductive surface that is required for a proper electrical ground. Loss of ground results in poor transfer efficiency, uneven coverage and the potential for arcing, which can cause a fire in the powder booth. The severity of these problems varies with the type of coating, the type and shape of the parts and the design of the fixtures. Cleaning fixtures on a regular basis is the solution.
Electric motor re-winders need to remove the insulating resin from copper windings and soften the copper wire so that it can be easily removed allowing the motors to be rebuilt.
Automotive engine re-builders are replacing chemical cleaning systems with burn-off ovens to remove the oil and grease from blocks, heads and other components so they can be rebuilt. These ovens eliminate the disposal problems and the potential liability associated with chemicals. Burn-off ovens are also used for debonding brake shoes and stripping insulating resin from electric alternators.
Extrusion and injection molding equipment used in the production of plastic products can become covered with plastic. Traditional cleaning methods are chemical stripping or burning the unwanted plastic with a torch. Chemical stripping results in disposal cost and potential liabilities. Torching creates smoke, which can be harmful to the environment and to the employees doing the stripping. Burn-off ovens do a good job of removing the plastic even in the small holes found in dies.

Credit: Carlton Mann is Engineering Manager – Cleaning Ovens at Steelman Industries, P.O. Box 1461, Kilgore, TX 75663; 903/984-3061.