Table of Contents
Infrared Radiation: Regulatory Requirements
The Clean Air Act regulates the emission of
compounds (VOCs) (40 CFR Part 60) and hazardous
air pollutants (HAPs) (40 CFR Part 61 and
40 CFR Part 63), and provides specific standards
of performance to control emissions from various types of coating operations
(40 CFR Part 60). Depending on the solvent
content of the coating material applied, sufficient VOC and HAP emissions
may develop in convection ovens to subject an operator to major
source requirements and Title
V permitting requirements.
Controlling VOC emissions can be accomplished in two ways. A coating
material with a lower VOC content can be used. Otherwise, air pollution
control equipment is required for infrared curing exhaust systems to recover
or incinerate the VOCs and HAPs before they are released from the facility.
Do exhaust air streams have air
pollution control equipment attached? Is that air pollution control
equipment working properly? Does the final exhaust air have concentrations
of pollutants below required levels?
Infrared Radiation: Common Causes of Violation
Emission of volatile organic compounds or hazardous air pollutants around
infrared radiation systems may occur causing limits established in Clean
Air Act Title V permits to be exceeded. The quantity of VOCs or HAPs
released from the curing coating material depends on the amount of organic
solvent in the coating formulation. The hazardous emissions in the
exhaust air stream can be captured and treated to prevent their release
to the atmosphere. Common air pollution control tactics include solvent
recovery, solvent incineration, and solvent concentration.
Infrared Radiation: Sources of Pollution
Volatized organic compounds and hazardous air pollutants (dependent on
the coating material formulation).
Parts which have been improperly cured (overcured or undercured) resulting
in the need to strip and recoat.
Infrared Radiation: Pollution Prevention Alternatives
Volatile organic compound and hazardous air pollutant emissions can be
reduced by using powder coating or waterborne coating formulations, rather
than solvent-based coating materials.
Proper curing can be achieved by optimizing the wavelength, exposure period,
and part arrangement.
Curing can be improved by introducing air into the system to distribute
latent heat more evenly across part surfaces.