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Abrasive, or "micro-abrasive" blasting is a common method of conformal coating removal on PCB and electronic circuitry. This process generates respirable dust that may become harmful if inhaled. Learn more about the various blasting media, their affect on health, and engineering control methods for controlling dust.
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Controlling Hazardous Dust from PCB & Electronic Abrasive BlastingPresented by Sentry Air Systems, Inc.
Definitions
Conformal CoatingMaterial applied to electronic circuitry to act as protection against moisture, dust, chemicals, and temperature extremes. Abrasive BlastingAlso known as “micro-abrasive blasting”, is a commonly used method for removing a thin layer of conformal coating from electronic circuitry in order to perform changes or repairs.
Common Coatings Include•Epoxy•Acrylic•Urethane•Silicone•Parylene•Ultraviolet-Cured Materials
Methods of Application•Spraying, Aerosol •Dipping, Liquid•Brushing, Liquid
The type of
conformal
coating used
dictates which
method of
removal would
be most
effective.
Micro-Abrasive BlastingExamples of Cutting Media•Aluminum Oxide•Biological Medias•Sodium Bicarbonate•Silicon Carbide•Acrylic and Plastic MediaHow it worksA cutting media is introduced into a compressed air stream which is ejected through a hand held nozzle. The air stream is directed at a section of the conformal coating that needs to be removed.
Micro-abrasive
blasting results in dust
generated from the
cutting media
which may be
hazardous if inhaled.
Workplace RegsCutting Media OSHA TWA Exposure
Limits 8 hour work day or 40 hour work week
Aluminum Oxide
15 mg/m3
Sodium Bicarbonate
5 mg/m3
Silicon Carbide
5 mg/m3
Acrylic, Plastic
None
Possible side effects from inhalation
Irritation to mucous membranes and upper respiratory tract, may cause lung injury, repeated or prolonged inhalation of large amounts may cause metabolic abnormalities, may affect the blood, kidneys, respiratory and cardiovascular systems, severe toxicity may also affect behavior and central nervous system, coughing and shortness of breath, irritation to mucous membranes and upper respiratory tract, may cause lung injury, repeated or prolonged inhalation of large amounts may cause metabolic abnormalities, may affect the blood, kidneys, respiratory and cardiovascular systems, severe toxicity may also affect behavior and central nervous system, coughing and shortness of breath, irritation to mucous membranes and upper respiratory tract, may cause lung injury, repeated or prolonged inhalation of large amounts may cause metabolic
In order to reduce the amount of respirable dust entering the operator’s breathing zone, consider a ductless containment hood with HEPA and Carbon filtration!
Air-Dust=Happy Lungs!
Sentry Air Systems HEPA filters are up to 99.97% efficient
on particles 0.3 microns and larger.
Our ductless
hoods require
no exterior
ductwork, are
lightweight,
modular and
portable!
These self-contained
workstations utilize a
powerful fan to pull
harmful dust and
particulate away from
the operator.
For more information on conformal coating removal and dust collection, contact Sentry Air Systems today!
www.sentryair.com
1.800.799.4609
www.sentryair.com/blog
