Sandblasting, using compressed air, has been traditionally used
to prepare surfaces for coatings. The sharp particles of sand, aluminum
oxide, steel grit, and other media abraded the particular surface.
Incidental corrosion, rust, and old coatings were removed in the process,
leaving a good surface for paint adhesion. Substrates other than steel
often could not tolerate this aggressive surface preparation and, as a
consequence, wet chemical strippers were employed to remove coatings and
hand sanding was utilized to remove corrosion, rust, and other oxides.
Aluminum, brass, and plastic composites, including fiberglass, were
treated in this way.
Airframes, including "Alclad" surfaces where a thin
coating of pure aluminum is bonded to the alloy surface, were
painstakingly treated to remove old coatings prior to repainting. Residue
from the use of these wet chemical strippers contributed to hazardous
waste generation and disposal problems, now considered to be an
international issue. The hazardous waste issue has greatly motivated the
implementation of a new technology for coatings removal, Plastic Media
Blasting (PMB.) It is similar to the sandblasting techniques employed on
steel surfaces, but uses modified equipment and engineered Solidstrip® Plastic Abrasive as the blasting
Recovered and air washed, screened and recycled Solidstrip® Plastic Abrasive has now been proven to significantly reduce the generation of hazardous waste. In addition, the use of PMB has proven to be faster, less damaging to the substrate, and much less expensive than wet chemicals.
The United States Air Force, Navy, Army, Coast Guard, and
commercial aviation are rapidly switching to PMB for stripping airframes,
ground support equipment, and helicopters, including rotors and composite
panels. PMB programs have also been initiated in the private sector for
ground transportation, marine, and electronic industry
practice, sandblasting techniques are greatly modified. PMB equipment,
designed for low operating pressures while maintaining effective medium
flow, is coupled with comprehensive operator training and Solidstrip® Plastic Abrasive. Since Solidstrip® Plastic Abrasive is harder than the
coatings to be removed, yet softer than the substrate, coatings can
actually be stripped three or four times without damage to the surface
(e.g., "Alclad" surfaces.) Similarly, fragile composites can be stripped
without exposing a bloom of fibers on the surface, leaving the gel coat
intact. This particular process is a patented technology of which Solidstrip®, Inc. is the exclusive licensee.
PMB is quickly becoming the procedure of choice for coatings
removal. Solidstrip® Plastic Abrasive is nontoxic, nonhazardous, and,
with training, is safe for operators to use. When these factors are
combined with the operational economics of PMB, a leading technology