Use of Plastic Blast Media to
Clean Press Parts
The flexographic packaging industry has made great strides in
reducing the total amount of solvents consumed and emitted into the atmosphere.
The reduction in the amount of volatiles in solvent inks and the conversion to
water-based inks have allowed many companies to grow while reducing their
overall emissions. Regulations have dictated the need for solvent-capture
systems that are costly, but also greatly reduce total emissions. (See editor’s
notes at the end of the article.)
Solvents and soak tanks are still common in packaging for
cleaning press parts such as ink trays, pumps and buckets. However, a new
blasting technology uses a unique plastic media to eliminate the need for harsh
chemistries and soak tanks. Using this technology, several companies have
greatly reduced chemical expenditures, disposal costs and operator exposure to
the corrosive chemistry.
Alliance Packaging (formerly Flex Pack) in Sacramento CA, has
taken advantage of the parts cleaner shown in Figure 1 to clean ink pumps, pans
and other press components. Alliance's Lou Figuera estimates they have cut the
consumption of cleaning chemistry in half, resulting in savings of about $500
per week. Use of ammonia, various soaps and pH conditioners have been all but
eliminated using the parts cleaner.
operator exposure to harsh chemicals was a primary concern" states Figuera.
"Eliminating the risk of exposure or injury was a major motivation to move
toward the blast technology"
The plastic blast media will remove dried-on ink, without
risk of damage to the part's surface. The 72"x36" unit is totally
enclosed, with four rubber gloves providing access through the cabinet front.
The blast stream is initiated with a foot pedal, and a hand-held nozzle then
focuses the blast on the parts requiring cleaning. The plastic media used in
this system is similar to the plastic media used in anilox cleaning systems, but
is somewhat larger in particle size and more effective.
the blast has occurred, the plastic is returned to a reclaim unit. The returned
media is sent through an elaborate air wash system, removing fine dust particles
from the dried-on ink. The good media returns to the blast unit again.
Over an extended period of time, (100-200 uses), the plastic
media shown in Figure 2 begins to break down and becomes too fine for cleaning.
This spent media, along with the fine dust from the ink, is captured in
collection bags and deposited in a tray for disposal as a non-hazardous waste
(as long as the material removed from the parts is non-hazardous) .
At Alliance Packaging, the reduction of 150 to 175 gallons of chemical
cleaning waste per week has significantly reduced disposal costs. A filtration
system reduces six or seven barrels of liquid waste to one 55-gallon drum of
solid waste, but the cost for disposal of the solid is still $150 to $200 per
barrel. Those with different filtration systems may experience greater savings.
Cost-efficiency is only one benefit of this system. "Cleaned parts are
now available for use in less than an hour, where previously they required an
overnight soak, then lots of ‘elbow grease’ to clean" concludes Figuera.
This provides a quicker cleaning process, one that reduces press downtime and
contributes to greater operating efficiency for the entire company.
Author: Dale Patterson, President of Absolutely Micro*Clean, LLC.
This article first appeared in FLEXO magazine, July, 1998, p. 54-55, as ‘Environmentally
PNEAC Editor’s Notes:
Mention of trade names of commercial products does not
constitute endorsement or recommendation for use by PNEAC or USEPA.
The described process removes solvent-based inks best. It
works well on both water-based and UV-cured inks. No cleaning solvent is
introduced into this process. Printers using water-based or UV inks can see
larger solvent emission reductions than those who clean with solvent reclaimed
from solvent-based inks. Dry and brittle residue is removed better than wet or