VOC Reduction
By Gordon Reeves © 2008
VOCs (Volatile Organic Compounds)are organic chemical compounds that have high
enough vapor pressures under normal conditions to significantly vaporize and enter the atmosphere. The United
States Environmental Protection Agency definition of a VOC is published in the Code of Federal Regulations.
It defines VOCs as “any compound of carbon excluding carbon monoxide, carbon dioxide, carbonic acid, metallic
carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions.
PROBLEM
Mold release is often sprayed from aerosol cans to assist in the continuous operation of high speed blow molding
machines. Some of these spray-can operations are repeated frequently with the spray directed to exactly the same
area of the blow molder. This is not only monotonous work for a machine operator, but it also contributes greatly
to increased VOCs because the necessary propellants in each aerosol can are almost always VOCs. (The material
safety data sheet for one brand of paintable mold release in an aerosol can lists contents by weight as 34% propane,
16% butane, and 49% trichloroethylene.) The propane and butane (50% by weight) are VOCs that are released into the
atmosphere only because the mold release is sprayed from aerosol cans. Most aerosol cans use similar propellants
with similar percentages of VOCs.
SOLUTION
G. P. Reeves Inc., located in Holland, Michigan, has developed a unique single nozzle mold release sprayer that is
both accurate and dependable. The sprayer uses normal shop compressed air as the propellant and is designed to
function with the mixture of trichloroethylene and lecithin that is commonly used for “paintable mold release”.
Replacing aerosol can spraying with an MRS1000 automatic sprayer will have the following benefits:
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1.Reduce Volatile Organic Compounds (VOCs). The MRS1000 sprayer eliminates the aerosol can and its
associated release of propellants (often propane and butane) into your atmosphere.
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2.Reduce labor cost. An automatic sprayer eliminates the need for a worker to be at or near the
spraying location.
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3.Less down time. The automatic sprayer and can be programmed to spray smaller amounts of mold
release with increased frequency resulting is more consistent machine operation.
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4.Reduced mold release cost. Mold release purchased in bulk – even in small one-gallon containers
is - much less expensive than purchasing in aerosol cans.
Yes, but we tried a sprayer and it didn’t work!
Competitors’ mold release sprayers use paint spray gun technology. Their extremely small orifices, needle
valves, and adjustable low fluid pressures are necessary for LOW FLOW, but often contribute to NO FLOW.
Adjustment to obtain a specific flow rate is impossible. Knowing actual flow rate is almost impossible.
Intermittent operation is especially difficult because, at low flow settings, starting the flow is much
more difficult than maintaining the flow.
Systems that don't work well with mold release
include pressurized reservoirs and paint spray type nozzles.
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How does the G. P. Reeves sprayer work?
The G. P. Reeves MRS1000 automatic sprayer uses microprocessor controlled alternately cycling positive
displacement piston pumps to measure and dispense the mold release to the spray nozzle. Every pump cycle
of each of the two pumps causes 0.065 cc of mold release to be delivered to the nozzle where air is introduced
to cause it to spray. The mold release flow rate can be programmed by the operator in 0.05 cc increments
between a minimum of 0.20 and a maximum of 0.50 cc per second. The MRS1000 sprayer accurately controls the
mold release flow rate through the nozzle. The flow rate will always be the programmed amount as shown on
the microprocessor screen. The spraying of the mold release at the nozzle is controlled by an air pressure
regulator. The mold release flow rate will not be changed by increases or decreases in spray air pressure or
changes in mold release viscosity. The MRS1000 is dependable because mold release flow is based on volumetric
piston displacement, not pressure drop caused by small orifices or needle valves. Every piston stroke has the
potential to develop more than 800 p.s.i. to force the mold release through our nozzle and our MRS1000 sprayer
doesn’t have any mold release orifices smaller than 0.046” in diameter.
MRS1000 mold release sprayer has wall mountable frame, sealed two-gallon stainless steel reservoir with low
level sensor, microprocessor controller in NEMA 12 enclosure, three solenoid valves, two positive displacement
lubricant piston dispensers with Viton seals, 10 feet of air and lubricant tubing, and a block mounted coaxial
spray nozzle. The controller will be capable operating the dispensers to cause from 0.20 to 0.50 cc per second
of mold release to be sprayed at a user programmed frequency. OFF time can be adjusted from 1 to 20 minutes with
one decimal place and ON time can be adjusted from 3 to 20 seconds with one decimal place. Electrical input from
the blow molder assures that OFF and ON times are based on machine operation and also eliminates spraying when the
blow molder is not operating. Sprayer retains memory during power interruptions and is designed to cause a complete
lubrication cycle upon power restoration. Mold release sprayer dimensions are approximately 18” wide x 16” high x 8” deep.
Download .PDF version: VOC Reduction
Contact: lubelogic@gpreeves.com
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