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The right tool for a
task not only gets the job done – it gets it done better
and faster. It is no different with dispensing
equipment. The right dispense system can turn ideas into product
and productivity into profit.
Dispensing two-part polyurethanes is a key element in Pleatco’s
production. Pleatco, located in New York, is a leading
manufacturer of replacement water filters for use in spas, pools
and Jacuzzi ® whirlpools. Pleatco’s replacement cartridges are
available for over 60 different manufacturers. All in all, there
are over 200 different models.
Making the filters to meet demanding specifications, yet cost
effectively, is a manufacturing necessity. Pleatco relies on its
chief operating officer, Lenny Kott, to produce top-quality,
uniquely designed filters to satisfy demanding manufacturing
requirements while controlling production costs. Kott is in
charge of production and filter design. His experience has
positioned Pleatco at the forefront of spa filter manufacturers.
In production, reliability is a must. You can’t make a filter if
the dispense machine is down. To Kott, the See-Flo 7
meter/mix/dispense system from Sealant Equipment & Engineering
is a “beautiful thing” because its reliability, coupled with its
flexibility, gives him the tool to make the Pleatco filters.
The Polyurethane Formulations
The different polyurethane formulations that Pleatco uses to
produce end caps for filters are chlorine-resistant and
color-coded. The polyurethane curing systems require different
mix ratios (6:1 to 2:1) to produce end caps with different
physical properties. The polyurethane ratio is changed to match
the filter properties and to maximize curability.
The Manufacturing Process
The filters are made in a variety of sizes from a pleated media
– a thick, polyester-type fabric. At each end of the pleated
material is the base. The base fixes the pleating in position
and allows the unit to become a filter. While other filters have
a separate metal or plastic end cap into which the polyurethane.
The polymer seals each end cap and becomes a permanent part of
the filter. And into the molded cap Pleatco includes several
other user-friendly features.
Filter Design and Manufacturing
For some models, Pleatco’s patented design incorporates threads
and a handle into the end cap, making it easy for the customer
to replace the reusable core or to attach the filter to his or
her water-purification system. Some filters include
disinfectants in the cartridge core.
To manufacture the filter, the mixed urethane is dispensed into
a mold and the pleating is inserted. The uncured urethane wicks
up the pleating as it hardens to form a tight seal to all parts
of the pleating. After a short cure time, the hardened end cap
is formed form the urethane, sealing the end of the filter while
providing support for the pleating. A release agent allows the
assembly to be quickly separated from the mold.
Processing the urethane with a short cure time to achieve the
rugged properties of the end cap is the result of years of
research and work by Kott, a self-taught expert on dispensing
urethanes. “Different filters demand different urethanes,” he
notes. “To achieve various degrees of hardness, you use
different mix ratios. And the filters have a complex design,” he
says, referring to Pleato’s patent on filter. The precisely
mixed urethane allows Pleatco to mold the versatile and unique
end caps.
The Manufacturing Process
The filters are made in a variety of sizes from a pleated media
– thick, polyester-type fabric. At each end of the pleated
material is the base. The base fixes the pleating in position
and allows the unit to become a filter. While other filters have
a separate metal or plastic end cap into which the polyurethane
and pleating are placed, Pleatco molds the entire end cap from
polyurethane. The polymer seals each end cap and becomes a
permanent part of the filter. And into the molded cap Pleatco
includes several other user-friendly features.
Filter Design and Manufacturing
For some models, Pleatco’s patented design incorporates threads
and a handle into the end cap, making it easy for the customer
to replace the reusable core or to attach the filter to his or
her water-purification system. Some of the filters include
disinfectants in the cartridge core.
To manufacture the filter, the mixed urethane is dispensed into
a mold and the pleating is inserted. The uncured urethane wicks
up the pleating as it hardens to form a tight seal to all pats
of the pleating. After a short cure time, the hardened end cap
is formed from the urethane, sealing the end of the filter while
providing support for the pleating. A realease agent allows the
assembly to be quickly separated from the mold.
Processing the urethane with a short cure time to achieve the
rugged properties of the end cap is the result of years of
research and work by kott, a self-taught expert on dispensing
urethanes. “Different filters demand different urethanes,” he
notes. “To achieve various degrees of hardness, you use
different mix ratios. And the filters have a complex design, he
says, referring to Pleatco’s patent on the filter. The precisely
mixed urethane allows Pleatco to mold the versatile and unique
end caps.
The Dispensing Equipment
Pleatco exclusively uses See-Flo 7 systems to meter, mix and
dispense the urethane formulations. “One of the beautiful things
about the machine,” says Kott, “is its flexibility. I bought the
machine to process entirely different ratios. But since we no
longer use that formulations, all we had to do to retool was
change the position of the isocyanate volumetric cylinder.”
High-Volume Use
The dispense systems earn their keep since Pleatco manufactures
thousands of filters. With two shifts a day during the peak
season, the two See-Flo 7 systems in production provide
around-the-clock reliability. In terms of volume, Pleatco
estimates it uses 4,500 pounds of polyurethane each week.
East Ratio Adjustment
Going from one ratio to another is an easy manual adjustment. To
change the mix ratio, one of the metering cylinders is simply
repositioned and locked in position. With a couple of checks to
verify the mix ratio, the system is ready to begin dispensing a
different formula.
Kott says, “Using these machines, I can run six or seven
different formulations without having to purchase a new machine.
This means the least amount of capital outlay without having to
go to the expense of buying new machines.”
Different Shot Sizes
Different filters require different amounts of mixed
polyurethane. In order to remain consistent, controls on
Pleatco’s See-Flo 7 units permit them to dispense exactly the
same amount – or shot – of mixed material each time the system
is actuated. Changing the shot size is another simple
adjustment.
Because all changes are manual (locked with physical hard
stops), there is no need to tweak a drive motor, check a digital
readout or make speed/motor compensations for wear. The position
of the metering pump determines the ratio, and it is consistent
and precise. The system’s off-line ratio check verifies the mix
ratio. The ratio check can be done at any time without
interrupting production.
Past Experience
The See-Flo 7 was not Pleatco’s first dispensing system.
Problems with prior equipment limited production and required
lengthy downtime in order to change ratios. That, coupled with
the abrasive nature of the filled urethanes, meant considerable
maintenance and little flexibility. Pleatco’s first dispense
systems were single-acting. “That,” says Kott, “limits
production. The double-acting cylinders of the See-Flo 7,
dispensing is continuous. You can move from one part to another
as quickly as you can dispense.”
Exact Mix Ratios
“The See-Flo 7 system precisely dispenses the two components I
need to make a polyurethane end cap to the filter, “ Kott
explains. “In my case, it’s critical that the mix is to the
exact ratio or it’s no good. The See-Flo 7 also provides me with
good cures from low (volume) to large shot sizes. Generally,
with variable ratio you’re not able to do this, but I can with
this piece of equipment.”
Dispensing is flexible. It can be used for either large or small
filters because the See-Flo 7 is a double-acting system – there
is no reload necessary. With production of filters increasing
each day, Pleatco would have needed several of the single-acting
systems to meet production.
Maintenance and downtime are day-to-day issues with a filled
material. Wear on internal components result in a poor mix ratio
that can turn the filters into pure scrap. With the metering
pump design of the See-Flo 7, the exact mix ratio is assured.
The hardened internal components minimize the wear from a filled
formulation. The meter cylinder includes dual sets of multiple
adjustable packing, thereby reducing the abrasive effect of
filled material. This, in turn, translates into higher
productivity.
Another positive feature of the See-Flo 7 is that it is not
affected by temperature. If the viscosity of the urethane rises
in the cooler months, the system will still dispense the same
exact volume. The positive displacement and balanced design of
the metering cylinders assure accuracy all the time.
System Versatility
The system’s versatility extends even further. Chris Schultz,
service manager for Sealant Equipment, notes, “By using
different metering pumps, you can easily hit ratios from 1:1 to
over 20:1 with no other changes, just the pump.” With over seven
different positive-displacement pumps, the See-Flo 7 is capable
of handling an extremely broad range of volumetric mix ratios
and viscosities. |
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