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Customized Solutions in Auxiliary Equipment Provide Maximum Efficiencies |
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by
Staff |
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Focus
Summer
2006 |
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When setting up the most efficient plastics
processing operation, careful consideration, design, and implementation of
auxiliary equipment that will support the entire production line can mean
the difference between marginal profits and over-the-top results. Gone are
the days when auxiliary equipment was treated as a mere ‘sidebar’ to the
overall molding or extruding operation.
In today’s highly competitive plastics
environment, auxiliary equipment provides customized solutions to maximize
efficiencies in a wide range of areas. From reductions in energy costs,
set-up times, maintenance, and waste to increases in output, safety, and
overall production, auxiliary equipment continues to shape the profitability
of processing operations large and small.
Plastics Business had the opportunity to take a
look at how auxiliary equipment is maximizing efficiencies for plastics
processors nationwide. The following case studies and testimonials are prime
examples of what ingenuity and careful design in auxiliary equipment can do
to produce outstanding bottom-line results.
Material Handling Efficiencies
Butler Plastics Co., Marine City, Mich., is a smaller-sized molder
specializing in short-run molding and light assembly for the automotive
industry. With its nine molding machines running three shifts/day, five
days/week, Butler makes several material changes per day and has found that
the Conair ResinWorks® system has reduced downtime dramatically, resulting
in substantial cost savings per week. The ResinWorks® system brings together
drying, blending, and conveying technology as one package.
Addressing critical processing issues of
plastics processors large and small, the system’s capabilities and features
provide a host of efficiencies to Butler’s operation. ResinWorks® features
include measured airflow to each hopper; easy access for clean-out;
integrated airflow and temperature control; protection against over-drying;
wireless source-to-destination protection; and high-performance modular
conveying.
Although Conair uses a menu of standard
components as a starting point, Butler’s ResinWorks® system, as with all
Conair systems, was custom-configured to meet the company’s specific
requirements – from the number of different materials being processed to the
number of molding machines being serviced. Core components including drying
hoppers, desiccant dryers, blenders, vacuum pumps, and loaders are
pre-assembled and delivered with material-handling controls, conveying pipes
and valves, and other components to ensure precise resin drying, blending,
and delivery.
With conventional machine-side drying and
material handling, it can take hours to make a simple resin change.
Unnecessary downtime and material waste are costly, and there can be serious
operator-safety issues as well. On the other hand, with ResinWorks’®
centralized drying and distribution, material changes are made faster
because resins can be pre-dried and conveyed to processing machines quickly.
According to Kevin Drummond, owner of Butler Plastics, “With our new system,
we’ve been able to cut down tool changeovers considerably. What used to take
one to two hours in material changeover now takes about 10 to 15 minutes.”
Furthermore, the materials are now pre-dried through Butler’s centralized
dryer system, which can load from twelve different locations. “Because the
material is already dried, we save significant time – up to two hours – in
the drying process alone,” stated Drummond.
Additionally, processors can remove individual
dryers from beside or atop machines, which can cut labor costs dramatically
and improve operator safety by eliminating manual handling of resin.
Cleanliness of the production area also is improved with the ResinWorks®
system. “The entire system is vacuum-based, so all the dust is drawn into
dust collectors,” explained Drummond. “Before installing the system,
material dust from the loading process was always a problem – but not
anymore.” Finally, the quality of the finished product can be improved with
better control over drying and blending and with a greater reduction in the
potential of contaminants.
In the new and improved ResinWorks® system,
which recently displayed at NPE 2006 in Chicago, many of the basic
components have been reconfigured to dramatically reduce its footprint,
thereby saving valuable manufacturing floor space. For instance, the main
electrical enclosure has been moved to the front of the system, making it
easier to access and eliminating the need to leave space behind the sleds
for service access. Likewise, individual drying air heaters have been moved
out of the way and underneath the hoppers.
Simplicity of operation is made possible
through several innovations. Whenever the full supply of drying air is not
required (when one or more hoppers are shut down for cleaning, for instance)
a new bypass valve automatically diverts air back to the dryer so that only
the right amount (CFM) of air is delivered to the operating drying hoppers.
New material distribution manifolds eliminate the often complicated tangle
of material conveying hoses. Instead, a single hose is connected to a slide
plate that is easily shifted back and forth to tap different material
sources. Individual electrical disconnects for each hopper can be isolated
electrically from the rest of the system so that service can be performed on
one hopper while the others continue to operate normally.
With all the system’s new features, Conair’s
ResinWorks® system has afforded Butler Plastics a multitude of processing
solutions that have proven to impact the company’s bottom line profits.
Cooling Efficiencies
Lifetime Products, Inc., Clearfield, Utah, is a plastics processor
specializing in the manufacture of residential basketball equipment, tables
and chairs, and outdoor storage sheds. To maintain the continuous process of
cooling machinery and tooling, which takes an enormous amount of power and
refrigeration, Lifetime was operating four separate AEC water systems. As
the facility reached maximum capacity, Lifetime began looking for ways to
run the plant more efficiently to conserve electricity. AEC worked with
Lifetime to consolidate its four chiller systems and four cooling tower
systems into one highly efficient cooling system for the 120,000 square foot
plant. The combined systems require over 890 tons of refrigeration and 1300
tons of cooling tower capacity.
Lifetime also would receive a financial benefit
from Utah Power. As one of the largest users of power in the state, it was
to Lifetime’s advantage to streamline its power systems and conserve energy.
In turn, this would alleviate the need for the power company to add
additional infrastructure to support the power usage and could therefore,
increase savings to Lifetime.
Lifetime Products and AEC agreed to install a
new cooling system, a modular pump tank system, and a motor control center
incorporating a programmable logic controller (PLC) for data collection from
sensors and output devices. Bob Adams, general manager of Lifetime’s
plastics plant, wanted to incorporate existing energy conservation programs
in the plant, such as the standardization on Baldor high efficiency motors
and upgrades of chiller technology to rotary compressor design. The ifm
efector upgrade for system feedback was recommended to monitor process
control. By applying ifm fluid sensors, Lifetime would receive consistent
programmable set-up, alphanumeric displays, small housings, and analog and
switching outputs.
The project began with AEC and Lifetime
addressing the two main water systems needed to cool water for plastics
processing: chilled water and cooling tower water. Consistency in
temperature and even distribution in chiller water is extremely important
for quality mold making. To accomplish this, Lifetime completed a multi-year
program with AEC to replace semi-hermetic compressor chillers with efficient
screw compressor technology. To conserve additional electricity, Lifetime
installed an AEC Winter Kooler system.
This system utilizes oversized evaporative
cooling towers with variable frequency drive fans and heat exchangers
instead of the usual fluid coolers. The PLC monitors wet bulb and may
initiate the start sequence for the Winter Kooler towers at nearly 70
degrees F. As the Winter Kooler system comes on-line, the PLC monitors and
disables the four 200 h.p. screw compressor chillers sequentially via
feedback to a PID loop. Two 30 h.p. fans replace the four 200 h.p. screw
compressor chillers, thereby saving over 900 amps per hour.
For Lifetime, the dry, desert-like climate in
Utah provides a natural cooling system almost nine months of the year. “It’s
really irritating to run the chillers when it’s 20 degrees outside,” stated
Lifetime’s Bob Adams. “When it’s cold outside, the PLC will turn off the
chillers and run the AEC Winter Kooler.”
Other features of the complete chiller system
include a PNI differential pressure monitoring system from ifm, which
monitors the cleanliness of the heat exchangers on the tower side. Lifetime
uses this sensor system as a preventative maintenance tool and can clean
heat exchangers before an equipment failure occurs. ifm efector’s
temperature monitors and remote sensing probes control fluid temperature
feedback on chiller and tower systems. Additionally, process water is
treated and sent through a filter to remove particulate matter before
circulating through process equipment. Automatic purge and differential
pressure alarms prevent the filters from clogging.
By giving the chilling system a rest for
several months out of the year, Lifetime prolongs the life of the chillers
while still maintaining the same, consistent process temperature. Lifetime
has been using the new cooling system since March of 2005. The energy
efficient system has saved the company tens of thousands of dollars and has
provided a comprehensive feedback control system for the plant.
Bottom-line Results
From pickers, blenders, pullers, cutters, hoppers, and conveyor systems to
sophisticated robotics and custom-designed systems utilizing a blend of
technologies (such as those outlined in this article), auxiliary equipment
of all shapes, sizes, and complexities continues to produce dramatic results
in reducing costs, saving energy, improving safety, minimizing maintenance,
and increasing bottom-line profits.
Conair is a global supplier of equipment for
plastics processors, manufacturing heat-transfer systems and
temperature-control equipment, resin-handling equipment, robots,
size-reduction and scrap-reclaim machinery, and downstream extrusion systems
for profiles and tubing. For more information on Conair’s complete line of
equipment and capabilities, visit
www.conairnet.com.
AEC, Inc. provides a broad range of auxiliary
equipment and technical services for processors in a number of industries,
including plastics. Products include, but are not limited to, cooling
towers, portable chillers, air coolers, powder resin handling systems, size
reduction/granulation, automated part and sprue removal, and a complete line
of downstream extrusion equipment. For more information on AEC’s products or
services, visit www.AECinternet.com.
ifm efector’s product line includes
inductive, capacitive, cylinder position, photoelectric sensors, object
valuation products, flow, pressure, temperature and level sensors,
predictive maintenance sensors, AS-9i Bus systems, connectors,
identification systems, and control systems for use in mobile machines. For
complete information on ifm efector’s product line, visit
www.ifmefector.com. |
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