| intern summary |
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Hood Flexible Packaging Saves $50,000 by
Reducing Film Scrap
Changes in Setup and Extrusion Reduce
Plastic Film Scrap in Printing Industry
| Company |
Hood Flexible Packaging,
St. Paul, Minnesota |
| Results |
Eliminated 104,000
pounds of plastic scrap film waste, saving $50,000
a year. |
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Process Background
Hood Flexible Packaging
manufactures bags and plastic film used to package food and
other items. Hood employs approximately 130 people and operates
24 hours a day, seven days a week. The company has three main
departments: extrusion, press and converting. The extrusion
department manufactures rolls of plastic film using a blown-film
process, then treats the film to accept ink. The press department
prints on the film which is then sent to the converting department
to be made into bags.
Incentives
for Change
Hood produced 900,000 pounds of plastic film scrap
in 1996, giving them a scrap rate of 6.5 percent. Knowing
that the average film scrap rate for the flexographic printing
industry is four percent, the company set a goal to reduce
the overall weight of their film scrap by 20 percent.
Identifying
the Main Source of Scrap
Because Hood knew that close to 50 percent of their film scrap
was coming from the press department, the MnTAP intern evaluated
each of its scrap-producing activities. A form was developed
to help press operators document when and how much scrap was
generated. Information was also gathered by weighing scrap
and using footage counters that measure the length of film
used.
The intern found
that between 70 and 75 percent of the film scrap from the
printing operation was produced during setup. Setup is the
process in which a print job is prepared to run on the press.
Equipment is readied, and print quality is tested and adjusted
at this time.
Train Press
Operatorts
How press operators do their job has a big impact
on the volume of scrap produced. By documenting how the more
experienced operators prepared for print jobs, Hood was able
to develop training to ensure that employees across all shifts
are following the same best setup procedures.
Press operators were
trained to stop the presses, whenever possible, while adjustments
are being made. An estimated 15 percent of the film scrap
was produced while the presses were running during adjustments.
Hood will also make certain that equipment needed during setup
is in place before the press is started.
As Hood formalizes
its quality procedures, they are stressing the importance
of ongoing training and the use of job standards.
Order Setup
Film
Hood was using off-specification film from their
extrusion department as setup film. While this in-house reuse
system reduced scrap in the extrusion department, it increased
the volume of scrap in the press department because the film
was wider and thicker than necessary for setup.
Two steps were needed
to reduce this film scrap. First, the extrusion department
needed to produce a lighter weight film just for setup. Second,
a regrind unit was needed to minimize the waste from extrusion.
Step 1: Film
Specifications
Printers can use setup film that is thinner and not
as wide as the film specified for the actual print job. Although
the same linear feet of film is required to prepare for printing,
the actual weight of the scrap is reduced.
Operators need to
know the standard length of setup film required for preparing
jobs for each press. It is also helpful for them to know if
a job has a history of difficulty and to order more film to
accommodate the additional adjustments.
Hood’s press
department now orders setup film from extrusion, specifying
the desired length and width, and 1.25 mil thick—the
thinnest film that will provide proper results.
Step 2: Regrind
Equipment
To manage the film scrap that is no longer being
sent to the press department for setup, the extrusion department
installed a second regrind unit and upgraded equipment. These
improved quality and reduced scrap at the extrusion process.
The scrap that is generated can now be reground into new feedstock.
When all of the scrap cannot be mixed with virgin resin to
make new film, the clear scrap film has a better sale price
for recycling than printed scrap.
Implementation
Team
An implementation team was designated to carry out the recommendations.
The team consisted of the Printing Department supervisor,
the Extrusion Department supervisor and the purchasing agent.
Previously, the three departments had not worked directly
together. Successful implementation required all three to
be involved.
Including the purchasing
agent in implementation planning helped expedite the purchasing
of the grinder and improved the timing of the project.
Additional
Recycling Option
Segregating film scrap at the printing presses would allow
for unprinted scrap film to be sold for a higher price than
the printed scrap. This option was not implemented due to
space constraints near the presses.
Results
The scrap rate from the press area has been reduced to 4.5
percent, exceeding Hood’s reduction goal. Because the
extrusion department was involved in the project, the waste
was not merely shifted between departments. To help maintain
the lower scrap rate, press operator training will be ongoing
at Hood.
Savings: $50,000
a year. Reduced scrap film by a projected 104,000 pounds for
1998.
More
Information
MnTAP has a variety of technical assistance services available
to help Minnesota printers and other companies reduce and
manage their industrial waste. If you would like assistance
or more information about MnTAP’s Intern Program, call
612.624.1300 or 800.247.0015 from greater Minnesota.
This project was conducted
in 1997 by MnTAP intern Kelli ideasy, a chemical engineering
senior at the University of Minnesota.
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