cutting: Five fundamentals
to increase efficiency? Focus on these pre press and
on press make ready issues.
Cutting Process Manager, Rock-Tenn Co.
is the focus of the folding-carton industry today.
Converters are faced daily with the need to cut costs.
An efficient die cutting press, for example, should
average about 88 percent run-time. To achieve this
level of productivity, short make-readies are a must.
problem facing converters is not how fast the manager
can push the operator to put a job on and get it running
but what is actually accomplished--or not accomplished,
prior to the on-press make ready
has shown that 80 percent of an efficient on-press
make ready is really out of the operator's control
and actually takes place before the job even gets
pre-madeready. This article looks at five fundamental
aspects of efficient folding-carton die cutting Each
represents a percentage of importance to the overall
concentrating on the efficiency of each aspect, not
only will your operation reduce downtime, but a machine-makeready
average of only one hour for a whole month is achievable.
I can personally attest to that.
Design -- ±20%
How can a carton's design play a part in speeding
die cutting? As brevity is the soul of wit, so are
a carton's simplicity and the die to cut it the key
to easier production. Three areas should be questioned.
Rule: Is it really needed, or is it used as a crutch?
Instead, try alternative types of scoring, such as
reduced bead creasing.
Slots: These are highly labor-intensive for both pre-makeready
and make ready In addition, they can leave scrap in
the load and can trip electric eyes. Eliminate hairpin
slots, if possible.
Features and Their Location: Opening features, glue
assists, reverse cuts, embossing and debossing may
all be necessary to a carton's design but add time,
cost and potential die cutting problems down the line.
The following design-related suggestions can go a
long way to smoothing production.
department manager prior to the final customer approval
must sign off on all designs going into production,
keeping in mind the rules of simplicity. (Make the
design miter- and machine-friendly.)
a designer has to rush something to a customer,
place a label on the design that reads, "This Design
is Pending Approval by Production Personnel. Any
necessary changes will be made, and a new design
will be generated for your approval."
buy into your salesman's line, "We can't change
this design because the customer has already approved
a CAD number to the individual carton design so
that die side and printed side are consistent in
Layout -- ±30%
Five aspects of the carton's production layout are
critical to the die cutting process. They will either
make or break your efficiency.
layout needs to be generated at the Estimating or
Design Sign-off Stage: Make sure the estimating layout
is approved by cutting before it is used for quotational
purposes. It isn't a matter of how many cartons we
can get on a sheet, regardless if it can blank or
not, but getting the most items on a sheet that will
run quickly and effectively. Knowing the number of
cartons per sheet and actual sheet size helps capture
a true price while estimating.
blanker operator input: Customer service, the estimator
and employees not directly involved in blanking should
consult the blanker operator to help prevent problems
before they happen. The operator will feel included
and want to make the layout a success when it hits
the press. Such cooperation also promotes an important
the sheet/layout through each phase of the cutting
press: How will it travel through the stripper? What
things can catch? Does the female stripper need carrier
rule in it? How will it blank? What areas will catch
on the grid or flat top? How much offset on the female
blanking grid will be needed for single/double-knife?
your company has blankers and non-blankers, lay out
the job with breaker knives so you can sheet blank-it
for the air hammer if needed. Prepare ahead of time
for those rush jobs.
the paper's grain direction and double-knifing to
eliminate internal stripping and assist in blanking:
Grain direction is more critical to die cutting than
it is to printing. Double-knifed jobs require special
attention to the layout. Most often, a stiff grain
sheet will be the only effective option. If you don't
have to strip, don't. This is a labor-intensive part
of the make ready process.
a vinyl or Mylar of the production layout: This can
help the die room or pre-makeready get started on
making in-house tooling, if necessary.
and Tooling -- ±30%
Although the die and tool constitute about 30 percent
of the on-press make ready, about 75 percent of the
pre-press and pre-makeready efficiencies lie in the
folding-carton die and tooling. Here, three areas
should be examined.
your homework: Ask your salesman about run quantities
and estimated number of production orders per year.
Investigate as to what die and tooling costs are actually
being built into the estimate?
timely orders. This helps reduce the cost of shipping.
Some suppliers will offer free shipping with five
working days notice. Enough time is also available
then to assemble "burned only" tooling in-house.
tools versus handmade and universal tooling: Know
the benefits and drawbacks of each to help determine
the best choice for the new size and style going into
production. (Refer to chart.)
what types of tools to order: Steel, maple or Rayform
dies; Strip Clip, regular or Power strippers; steel,
flat-top, universal or Rayform blankers; and matrix,
phenolic, steel or hand-cut Female Counter Plates
are some of the choices.
Set Up -- ±10%
Pre-press set up constitutes the other 25 percent
of pre-press and pre-makeready efficiencies. A variety
of easily-accessible equipment and an organized method
to accomplish set up are vital.
items include a counter-transfer machine; an Easy-Set
table; extra storage cassettes; a hoist and systematic
storage with humidity control.
lift cart is an essential element to maintain a one-man
crew for pre-press set up as well as worker safety.
Finally, a Centerline system allows dies, strippers
and male blankers to be set almost exactly in frames
with minimal adjustments (if any).
to method, nothing beats organization: A place for
all components and all components in their place.
File folders should be kept with saved job information
for both diecutter operators and pre-makeready personnel.
Also, cleanliness and accuracy must be the watchwords
An efficient die cutting operation now moves into
the final stages. For on-press make ready, four areas
stand out in need to special attention.
histories: Knowing the proper information about a
job will only speed on-press make ready when the job
is run again. This data includes feeder, tonnage and
delivery load settings; Bernoulli (Air) bar between
platen and stripper, and the stripper and blanker;
and the location of the extra knife and counters.
the Pit Stop Concept: Have a neighboring pressman
set the feeder while two others take the die-tools
out of the press. Then, have the same pressman set
swords and perform line clearance while the diecutter
operator and assistant are inserting the next job's
all necessary tools at hand: This list encompasses
Allen and crescent wrenches; die and nick grinder;
spot-up tape (self-adhesive); a toolbox; make ready
knife; and tape (masking and two-sided).
available machine and tooling alignment techniques:
For tools, these might include T-Rails; plastic bolts
for male and female strippers; 1-mm plate micro adjusters;
and a Centerline system (the same unit previously
used in pre-press set up).
Quicklock System from The Bobst Group is one new piece
of technology that will help eliminate 95 percent
of all press adjustments, thus saving precious time
on the make ready, and virtually eliminates the need
preventative maintenance, along with records of diecutting-press
footprinting or press leveling to use as a basis of
operation, wrap up the on-press make ready requirements.
To make a folding-carton die cutting operation as
efficient as possible, keep in mind and make use of
these other important information resources: Expertise
of machine manufacturers,information and advice from
die and tool suppliers; the Bobst ABCq book and other
training manuals, independent consultants and trade
associations such as IADD and its associated die cutting
and diemaking seminars.
Q 2001 Intl. Assn. of Die cutting and Diemaking, Crystal
& Tooling Choices: Laser vs. Universal
|Pre press labor reduction
||Pre press labor-intensive
|1- to 1.5-hr setup time
||4-hr average setup
|Pays off over time
||Never pays for itself
|Accurate as CAD program
||Margin for human
|Minor press adjustments
||More individual adjustments
|Cuts chance of mechanical downtime
of mechanical downtime
|Cost of dies/tools are decreasing
||Cost of labor is
Source: Rock-Tenn Co.
|James Banister, cutting process
manager at Rock-Tenn. Co., Milwaukee, has 10
years of folding-carton converting experience.
He holds a degree from Moody Bible Institute,
Chicago, and is currently working towards a
master's degree in business administration.
He can be reached at 414/374-8214,
fax: 414/374-8269, [email protected]
Copyright © 1992-
Packaging Graphics. All rights
reserved. James Banister. No part may be reproduced
without prior written approval.