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Question and Answer

Decreasing Downtime on Your Foil Stamping Press

by Chris Van Pelt

August-September, 2001
Everyone wants to get the most out of their foil stamping and embossing equipment. Less downtime and increased production speeds usually translates to greater profits. True production speed is the actual number of impressions that can be produced per shift. It is effected by several factors. Some are human factors that must be addressed through proper training and management. Some are supply factors such as having the correct foil and paper combinations established. Some are equipment factors. This article will look at equipment factors that effect productivity and material waste, as well as identifying important features required to reduce material waste and downtime. If maximum productivity and profits are to be achieved, these features should be considered when analyzing your foil stamping and embossing equipment.

How large of a foil roll will the machine accommodate?

This is not just a factor of how much space is available for the foil roll, but also the ability of the foil tension system to control oversize rolls. The larger the foil roll the machine can accept and control, the less downtime needed to change foil rolls. Obviously, when producing long run work, using 3,000’ rolls instead of 1,000’ rolls will decrease the foil roll change over time by 2/3. Many foil suppliers are now supplying slit and re-reeled foil rolls that are wound extremely tight. On larger platen presses, roll sizes as large as 10,000 feet are now being used.

How accurate is the foil advance system?

Many foil presses have foil draw systems that require an excessive amount of extra foil advance to assure that an overlap condition will not occur. This wastes foil and increases downtime by increasing the number of foil rolls required. For example, if you are using a 3,000’ roll to imprint a 2” area, the difference in pulling 2 1/4” and 2 1/16” is 1,454 additional impressions per roll. This can make a big difference in how many times you must change the foil rolls.

Can the foil tension control be adjusted while the machine is running, and is there an information feedback system for the operator to make this adjustment?

The operator installs and sets the tension control for a 6” diameter foil roll. As the roll gets smaller, the tension on the foil increases. Excess foil tension will effect imprint quality, and may eventually break the foil. Many mechanical tension controls require that the machine be stopped before an adjustment can be made and, most likely, do not provide any feedback information to the operator. Without this feedback, it is sometimes necessary to readjust the mechanical tension system before correct tension is properly set. Electronic tension controls are available and can be safely used to adjust foil tension while the machine is running. They can also be equipped with a display to provide the operator with precise feedback on the adjustment being made.

How long does it take to remove the old foil roll and install a new roll?

Foil roll changeover can be a hassle on many foil presses. Ideally, foil rolls should be easy to install and remove and the foil web should be able to be strung through the machine in a reasonable time period. A well-designed press will accomplish this with minimum tools or no tools at all.

Does the machine feeder have a pre-loading capability?

Some pile feeders can be pre-loaded and some cannot. Feeders that can be pre-loaded (particularly high capacity feeders) dramatically reduce paper loading downtime. Pre-loading allows a new stack of paper to be loaded in the machine while the machine is running. This allows a full stack of paper to be loaded and ready to feed as the last sheet is fed from the previous stack. Using pre-loading, downtime between each load drops from one to two minutes to a few seconds. Figuring 15 seconds per load on equipment with a high capacity feeder, total downtime per day can potentially drop from 20 - 40 minutes to 5 - 10 minutes each shift.

Many larger platen foil stamping presses are now running as a non-stop operation. The pallet of sheets is usually first placed on a jogger/aerator to assure smooth feeding of the sheets through the press. The sheets are then placed into the feeder pre-pile station in front of the feeder. As soon as the level of sheets in the feeder is depleted, the new stack is brought in without shutting down the press. On the delivery end, there is a delivery curtain or shutter belt that replaces the skid or pallet and enables you to remove the full skid and replace it with a new one for continued non-stop operating of the press.

How long does it take for the machine to come to set point temperature and how quickly can the temperature be adjusted and stabilized?

Some foil stamping presses take so long to come up to temperature that they have timers installed so the machine can begin heating before working hours start. Other machines may not have this feature at all and heat up slowly, creating unwarranted press downtime. The key factors to heat up time are the size of the area being heated, the amount of wattage (energy) being applied to the heated area, the thermal conductivity of the area being heated, and level of insulation to reduce heat loss. For maximum efficiency, the heated area should be made of a good thermal conductor, have sufficient wattage and limit unwanted heat loss to minimize heat up downtime.

Can impression pressure be adjusted while the machine is running?

The ability to make impression pressure adjustments while the foil press is running is an important feature. During the course of a press run, it is not unusual for minor impression pressure adjustments to be made as makeready material yields under repeated application of pressure. Stopping the press to make these adjustments will decrease productivity, and, of course, potentially increase press downtime significantly.

Does the press have a programmable foil draw?

Using a mechanical or electric foil draw that cannot be programmed to perform a sequence of various repeat lengths can be extremely wasteful when running certain jobs. Companies who sell programmable foil draw equipment advertise that customers typically reduce foil waste between 18% to 78%. As stated earlier, using a programmable foil draw that minimizes foil waste also reduces the number of foil rolls that must be mounted on a given job.

Does the machine have a counter with an automatic interrupt?

Material waste caused by overruns can create additional unwanted waste and unnecessary press running time. In addition to paper waste, you must also add foil waste, labor waste and lost production time. Having, and using, a counter with an automatic interrupt feature can reduce overrun waste almost completely.

Has the foil stamping press been properly serviced and leveled to achieve the best results?

Having a properly leveled press is an often over-looked area that can cause havoc on the operator’s makeready. Bearer blocks that are placed on each end of the chase can help with leveling the press, but the constant pressure and up and down motion will eventually create an unleveled press over time. It is recommended to periodically have the press manufacture service the machine and properly level the press. This can save literally hours of makeready and set-up time.

In addition, the constant pounding of the press can create an un-level honeycomb chase. Depending on the usage, the chase should be surface ground periodically by .003 to .005 thousands to level off the chase. This, again, can decrease makeready time significantly.

Too often, foil stamping and embossing is considered an art form rather than a production process. Companies who produce foiled and embossed products need to reassess this attitude. Production principles demand that equipment be operated efficiently to maximize profits. Equipment capabilities and features vary, and certain features (or the absence of these features) can significantly affect productivity. Identifying these features and understanding how they effect your bottom line is the first step toward decreasing press downtime and reaching your profit goals.

Chris Van Pelt is Vice President of Therm-O-Type Corporation. He can be contacted at 941-488-0123 or e-mailed at cvpvpe@gte.net.