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Question and Answer

Makeready and Set-Up for Large Format Combination Stamping

by Staff

November/December, 2009
In today’s competitive environment where a quote that is just a few dollars less may win the job, it is more important than ever to make sure makeready and set-up times are kept to a minimum. To accomplish this, having an organized system for each type of job is the key. This can be especially important for multiple-up combination foil and embossing jobs where the operator must balance the coverage of the foil and the depth of the embossing in one pass. InsideFinishing has put together a Q&A forum on the subject of combination foil and embossing that can help operators and managers make sure they are getting the most out of their embossing dies and running at optimal speeds.

What are some of the recommendations that can decrease set-up time when mounting counters on a combination job?
First, in most applications, “floating” the counters on the makeready plate is recommended. For larger, multiple-up jobs, the counters can be mounted on Mylar strips so three or four counters can be floated on one strip v. having a separate Mylar piece for each counter. This in itself can save as much as an hour of makeready time if eight or twelve dies and counters are involved with the job. Floating the counters has two basic advantages. First, it allows a small amount of movement for the counter to fit into the die as the sheet passes through the press. Secondly, it provides an area under the counter for patching the makeready and building up soft areas for complete foil coverage. Again, this is important in saving time v. having to build up the makeready under the plate.

Another recommendation with counters is to make sure they are prepared to mount well before it is time to makeready the job. Pre-cut and mount double- sided tape to the back of the counters prior to going on press. In addition, it is recommended to always use locator pins with the counters and to make sure that they are pre-set into the counters before mounting. In addition, check that the press is set at the proper tonnage for the depth of the embossing and coverage of foil. Although adjustments may need to be made on press, working with a starting point will help decrease starts and stops during the set- up process.

What are the different options available for die lock-up to decrease makeready time? Do specific recommendations exist for building up the makeready to make sure the foil fills in properly on a combination job?
Initially, it is best to build up the makeready under the makeready plate to balance the die depth and foil coverage. It is common to use a press paper (2 pt. to 4 pt.) to accomplish this. Once this has been built up properly under each die to a reasonable height, further patching can be accomplished under the Mylar with a floating counter. Again, this can be a timesaver for last minute patching for low areas that may not be covering properly, v. having to continue to patch under the plate. It also allows the operator to patch in the exact spot under the counter. If the detail of the die is of less importance or if the depth of the die is just too deep for the paper stock, the counters can be “capped” to decrease the need for as much makeready or patching. This is not recommended for very detailed combination dies, because it will usually lose a lot of the embossed image on the paper; however, it may be necessary for some applications. This can be accomplished with press paper and glue, or a special capping material available through the die supplier.

What adjustments should be made to ensure the combination job runs efficiently during the production run?
A combination job can be more sensitive to heat than a standard flat stamp or blind emboss. Because of this, it is more important on this type of job to make sure the makeready is correct and the foil is covering correctly at the press running speed. This is especially important on multiple-up jobs on high -speed presses that can run at 3,000 to 4,000 sheets per hour. The speed of the machine and the air blast unit (that most high-speed machines include) can cool down the press considerably. Preparing the makeready at press speeds will use more sheets during set-up, but will actually decrease the overall sheets wasted during the run and will keep the press running once the job begins. If the makeready is conducted with just putting a few sheets in at a time and then starting and stopping, the operator is going to be chasing the low spots on the sheet and starting and stopping constantly throughout the press run.

Another quick trick of the trade when tight registration and lighter stocks are involved is to include ¼? rubber or corrugated between the dies to keep the sheets flat as they pass through the press. Again, this can be very helpful with a job that includes eight, ten, or even more images on the sheet.

Is there technology with newer foil stamping equipment that can help with the efficiency of running a combination job?
As stated earlier, it is more important than ever to have efficient systems in place to keep makeready and set-up to a minimum. One way to help in this regard is to have up-to-date and efficient machinery to run the job. This becomes even more important on more difficult jobs, including combination foil and embossing on larger sheet formats. Newer equipment today includes such things as digital heat controls where different zones on the chase can be adjusted. This can save patching and makeready time and help with overall foil coverage. Newer presses, in many cases, include servo-driven motors to help with the accuracy of the foil and foil pull, and have built-in computer systems to measure the foil step and repeat. Having the correct foil step and repeat may save several hundred dollars on a combination job, especially if it is a holographic or specialty foil where cost is a real factor. Newer equipment is going to run at higher speeds with better controls, feeders, and feed tables. This all can be calculated in the cost of the job and may save more than can be imagined on press time alone.

Just a few adjustments in how the makeready and set-up of a combination job is completed can save the operator an enormous amount of overall time, which can translate into lower costs and more profits. Paying attention to the small details can make the difference.