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Technology Focus

Die Lock-up Holding Tight with the Times

by Jeff Peterson

November-December, 2004
Locking up hot stamping dies, for many years, has been relegated to positioning the dies on press, using a honeycomb mounting system with toggle hooks or with a bunter post system that uses a bunter front plate and bunter posts. Especially for larger jobs where there are several dies to position, the honeycomb mounting system has become standard procedure in the industry.

When there are several dies on press for a single job, it can take an operator literally hours to position dies, especially if tight registration is involved. In today’s fast-pace working environment and customers demanding quicker turnarounds, foil stampers have begun to demand ways to decrease makeready and set-up on press. Based on these demands, there have been several new innovations that have entered the market to help specifically decrease die-lock up and registration time on press.

Magnetic Lock-up Systems
Locking up just one die for short to medium-sized runs on press can still be one of the more cumbersome procedures in the foil stamping process. It is most commonly accomplished through the use of toggle hooks and a honeycomb chase or even with die-mount tape that is both messy and an antiquated method of locking down dies.

Universal Engraving, Inc. (UEI) manufactures and markets its patented UniMagnetic® System for fast easy positioning and changeover of dies. The steel-backed dies are quickly positioned and securely held into place on UEI’s UniMagnetic bases. The base can be attached to any standard honeycomb chase, and has been specially designed to provide the ultimate holding power, even under the heat and pressure of a foil stamping press. The bases are also precision engineered to high tolerances to ensure a consistent flat base, which further helps to reduce makeready and setup. The UniMagnetic dies are available in both copper and brass and are manufactured with the same quality as UEI’s traditional dies. Flat foil stamping, single-level embossing and debossing, as well as Unifraxion (refractive) dies can be made for the UniMagnetic System.

Thermo Magnetic Systems (TMS) has also developed a magnetic plate and die system. The system, which is now being distributed in the U.S. by Graphic Dies Inc. and Adolph Bauer Inc., utilizes a magnetic plate produced with strong short-field magnets to ensure a flat, secure surface area with consistent heat conductivity. The system also includes steel-backed dies that are available in magnesium, brass, and copper. In addition, TMS has developed a water wash-out Pastix die material that can be easily produced and can withstand temperatures up to 338 degrees Fahrenheit. It is manufactured from a photopolymer material with a memory allowing the die to return to its original form, saving makeready time on press. It can be an excellent choice for shorter run jobs that need quick changeover.

These magnetic systems have proven to be an excellent choice for operations that have short-runs and need very quick change-over from one job to the next. Invitation and stationery work is a great example of the type of jobs that would work well for these types of systems.

Decreasing Multiple Die Lock-up
Bobst Group USA has developed a system utilizing steel plates for mounting embossing and foil stamping dies. The Foilmaster Job Saver Pack was developed for the SP 76-BM and SP 102-BMA. The embossing plates are easily removed from the job saver chase. This allows the operator to prepare the job off-press and provides the flexibility of preparing future jobs while the machine is running. The dies are easily mounted with drilled and tapped holes, utilizing a pin plate-locating system. In addition, once the job is complete, the operator can store the steel embossing plate with the dies already in position for future runs. This could save hours of set-up time when the job runs again. It also can decrease the need for purchasing multiple chases, saving the cost of the chases as well as the time to bring a chase in and out of the press.

Another product has been recently introduced as well for multiple-up die lock-up and registration. The Die Co-Ordinator, developed by Insight Graphic Systems Ltd. of East Kilbride, Scotland, is a separate workstation, which sets dies directly from the printed sheet, automatically overcoming board or paper stretch and heat expansion from the foil stamping process. It can accurately position foil stamping or embossing dies on the honeycomb chase without needing either a printed sheet or film overlay. The unit includes an AutoScan feature that captures each registration point on the sheet. The AutoScan takes a snapshot of the whole registration area and automatically generates a keyline mask, the effects of paper or board stretch are incorporated and therefore eliminated. The system allows the user to take existing artwork created through the computer-to-plate process and position dies using digitally rendered images. Foil stamping and embossing jobs can now be created at the pre-press stage even before the dies are made with this type of system. The Die Co-Ordinator is being manufactured and marketed in North America by Sterling Toggle, Inc.

Universal Engraving, Inc. has recently introduced its patent-pending UniLock-Up System that can save literally hours of die lock-up time on press for the operator, especially for large sheet applications with multiple-up dies. It is a complete system that arrives ready to run because all of the set-up is taken care of and the operator has minimal installation. A press layout is provided to UEI for a particular job and a steel plate is then cut to precision tolerances with incorporated specialized mounting studs, which lock and hold either the brass or copper die in registration to the printed sheet. And, to ensure precise registration, each die position has the capability to be slightly adjusted before final lock-up. The steel plate is easily and quickly locked down to the honeycomb chase with special toggles provided by UEI. Once the job is complete, the steel plate with the mounted dies can be stored away for reruns in the future.

Locking up dies has always been considered a cumbersome portion of the foil stamping and embossing process. However, as discussed throughout this article, suppliers to the industry are listening to customers and helping develop better and faster methods that can save production times and help put a little more on the bottom line. Everyone can relate to that! n

References:

Adolph Bauer Inc., (781) 767-4350, www.adolphbauer.com

Bobst Group USA Inc., (973) 226-8000, www.bobstgroup.com

Graphic Dies Inc., (562) 946-1802, www.graphicdiesinc.com

Sterling Toggle, Inc., (631) 491-0500, www.sterlingtoggle.com

Universal Engraving, Inc., (913) 541-0503, www.ueigroup.com