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Question and Answer

Makeready Efficiencies in Foil Stamping/Embossing

by Staff

February-March, 2011
Today, more than ever, pressure is on for print finishers, printers and packaging printers to deliver shorter runs with multiple re-orders where stock levels are monitored in real time. When the customer places the order, the finished goods need to be delivered the next day.

Makeready is one significant area where huge efficiencies can be gained (without spending a lot of money) that will allow on-time delivery, within budget and without compromise of quality. The following Q&A addresses tips for optimizing makeready on foil stamping/embossing jobs in order to cut production cost, lower pricing, decrease delivery times and gear up for short-run jobs.

What areas need to be considered to achieve makeready efficiency?
There are several simple techniques that can be used to make foil stamping more efficient. These include analyzing the processes, taking as many processes off-press as possible, prioritizing and optimizing the processes, minimizing as many sources of variation as possible, using technology, managing materials and workflow and constantly reviewing and refining each process and sub-process.

The first stage to optimizing press makeready time is to understand that the makeready process is a series of sub-processes. Typical stages include setting the feeder and delivery, positioning the foil reels and stringing through the press, calculating and programming the foil advance, locking dies on the honeycomb, registering the dies to the sheet and patching-up.

Once the stages have been determined, efforts should be focused on the sub-processes that will yield the best return. The first and most obvious step is to take as many processes off-press as possible. This is a simple application of the widely used SMED / Lean Manufacturing process. It makes sense that since the foil stamping equipment is very expensive, idle time must be reduced. If a process cannot be taken off-press, try to manage the process so that the press operator has to spend as little time on it as possible. Many of the processes can be moved to pre-press stages that can be performed in advance of the press makeready. Most of the processes can be performed either off-line or optimized to reduce total makeready time by over 65 percent.

What processes should be taken off-press to achieve maximum efficiency in makeready?
Locking up dies on the honeycomb chase should always be a pre-press function. Locking up dies on-press is a huge waste of resources and should be avoided at all costs. Traditionally, most companies position dies using a vinyl; however this is prone to human error and poor accuracy with results varying from operator to operator. Even with dies locked up off-press with a vinyl, considerable amounts of time can be expected in making adjustments on-press.

Consider investing in a modern, proven and efficient die registration system using state-of-the-art servo motors that always move to the correct position every time, eliminating mechanical variation. This will increase the accuracy of positioning the die and reduce a possible source of process variation (human error). The operator should only move the die on the honeycomb to the preset positions. The registration system should be able to be calibrated to each honeycomb/press combination (fingerprinting) and automatically compensate for heat expansion of different honeycomb materials (e.g., steel and aluminium). This will reduce another source of process variation (different materials).

Finally, the system must be able to factor in board stretch from the printed sheet, as well as work directly from a .pdf of the foil stamping separation. The sequence used to lock up the dies can make a difference to the patch-up when the job re-orders. Number the dies and lay the dies in the same sequence every time, which means that the same patch-up sheet can be used.

When the dies are registered to the sheet on press, 80-percent perfect positioning each time with a maximum position variation of 0.005" should be achieved. Board is a volatile material and the image can vary from pallet to pallet, so registering the dies to the sheet has to be done on-press. However, if the lock-up process has been optimized, this should be reduced to a matter of a few minutes, if at all. Typically, this can save at least one hour on-press for a job with eight dies.

Note: the first time a job is foil stamped, the operator will have to patch-up the sheet from scratch. However, if the same layout sequence for the dies is used and they are locked up on the same honeycomb and stamped on the same press, the patch-up sheet can be used from the previous run as a starting point. This simple stage can reduce the patch-up process dramatically.

What advantages can a good foil management system provide in the efficiency stream?
It is important to invest in a good foil management system that can work either from a manual set-up or a .pdf to record the position of each foil area on the sheet. This information can be used to calculate the optimum width of each foil reel and its position on the foil shaft and create a cutting program. If the press has removable shafts, having a spare set for each drive will reduce the foil reel setup to a simple lock and load operation. The foil management system needs to be able to calculate all the constant pull and long/short pull combinations automatically, indicate how much foil is needed and recommend the optimum advance program for each drive, as well as indicate when to stop the press for changeover on long runs.

From the sheet width, the guides for the feeder and delivery can be set so that the sheet is centered on the press. The foil management system must combine the information for the above processes into one page, thereby providing a simple printout that is prepared ahead of time and included in the job bag. This will save precious machine time.

Material management plays an important role in the efficiency process, and a good foil management system will allow the exact calculation of material required so that only what is needed for the job is used. Trying to save a few cents on material can cost hundreds of hours in the long run on press makeready and in production if the press has to run slower. The 80/20 rule applies here – 80 percent of the material used regularly comes from 20 percent of the stock grade/shade options available. Be flexible with the foil ordering process. Use the full range of standard supplier lengths and widths. Be prepared to cut the foil to suit the reels and don’t just work on standard lengths. The foil management system can allow the use of off-cuts on the next job so nothing is wasted. In many cases, 15 percent or more can be saved in material on a job. Inventory can be reduced by a similar amount–improving both profitability and cash position at a stroke.

Accurately locking up the dies, fingerprinting the honeycombs, calculating an optimal advance program along with reel positions and reusing the patch-up sheets will significantly improve the overall makeready process.

How can digital workflow technology minimize sources of variation in the makeready process?
The biggest source of process variation in manufacturing is human error. Foil stamping and embossing makeready relies on human operators. However, it is possible to provide operators with the tools to do their job better and to reduce the effect of variation. The current method of locking up the dies is the major source of human error and variation, so a good die registration system will pay for itself over and over again for a modest investment. Using the same honeycomb/press combination and patch-up sheet for re-orders will provide a good start. Using digital technology wherever possible to lock up dies and calculate foil programs will reduce the amount of human measurement (and error).

A proven die registration system exists in the marketplace that uses digital workflow and has been used daily for foil stamping and embossing by the leading print finishers, book printers and luxury packaging printers in Europe and the USA for more than 10 years. Printers are used to creating separations for process colors, pantones, varnish, etc., and the original artwork is designed for this purpose. Generating a .pdf for foil stamping and embossing operations can be reduced to a one-click operation at the imaging stage. The .pdf also replaces the cost of producing a vinyl film.

Make sure all materials for the next job to be run on press are properly prepared and delivered to the press ahead of time. If the press operator has to leave the press to look for foil, dies, vinyl, sheets, etc., a lot of valuable machine time is being wasted. If a .pdf is being used to lockup the dies (this is the preferred, modern method), make sure that the imaging department prepares the files well ahead of time. Whenever a new job is logged in for production, each person in the chain should know exactly when and what is needed to make the work flow smoothly. Nowadays everyone is under pressure, but if tasks are assigned (e.g., imaging department to prepare .pdf, pre-press to lock up dies and cut foil, etc.) in a timely manner, there should be no reason for the press to stand waiting.

In today’s economic climate, it goes without saying that it is imperative to examine production methods in order to improve profitability and stay ahead of the competition. On an endnote, consider the following calculations:

If an average of 48 dies are locked up each day (both foil stamping and embossing), a savings of more than $900,000 over five years could be realized in machine time by using a good die registration system. If an operation spends $150,000 a year on foil, a savings of $300,000 over five years could be realized in machine time and materials by using a good foil management system.

InsideFinishing would like to thank Des O’Keefe, founder of Insight Graphic Systems Ltd., a company specializing in registration systems on litho, foil stamping and embossing presses for more than 20 years, for providing the information in this article. Insight Graphic Systems has installed more than 40 die registration systems (Die Co-Ordinator) worldwide over the last 10 years and has developed a foil management system (Foil Co-Ordinator) to complement its die registration system. For more information, call +44 1369 840088, visit www.insightgraphicsystems.com or visit U.S. Distributor Diversified Graphic Machinery at www.dgmna.com.