Frugal Foil Usage

Reducing foil waste can be simple. Experts tell you how.

FOIL STAMPING AND embossing is, innately, a very wasteful process. Material waste is part of the package-enhancing technique.

While foil scraps will probably never be eliminated from the process, designers, equipment suppliers, and end users are finding ways to reduce waste and save converters, printers, and their customers money. How? Stamping and embossing equipment suppliers recently chimed in to answer that question.

Plan carefully

Foil often graces packaging in the form of ornate designs or borders—accents to the overall design layout. This usage of foil automatically lends itself to foil waste, since only a fraction of the foil surface area is used. Add that to the fact that many stamping and embossing machines advance the foil more than is needed and the result is a lot of foil bound for the trash.

This can be easily remedied if the layout is carefully thought out, and the machine is designed for accurate and calculated foil advancement, said Chris Raney, vice president, Bobst Group Inc. It's a simple concept, he said: "The more precise the machine advances, the smaller the distance, the less foil you use."

"Careful planning of a job coupled with a machine that can accurately control the foil advance is absolutely critical to get the maximum usage out of a reel of foil. The job planning needs to take into consideration the size of the image to be stamped and the distance between the images, including the safety that you need to allow between one image and the next—directly dependent on the accuracy of the machine control. The goal should be to calculate the job so that the maximum amount of foil can be used," Raney said.

Not only can converters save foil between image repeats, they can also reduce waste by minimizing the foil width. But, again, equipment that can tightly track the foil will afford operators greater control, therefore reducing the foil trim needed between the image and the edge of the foil.

To help with machine control and calculation, there is software—such as Bobst's OACS (Optimum Advance Computing System)—available to help operators quickly and accurately calculate foil usage to ensure that it is kept to a minimum. All in all, with well-thought out layouts and requirements, converters can save hundreds of thousands of dollars, Raney said.

Know your machine specifications

The optimum speed and temperature for stamping and embossing varies from equipment brand to equipment brand. Knowing this information can save foil by cutting out the guesswork.

"Know the run temperature and speed recommended by the foil supplier. This will save time trying to figure out when the foil will release properly. Too many customers do not know what the foil supplier recommends for temperature and speed," said David Stollenwerk, executive vice president, American Die Technology.

Not only does this knowledge help save foil, but it also reduces the waste of all materials and tools, including substrate, foil, inks, and wear on the stamping and diecutting tools, Stollenwerk added.

"There are no cons to investigating and learning this information from the foil suppliers. There are strictly pros to learning more about your operation," he said.

Buy equipment with specific features for better control

There are two types of foil pullers, explained Bob Weidhaas, Sr., consultant to and founder of the Weidhaas Group. Mechanical pullers afford limited control over how much foil is pulled, resulting in a lot of scrap foil. Programmable servo foil pullers offer much greater control over the amount of foil pulled.

"[Programmable servo foil pullers] allow operators to minimize waste by programming the amount of foil released," Weidhaas said. "It also provides a 'step and repeat' system that allows someone to program the machine to rewind, or essentially reuse areas of the foil roll that have not been stamped by rewinding the foil back into the foil unit and then stamping with the unused areas of foil."

Several stamping and embossing equipment manufacturers offer this feature, but new features to help in this endeavor are emerging. One such feature, exclusive to Weidhaas, is a time-delay function that allows users to control the amount of time between the last impression and the next release of foil. "This is important because foil will stick to the die, and the timed delay can be critical to the success of a job, particularly a job with a large foiled area," Weidhaas said. "In many cases, operators can avoid wasting the material and the substrate they are stamping by delaying the next stamp by one-tenth of a second to avoid the problem of the foil roll not releasing from the stamped job. This causes the foil to rip or the job lifts from the platen and sticks to the advancing foil roll. The foil delay on the Weidhaas foil unit allows an operator to control the timing of the foil release between impressions to customize the release based on the type of material used. This programmable servo foil puller with a timed delay feature saves users 50-60 percent in waste material in addition to the time associated with rethreading foil."

Save time before and during the production run

Reducing the amount of time it takes to set up stamping and embossing equipment, as well as controlling the pressure and temperature during the process, can play a big role in saving material, Raney said.

The benefits of quick makereadies are seen across the board in many different processes of converting and printing packaging. The faster a stamper or embosser is brought into register, the less foil is wasted. "Reducing makeready time can mean saving the job on an expensive honeycomb plate—an expensive option," Raney said. "A better way is to mount the dies on a plate that can be stored for the next time the job is run. The dies are then all in position and the job can be set into register much more quickly. Alternatively, there are systems on the market that allow very quick and easy moving of the stamping dies. These systems mean that moving the dies to get into register can be done much more quickly and accurately than ever before."

Once the foil is in register, the operator's job is not done. Accurately and consistently controlling the pressure of the stamper or embosser, as well as the temperature of equipment, is important. "Not enough temperature and the foil will not transfer correctly, leading to waste. Too much temperature is not good either. Optimum foil transfer should be done at the right temperature. Also, when there is a jam up, you need a machine that automatically reduces the stamping pressure. This ensures that, without a sheet in the machine (due to the jam), the foil does not get transferred to the embossing dies, which leads to waste and to unnecessary downtime," Raney said.

Control tension

If a foil breaks during a run, the downsides to the situation are obvious—wasted foil and time. To prevent breakages, using equipment that can accurately control foil tension is key.

"Foil breaks can be reduced and avoided by accurately controlling the foil tension during the run," Raney said. "The latest systems on the market dramatically reduce the tension on the foil and maintain it consistently during the run. This reduced tension reduces the likelihood of foil breakages and waste."

by Kate Sharon

Associate Editor