Sheet-fed cold foil production challenges: The Importance of Foil Tension Control
Cold foil continues to grow in the sheet-fed folding carton and commercial printing markets. The beauty of metallic effects on packaging and graphic products along with the inline efficiency that cold foil can deliver (time and production cost savings) compared to the multi-step, tooling intensive hot foil process or buying and inventorying costly metalized board is pushing more and more printers to add cold foil. Plus, producing your own metalized surface where needed in the print layout and on demand eliminates additional cost of having to print an opaque white over the metalized board as well it is more environmental.
Many printers that have cold foil units with old-fashioned unwind/rewind technologies, struggle with production challenges that effects their quality and profitability. Foil tension control is one of the crucial components of cold foil units that is often overlooked. Cold foil is essentially a thin film material, proper tension control is critical to gain maximum production performance and quality. The foil is typically a 12-15 micron (0.0005”-0.0006”) thick film consisting of a PET base carrier with a very thin 2 micron (0.00008”) metalized layer on top. Any fluctuation in the film’s tension can cause this thin metalized layer to crack or flake.
So how can tension control effect your cold foil results? The thin metallic transfer layer of cold foil is vulnerable to cracking and flaking which can cause pin-holing or defects in the foil image possibly requiring a job rerun and creating costly waste. Improper tension of the foil web can create wrinkles in the foil film, especially full width or wide reels creating inconsistencies in the foil transfer again requiring a job rerun and costly waste. Too much tension can collapse the rewinding core onto the shaft and the entire roll must be manually cut off causing excess debris and machine downtime.
This added waste can quickly affect your job profitability since the substrate is the major cost of the job.
Traditional cold foil systems are simple unwind/rewind tension systems that are controlled by mechanical clutches, which do not have fine enough control for thin film substrates. Some cold foil units use their differential shafts to allow tension slippage but this creates excessive heat and wear on the shafts requiring costly repairs. Some machines even use a water mist to help control rewind roll telescoping, reflective of antiquated rewind technology from 50 years ago.
In addition to creating excessive waste the foil tension control systems on these traditional cold foil systems cannot consistently keep up with the 18-20,000 SPH performance of modern high speed presses. This further decreases printers profits by limiting throughput.
So how can you overcome these challenges? VINFOIL’s OPTIMA cold foil unit answers the need to improve tension control of the foil, improve cold foil production performance, reduce waste and downtime making cold foil production easier and more profitable.
It starts with VINFOIL’s unique DFD Direct Foil Drive system which uses modern servo technology to perfectly control the film tension thru all speeds, all foil widths, up to 20,000 SPH! Plus, the foil face never touches a roller to eliminate flaking. DFD servo technology eliminates wrinkles in the film, foil cracking, flaking and subsequent pin-holing and foil transfer defects. Apply cold foil without the limitations and with greater profitability.
MFU foil saving system description: Blue is the first pass of the foil thru the print station, green is the second pass of the same foil thru the print station, red is the third pass of the same foil thru the print station then the foil is either rewound or vacuumed away to a foil waste system. Integration of the VIFOP software with servo automation aligns the unused foil between images to achieve the highest foil utilization!
VIFOP – VINFOIL Intelligent Foil Optimizing Program calculates the lowest possible foil consumption,and automates the OPTIMA job settings. The VIFOP adjusts the Optima to your print layout you don’t have to adjust the print to the cold foil unit!
VINFOIL automation simplifies the cold foil changeovers delivering unmatched performance and cost-effectiveness.
If you are looking to improve your profitability then take a close look at VINFOIL technology.
VINFOIL has cold foil solutions for small, medium and large format presses as well as wide web fed press applications. VINFOIL fits on all manufacturers sheet-fed presses, Heidelberg, Koenig & Bauer, Komori, Mann Roland both existing and new presses.
Matik is the North American distributor for VINFOIL supplying parts, service, installation, training and ongoing project support.