New patented tape system - uniting of opposites

The flexographic printing industry must often face huge challenges. Ever tighter printing deadlines, rising costs, and more stringent quality requirements demand greater standardization of production processes. However, this is only possible if all components are optimally harmonized and offer reliably consistent quality. With a new patented tape system, tesa SE, one of the world’s leading manufacturers of high-tech tape products, offers a dependable and efficient solution. Just what is an “intelligent” tape system?
The challenge when developing a tape for plate mounting lies in the conflicting requirements posed by the individual process steps involved in flexographic printing.

Mounting process
This area offers great potential for the optimization of production processes – namely in the selection of the right tape. “Intelligent” tape systems can help save time by offering the lowest possible tack, particularly when correcting the position of plates during mounting to achieve optimum registration, making it simple and quick to reposition the plate. In this context, it is important to note that surface stickiness has nothing to do with actual bond strength. Try this out by putting some honey between your thumb and index finger: The high tack is apparent; it feels very sticky. But would you trust honey to provide a reliable bond between two objects? Of course not. You can easily pull your fingers apart again proving that just because something is sticky does not mean it is ideal for bonding two things together.

• Requirement: low tack

Printing process
During printing, on the other hand, the tape must offer strong bonding of the tape to the sleeve or cylinder, as well as from plate to tape to prevent the edges lifting. If the bonding is not sufficient, the negative effects on print quality are easily visible. In the worst case, the printing plate could detach entirely, causing damage to the press. In addition, the cleaning process exposes components to solvents which must not react with the tape, since this could also cause the plate edges to lift.

• Requirement: high bond strength and resistance to solvents

Demounting of plates
When printing is finished, the plate must be easily removable from the tape. During demounting, the plates must release easily without stretching or tearing, and adhesive residue must not transfer to the back of the plate.

• Requirement: easy removal of plate without adhesive residue

Removal of tape
It should also be possible to easily remove the tape from the sleeve; the sleeve must be free of residues in order to minimize the time required for cleaning work and for the preparation of the next printing job.

• Requirement: easy tape removal without adhesive residue

So how can these highly conflicting requirements be reconciled?
We offer a new patented tape system which is based on the tesa SNAP-ON technology, a solution which can solve these problems:

• easy repositioning of the plate
• secure bonding of the plate
• easy plate demounting
• easy tape removal

How does the adhesive system work?
The new patented acrylic-based adhesive can be illustrated using the SNAP-ON model for each process step. During the mounting process, the plate lies only lightly against the adhesive. Low tack allows the optimum print register to be found quickly and easily. When the plate is rolled on, a procedure we recommend be performed using a rubber roller, the plate literally “snaps” into the adhesive. This generates strong bond strength. During the printing process that follows, this ensures reliable bonding of the plate and prevents its edges from lifting. Result: This can reduce machine downtime and increase productivity. When the plate is demounted following printing, it is free of tape residue. The faster the plate is demounted, the more easily it separates from the tape. You can almost hear it “snap out” again.

Summary
Reconciling opposites: With our new tape system based on the new products in the tesa Softprint® range, we have succeeded in developing a solution which fulfils the conflicting requirements placed on plate mounting tapes while aiding the flexographic print industry in responding to changing market demands. In addition to this new tape system, the new tesa Softprint® product family also offers our familiar high print quality based on the foams we have specially matched to meet the needs of the flexographic printing process. For further information on tesa Softprint® products and an informative video on our new SNAP-ON technology, visit us online at www.tesa.com/industry/paper-print.

By Jürgen Dostal and Steffen Ebenau, International Product Managers for Print and Web Processing at tesa SE.