It’s a Fine Line
Walking a tight rope is tricky business; one slip of the foot can cause a whole mess of problems. Plate mounting is much the same. It is an intricate part of the printing process, and requires much attention.
As market manager of paper, print, and film for tesa tape, Joe Prunier is familiar with converters’ plate-mounting nightmares. “I can give literally dozens of examples of when we have received calls from our customers (who say they are) having problems with edge-lift, bubbling, poor print, registration problems, adhesive delamination, and foam splitting,” he says. As a result of these drawbacks, materials are wasted and money is lost. It is critical to mount plates properly—the first time—to save valuable materials and dollars, and to prevent unwanted headaches.
“Improper mounting results in a slow makeready and
machine downtime as the plate is re-mounted,” says Mark Gibis, vice president of sales for Doyle Systems. “Also, re-mounting the plate increases the risk of accidental stretching.”
Doyle Systems offers a plate-mounting machine that holds the plate in place once it is in register to prevent stretching. “The operator can use the two adjusting wheels situated on the right and left hand side of the plate-bed to ‘swivel’ the plate bed for perfect registration,” Gibis explains. “Because the bar is still holding the plate precisely in position, the operator can then remove the backing on the tape and press the plate onto the cylinder. The holding bar prevents the plate from shifting while the operator tacks it down, achieving perfect registration every time.”
Many companies that supply plate-mounting tapes can also provide customers with a wealth of troubleshooting advice. “Make sure the plate surfaces are in 100 percent contact with the cylinder surfaces,” says Prunier. “Also, remember these are pressure-sensitive adhesives. That means putting pressure on the tape to ensure a correct bond is important. Using rubber rollers or soft squeegees to add more mounting pressure will help a lot.” In addition, using the correct adhesive combination for the plates and sleeves/cylinders goes a long way.