1. Delaminatioin:
This is the problem where the two webs which were laminated together are somehow not adhered properly. This problem arises wheneverlamination machine is to be stopped for any defect or some other reason and this then has to be removed while slitting.
2. Blocking in the laminate:
The problem of blocking in the laminate results if the lamination adhesive application is such that some portion of adhesive is not entirely in between the two webs due to which one web tends to stick over the other one which during storage over a period of time, with the pressure of rolled laminate tends to block the laminate.
3. Lamination wrinkles:
Two different forms of wrinkles can occur: those which form in the lamination nip, and those which appear some time after lamination. Both of these wrinkles are closely associated with the polyester base film lamination which supports the photopolymer layer but are caused by factors independent of the base film.
4. Tunnelling:
Web tension of the two substrates lamination should be proper otherwise this problem can come. Second reason may be the ratio of the adhesive can be different or some different grade of adhesives.
5. Adhesive line:
Foreign particles like dust, dirt and some unwanted matter may stick to the engraved cylinder which makes a continuous line in the laminate. This problem arises time to time hence it is important to clean the cylinder within specified time to eliminate the problem.
6. Curling:
The cause of curling during drying is two sidedness and therefore non uniform dimensional changes when exposed to temp and humidity. Due to this shrinkage takes place in the coating side and curling occurred.
