The appearance during laminating
The laminating product has bubble or spot before curing, but after curing, the bubble or spot is not so obvious or eliminated.
Check the bubble and spot to see if there is other impurity inside, this is very important.
Check the shape of the bubble and spot is regular arrayed or not.
Before curing, it has no bubble and spot, but after curing, it has it.
The bubble and spot only appears on the printing area, and the blank area without bubble and spot.
The first phenomenon can be solved by curing.
Environment factors: Dust and inpurity, and clean it. Filter the glue if there is impurity inside. If too much humidity, the water inside air will adhere to the surface of material especially plastic film with high hygroscopicity like nylon, glass paper, it will easily cause bubble.
When mix the glue with solvent, the quantity of glue is not enough, it cause the gluing is not enough; LPI of anilox roller too small causing gluing not enough.
The residual solvent still stay on the material, then it need higher oven temperature; Tension of the material is not good also will cause this problem.
Printing ink and laminating glue is not matching well, the printing ink is not dry completely, after lamianting and curing, the residual solvent erosion the printing and laminating layer.