White spot to handle tough? Teach you 7 and it!

Vitiligo is a solvent-free composite flexible packaging factory one of common problems. White spot, refers to the composite of ink after the places are different from other parts of the white dots. White spot once produced, it is more difficult. 1, printing ink and glue incompatible especially full version printing ink is easier to produce. This is because the ink has bad compatibility with adhesive, is usually caused by poor match. 2, poor surface finish of glue roller, composite roller or with foreign body show the local discontinuous duplicated spots at this time. Two spots can be measured by repeated spacing to judge what is the root of roller on the foreign body, clean can. 3, poor ink cover rate produced white spots where performance for white and light color ink white spots, and the dark part looks good. The solution is to increase the hiding power of white ink, such as white ink fineness examination, grinding fineness good ink, improve the covering power, the simplest method is to reprint a white ink. Can also be used when buying ink fineness and covering power of inspection, qualified before use. 4, adhesive coating, low amount of glue not enough glue can infiltrate into all of white ink, poor compatibility with ink or adhesives. Composite aluminum plating film or aluminum foil more prone to white, aluminum plating on aluminum foil surface and reflected light through the bubble in cross section, will produce refraction or diffuse, form a white dot. Solution: can increase the coating weight, appropriately control the tension of composite, the coating evenly. 5, base material membrane tension uneven uneven tension of basement membrane, before entering the compound roll at a discount, cause local composite effect is poor, appear bubbles, macro performance for vitiligo. 6, composite and composite coating pressure parts or glue parts improper pressure setting, the size of head. Uneven pressure makes the air in the glue solution cannot be expelled in the composite process. In addition, composite when the second base material and composite roller Angle cannot too big, otherwise easy to mixed air bubble. 7, two substrate membrane surface roughness is too big, additive floating past substrate membrane surface roughness is in commonly 0. 08 ~ 0. 16um（ Using solvent-free film surface roughness should be more low) 。 If above the roughness, the membrane surface concave and convex, rugged, printing ink and adhesive can bump hole fill and level up, resulting in the composite bubble. If basilemma additive quality partial inferior or heat buoyancy, also can produce white spot.