What are the reasons of the white dots on aluminum plating film?

Aluminum plating film are mainly used for packaging precision instrument devices such as batteries, lenses, and some products cannot be exposed to the light or the air, so using manufacturers are very strict about the quality of the aluminum plating film, white spots, for aluminum plating film, is a headache thing, so why the white dots on the aluminum plating film? Compound aluminum plating film white phenomenon can be described, after composite products have clear white spots on the performance, and the white spots can be random distribution, uneven size. Two kinds of circumstances, one kind is: when the plane, but largely disappeared after curing; Another is that the plane from time to tome, not disappear after curing. The biggest question that the latter is apparent. These spots are most likely to appear in full white or light color printing effect. Actually it should be said that want to appear this kind of white dots, usually in full version ( Except for) 。 Only white and light color covering power difference is easy to see. The causes of the phenomenon of white dots is more, there are three main reasons: 1, ink too wide bottom big or particle size distribution, generally affected by the size of white ink. Adhesive of ethyl ester is a good solvent ink, the ink particles infiltration results of different particle size are different, through the shade of the oven to dry after a change will produce differences, will look to produce 'white'. Generally such a case, the machine is apparent, phenomenon of white dot will reduce after curing, may disappear. 2, high adhesive surface tension, on the aluminum plating film spreading effect is poor. This is the aluminum plating film 'white' one of the main reasons. Adhesive coating effect is not good, after printing layer, will make the change on different parts of the colour and lustre, in front of the same effect, sometimes will produce a lot of spots. 3, equipment, process. This reason is workers don't realize the particularity of composite plating aluminum film, aluminum plating film composite has its unique places; On the other hand drying, coating equipment, the system itself is no guarantee that the adhesive evenly coated in full or there is no guarantee that fully volatile ethyl ester. There are other reasons, such as full bottom printing network cable roller checker too shallow, reduce the ink covering power, etc.