Composite film 'stick' big collection

Composite film printing after the mark has been dry, but in good printing reel or bag storage period appeared after the glue on the back of dirty phenomenon, serious when broken between calendar does not open, figure ink layer dye migration, caused the product scrap. This kind of phenomenon and plastic, printing ink, temperature, solvent evaporation speed, operating environment of air volume, is closely related to factors such as light. At present, the links of ink resin composite membrane used in the gravure printing ink belong to solvent-based inks, mostly as a link of material resin, ask its bonded to solid and printing film, printing adhesion after winding, has certain softness, and ability of high temperature, in a certain range is not affected by external factors change. In addition, when processing and printing ink, if the grinding time is too long, produced by the grinding temperature is too high, lead to link material resin part degeneration, will also bring certain influence to the adhesion. Second, the gravure printing ink after the printing was not completely volatile solvents in when the residual solvents in the printing ink layer reaches a certain concentration, printing ink layer keep micro melting ( Wetting) State, which directly led to the adhesion problem. So we must to control residual solvent quantity of them. In addition to the volume of solvent residual is affected by the solvent release link material resin, also affected by the following factors. 1, solvent volatilization solvent contained in the printing ink film belongs to the mixed solvent, each kind of solvent volatilization rate is different. If the purity of solvent unsuitable or excessive use of the slow drying solvent, is under normal conditions will have serious problem of residual solvents. In addition, the surface properties of pigment, the concentration of the specific surface area and also have certain effects on evaporation of the solvent. For the same pigment, solvent evaporation rate decreases with increasing the concentration of pigment; For different pigments, in general, small pigment density, solvent volatilization rate is low, the pigment particles small, solvent volatilization rate is low. 2, dry conditions drying conditions including drying air temperature, air velocity, Wind speed) , drying device structure, etc. Poor drying, solvent residual amount will increase. Therefore, we should create a good drying conditions as much as possible. Increase the air temperature, air velocity, Wind speed) , no doubt can strengthen dry conditions. But it should be noted that in the case of a printing ink layer thick, if dry too fast, can make the ink layer surface rapidly conjunctiva, lead to internal solvent can't escape, it will make residual solvent quantity increases. Moreover, the temperature is too high, it is easier to soften ink film. 3, printing speed of the fast printing speed, decided the printing quality can get the length of the drying time. So, should be the first to ensure the printing ink layer under the condition of fully dry, to enhance the printing speed. 4, drying medium ( Air) If the humidity of the moisture in the air into the ink, will cause the comprehensive volatile solvent variation. Drying medium ( Air) Water abundant, also inhibits the evaporation of the solvent. Double environment humidity, drying speed of ink generally slow to nearly double. It is for this reason, in the rainy season the most easily occurred in printing composite membrane adhesion failure. In high humidity environment, therefore, should as far as possible to slow down the printing speed, and reduce the ink contact with air, to ensure that the ink can be fully dry. Printing workshop of relative humidity generally should not exceed 70%. Of course, also cannot too dry, otherwise, easy to cause electrostatic problems. 5, printing film membrane made of different materials for the selectivity of solvents have different absorption tendency. Aluminum foil, polyester as the absorbent film, such as less residual solvents in general; Department of polypropylene film easy residual hydrocarbon solvents, and film (water imbibition Such as nylon, cellophane) Is easy to residual alcoholic solvents. Some film to add fertilizer also can affect the volatilization of solvents. Thus increasing the amount of residual solvents. Film printing, loosely put inside wire woven baskets, best to continue ventilation dry ink layer, curing after cutting, bag making, film printing bag, after dressing, vertical in cartons, reducing the pressure between the membrane surface. Three, the printing ink adhesion fastness of the printing ink layer adhesion fastness bad, it is easy to make the printing ink film under the condition of stress transfer to another layer in contact with membrane, resulting in adhesion. The causes of ink adhesion fastness bad are the following points. 1, whether the wrong with ink, or a mixture of different kinds of ink. 2, composite film corona processing bad or excessive moisture absorption. The additives precipitation in 3, composite membrane, or air is dust adsorption onto the membrane, which affect the printing ink adhesion. 4, ink, bleaching and metamorphism. 5, poor drying. Four, some other main question 1, plastic gravure ink ink bad the links of some plastic gravure printing ink of the low melting point material, the operating environment under the condition of high temperature, relative humidity is big, easy to adhesion. Countermeasures: (1) when conditions permit, workshop to install air conditioner operation, to control the room temperature 18 ℃ & ndash; Between 20 ℃ and relative humidity below 65%; (2) replacement ink good ink. 2, thin plastic film printing and packaging eligibility bad reasons: (1) the packing and added to the resin composite film; (2) resin in the opening agent. Countermeasures: replacement of composite membrane.