How to exclude the white point of composite bags and adhesive failure

Packaging and printing the major technical problems bothering people for a long time, problems are mainly concentrated in: (1) ink migration; (2) ink film yellow; 3. Print the white dots; (4) back to the viscosity and adhesion; (5) pale and faded; 6. Ink film floating white; All landowners pinhole and the porosity; Today can't transfer the ink; The color of pet-name ruby bite ( Commonly known as string of color) And fade; Attending luster difference ( White) 。 These printing technology difficult problem has become a common production failure. Print the white dots. The problems are a reminder that in printing ink storage, in use process, the stability of the ink is the result of the interaction of the product system component parts. Ink solvent polarity of different intensity, the activity of ink additives on the paint surface adsorption also can have different effects. Everyone clear links and active additives on the paint surface will produce competitive adsorption, it mainly depends on links material, the size of the active additives and pigment surface affinity. Physical adsorption as a result of the printing ink particle surface active additives affect polymer chemical adsorption, so the surface active substance in physical adsorption on the surface of the pigment is unstable. From this point, the active dispersant in the printing ink system, friction resistant wax even amide resin materials such as links to material add too much, will affect the packaging and printing ink ink film adhesion, moreover in the process of grinding, because of too few scattered additives, especially add the improper order, especially scattered time too short, after the computer printing a lot of pinhole on the surface of the white dots and post-press composite white fault occurs. In order to prevent such failure, should be reasonable selection activity of ink additives, or appropriate to extend the time of grinding disperse ink, fully mixing when printing ink to printing again after. Back to stick and adhesion. In recent years, in the southern jiangsu area, composite printing ink stick back or adhesion, gravure than in the past, table printing ink and printing enterprise. Most of the time of the fault on 7 ~ 10 months. Often after packaging printing, printing ink dry film after a short period of time is not to stick or adhesion phenomenon, but in the rolling process after printing or printing delivery users after a period of time, there will be a ink film feel is not smooth, the point at which the trigger sticks or cutting, repackaging adhesion in a serious phenomenon. The emergence of this phenomenon is actually a composite packaging ink link caused by material softening point is too low. When diluted in printing ink, add too much slow dry agent or inhaling too much moisture and the table dry wet ( Commonly known as focal bone skin) As a result of. In order to prevent the failure of repeated, one is to strictly choose normal manufacturer production with technical parameters of the ink products; 2 it is to should strictly according to the evaporation of the solvent when printing speed or the evaporation rate, selection of mixed solvent is not choose the containing water; Three is in the packaging and printing, stained with oil and wax class of substances such as surface treatment of substrates; Four is in the printing ink film again after dry again on the second overprint; Five is to choose link material softening point of high ink.