How to solve the problem of false bonding of laminating products?

In order to improve the surface gloss effect and mechanical resistance of the printed product, the film is a surface treatment method of printing which is often used, and is suitable for the outer packaging of various commodities, and can protect and beautify the product and increase the added value of the product.

In the process of film coating, the most common quality failure is that the film and the printed product of the film product are not bonded properly and are easy to fall off, which will directly affect the use effect and life of the subsequent film product. In order to solve this problem, it is necessary to comprehensively consider the combination of printing ink, printing process and laminating process.

Printing ink

The laminating process is relatively simple, mainly by bonding the printed product and the film together by an adhesive. The porous porous structure on the surface of the non-image area of ​​the printed product is beneficial to the penetration and diffusion of the adhesive. Therefore, the ink in the printed image area is the main reason for the mismatch between the printed product and the film.

The effect of the ink on the filming effect is mainly the effect of the surface properties of the ink after drying on the adhesive. When the ink is dried, the main component of the surface layer is an ink thinner, and some other substances are also contained. For example, the powdery particles in the white ink component may be floating on the surface layer of the ink due to insufficient binding force with the binder, and then dried; The aluminum hydroxide in the oil component is also light in the surface layer of the ink; the film-forming resin of the gloss paste component can improve the film forming effect of the ink and is also on the surface of the ink.

When the film is coated, the white ink pigment particles on the surface of the ink will hinder the adhesive and affect the further penetration of the adhesive on the surface of the ink layer; the aluminum hydroxide in the Weiley oil will easily form a barrier layer, hindering the adhesion. The interaction between the agent and the ink layer leads to foaming or poor adhesion; the bright light paste is beneficial to the film coating, and its composition is similar to that of the adhesive (the main component is a conjugated multi-bonded terpene resin), and the affinity effect is obtained. it is good. Therefore, when adding an ink thinner, it is necessary to consider the film coating effect of the product.

In addition, the particle size of the ink also affects the filming effect. If the particle size is too large, it will affect the bonding effect between the film and the surface of the printed product, and foaming may occur easily, and the bonding may be unrealistic. In particular, gold and silver inks are not suitable for film coating because the metal pigment particles are separated after the ink is dried, which hinders the bonding of the ink layer and the adhesive.

printing art

The print before the film is required to be printed. As mentioned above, the surface properties of the dried ink will affect the film coating effect, and under the premise of using a suitable ink, the printing web, the thickness of the ink layer, the drying effect and the like may also cause the film to be untrue.

If the printing format is too large (or printed in the field), the contact area between the surface of the paper and the adhesive will be reduced, which will increase the adhesion of the surface of the printed product and the adhesive, and the quality and service life of the coated product will be greatly reduced. . Therefore, it is necessary to avoid laminating large-format or printed products printed on the ground.

If the ink layer of the printed product is too thick, the hindrance to the adhesive will be aggravated, which will directly cause delamination and thus cannot be bonded. Comparing the characteristics of the ink layer obtained by various printing processes, the thickness of the ink layer of the offset printing is the lowest, which is 1~2μm. Therefore, it is best to select the offset printing for the printed products that need to be coated, and pay attention to controlling the overprinting effect and printing of the color printing. The final ink layer thickness.