Perfect binding printing, Perfect binding book printing, adhesive binding, book binding adhesive, book print
Product Type: Book
Printing Type: Offset Printing
Book Cover: Soft Cover
Material: Cover 250GSM Art Paper Inner Page 157GSM Art Paper
Printing: 4+4color Printing
Paper Type: Art Paper
Surface Finish: Varnishing
Binding: Perfect Binding
Origin: Shenzhen, China
Tips of printing:
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.
The coating 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 and hinder the adhesive. The interaction between the agent and the ink layer results in blistering or poor adhesion; the gloss 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.
The print before the film is required to be printed. As mentioned above, the surface properties of the dried ink will affect the filming effect. However, 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 printed ink layer is too thick, the barrier effect on 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.
Similarly, undried ink can cause the film to swell and elongate, causing the film product to foam and thus fail to bond. The key to solve this problem is to ensure that the ink is completely dry before the film is coated. It can be accelerated by means of auxiliary drying, but the use of the ink adjuvant should be minimized because the excessive use of the drying oil will increase the smoothness and fineness of the surface of the ink layer. , thereby increasing the adhesion of the film product is not true. At the same time, we must also pay attention to reduce the use of dusting and the impact of the workshop environment on the film of the printed product, because the dust on the surface of the printed product and the dust impurities adhering to the surface of the printed matter in the workshop will act with the adhesive, resulting in The "false bond" phenomenon makes the print and film easier to detach.
Film coating process
The film-coated product is finally completed by a laminating process, and the film quality depends on the implementation effect of the film-coating process. The coating process parameters mainly include the drying effect (ie, coating film process), composite temperature, composite pressure, coating condition of the adhesive, and film coating speed. Here, the author analyzes the three aspects of the drying effect of the adhesive, the bonding effect of the adhesive, and the effect of the film pressure.
1. Drying effect of adhesive
The drying effect of the adhesive is similar to the effect of the drying of the ink on the surface of the print on the quality of the film. If the solvent is not completely dried, the film will expand and stretch, causing foaming, which may result in poor adhesion.
2. Adhesive binding effect
The bonding effect of the adhesive mainly considers two aspects. First, the coating of the adhesive requires both the uniformity and good effect of the adhesive on the surface of the film, and the thickness of the adhesive according to the surface characteristics and structure of the printed product: the thickness is too thin, which will reduce the bonding of the adhesive. Force; thickness is too thick, which will affect the drying speed. The second is the composite temperature, which affects the molecular energy and molecular force of the adhesive. When the molecular force is too small, the adhesion of the coated product is too small. In addition, if the composite temperature is too high, it will cause damage to the film structure, and the composite temperature is generally required to be controlled at 70 to 90 °C.
3. Effect of film pressure
The effect of the film pressure is affected by two factors, the composite pressure and the film speed. The composite pressure will promote the penetration and diffusion of the adhesive. The size of the adhesive should be considered in combination with the coating material and other processes. The coating speed is also a multi-influence parameter, and its size will affect the coating thickness and drying speed of the adhesive. Adjust with other factors at the same time.