Talking about: Print Box Finishing Process

1. Polishing

Coating not only enhances the surface brightness and protects printed graphics, but also does not affect the recycling and reuse of paper, saving resources and protecting the environment. Therefore, it is widely used in the surface finishing of carton packaging. The glazing coating mainly includes solvent coating oil, water-based coating oil, and UV coating oil. Due to the poor efficacy of solvent varnish and its unfavorable environmental protection, the application range is greatly limited.

(1) Coating

1 Waterborne varnish uses water as solvent, non-toxic and odorless, eliminating the harm to the human body and the pollution to the environment. It has fast drying speed, good film transparency, stable performance, good smoothness on the surface of the coating, suitable for postpress processing. Wide range of properties, good heat sealing performance, safe and reliable use. It is increasingly valued by food, medicine, tobacco carton packaging and printing companies.

2UV coating depends on the irradiation of ultraviolet light to make chemical reaction inside the uV coating to complete the curing process.

Due to the effect of ultraviolet rays, UV light is instantaneously dried when it is glazing, and there is no volatilization of the solvent during curing, which will not cause environmental pollution. The use of UV Varnish prints, high surface gloss, heat resistance, wear resistance, water resistance, light resistance. However, due to the high price of UV varnish and the high performance requirements for the machine, it is currently only used in the coating of high-grade cartons.

(2) Polishing

1 stand-alone coating

Use a special coater or calender to finish the carton finish.

2 online coating

Printing and coating are completed once. With the features of high speed and high efficiency, it reduces the trouble caused by the loss of printed products due to the turnover of semi-finished products. The glazing can be performed using the printing unit's wetting device or inking device, or it can be affixed on-line with a separate glazing unit on the printing press. The use of glazing unit for coating production, high efficiency, stable coating quality, glazing unit is monitored and controlled by the printing press control center, such as horizontal and circumferential register adjustment of the photic resin sheet, diagonal register adjustment and so on. The on-line glazing unit can evenly coat the entire surface of the carton or a partial image. Polishing can be done either with blankets or with a flexographic plate for fine localized coating; both aqueous and UV coatings can be applied. The on-line glazing device can be divided into two types, roller glazing device and squeegee glazing device.

3-roll coating

A roller coating device was used to transfer the varnish to the carton surface. The amount of coating and pressure of the coating unit are controlled by the press control center. The coating liquid supply mechanism like the coating machine of Heidelberger presses can control the whole process of the coating liquid supply. The coating liquid is pumped from the liquid storage tank through the hose to the coating liquid tray in the electronic double diaphragm pump. The height of the liquid surface and the circulation of the coating solution are monitored by a potentiometer to ensure that the coating solution is evenly supplied. The ultrasonic monitor can monitor the coating quantity of the coating solution at any time. KBA Rapida 105 offset printing machine roller glazing, there is a two-roller system as a clockwise operation, there are also three-roller system can be used as a reverse operation. When the two-roll type operation is performed in a clockwise manner, the metering roller is disengaged, and the coating amount is adjusted by the pressure between the polishing liquid fountain roller and the liquid transfer roller, and the structure is simple. When working in the three-roller reverse running mode, the glazing roller and the liquid hopper roller run in the reverse direction, and the glazing film layer with good brightness can be obtained: at the same time, when the high viscosity glazing solution is used, it is not necessary to increase the pressure between the rollers excessively. To achieve a thin and uniform coating purpose. The roller glazing device has the characteristics of short transmission path, less contact points, difficulty in drying of the coating liquid, uniform transfer of the coating liquid, and simple and convenient operation.

4 blade type polishing

The closed squeegee glazing system consists of a ceramic anilox roll and a closed squeegee and a flexible resin coated roll.

Its main advantage is that by selecting different ceramic anilox rollers, coating can be done precisely according to the required amount of coating, saving on glazing oil; with an anilox roller, glazing coating device and full-surface coating, local Polishing function. Usually consists of two scrapers and a ceramic anilox roller for metering purposes. The upper and lower scrapers and the anilox roller form a closed box structure, and the gloss liquid is pumped through the pipeline. The squeegee type glazing device has the characteristics of uniform and constant gloss, high quality, good effect, good environmental protection, economy, and easy realization of high-speed glazing. And can adapt to the carton surface of the gold, silver coating, coating coating can achieve a very high wear resistance.

2. Hot stamping

In the fierce competition in the market, in order to increase the added value of the products and to effectively carry out anti-counterfeiting of packaging, more and more packaging cartons use the hot stamping process. Hot stamping with ordinary hot stamping, cold stamping, embossing hot stamping and holographic hot stamping and other methods. Common common hot stamping processes include flat and flat hot stamping and round flat stamping. Because the round flattened hot stamping is a line contact, it has a wide range of hot stamping substrates, is suitable for a large area hot stamping, and has a high stamping precision and is widely used.

(1) Cold Stamping

Instead of using a heated metal plate, the metal foil is transferred using a method of printing an adhesive. The cold stamping process has low cost, energy saving and high production efficiency, and is a promising new process.

(2) Embossing Hot Stamping (also called three-dimensional hot stamping)

The use of modern engraving techniques to make up and down with the negative and positive molds, hot stamping and embossing process once completed, improve production efficiency. The mold produced by electro-engraving can be curved to achieve a three-dimensional embossing effect that can hardly be achieved by a mold produced by a general etching method. The emergence of embossing and hot stamping enables the hot stamping and embossing process to be completed at the same time, reducing the number of waste products that are generated due to process inaccuracy and overprinting.

(3) Holographic identification

Using computer technology to change the amplitude and frequency of the grating, the effect is more vivid and clearer than the calculated pattern. If such a hologram is used as a copy of the original, a large number of holograms will be lost, thereby achieving the purpose of anti-counterfeiting. According to the characteristics of the hologram hot stamping marking, it can be divided into continuous holographic marking hot stamping and independent holographic marking hot stamping. Continuous holographic logo hot stamping is a new generation of ordinary laser holographic hot stamping products. Independent hologram marking Hot stamping is to make the holographic logo on the anodized aluminum into a separate trademark pattern, and there is an alignment mark next to each pattern.

Holographic identification not only can have very good anti-counterfeiting performance, but also can make special numbers or characters in the holographic logo according to customer needs. The holographic logo is stamped onto the packaging carton, and not only is the hologram logo stamped on the surface of the printing material, but also has a very high overlay accuracy, and is increasingly used in high-grade carton packaging.