The key points of embossing and the third after pr

2022-08-19
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Key points of embossing and post printing of holographic logo (III)

(III) key points of production process control (1) load the material to be pressed before molding, so that the holographic pattern is located in the center of the film. For unqualified materials, such as eccentricity and looseness of coiled materials, it is necessary to reprocess them to be qualified before starting the machine, otherwise synchronous adjustment will be affected

(2) the cutting and installation of holographic metal templates are very important for molding production, which determines the quality of molding hologram to a great extent. First, cut the metal template according to the actual pattern, and the flat pressing area should not exceed 10cm × 10cm; For rolling, ensure that its size meets the size required for plate installation. If the cutting edge is uneven and smooth, it can be polished with fine sandpaper to prevent damage to the die roll. Then measure the thickness of the template, and take at least three measuring points on each side. Unqualified templates cannot be used on the machine. When installing the template, try to install the template in the center of the molding machine, It is easy to adjust the pressure evenly. Weiner said, "we believe that there is no force. Ensure that there is no foreign matter between the mold roll and the template. For rolling, it should not be too loose or too tight, otherwise the template is easy to deform or crack.

1 don't just ask for the cheapest (3) Temperature setting the molding temperature should be set according to the type of raw materials, pressure and production process speed. If the temperature is too high, the raw material is easy to deform and the aluminum powder is easy to fall off; If the temperature is too low, the molding image is not clear and complete

the high elastic state of polyester film is about 150 oC, and the molding quality of PVC hard film is the best at 70 ~ 150 oC. The molding conditions of holographic imprinting film are similar to that of polyester film, and the thickness of raw materials is generally 30 ~ 50 μ M. Therefore, it is better to set the temperature of the pressure roll for rolling at about 100 OC, and the temperature of the molding roll at about 150 oC

(4) tension and pressure for molded coil, adjust the tension of unwinding and rewinding before molding, so that the film tension does not shake, so that the product can be smoothly embossed. In general, if the tension is too large during the initial unwinding and rewinding, the rewinding is easy to wrinkle, resulting in "burst tendons" and other phenomena; If the tension is too small, the winding is uneven, and wrinkles are easy to occur

the pressure should be determined according to the type of raw materials, molding temperature and the condition of the template. If the pressure is too high, the template is easy to be damaged and the aluminum powder falls off; The pressure is too low, and the molded image is not clear and complete. For round pressing, the initial pressure of the pressure rollers on both sides is generally about 68947pa. After the molding starts, increase the pressure slowly and evenly, but the profit is high. The roller pressure is relatively complete at 0.34 ~ 0.41mpa

(5) synchronous adjustment synchronous adjustment is very important for quality assurance in hologram products. If the molding equipment does not have an automatic adjustment device, the molding image should be carefully checked after the molding starts, and the synchronization device should be adjusted in a small range until the molding is synchronized. During the production process, continuous adjustment should be made to keep the molding synchronized

(6) other thermoplastic materials will generate a lot of static electricity during processing, which will absorb dust and affect the molding quality and life. At the same time, the molding machine operates under high temperature and high pressure, and the dust does great harm to the machine body. Therefore, the molding workshop needs to be dust-free and the dry humidity is appropriate. After shutdown, the dust cover should be covered and regular maintenance should be carried out

(IV) post press processing

the hologram copied by molding can be directly applied in some occasions (for example, as a handicraft) after being protected and properly cut. However, if it is applied to the object surface of Zejun on a large scale (such as the anti-counterfeiting mark of book cover or certificate), it is too inefficient to paste it manually. The hot stamping transfer technology developed in recent years has effectively solved the above problems. Using the hot stamping transfer technology, the hologram can be transferred to paper, fabric, metal, ceramics or other plastic materials with high efficiency by mechanical operation, which is convenient, labor-saving and can ensure the quality

1. Evaporate reflective layer

in order to make the embossed holographic image easy to view under white light, a layer of aluminum film is plated on the PET film of the embossed rainbow hologram to form a reflective layer. Using the anti sealing effect of aluminum on light, we can clearly see the colorful holographic image, which is the reflective holographic logo

vacuum aluminum plating is carried out in the plating bath. The aluminum wire is atomized and deposited on PET film under high vacuum, and the coating thickness is generally 40 ~ 50nm

if inorganic compounds, such as oxides or sulfides, are used instead of aluminum, and a reflective layer is formed by vacuum evaporation, the holographic image can be seen at a certain angle, while in other positions, only the oil pipe, power supply and oil filling can be connected, and then the initial operation can be stopped to see the underlying printed matter. This is the transparent holographic logo

2. Transfer

transfer is a copy method that uses indirect means to print images on objects with the help of transfer materials with holographic images. It is mainly suitable for occasions that require a large number of holographic products to be copied, which is a commonly used copy method at present. There are generally two methods of transfer, namely, self-adhesive paste method and hot stamping transfer method

(1) the hologram imprinted by self-adhesive method and rolled by aluminum plating should be easy to separate and transfer one by one, so as to be applicable to different products and complete the replication of holographic products. A layer of pressure-sensitive adhesive can be coated on the aluminum layer and laminated with anti sticking paper (peel paper). After die-cutting, the hologram can be bonded to the product. This is the bonding replication hologram, and its basic composition is shown in Figure 3

Figure 3 composition of laminating copy hologram

1 - substrate 2 - diffraction layer 3 - reflection layer 4 - bonding layer 5 - stripping layer

the equipment for coating the bonding layer and laminating the stripping paper is shown in Figure 4

Figure 4 working principle of coating and laminating machine

1 - anti sticking paper unwinding 2, 4 - laminating roller 3 - winding 5 - drying 6 - coating 7 - Pet hologram 8 - unwinding

(to be continued)

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