In modern printing, whether it is flexographic printing or gravure printing, are mainly rotary printing; in many fields of offset printing, rotary printing is also the most important way. However, the web printing materials used in rotary printing are likely to cause difficulty in printing due to the adsorption of dust and other impurities, which will lead to a decline in the quality of printing and an increase in the rejection rate. First, the impact of dust and other impurities on printing During the production or stacking of plastic paper rolls or rolls, a lot of electrostatic charges will accumulate due to friction, resulting in higher or even very high electrostatic voltages. When the roll printing material is placed on the printing press and people touch the unwinding roller, the human body may become a cathode (earth electrode), causing the printing material to discharge to the ground. This discharge voltage can be as high as 20,000 volts, which makes people shocked by unimaginable. Fortunately, although this voltage is very high, the power and current intensity are very low, otherwise it will kill people in an instant. Although this electrostatic charge is not fatal to humans, it will attract dust, packaging materials, fibers on clothing, hair, tiny creatures, residual ink particles, etc. from the surrounding environment to the surface of the printing material for printing, compounding, and printing. The production of light and other processes causes difficulties. Dust and other impurities will be transferred to the plate cylinder and adhere to the plate cylinder after contact with the plate cylinder, which will damage the ink transfer performance of the plate. In order to remove the dust adhering to the plate cylinder, the operator had to stop the cleaning. If there are many dust and other impurities attached to the printing material, it is often necessary to clean it once in less than half an hour. Cleaning the printing plate cylinder will not only prolong the printing production time, resulting in loss of production efficiency, but also restart printing after each cleaning, there must be a period of adaptation process, inevitably will consume a part of the printing material, accumulated over time, and the resulting losses Considerable. How to deal with such problems correctly, the relevant experts suggest that the following aspects should be given enough attention. 1. Paper and cardboard dust removal Impurities such as dust may come from papermaking, slitting, die-cutting, slotting, envelope windowing process, and napkin production lines, so they must be completely removed, otherwise it will affect the quality of printed products and reduce production efficiency. 2. Plastic film and metal foil to remove static electricity Both plastic films and metal foils are more prone to static electricity, so before printing, you must do a good job of dust removal and cleaning, in order to minimize additional auxiliary time such as shutdown and cleaning in printing production, improve production efficiency, and also try Avoid customer rejection caused by product quality problems. 3. Clean food and medicine bags before forming Food and pharmaceutical packaging bags must be heat-sealed to make packaging bags. Thermoformed packaging materials must be absolutely clean before molding. The cleanliness of materials used for vacuum packaging must meet quality standards. 4. Dust removal before polishing Regardless of whether the paper, plastic film or metal foil is glazed, dust removal treatment should be carried out first. Dust and other impurities adhere to the printing material, which will greatly affect the polishing quality. [next] 2. How to effectively remove dust and other impurities Since dust and other impurities are attached to the surface of the printing material by electrostatic adsorption, the charge must be eliminated first, and other corresponding measures must be adopted to completely remove the dust and other impurities to meet the requirements of printing and other processing. After the printing material is destaticized, it can avoid the adsorption of dust and other impurities. 1. How to eliminate static charge The methods to eliminate static charge are: (1) Transfer the electrons directly from the printing materials; (2) Transfer electrons through contact with other materials; (3) Transfer electrons by contact with ions in the surrounding air. 1. Transfer the electronics directly from the printed materials In an environment with high humidity, directly ground the printing material, the electrostatic charge on the printing material can disappear, so that it no longer retains high charge, which meets the printing process requirements. 2. Transfer electrons by contact with other materials The electric charge that has been ionized is similar to the conductor tending to discharge from the charge to the object. In this case, using a fiber brush, using low-energy elements such as polonium and iridium to generate radiation with the ions in the surrounding air, can neutralize the static charge on the surface of the printing material, but this method is only used in certain special occasions. Under normal circumstances, you can use DC or AC high voltage to neutralize the static charge on the surface of the substrate to eliminate static electricity. The commonly used method to eliminate static electricity is to eliminate static electricity with an electrostatic rod. The electrostatic rod is composed of steel needles, and the distance between the two needles is very small. Place the electrostatic rod on top of the printing material and neutralize the electrostatic charge with the current generated by a very high AC voltage of 50Hz or 60Hz. Recently, DC pulse current has also been used to neutralize electrostatic charge. The current used is a high-voltage bipolar pulse current. Different transmission frequencies, powers, and polar directions can be selected according to the electrostatic charge intensity and other characteristics required for neutralization. Using a constant DC current is also a more effective method to control the electrostatic charge with a continuous DC current. This method is especially suitable for high static charge and high-speed printing conditions. The static generator is another technology, which can be used not only to eliminate static electricity, but also to establish an electrostatic field. This electrostatic field can be used in more industrial fields, making its production process more efficient. 3. Transfer electrons by contact with ions in the surrounding air Ionized air can also be used to eliminate charge. It is achieved by mechanically spraying the ionized air in the working environment on the surface of the printing material. This device is called a charge ionization eliminator. It can use needles or rods of various shapes as electrodes. The strong air flow of ionized air is blown toward the surface of the printing material through the muzzle-shaped nozzle. 2. How to remove dust and other impurities For printing materials to reach an acceptable level of printing, it is not only required to eliminate the electrostatic charge on the surface, but more importantly, to remove all dust and other impurities adsorbed on the surface. After the charge is eliminated, the adsorption capacity of the printing material for dust can disappear immediately, and it can avoid re-adsorption of dust in the surrounding environment, but this does not mean that the dust and other impurities that have been adsorbed on the surface have been removed, so other measures must also be adopted in conjunction . The easiest way is to use a brush to clean the static charge after removing it. But this method can only remove larger particles, not completely. A more effective method is to use an ultrasonic generator to generate a powerful compressed air flow, and to blow compressed air to the surface of the printing material through a nozzle that is the same width as the paper roll and is very close to the paper roll, producing a role similar to an air knife to clean dust. . It acts like a vacuum cleaner, the dust will not return to the surface of the printing material. Although the nozzles of different brands have different geometrical contours, all of them use their own patented technology to make the airflow reach a very high speed. The airflow speed generated by some nozzles can reach more than 560 kilometers per hour, which can effectively remove the adhesion Dust particles on the surface of the printing material. In addition to the above method for removing dust particles by a powerful compressed air flow, there are also methods for removing particles using adhesive tape. The method uses a device with a simple structure and easy installation. The Whole Body Vibration Machines are very important for overall training in fitness centers, especially for female fitness lovers. Because it can enhance the effects of fitness training and also adds novelty, variation and fun. Our whole body vibration machines not only offer a Total Body Training, but also make you enjoy a massage training. For a professional gym club, whole body vibration machines are a key gym device in fitness as it enhances flexibility and range of motion while strengthening muscles and balance. What's more, the Whole Body Vibration Machine is the scientific answer on non-surgical body shaping. Whole Body Vibration Machine Gym Body Slimmer, Body Vibration Machine, Whole Body Vibration, Fitness Body Shaper, Body Building Euipment, Exercise Equipment, Inexpensive Exercise Equipment Guangzhou Kangyi Sporting Goods Co., Ltd. , https://www.ganasgym.com