Dongguan Beite packaging materials Co., Ltd. is the first choice of flexible packaging manufacturers, specializing in the production of plastic printing composite packaging: composite bags, suction mouth bags, aluminum foil bags, paper plastic bags, vacuum bags, anti-static bags and packaging film; self-supporting bags, bone sticking bags, three (four) side sealing bags, middle sealing organ bags, self-supporting bottle mouth bags and plastic printing composite films. Products are suitable for food, daily chemical, electronics, washing, toys, medicine, stationery, hardware, cosmetics, daily necessities, agricultural products, industrial products and other industries.
Causes
1. No ink line mark. The main reason is that the ink mixed with hard impurities, such as sand, these hard particles embedded in the blade of the scraper. Sometimes the line marks of this kind of scraper are also dotted lines, which can easily damage the printing and scraper.
2. Thick continuous blade line mark with ink. This is mainly due to some coarse soft particles or impurities against the scraper, or blade damage. This is the simplest and most common blade line mark.
3. "Meteor" shaped blade line marks. This kind of scraper line mark usually appears in the printing plate roller's dot is very shallow or not engraved dot, and sometimes appears, which is very harmful to the product quality. The causes of this kind of scrapers line marks are relatively complex. Over the years, some people have made explanations from the aspects of ink, plate making and printing environment, but so far, none of them is relatively perfect. The better one is "active particle hypothesis".
4. Fine wire like continuous scratches. This kind of blade line trace is small, like hair silk, often appears in the printing process, and it is difficult to observe on the printing machine. When it is found, a large number of products have been printed, so it is very harmful to the quality. This kind of line mark can be divided into two kinds: one is soft, which can be wiped off with bamboo knife, mainly caused by impurities; the other is that it appears hair like at first, and then slowly presents zonal distribution, which can not be wiped off with bamboo knife. The causes are very complex, involving ink, plate making, environmental temperature, humidity, scraper hardness and other aspects, which need specific analysis handle. Generally speaking, there are several aspects as follows: A. plate roller. Roller surface finish is not good, roller surface chrome coating hardness is not enough, version roller is too smooth, no lubrication effect is easy to produce. b. Ink. Ink fineness is not enough, pigment particles are too large, the ink use process mixed with particulate impurities; ink dilution is not standardized, resulting in solvent impact phenomenon; ink antistatic performance is poor, ink lubrication performance is poor. The use of high hardness pigments produces lines. c. Environmental aspects. The temperature, humidity and cleanliness of the air in the printing workshop will also have an impact. d. Scraper. A hard blade produces more lines than a soft one. In addition, if the scraper line mark can not be handled in time, a large bunch of scraper line mark will be generated around the line mark with the scraper swing back and forth.
Countermeasures
The knife must be smooth and careful when loading. Before loading, check whether there is a gap in the blade. After loading, the blade must be grinded carefully. If there is a wire in the printing process, stop the machine and grind it carefully. It is strictly forbidden to mix the oil of grinding knife into the ink.
It is necessary to control the environment and reduce dust in order to eliminate the fault. The color printing environment should be kept as closed as possible. Air filter can be installed and dust content can be tested. Otherwise, it is difficult to produce high-quality products.
The cutter wire caused by the plate roller generally appears in the part of the shallow net, such as the plate is rough, the gradual change is too uneven, the mesh depth is not suitable, etc. Generally, the plate should be grinded with metallographic sandpaper. Attention should be paid to the uniform force when grinding. If it is particularly serious, it should be returned to the plate making plant for treatment.
Reduce the viscosity of the ink. If the viscosity is too high, the printing ink dries too fast, which increases the friction between the plate roller and the scraper, making it difficult for the scraper to scrape off the cutter thread formed by the printing ink.
If the knife thread is caused by ink, it is generally caused by waste or uneven dissolution of ink in the ink. Filter the ink or reselect the solvent with strong solubility or change the ink.