Gravure printing machine is gravure printing equipment, generally used for the color printing of plastic film, but no paper printing glue has been reported. After the paper is printed with hot melt, it can be used for packaging various medical products. Therefore, gravure printing machine is used. The sizing used for paper products is an innovation. It is a pioneering enterprise that uses the original equipment to carry out technological innovations and develop new products. Through this technological innovation, companies have saved many of the costs of acquiring equipment and have also increased the utilization of existing equipment.
1, gravure printing rubber control system:
The system itself that affects the distribution of printed rubber has the following parts:
1.1, rubber roller - cable roller - scraper - plastic tank system.
This system determines the amount of glue to be applied, and ensures that the glue is distributed at a certain density and is spread on the surface of the paper. The coating state of the glue is determined by this system.
1.2, plastic tank design:
The design of the glue tank plays an important role in the printing process, because the hot melt melts a process. That is: heating - melting - aging (yellow, black appear). Therefore, in order to make the hot melt melt better, it is necessary to make the glue tank have a certain heat capacity so that the glue tank is kept at a constant temperature and for a long time. The temperatures in the glue tank are the same throughout. In view of this, the design requires a glue tank wall. Thick, the middle of the tank should have vertical bars to facilitate heat conduction. The width and depth of the tank should be determined according to the width of the printing paper and the diameter of the roller.
1.3. Blower: The room temperature and ventilation conditions affect the hardening rate of the glue. Using the advantages of several groups of blowers in the printing press, one to two groups of blower accelerators can be used to accelerate the curing of the glue.
1.4. Rewinding: The winding must begin at the end and the core must be firmly adhered.
Second, raw materials:
2.1. Hot Sol: Generally speaking, general hot melt can be used. The melting point of hot melt produced by different manufacturers is different, and some differences are relatively large. In order to ensure excellent coating state, careful identification should be used before use.
2.2, polyethylene wax: mainly used to control the tightness of the bond. Its mix ratio determines the quality of the package. Its selection must also ensure quality, be careful not to bring in refractory crystals, impurities, etc. Also consider its compatibility with the hot melt, if the surface of the solution after the formation of a thin layer of liquid should be more stirring, mixing can be used before, otherwise printed on the paper are wax instead of glue, you can not be used for the next step Produced.
2.3, with plastic paper: paper selection, first, according to the requirements of users to choose. The second is to pay attention to the tension of paper tolerance. Otherwise, in the printing process, breaking is a common phenomenon, in general, the paper tolerance is far less than a variety of plastic film; such as OPP, PET, NY and so on. Therefore, starting and starting the vehicle should be steady, slow, uniform, sudden and sudden stoppage, which will lead to paper breakage and cause a great deal of waste. On the other hand, the force exerted by the paper roll on each guide roller must be consistent in direction and consistent in size, otherwise it will also be broken. Stopping, sometimes making driving testers lose confidence in the test, and then the paper storage time, in general, do not exceed one year, otherwise paper whiteness, toughness, etc. will be greatly affected, this must be paid attention to , It is best to buy it.
3, process factors:
3.1. Matching of hybrid glue and cable roller: In order to make the amount of offset on the paper suitable, and the cable is clear, it is necessary to consider different sizing amounts to take different cable rollers. This is often negligible and generally follows the following working principles. The larger the amount of glue, the less the cable used for the cable roller; the smaller the amount of glue, the more cable used the cable roller. General manufacturers can prepare three sets of network roller. That is, one set of 80 lines is used for the highest adhesion fastness, and the coating amount is also the largest, 100 to 120 lines for a moderate adhesion speed, a set of 130 to 150 lines for ordinary bonding. The smaller product. In addition, the rubber roller and the cable roller must be parallel and have a certain pressure when they work. Otherwise it will cause partial lack of network cable, glue transfer is not much, and then one is the diameter and width of the roller and roller, it is also a factor that should be considered, and strive to find out the common specifications in use, as far as possible without affecting the production , But too much to make rubber roller and cable roller, causing unnecessary waste.
3.2. Adjustment of the hardness of the rubber roller: The rubber roller in the system provides a certain pressure to force the adhesive to squeeze out from the mesh and disperse on the surface of the carrier paper. The hardness of the rubber roller has a great influence on the dispersion of the rubber. It is worth noting that there are two aspects. First, the hardness of domestic rubber rollers is generally not high, and there are certain differences in the hardness of different manufacturers. Secondly, the elasticity of rubber rollers will decrease with the extension of the use time. The hardness and hardness of the rubber roll determine the amount of glue transferred up. We must choose the appropriate soft and hard rubber roller to make the clear glue line printed on the paper clear.
3.3, the system clean-up: due to the characteristics of hot melt: heating melt cooling solidification. Therefore, we must pay attention to the cleaning of the printing system, various guide rollers, air outlets, and two ends of the cable roller. In particular, sometimes breaking the paper in the plastic slot will bring a lot of glue to the system. The paper was crushed, emptied and printed on the rubber and so on.
3.4, driving the relevant matters needing attention: before driving, first calculate the amount of good plastic, if you want to continuously drive the pre-heated plastic with good, poured into the plastic tank in a molten state, after one to two hours of constant temperature, after checking the plastic wax Only when the melt is relatively even, can you drive the car. Secondly, because the plate roller is not immersed in the rubber tank, the temperature is low and it cannot drive. You should allow the roller to immerse in the tank for 10 to 20 minutes until the temperature of the screen roller and the glue is almost the same. Can drive, then glue should be liquid. When you drive again, you should straighten the web so that the force is in the same direction and consistent in size so that the paper is not pulled off.
4, the workshop environment:
Dust: The dust in the workshop air will adhere to the paper, destroying the firmness of the adhesive. Especially at the air outlet, strong airflow will trap dust particles and spread it to the paper glue, which will affect the product quality. Therefore, in addition to keeping the workshop clean, the filters at the air outlet should be frequently cleaned and replaced.
Above, we discussed some factors affecting the printing machine's printing and some methods for improving the printing effect. The normal production process is more complicated. When analyzing a certain quality problem, we need to consider more comprehensively.