In our flexible packaging industry, there are usually such descriptions: seven points printing, three points printing. Plate roller is one of the important carriers of our flexible packaging printing , which determines the quality of gravure printing, the effect of product packaging, and directly affects product brand communication and market competitiveness.
I can't catch the standard hue
When the hue of the ink is not the same and the viscosity of the ink is not controlled, the hue problem that cannot follow the standard sample will occur. However, when these factors are eliminated and the color sample cannot be tracked during printing, the problems of the plate roller must be considered. Generally speaking, as long as the plate roller is clean, this problem can be controlled.
Cleaning and maintenance of the plate roller is very important. Only by doing meticulous cleaning and maintenance of the plate roller can the subsequent printing quality and the life of the plate roller be guaranteed. Therefore, enterprises should establish standard plate cleaning standards and maintenance workflows, as shown in Table 1.
Table 1: Printing shop cleaning roller standard
Second, the reversion rate in the workshop remains high
Printing plate rollers always have problems, and the rate of reprints is high. The cost of reprinting a plate can range from more than 100 to more than 1,000. Frequent plate faults include chrome loss, bruises, bumps, scratches, and oxidation. The high return rate is a direct reflection of problems in the internal management of the workshop and will increase the production costs of the enterprise.
Effectively reduce the plate return rate of plate rollers. This is also the focus of our production management. We recommend:
1.On the basis of the plate roller cleaning described above, establish a plate roller management group, that is, a plate roller group;
2.Develop a suitable roll management system for the workshop, and use reward and punishment measures to strengthen management;
3.Develop appropriate dedicated plate roller use tools, that is, plate transport trucks, and train plate rollers to use safe standard operating procedures;
4. Establish traceable standard roll records of plate rolls to monitor the use of plate rolls.
3. Low production efficiency in the printing shop
Whether we are in the normal production, because the plate roller is wrong, the plate roller serial number is wrong, or it is found that the plate roller has a problem, and what is more serious is that everything is ready, the normal production is started, and the plate is found. The roller has quality problems and cannot be produced. It can only be disassembled and replaced. This phenomenon is more than one. The most direct impact is that the order cannot be completed as planned, the delivery time is delayed, which causes contract liability compensation. At the same time, it will disrupt the overall production arrangement plan and cause the up and down processes to operate normally.
1.Establish a reasonable plate transfer management system;
2. Establish the internal tube control degree of the plate roller before the machine is inspected; (this suggestion is best enforced)
3. The quality awareness of the operators in the training workshop can be combined with data and field operations.
Table 2: Internal Quality Receipt Form for Gravure Plate Roller
Fourth, common quality problems of plate rollers
During the printing operation, common plate roller problems are: scratches, bumps, bumps, plate concave, chrome drop, etc.
Scratching refers to the presence of one or more scratched lines throughout the entire page during and after printing. It is very clear and visible. Copper may be exposed severely, which will affect the quality of the printed matter. In other words, the scrap of the plate roll needs re-engraving.
The main cause of scratches is improper printing operations. There is a misunderstanding in our existing operation methods: when printing blade pressure is adjusted, some of our printing masters use manual pressure to press the knife instead of adjusting the pressure of the blade through the blade cylinder. In addition, when there is a problem with the quality of the scraper, it is usually narrowly understood that the pressure of the scraper is too small. The scraper pressure value is used to control the scraping of the cleaner. There are also people who directly turn off the swing stroke of the scraper to solve the problem. If the above method is used for operation, the friction between the squeegee and the plate roller will be directly increased. Under high-speed printing conditions, the direct contact between the squeegee and the plate roller will be hard and hard, and the elasticity it should have is lost. In this way, the pressure of the squeegee blade is too high, the friction force increases, the blade will soon be flattened, there will be flipping, the plate roller will be damaged, the dots and chrome layer will start to become shallow, so that the blade line appears at a certain position on the page Cause damage to the plate roller and doctor blade.
Solution: When assembling the doctor blade, pay attention to the parallelism of three points and one line. Cultivate employees to master the correct operation and use of the squeegee and understand how to handle printing quality problems by properly adjusting the squeegee.
2, bump, injury
During the transportation of the plate roller or during the printing operation, foreign objects hit the roller body, resulting in local area scars and affecting the information of the graphic parts.
The main reason for bumps and injuries is that the plate rollers did not pay attention to the protective measures or the action range was too large during the transportation process, and the printing machine operation procedures were caused by deviations. This is because employees are too random when disassembling and disassembling plate rollers. They do not use special plate roll disassembly tools. Operators are not trained and their actions are not standardized. When the printing shop uses plate rollers, the operation is not standardized, and the procedures during the operation are problematic. Hits and injuries mostly happen to new employees or employees who are not responsible.
Suggestion: Develop appropriate and correct plate roll in and out management standards and operating procedures, which can train employees to correctly operate and use plate rolls, and make suitable plate roll special tools, such as plate transport vehicles, plate loading vehicles, etc.It is more important to pay attention to Good quality and responsibility training.
Intaglio refers to the indentation in a certain area of the plate roller before or during the production process, resulting in the incomplete printing of the graphic parts.
The main reason for the plate concave is the supplier of plate rollers. Such problems are relatively rare in the regular plate roller suppliers. But there is one phenomenon that deserves our attention, that is, missing carvings.
It is recommended that in addition to the regular inspection of each batch of plate rollers, it is more important to carry out a detailed inspection of the roller body of each plate roller. When printing on the machine, when cleaning the plate rollers, pay attention to the feeling of the hands when contacting the plate rollers. The difference between the recessed plate and the normal roller body is obvious. This must be summed up to better discover it. Secondly, after the complete sample is shot, it must be carefully checked to find the above problems.
4, chrome off
The discontinuous or continuous chrome layer peeling phenomenon occurs in the plate roller body in a certain area, which directly affects the product's graphic information cannot be printed and appears incomplete.
The main reason for the chrome drop is that the thickness of the chrome layer of the plate roller and the treatment effect are unqualified, and the main reason is that the storage environment and poor operation, maintenance and cleaning in the post-printing period will cause chrome drop. At present, many flexible packaging companies are talking about the concept of cost saving, and platemaking factories also have such a concept. When choosing a plate roller supplier, companies should not only consider the price, but also the quality. Some platemaking plants on the market cost 0.13 yuan per square meter, and some say that I can only pay 0.1 yuan, and there are lower ones. It is true that some companies may have room for cost in technology and management. They can compete at a lower price in the market while ensuring quality, but this is only a small number of low-priced plate rollers. There is a certain deviation in the treatment and thickness of the chrome layer. Secondly, the overall brightness of the plate roller, the quality of the dots and the ends of the plug will also have deviations. Therefore, we have to choose high-quality suppliers to ensure the quality of our products and plate rollers and reduce losses.
It is recommended that companies choose suitable quality, price and reputable flexible packaging plate roller suppliers to cooperate.The plate roller is best placed vertically.The roller body is wrapped with a breathable plastic film.The outside is wrapped with corrugated paper and placed in a designated area. It should be dry and ventilated, without humidity. The operator is strictly forbidden to touch the roller directly by hand, and there should be special tools for protection. Roller should be protected with special anti-rust oil.