First, printing plate
The quality of the printing plate determines the printing effect. If offset printing is to achieve high quality, then every aspect of the plate making process must be standardized and meet the standards.
Water PS plate material should not be stored for too long, should be stored in a dark, moisture-proof, dry, well-ventilated environment, to ensure that the plate does not suffer any damage. Only in this way can it be ensured that the printed screens, patterns, and texts reproduced in the print are good, that there is no lack of pen strokes, that the layout of the screens is clearly structured, and the pattern depth is consistent. It is also recommended that the printing factory choose to use 1 to 2 manufacturers' quality plates and kits for long-term use in order to be proficient in proper exposure and optimum development time. Solar printing plates use a scattering film for double-exposing printing plates, and the printing effect will be better. Whether you use the version of the kit or self-developed developer, you must first develop the test, and then proceed to formal work. Correctly grasp the developer's fatigue level, absolutely avoid the improper development of the amount of developer caused by the depth of the printing plate is not the same as the drawbacks. In addition, attention should also be paid to the cleaning work of the printing plate glass, whether the suction of the printing plate is even and whether the film is close to the plate material film. If the pumping is not tight, it can easily cause the printing plate texts and outlets to send out imaginary flowers, and even some of the outlets will not come out of the sun, affecting the copying effect of the manuscripts, causing the manuscripts to be reproduced badly, etc.. In case of major books and publications, reduce them. Production costs, improve the printing plate's resistance to printing force, it is best to put the sunning PS plate in the oven for 5 to 8 minutes, and the correct understanding of the oven temperature 230 °C ~ 250 °C. The operation must be standardized, and the plate must be handled cleanly. If necessary, use 3% phosphoric acid solution for the surface treatment of the PS plate to reduce the chance of the plates being dirty and improve the quality of offset printing. The film in the books and magazines must be clean and there must be no dirt on it. The cutting must meet the standards and must not be too small. In order to facilitate the layout, the tape should not be too large during the imposition, and the paste should not be too much. The pattern and text should not be too close. When the sunscreen is vacuumed, the pattern of the PS plate, the text is false, or the stroke is missing. , affect the quality of books and prints.
Second, signature proofs
The level of quality of signature standard proofs is a reliable symbol for guaranteeing balanced ink consistency in offset printing publications. The work of signing the books before the opening of the books is very important. They must possess rich work experience and a certain degree of artistic art and culture, as well as a high degree of responsibility for work. The person who is responsible for signing the sample should send the ink proofs signed by the operator to the machine operator. It must carefully and carefully check whether the size of the printed version of the sample, the binding procedure, the printing pressure, and the ink color on the surface of the printed product are uniform. Approach or meet the standards required for normal printing. Before the ink color was confirmed, the operator of the machine could not start printing. Signed ink standard proofs should be kept properly and posted on the sample stage. During the normal printing process, the operator of the machine must diligently check the prints on the machine against the standard ink proofs on the sample stand to prevent the printed inks from being printed with different shades of ink and from the requirements of proofs. If the volume of products is large and the cycle needs urgently more than one offset printing machine to print a single book, all the ink proofs that sign the offset printing machine of this book must be printed by the first machine that prints on the same standard. Each printer must have a standard ink signature proof. All printed books and magazines are printed according to the ink color standard of this kind of printing. They must not be sloppy and deviate from the ink proofs. When printing, according to the actual condition of the paper, the ink color of the print should be slightly larger than the ink of the signature, so as to prevent the ink color of the ink from being changed due to the drying of the print, resulting in the ink of the printed book not satisfying the requirements of the signature.
Third, ink auxiliary materials and ink roller
Whether the ink mix and the adjustment of the ink roller is appropriate, whether it can maintain good printing performance during the entire printing books and periodicals, this is also one of the main factors that the offset printing can guarantee the uniform ink color. When printing the same batch of the same book, as much as possible using the same manufacturer's ink as required to avoid the mixing of inks from different manufacturers or different labels, resulting in inconsistency in the hue and color density of the used ink, resulting in serious ink in the printed books and periodicals. Inconsistent. Whether it is a single shift or multi-shift production, auxiliary materials for inks, such as No.6 varnish, release agent, etc., must be metered and added in the same proportion, and resolutely prevent accessory materials from appearing indiscriminately. Appropriately added according to seasonal temperature changes, such as high temperatures, high ink fluidity performance is unstable, try to add the original ink, keep the original ink for printing; low temperature in winter, ink flow is poor, as little as possible to add some 6# oil, add more The ink density will be reduced and the printed text will be black and light at the time. However, after the ink is absorbed by the paper and penetrated and dried, the text is dark, and the printed product is dull and dull, and it is also easy to cause instability of the ink properties, resulting in serious ink emulsification, fouling of the layout, and the like. Therefore, the auxiliary materials for ink should be reasonably controlled and properly used, otherwise it will affect the quality of books and periodicals and cause malpractices such as uneven ink.
In terms of ink roller, we should choose a variety of properties of domestic famous manufacturers and test rollers with complete testing equipment and ISO 9002 certification. It requires a moderate hardness and a good viscous surface on the roller. When adjusting the ink roller, a single person should hold the plug that meets the standard and adjust whether the tightness of each roller is the same and whether the left and the right balance. At the same time we must ensure that the pressure of the ink roller is moderate, and the left and right pressures must be in parallel. The even ink roller and the ink roller cooperate well with each other to keep the printing plate uniform and minimize the inconsistency between the ink and the ink before and after printing. , And carefully check whether the surface of the roller by the plate is smooth and smooth, whether there are big flaws, such as indentation, scratches, or poor adjustment of the ink, causing local conjunctiva and crystallization. In the printing process, especially large-volume books and periodicals, in order to ensure the quality of books and periodicals, it is necessary to frequently clean the ink on the ink roller, paper powder, dirt ink and printed waste. Keep the ink roller's good ink-transmitting property, reduce the wear on the printing plate to ensure that the surface of the printed book and print is clean and tidy, with clear graphics and uniform and glossy ink.
Fourth, paper
Paper smoothness, ink adsorption, elastoplasticity, water content and whiteness, pH and other technical indicators, affect the printability, which all play a decisive role in the quality of books and magazines printing. In order to ensure the quality of the overall quality of the printing paper, the paper must be standardized. The same weight of paper, due to different manufacturers, the technical standards inherent in the production process are not the same. Therefore, in order to ensure the quality of the printing of books and periodicals, the same batch of books and periodicals must use the same manufacturer's paper, and it is the same batch. Eliminating indiscriminate use of paper with different manufacturers' weight, so as not to cause the appearance of books and printed papers with different shades of color. The same amount of ink is printed on the paper. Because the different colors of the paper are different, the amount of ink absorbed is not the same. The inks of printed products are also inconsistent, which affects the overall quality of the publications. For those papers with low smoothness, some printing pressures should be appropriately increased during printing, and some ink supply volume should be increased to prevent the paper from being loose, the amount of ink sucked is large, and the phenomenon of ink dullness after printing is dry. For papers with relatively poor paper quality, they must be taken seriously in the printing process of books and magazines. Don't be swayed, and you must resolutely print according to the color standard of the ink sample.
Fifth, fountain solution and water roller
The use of fountain solution and water roller to adjust the ratio is correct and appropriate, which is the fundamental guarantee for the consistency of the ink color of printed books and periodicals. In the printing process of books and periodicals, the distribution of fountain solution should be appropriate. No matter whether it is a single class production or a multi-shift printing, the concentration of fountain solution must be strictly established according to the unified proportion standard, and the stability of the fountain solution pH value must be ensured. In the case of water, the printing plate uses the minimum amount of water supply to obtain the best print quality, as long as the printing plate is free from dirty, non-dry printing, and the quality of the printed product. In the printing process, it is often necessary to inspect whether the pressure between the water roller and the printing plate is tight and the water roller is in balance between the adjusting water roller and the uniform water roller. This is a key issue. In particular, when adjusting the water roller, a single person should hand-hold steel plugs that meet the standard requirements and test the pressure of each roller equally and tightly.
In the normal printing process, the water fleece jacket and the uniform water roll body surface should be kept clean, clean and free of dirt, ink and other impurities. If the dirt impurities are too thick, it will affect the water supply status during printing. Due to insufficient water supply on the surface of the printed product, the surface of the printed product has become dirty, the font has become thicker, and the water supply on the layout has been uneven. As a result, the ink on the surface of the printed product has a dark and uneven color. In order to ensure the consistency of the quality of the book printing ink, it is necessary to immediately clean the ink stain on the surface of the uniform water roller, replace the water velvet cover, and maintain a uniform water supply of the water roller. Only in this way can a stable and good water supply condition be maintained. , Print out uniform and good ink and paper publications.
Six, blanket
In the printing process of books and books, the various properties of the blanket itself, and the use and maintenance of the blanket, are directly related to the reproduction of the manuscript, and the printing capacity of the printing plate. It also determines the transfer effect of the ink and the quality of the book printing. Happening. When printing, it is best to choose a blanket that is uniform in thickness, free from scratches, creases on the surface, and has good surface texture. It is recommended that the printing plant should use the air-cushion blanket cloth on the machine to maintain good ink absorption and good ink transfer during the printing process. When printing, depending on the smoothness of the paper surface, the tightness of the surface of the paper, and the condition of ink absorption, the surface of the blanket is kept clean, and the printing dust such as paper powder and paper stuffing on the surface of the blanket is cleaned in time to prevent the surface of the blanket. The dirt and printing waste accumulated too thick, and the rubber layout part was pressed and deformed due to the roller compaction during printing, resulting in the printing of printed books, prints, texts, inks due to local pressure, and blotting, affecting the balance of ink in books and periodicals. . Under normal circumstances, the blanket is slightly under pressure, the imprinting is imaginary, and it is better to use a rubber reducing agent to restore the blanket. If the frontal effect is not ideal, take the open area of ​​the blanket and rub it with reducing agent from the back. This works well, for the site of severe pressure reduction is invalid, paste to be accurate, as far as possible with glue and thin paste is not easy to thick, it is necessary to make up the patch can not be raised, otherwise the dark part of the raised part is also easy to wear off the version. In order to prevent the appearance of conjunctival crystallization and cracking on the surface of the blanket, the blanket should be thoroughly cleaned and maintained from time to time to restore the blanket's good elasticity and good ink absorption to complete the best pattern transfer printing. process. Only in this way can the occurrence of aging of the blanket be slowed down and the consistency of the ink color in the printing of books and periodicals can be guaranteed.
Seven, printing pressure
Printing pressure is an important factor in the transfer of ink during the printing process. The appropriate printing pressure in the printing process of books and periodicals prints the printed pages, texts and patterns clearly and cleanly, and the characters are not deformed and the ink is uniform and reliable. In the printing process, according to the quality of the paper used for the publication, the rubber roller and the padding material of the printing plate should be properly and reasonably selected, and the pressure between the three rollers should be properly adjusted. This is neither too large nor too light, ensuring the most appropriate Good pressure, so that the book printing process is always in the best state of uniform ink transfer.
Eight, printing speed
The printing speed is the fundamental guarantee of high efficiency. The stable printing speed is a reliable basis for stable ink transfer in the printing process of books and periodicals. In printing, the printing speed is directly proportional to the strength of paper peeling. The size of the peeling tension directly affects the degree of darkness of the printed book. Under the condition that the printing pressure is constant, the printing speed determines the ink transfer effect, which directly affects the printing quality of books and periodicals. So in bulk books
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