Coated paper is an important material for the packaging, decorating and printing process. The print quality of the product depends to a great extent on the advantages and disadvantages of the material itself and the extent to which the operator grasps the characteristics of the paper. In other words, in order to print coated paper products, corresponding technological measures must be taken according to the characteristics of the paper. Therefore, it is necessary to understand and understand the technical requirements for printing coated paper.
The classification of coated paper is based on the difference in the filler and calendering process, and is generally divided into single-sided light and double-sided light. Divided casein paint from the nature of the coating. So coated paper is also called coated paper. Because some domestic coated paper due to defects in the process, so easy to produce varying degrees of powder and stretching variation, in particular, single-sided coated paper is more prone to curling ills, affecting the accuracy of overprinting. Some arts and crafts of printing coated paper are not properly handled, and it is easy to produce dirty (bottom), powdered, slow-drying, and lack of bright star light. Therefore, the following issues should be noted.
1. Before each batch of coated paper is put into use, a series of problems related to printability, such as smoothness, pH, absorption, drying, stretchability, and surface bond strength, shall be tested and analyzed. The characteristics of paper, to take appropriate technical measures, such as adjusting the ink viscosity, fluidity, dryness and anti-stick measures to achieve standardized scientific production, to prevent the occurrence of bad printing;
2, to put a good pad version of technology and printing pressure debugging, to ensure that the printing ink layer even and bright. Coated paper printing pressure should be obtained evenly and properly, the pressure is too heavy to easily produce powder off the bad situation, and can easily cause the dot blot imprinting ills, and increase the printing plate wear. On the contrary, it is easy to cause dot blotting is not strong, and blindly increase the ink layer to compensate for the lack of pressure caused by the layout of the flowers, so easy to produce sticky, slow dry, overprint and other adverse consequences, so the pressure of printing coated paper to be uniform Should be appropriate. Lining is made of neutral hard materials.
3, use the coated paper printing trademark, packaging products, often with a light color as the background color, made by overprinting. This improper printing of the right process, but also easy to produce some problems and affect the quality, so, in the deployment of the base color ink, it should try to use heat and light resistant ink, and dilute the best use of bright paste deployment, so you can put the background color The final printing effect is better, so as to prevent the bottom color from printing and rubbing the ink layer.
4, due to the copper plate about the surface is smooth, poor ink absorption ability, when printing the large version of the field version, should try to do "deep ink thin printing." That is, the ink phase is appropriately deepened so that the ink layer is correspondingly or thin when printing, that is, it can meet the requirements of printing hue, and it can also reduce the chance of occurrence of imprinting at the end of the print, and can prevent overlapping of the ink on the ink. In addition, due to the poor adhesion of the paper, the printed ink layer is sometimes easily discolored due to powder loss. For this purpose, the first color of ink can be used as No. 19 resin oil as the transfer ink. In order to make the laminated ink layer bright, you can add some bright oil and dry oil in the ink.
5, coated paper due to a lot of paint, printing process often encounter de-powdering and print layout appear dark phenomenon. In this case, attention should be paid to checking whether the process of the plate-making process, such as the presence or absence of the pad on the printing plate, is too heavy. If the paper surface pressure is too high, it is easy to crush the coating powder on the surface of the coated paper, resulting in de-powdering and Dark spots. In addition, we should also check whether the ink viscosity is appropriate. If the printing ink layer is over-thick and sticky, it is also one of the reasons that causes the paper surface to fall off powder and accumulate the layout. In this case, you should consider applying auxiliary materials to adjust the ink. Quality, the above quality problems can be better overcome.
6, to make a good coated paper printing anti-adhesion process technology. Coated paper is weak in ink absorption, and the back is relatively smooth, so that the printing of large-printed pages or multi-color overprinting, easy to produce sticky problems, it should take measures to overcome the stick, such as the amount of light to take the first The anti-sticking agent is evenly mixed to make it liquid and then added into the ink and mixed well. When printing, a good anti-sticking effect can be obtained. However, the amount of anti-adhesive agent should be properly controlled and cannot exceed 4%, so as to avoid adverse effects such as ink emulsification, printing ink layer blooming, and ink layer glossiness decreasing.
In short, as long as the properties of printed copperplate paper are mastered and the correct printing and operating techniques are closed, not only printing efficiency can be improved, but also the printing quality can be effectively guaranteed.