Printing of Gold (Silver) Ink on the Offset Press (II)

Third, the printing should pay attention to the problem 1, the adjustment of the equipment Offset gold (silver) ink transferability compared with the general ink is worse. In order to guarantee the smooth printing of gold (silver) ink on the offset printing press, the three leveling work of the machine should be done before printing the gold (silver) ink. The pressure of the water roller, the ink roller and the roller must be leveled. Roller liners are preferably lined with a neutral liner. The gold and silver powders in the gold (silver) ink generally have a sheet structure. In order to ensure that the gold powder and the silver powder are smoothly and evenly transferred to the surface of the substrate, the printing pressure when compacting, flattening, and printing the gold (silver) ink is relative to the ink. The pressure of other inks should be properly adjusted. The printing plate can be increased in printing pressure. The printing pressure of line printing and text printing should be appropriately reduced, so that the printed version of the gold (silver) ink layer is thick and uniform. The visual effect is good, and the gold (silver) ink on the lines and the text version can avoid the undesirable phenomena such as the enlargement of the print, the stencil, and the ambiguity of the writing.
2. The fountain solution The effect of printing gold (silver) is good or bad. The preparation of the fountain solution is also worth the problem. It must be correctly mastered. Generally, the dampening solution prepared from ammonium dichromate and phosphoric acid is used. The pH should be strictly controlled at about 3 to 4, and gum arabic should also be properly added to enhance the decontamination effect. The solution prepared with 2 parts of isopropyl alcohol and 8 parts of clear water with small surface tension, good wettability, and reduced water content on the plate can also be used as a fountain solution, and the effect is also very good. When printing gold (silver) ink, the water on the surface of the printing plate should be uniform and should be kept to a minimum.
3, printing speed When printing gold (silver) ink, the speed of the printing machine can not be too fast, with 3500-4000 pieces per hour is appropriate. When the printing speed is too high, the temperature of the ink roller increases significantly, and the gold (silver) ink is not only easily oxidized and darkened, but also the transitivity is deteriorated, causing a large amount of gold (silver) ink to accumulate on the roller, and on the substrate. The gold (silver) ink layer is lightly flowered.
4, the deployment of gold (silver) ink and use of gold (silver) ink printing the greatest impact on the quality of the product is the gloss problem, therefore, the gold ink should be with the current use, each time the printing adjustment time can not be too much So as not to waste.
In the printing process, the gold (silver) ink in the ink fountain should be correctly mastered, and the new ink should be added in due course according to the printing situation. The premature deployment of gold (silver) ink and the lack of new ink in production for a long time can easily cause the gold (silver) ink layer to have a lower gloss. After a batch of products are printed, the remaining ink will have problems such as swelling, reduced viscosity, and darkening of the gloss after it is stored for a period of time. This will affect the printing effect and should be discarded. No further use can be made. 5. Control the temperature and print gold (silver) Ink should master the temperature in the printing room, generally controlled at 22 ~ 25 °C, the temperature is too high or too low on the printing of gold (silver) are detrimental. If the temperature is too low, the flowability of the gold (silver) ink will be reduced; and if the temperature is too high, the transferability of the gold (silver) ink will be poor.
When the temperature in the printing workshop exceeds 38°C, the rubber roller can easily dry the skin and affect the ink transfer. At this time, spraying the rubber roller with the dibutyl ester solvent used by the mosquitoes of the household can provide a certain mitigation effect.
When printing gold (silver) ink, be careful not to let the wind blow the offset printing machine directly.
6. Paper The choice of paper for gold (silver) products is crucial, and the paper properties must be compatible with the process characteristics of gold (silver) ink printing. Offset paper and letterpress paper have strong ink absorption, and gold (silver) ink does not show the metallic luster of gold (silver) ink well after printing. Good surface quality copper plate, glass paperboard, whiteboard paper (slightly time) are more suitable for printing gold (silver) ink, metal luster is more likely to show up, can give people an artistic beauty.
7. Drying problem After printing gold (silver) ink, do not rush to dry the printing product, because the drying speed of gold (silver) ink is slower than that of general ink. Do not add more dry oil, or gold (silver) ink particles. It will become thicker and there will be more ink on the ink roller, which will cause the adhesion of the printed product.
In order to prevent the gold (silver) ink layer from coming off in contact with air or other chemical substances, after printing the gold (silver) ink and other colors, it is necessary to overprint Veoli oil once again or to coat the printed product.
In the process of gold (silver) ink offset printing, it often encounters problems such as heaping ink, stencil printing, powdering, lack of bright color, lamination, and stickiness. There are many factors that affect the quality of gold (silver) ink offset products. As long as we constantly explore and sum up experience in various aspects, we must carefully understand and master the printing performance of gold (silver) powder and linking materials, and correctly deploy and strictly operate the process. Is fully able to obtain satisfactory printing (silver) packaging products.