White spots in printing are relatively common problems in the printing process of adhesive labels. Mr. Qiang Yongsheng, Technical Service Manager of Dongguan Ande Label Material Co., Ltd., based on the experience collected from customers over the years, summed up the causes of white spots in the printing process of adhesive materials, and proposed corresponding solutions. share it. In general, there are four main reasons for the problem of printing white spots: rough label materials, powder dust, static electricity, and dust in the workshop environment. This article will give solutions to the above four problems. 1. White spots caused by the rough surface of the material At present, in our country, the printing of self-adhesive labels is mainly based on two printing methods: letterpress and flexographic. These two printing methods have high requirements on the surface roughness of the self-adhesive materials. For example, the self-adhesive material of coated paper surface material, if offset printing is used, its surface roughness (the difference between the height of the material surface) is less than 1.4 microns; but when using relief and flexographic printing, its surface roughness needs to be less than 0.7 microns to ensure printing No white spots appear during the process. This is because the printing pressure of the latter two printing methods is much lower than that of offset printing. If the surface of the self-adhesive material is not smooth enough, some of the surface of the material will not be printed with ink, which will form white spots. This phenomenon is particularly likely to occur in In the process of printing large area dot graphics. Under high magnification, the characteristic is that there is no ink at all in the white spot area. This is because the white dot area is lower than other areas, and the ink on the printing plate is not transferred to the surface of the material. There is another obvious feature of printing white dots due to the insufficient smoothness of the material surface, that is, the white dots are often large in area, and in most cases the full version is very obvious. Encountered this type of printing white dot problem, we can solve it in the following ways: 1. Replace qualified materials. The surface of the self-adhesive material is not smooth enough, which is a material quality problem. We can ask the material supplier to replace the qualified material for production. 2. However, as far as the author knows, in most cases, the replacement of materials can not guarantee the construction period, because the production cycle of self-adhesive label printing enterprises is quite compact. Moreover, the printing factory needs a series of preparation work to replace the work. Once the material is not suitable for printing, the preparation work is done in vain, which seriously affects the production efficiency for the printing house. If this is the case, we can consider printing a layer of primer or dilute agent on the surface of the material. These two printing aids are basically colorless and will not affect the color of the printed matter much. After printing these two additives, the surface of the material will be filled flat, artificially improving the smoothness of the material, the phenomenon of printing white spots will be greatly reduced. Medical Record Trolley,Confidential Medical Record Trolley,Steel Medical Record Trolley,Detachable Medical Record Trolley NANJING TIANAO MEDICAL INSTRUMENTS MANUFACTURE CO.,LTD. , https://www.tianaomedical.com