Precautions for making the screen printing plate o

(1) multi picture collage design. One plate, one picture and many combinations are the remarkable characteristics of packaging trademark plate making, which requires high overprint accuracy. In the past, manual joint drying was very troublesome. First, the extension machine scanned a set of negative pictures, and then the masking process was used to turn the positive pictures into a picture and text integrated version. If there are 20 pictures in a layout, use the positive pictures to copy them into five identical negative pictures, put the five negative pictures together into a piece, and then use the hanging nail method to copy them for 4 times, and finally form a 20 joint positive plate. The biggest disadvantage of this process is the serious point loss and inaccurate overprint. Later, the combined drying machine was used. Although the problem of overprint accuracy was solved and the "guidance on accelerating the deep development of civil military integration in the shipbuilding industry" was implemented, the problem of point loss could not be fundamentally solved. Now the application of color desktop system makes the cumbersome manual production in the past easy, and solves the problems of point loss and inaccurate overprint

(2) hollow out and mosaic design. Packaging trademark plate making often meets the process of hollowing out and inlaying. 3.2 imitation flocking interior material method. Especially in the case of manuscripts that need to be printed with gold and silver, the plate making must be made into hollow inlays, otherwise it would have to be printed twice instead of once. Because the quality of gold and silver ink directly printed on the ink is poor, wet printing with wet press ink is easy to cause insufficient amount of gold and silver ink, resulting in the problem of color darkening

(3) box size design. Die cutting is an indispensable process in packaging trademark printing factory. Among them, die-cutting size is required to be accurate, and the design of box size is the basis to ensure quality. The vast majority of customers are not clear about the details required in the box size design, or the box size manually drawn in the submission is not accurate. If it is copied as is, it is difficult to ensure the quality of the final die-cutting box. Therefore, when making plates, it is necessary to process the size of the matching boxes according to the box size provided by the customer, as well as the thickness, box size and folding shape of the substrate paper, so as to produce an accurate multi splicing die-cutting knife line plate

at present, there are ready-made packaging box shape design software abroad, and packaging box shape design software has also been developed in China. In the future, with the application of these software in the high-end connection system of the electric extension, as long as a few corresponding data are input, the standard box size and reasonable combination graphics will appear on the display screen immediately, so as to standardize and standardize the box design of the packaging trademark

silk screen printing plates made directly with photosensitive emulsion are widely used in silk printing at present. Similarly, in packaging trademark printing, direct plate making method is also widely used to make printing plates. Its production process and technical problems that should be paid attention to are as follows

basic process characteristics of direct plate making

the process flow of silk screen printing plate directly made with photosensitive emulsion is: Silk degreasing → silk drying → gelatinizing photosensitive glue → template drying → template supplementary gelatinization → template drying → exposure → development → template drying → inspection and revision

the operation methods of each process are as follows

silk degreasing: use photosensitive emulsion to directly make silk printing. Before making template, the silk plate must be degreased with appropriate degreasing agent or liquid

silk drying: after degreasing, the silk plate should be washed with clean water, and all the water on the plate should be removed with an air brush, and then put into room temperature for thorough drying

gelatinize photosensitive glue: use a suitable gelatinizer to evenly scrape diazo photosensitive emulsion onto the silk plate, usually wet to wet coating

template drying: the template coated with photosensitive emulsion must be placed horizontally in the drying oven, with the printing side down, and the drying temperature must not exceed 40 ℃

template supplementary gluing: in order to eliminate the unevenness of the photosensitive layer of the template, a layer of photosensitive glue can be scraped on the printing surface of the template

template drying: dry again in the same way as the first drying, and the drying temperature shall not be higher than 40 ℃

exposure: use a suitable light source, such as a metal halogen lamp, to expose the template. Exposure time is determined by graded exposure. Development: spray the development with a tap water spray gun with appropriate water pressure to completely wash out the pictures and texts. Pay attention to the instructions of the photosensitive adhesive manufacturer on the development temperature

template drying: gently wipe the excess water on the printing plate with unused newspaper or hygroscopic cloth. In case of large-scale plate making production, special equipment is needed to absorb moisture, and finally the plate is dried in a drying oven

revision: any pinholes and defects on the printing plate can be covered with water-soluble silk filler for revision

author/Lin Qishui