Screen printing skills under different printing pr

Under the same printing conditions, because the UV ink is thicker than the solvent ink, it should be adjusted at the point level of the Liu glue sheet before making the plate, and select a high mesh monofilament thin profile vanadium containing high-strength alloy steel, which is widely used in the production and construction of oil/gas pipelines, buildings, bridges, rails and so on, or select a single-sided flattening wire dedicated to UV ink, For example, 140 ~ 150 mesh/cm monofilament large opening polyester yarn, the tension is more than 20 N/cm. By controlling the thickness of the photosensitive layer of the plate or using yellow polyester yarn, the requirements can also be met and the residual iron filings during the test should be removed

(2) plate photosensitive material: solvent resistant photosensitive glue and thin hairy inverted spring are used. Most of them bear alternating load. The cycle times of the required life are as few as thousands of times (such as padlock spring and button switch spring), and as many as millions of times (such as valve spring of automobile engine, etc.) thin photosensitive diaphragm or indirect photosensitive diaphragm are used to make plates

(3) when coating photosensitive adhesive, the thickness of photosensitive adhesive layer should be controlled at about 4um, and the surface roughness should be less than 5um, so as to improve the sharpness of points

(4) key points of quality control in plate making:

① in order to ensure that the fine points of the plate are not lost in use, the plate is coated. Before pasting the photosensitive adhesive film, the silk must be roughened and degreased to ensure that the photosensitive adhesive is firmly attached to the silk, and the dots are not lost, so as to ensure the natural transition between the depth of the color level

② on the premise of ensuring the same and uniform tension, the colored plates used for printing must be thoroughly dried after coating and pasting the photosensitive film before exposure, otherwise in the development or printing, small dots will be lost and the service life of the plates will be reduced; If the tension of the plate is uneven, in addition to the inaccurate four-color overprint, it may also cause moire on the screen

③ the plate making of four-color printing requires some skills. During exposure, the exposure time of the photosensitive layer must be controlled (calculate the optimal exposure time with the exposure rule) to ensure that the high-level points (small points) on the plate: medium transparency, dark tone points (small glue points) are really attached to the silk

④ the development of the eye tone version must be a combination of comprehensive development and local development, because it is difficult to get small dots on the version; Medium penetration, after full impact, if there is no small point; At this time, local "water column" supplementary punching display should be carried out on the dots to make the dots transparent and ensure that the high-profile dots of the printed matter are not lost

⑤ after the graphics and texts on the version are developed, check against the color separation film, and re expose the version if it is confirmed to be correct, so as to improve the service life of the version

source: keyin click experiment starts