As a kind of environmental protection printing, flexographic printing has developed rapidly. The flexographic printing plate has high elasticity, high printing resistance and high resolution. To produce high-quality printing plates, in addition to high-quality plate materials, high-quality plate-making technology and plate-making equipment are also required. This article takes the JS900 flexible plate-making machine as an example to introduce the technical characteristics of flexible plate-making.
1. Flexible plate-making machine
JS900 flexible plate-making machine integrates four processes: exposure, plate washing, drying and post-processing. All production procedures are controlled by high-quality electrical appliances, with accurate data, high precision, and simple operation. The functions of the device are as follows: 1. Exposure: A special South Korean plate-making lamp is used as the exposure light source, and the light source is stable. 2. Plate-washing: Two-way automatic plate-washing is adopted. The brush is fine and has good stiffness. It can produce more than 200 lines of net-line version and finer lines and small text. 3. Baking version: constant temperature control and even heating. 4. Post-processing: Adopting Shanghai famous brand debonding lamp, mixed exposure, time-saving and high working efficiency.
Second, the flexographic plate-making process
Process flow of flexographic plate making: manuscript → film (negative film) → exposure → rinsing → drying → post-processing.
1. Manuscript: The manuscript design suitable for flexible printing should have the following characteristics: â‘ There are many colors, but there is little overprinting; â‘¡ There is no need to reproduce particularly small details; â‘¢ The network cable is not too high, but it can achieve the effect of color printing; Packaging and processing.
2. Film (negative film): ①It meets the requirements of plate-making, with clear graphics and accurate size specifications; ② Use frosted film; ③ Require the same density of film four corners; ④ Use medicinal film orthographic; ⑤ Use transmission density meter to measure the white density It is below 0.06; the black level density is above 3.5.
3. Exposure: Back exposure and main exposure:
â‘ Back exposure: The support film of the photosensitive resin plate is laid flat in the exposure drawer to receive the exposure. The ultraviolet light passes through the support film to cure the photosensitive adhesive layer. The purpose is to establish a solid base, and also control the depth of the plate wash, and strengthen the bonding force between the support film and the photosensitive resin layer. The back exposure time is determined according to the required substrate thickness.
â‘¡ Main exposure: the support film of the photosensitive resin plate is facing down, and the protective film is facing up. Tiled in the exposure drawer, tear off the protective film once, and then paste the film surface of the film on the photosensitive resin plate, cover the vacuum film on the film (non-drug film surface), vacuum, so that the film and the photosensitive The resin layer fits tightly. Ultraviolet rays pass through the vacuum film and the film transparent part, so that the photosensitive part of the plate is polymerized and cured. The length of the main exposure time is determined by the plate model and the intensity of the light source. If the exposure time is too short, the slope of the picture and text will be too straight, the lines will be bent, and the small characters and small dots will be washed away. On the contrary, if the exposure time is too long, it will be masked and the handwriting will be blurred. If there are large, small characters, thick and thin lines on the same printing plate, they can be covered with black film to expose separately, and the small parts will not be lost by washing to ensure the quality of the printing plate.
4. Rinse: Dissolve the non-photosensitive part, and retain the photopolymerized relief. The length of the plate-washing time is determined by the thickness of the printing plate and the depth of the printing pattern. The plate-washing time is too short, and the unphotosensitive resin will be left on the plate to affect the plate-making depth. Fall off.
5. Drying: remove the washing solvent and restore the printing plate to its original thickness. The baking temperature is generally between 50-60 degrees. The baking time is determined by the thickness of the plate and the length of the washing time. Generally, the thick version is two hours and the thin version is one hour. If the baking time is too long, and the baking temperature is too high, the printing plate will become brittle and affect the printing life. If the baking temperature is too low, the drying time will be prolonged. If the baking time is too short, the rotten version will occur during printing.
6. Post-processing: that is, desticking and post-exposure. Thoroughly harden (polymerize) the photosensitive resin to achieve the desired hardness index, and eliminate the viscosity of the printing plate to facilitate ink transfer. The post-processing time is obtained from the test, the purpose is not to crack or stick.
Washing And Drying Storage And Organization Tools
Washing And Drying Storage And Organization Tools,Laundry Soft Shoe Brush Artifact,Clean Soft Bristled Plastic Brushes,Non Slip And Seamless Hanger
Huayao Master (Puyang) Automation Equipment Co., Ltd. , https://www.huayaomaster.com