In the process of printing, phototypesetting film is a material that is often used. Please pay attention to the following items in the use of phototypesetting film:
1. Although the general photographic film is a bright room film, the film loading process can be completed under the indoor light source, but in actual production, it should still strictly abide by the operating regulations, install the film into the film loading box as required, and the cover on the stage , Tighten the screws on both sides of the top of the box (note that both sides are forced to maintain balance) and then tear off the protective film guide, so that the two sides of the film exposed at the film exit are parallel, and the width is about 1.5 ~ 2cm. The bottom of the box prevents the film from falling.
2. Each batch of film should be tested for basic density and dot linearization before being put into use, and then take corresponding technological measures according to the test results, such as adjusting the laser focal length, exposure, developing and fixing temperature and time to achieve Standardized and scientific production to prevent unqualified products.
(1) Film density is divided into high density and low density. Low density refers to the density of the completely unexposed area after the film is developed, generally around 0.05. The lower the low density value, the clearer the film, and the better the quality of the printing dots. High density refers to the solid density of the film after processing at 100% exposure. Generally, the printing film used for printing on coated paper requires a high-density value of not less than 3.5, usually 3.5 to 4.5, which can ensure that the image information on the film is transferred to the printing plate well during printing. When printing on newsprint and offset paper (including map paper), the high density of the paper can be reduced due to the paper's strong ink absorption and high printing speed.
(2) Linearization means that in the color separation platemaking, it is required to ensure that the dot value set in the computer can be truly reflected on the printed film. Taking 50% neutral gray as an example, the place where 50% dots of graphics and text on the computer are required to be output to the printed film must also be 50%, and the dot error should not exceed 1%, otherwise it will cause distortion of the printed image This is particularly evident in color four-color printing. However, it is difficult to guarantee the stability of the film development and fixing conditions, so it is more rigorous to test the linearization every day.
3. Adjust the concentration temperature of the display fixing solution and the display fixing time.
(1) Other conditions remain unchanged. The higher the concentration of the developer and the higher the temperature, the higher the density of the film. If you use domestic developer (for example: Abbey SH-1000) to develop the film, you generally need to dilute the chemical solution according to 1: 4 ~ 1: 3. It should be noted that if the development temperature is set too high, the developer will evaporate and oxidize. The speed is too fast and it fails, causing the film fog to be too high, and the high density can not meet the requirements. The recommended temperature is 34 ~ 36 ℃, and the density should be measured and linearized when the developing temperature is stable and reaches the set temperature.
(2) Other conditions remain unchanged, the higher the concentration of the fixing solution, the higher the temperature, the lower the film film haze (low density), the dilution ratio of the general domestic fixing solution is 1: 4, and the excessively high fixing temperature setting (Or excessively high temperature in summer) will cause the fixing solution to fail due to evaporation or oxidation too fast, resulting in excessive film haze, but also will make high density can not meet the requirements, and will form the liquid crystals attached to the fixing roller , Scratch the film, so the recommended fixing temperature is 28 ~ 32 ℃, fixing time is 30 ~ 35 seconds.
4. The laser phototypesetting film contains an anti-halo layer. Some of it will fall off during the fixing and water washing process, forming light blue water spots on the film base. It can be eliminated by adding an appropriate amount of hardener to the fixing solution. The washing tank should be kept clean frequently, and the water in the sink should be drained off after work every day and wiped dry with clean gauze. Before adding water each time, let the water drain off to remove the rust. At least once a week, insist on cleaning the water roller.
Decoiler Straightener feeder machine in the short space design were especially developed to meet the needs of customers with not enough space. They offer process reliability even for the most demanding materials. They are optimally suited for the manufacture of structural parts as well as for processing of high-strength materials – even for the higher ranges of strip thickness.
Recently, feeder-Straightener up to 2000 mm stock width and approx. 9mm thickness, coil loading up to 20tons.
The principles of Decoiler straightener feeder is that the motorized Decoiler (Coil Reel) with drive continually moves the strip into a bottom coil loop supplying the Feeder-Straightener,and then feed the strips into the power press machine as well.
Decoiler straightener feeder machine is widely used in sheet metal stamping, auto parts industry, hardware stamping industry, home appliance industry, electric appliance industry and etc.
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