(D) Preparation of new blankets In the preparation work, sometimes the blankets and liners need to be replaced (but not all are required), but when printing four-color long-lived jobs or when the quality requirements of the jobs are relatively high, If a damaged blanket is still used on the press, then it will make a big mistake and it will cause huge losses.
After the blanket has been contaminated with ink, it must be wiped clean until there is no stain on the surface. In the previous printing process, if the blanket has been dirty, even a small dirt spot should be replaced with a new blanket. When the previous job has been completed, but the ink supply system has not yet been cleaned, it is the best time to determine if a blanket has small spots. Apply the adhesive to the plate and allow it to dry, then apply it and transfer it. On the blanket, there is no dirt on the blanket at a glance.
About the maintenance of blankets, blankets, and blanket installation steps, etc., can be summarized as follows:
A, first remove the old blanket, then wipe the cylinder body clean;
B. Fix the bite of the blanket, and then put a pad with appropriate thickness under the blanket. To prevent the blanket from being misaligned in the printing process, insert the pad into the gap of the roller slightly;
C. Slowly press the printer until the trailing edge of the blanket can be fixed by the tail clip. During the press jog, the tension on the blanket is kept constant. Use a tail clip to hold the trailing end of the blanket, and use a large wrench to tighten the screw so that the blanket tension is appropriate;
During the commissioning phase, the basic conditioning steps of the traditional wetting system are listed below (however, the operating sequence of the continuous wetting system differs somewhat from this):
A. Put a clean water roller sleeve where needed;
B. If necessary, measure and adjust the pressure of the dampening roller;
C. Formulating fountain solution according to manufacturer's instructions;
D. Measure the pH, conductivity, and temperature of the fountain solution and adjust the fountain solution until proper performance is achieved. The pH and conductivity depend on the plate, paper, and ink parameters. The water used to formulate the fountain solution also plays a major role in the pH and conductivity of the fountain solution.
E. Open the circulation pump and inject the fountain solution into the water tank or the circulation tank;
F, adjusting the contact position of the ductor roller with the fountain roller, and controlling the amount of water transferred to the fountain roller;
G. Set the ductor roller and the fountain roller (these are only preliminary settings).
If a continuous wetting system is used, the basic operation steps may include the following, but since the characteristics and performance of the wetting system of each manufacturer are also different, it is necessary to refer to the manufacturer's instructions.
A, add anhydrous alcohol or alcohol substitute (the amount added is the minimum amount required for the system). Add dampening fluid to the circulation tank, open the circulation, and fill the tank. Check the pH, conductivity and temperature of the solution;
B. Open the system's drive motor and check that the metering roller engages with its drive gear. Adjust the wetting control of two printing units to achieve normal printing speed;
C. Initial adjustment of the metering roller. Adjust the metering roller until its two ends almost touch the chrome roller. Tighten the screws on the gears and the screws on the operator side until there is no thick layer of water on the metering roller, then tighten the screws 1/4 turn or 1/2 turn. The metering roller must be parallel to adjust the total water supply. Some metering rollers can adjust the tilt. Therefore, for the initial setting of this roller, consult the printer manual.
D. Adjust the speed of the chrome roller. The chrome roller controls the amount of water transferred to the printing plate. During the printing process, the adjustment of the chrome roller speed can play a role in compensating for changes in temperature, changes in humidity, evaporation of alcohol, and ink drying.
(5) Commissioning work of the ink supply system
The basic operation steps for setting up and maintaining the ink supply system are as follows:
A. Check the production order to ensure that the ink used is correct. If necessary, mix the ink according to the customer's requirements.
B. Inject ink into the ink tank and adjust the flow of ink transferred from the ink fountain roller to the ink distribution roller. When the uniform ink roller is in contact with the ink fountain roller, the ink fountain roller is rotated for several weeks, the ink fountain key is adjusted, and a thin layer of ink is evenly deposited on the ductor roller.
C, start the printer, make a series of ink roller ink. Determine the amount of ink that should be transferred to the substrate based on the specifics of the image on the plate, and adjust each ink key accordingly.
D. Set the swing amplitude (rotational amount) to 50% and set the speed of the ink fountain roller.
At present, many printers are equipped with a remote control console. If the printer is equipped with a plate scanner, the scanner can scan the plate and automatically reserve the ink fountain key through the obtained scan data. If there is no plate scanner on the press, place the plate on the console, and evaluate the ink demand at each place of the plate. Even if the area on the plate does not require ink, in order to ensure that the ink roller can be fully To lubricate, it is also necessary to keep the ink knife key slightly open, ensuring a minimum amount of ink.
According to statistics, black èèèèèère èèèère (ie KCMY) is the most commonly used printing sequence on multi-color printing presses. In 80% of cases, this type of printing color order is used. In addition, there are 7% of cases. The CMYK color sequence was used, and 4% was YCMK color sequence.