1. Grasp the book printing process requirements
(1) Familiar with standard samples (samples). Including the color of the sample, the main features of the image and the main technical requirements.
(2) Review the printing sequence. If there is anything wrong, it is necessary to propose amendments.
(3) Understand the main performance characteristics of printing materials.
(4) Master the main properties of the ink and solvent used.
(5) layout design, size, location, registration accuracy and printing pressure requirements.
2. Preparation check
Sheet-printing plate inspection. Whether the color version is damaged or not, and whether the plate size meets the requirements.
Plate cylinder inspection. The marking of each color plate cylinder is clear, and the circumference of each plate cylinder is measured to select the roller gear.
Check the bearing quality. The bearing clearance must be within the specified range. The bearing surface is clean and lubricated.
Printing materials, inks, additives and other quality inspection.
3. Printing press cleaning and inspection
When the printing press has just printed a batch of jobs and has not completely cleaned up, the equipment should be cleaned and checked. The main parts are as follows:
A. Remove the spool shaft and inspect it for damage.
B. Clean the ink in the ink tray and ink fountain.
C. Clean the ink pump and hose.
D. Clean the ink roller.
E. Clean plate roll and anilox rollers.
4. Adjustment of book printing presses
(1) Adjustment of the parallelism of the first printing unit, main parts:
Plate roll and impression cylinder;
Plate cylinder and anilox roller;
Anilox roller and ink fountain roller;
Measuring tool: feeler gauge (thickness 0.05mm)
(2) Adjust the registration of the rollers in the first half of the printing press so that the registration lines coincide and meet the regulatory requirements.
(3) The first half of the printing press gives ink.
(4) Adjust the second half of the printing press register.
(5) The latter half of the printing press gives ink.
(6) Adjust the working status of the ink roller to keep the ink uniform and the ink volume meets the requirements.
(7) Adjust the tension of the tape to maintain the stability of the tape tension during the printing process.
After the above process is all normal, it can be tested.
(B) Test and Printing
The trial printing process is as follows.
(1) Turn on the machine, make the impression cylinder in the press position, and perform the first test printing.
(2) Check proofs. Including the accuracy of registration, the situation of printing position, etc., if problems are found, further adjustments should be made so that the printing plate printing cylinders can achieve correct registration in both vertical and horizontal directions.
(3) Start the ink pump, adjust the amount of ink, and give ink to the ink roller.
(4) Power on the second test.
(5) Check the second test proofs. The inspection items are as follows:
Color density: When the color density is not normal, the viscosity of the ink can be adjusted, or the number of lines of the anilox roller can be changed.
Chromatic aberration: If the color difference cannot meet the requirements, the ink should be replaced.
Other deficiencies: Check and adjust as the case may be.
(6) After a qualified product is printed, a small amount of printing can be done before inspection can be conducted.
(7) In the printing process, it is necessary to always pay attention to the situation of registration, the color difference and the amount of ink, the drying conditions, and the change in the tension of the tape, etc., in order to make adjustments at any time.
