The technological process of book printing;
Imposition-Exposure-Development-Wiping-Bake-Plate printing one by one
Lithographic printing is mainly offset printing. Now take offset printing as an example to introduce the technological process of book printing and the work of pre-press, in-press and post-press.
1. Pre-press preparation
The preparation work includes: paper mixing treatment, ink preparation, dampening solution preparation, printing plate inspection, printing pressure adjustment, etc.
Paper humidity control is mainly to prevent the uneven moisture content of the paper caused by the environmental climate and cause the paper to deform and generate static electricity. This phenomenon is absolutely forbidden in printing.
2. Trial printing
After the pre-press preparations are done, you can load paper, plate, and start-up debugging. During start-up operation, the paper feeding mechanism, paper delivery mechanism, ink feeding device, water feeding device, printing pressure and other aspects must be adjusted to ensure smooth paper feeding, moderate water supply and ink supply, and appropriate printing pressure. Produce high-quality prints.
After the above work is ready, turn on the machine for a while to make the ink supply and water supply moderate and even, and then add some printing paper on the paper feeding table for trial printing. If it is multi-color printing or color printing, registration adjustment is also required to determine whether the layout position is appropriate, whether the graphics and text are skewed, whether the head, foot, left and right size and direction are registered (usually register with the rule line) adjust). After the registration operation is completed, trial printing is started, and a few samples are printed for quality inspection.
Ink preparation work includes the preparation of special inks and the addition of some additives to conventional inks. If the viscosity of the ink is not suitable, you should add a varnish to increase or decrease the viscosity; if the ink is not dry, you can add a dry bath agent. Adding various additives must be based on the process, equipment, paper and environmental temperature, etc., and the amount should be appropriate.
Printing plate inspection includes: printing plate type, color inspection, printing plate thickness inspection, printing plate mouth size inspection, rule line inspection, printing plate depth inspection, and the quality of layout graphics, whether there is dirt Inspection of damage, scratches, etc.
Printing pressure adjustment: According to many factors such as printing plate thickness, paper specifications, blanket thickness, lining material thickness, printing process requirements, etc., select the appropriate cylinder lining so that the printing pressure meets the printing process and quality requirements.
3. Formal printing
Official printing
Before the formal printing, add some pass paper, and reset the counter to zero after the pass paper is printed. Sampling inspections should be carried out frequently during printing, paying attention to the changes in water and ink, the printing force of the printing plate, the cleanliness of the blanket, and whether the printing machine’s oil and air supply conditions and operation are normal.
Four, post-press processing
After printing every day, or when each batch of printed parts is completed, post-printing processing operations must be carried out, which include: cleaning of ink fountains, ink rollers, water rollers, blankets, and impression cylinders, and processing of printing plates and printed sheets. And the maintenance of the printing press.
Five, cover and color page special printing and other processes
