Prepress preparation and trial printing of the hot

Prepress preparation and trial printing of album printing

(I) prepress preparation of album printing 1. Master the requirements of album printing process with load measurement and load feedback device in this unit

(1) be familiar with standard samples (samples). Including the color condition of the sample, the main characteristics of the image and the main technical requirements

(2) review the printing color sequence, and put forward suggestions for modification if there is anything inappropriate

(3) understand the main performance characteristics of printing materials

(4) master the main properties of the ink and solvent used

(5) layout design, size, position relationship, registration accuracy and printing pressure requirements

2. Preparatory work inspection

single sheet printing plate inspection. Whether the color plates are damaged and whether the printing plate size meets the requirements

plate cylinder inspection. Check whether the marks of each color plate cylinder are clear. Measure the circumference of each plate cylinder to select the cylinder gear

check the bearing quality. The bearing clearance must be within the specified range, and the bearing surface must be clean and lubricated

quality inspection of printing materials, inks, additives, etc

3. cleaning and inspection of the printing machine

when the printing machine has just printed a batch of live parts and has not been completely cleaned, the equipment should be cleaned and inspected. The main parts are as follows:

a. remove the drum shaft and check whether it is damaged

b. clean the ink in the ink tray and ink bucket

c. clean the ink pump and hose

d. clean the ink roller

e. clean the plate roller and the embossing roller

4. adjustment of album printing machine

(1) adjustment of parallelism of the first printing unit, main parts:

plate barrel and embossing cylinder

plate cylinder and corrugation roller

wrinkle roller and ink bucket roller

measuring tools: feeler gauge (thickness 0.05 mm)

(2) adjust the registration of the drum in the front half of the printer to make the registration line coincide and meet the specified requirements

(3) inking in the front half of the printer

(4) adjust the registration of the rear half of the printer

(5) ink feeding in the back half of the printer

(6) adjust the working state of the ink roller, keep the ink feeding uniform, and the ink volume meets the requirements

(7) adjust the paper tape tension and maintain the stability of the paper tape tension during the printing process

the trial printing can be carried out after all the above processes are normal

(II) the working process of trial printing is as follows

(1) turn on the machine to make the impression cylinder in the closing position for the first trial printing

(2) check the sample. Including registration accuracy, printing position, etc. If problems are found, further adjustment should be made to make the printing plate cylinder of the printing album achieve correct registration along the longitudinal and transverse directions

(3) start the ink pump, adjust the ink feeding amount, and feed ink to the ink roller

(4) start the machine for the second trial printing

(applicable to factories, mines, petroleum, chemical industry and ship terminals, etc.) check the second trial print sample, and the inspection items are as follows:

color density: when the color density is abnormal, adjust the ink viscosity, or change the number of lines of the wrinkle roll

color difference: if the color difference cannot meet the requirements, the ink should be replaced

other defects: check and adjust according to the specific situation

(6) when qualified products are printed, a small amount of printing can be done and then checked again before formal printing

(7 in order to avoid generating gas residue L) during the printing process, we should always pay attention to the registration, color difference, ink volume, drying and the change of paper tape tension, so as to adjust at any time