In actual printing, the problem of false graphics and text on the printing plate is mainly caused by the operation link of plate making, which has many causes. According to the causes, it is divided into the following categories:

1. Virtual version caused by dirt

Causes: ① foreign matters or dirt are attached to the glass, printing film, composition film base and printing plate of the plate printer; ② Foreign matters (such as hair, etc.) are mixed between the print film and the make-up film base, and between the printing plate and the film; ③ If the printing time is too long, the printing glass and film will generate static electricity and absorb dust in the printing process; ④ There are defects such as drug spots and white spots on the surface of PS plate.

2. A false version caused by a print film

Reason: ① the density of print film is not enough (should be above 3.5); ② The fog transition of the base of the mosaic is too high; ③ Improper splicing of film round plates, too narrow edges outside the drawing (more than 3cm away), too crowded splicing (0.5 ~ 1mm), resulting in arch collision, etc; ④ The interval image of the transparent tape of the mosaic film is titanium (more than 7mm away) or the paste is too thick; ⑤ Put the film upside down when printing.

3. Virtual version caused by insufficient vacuum pumping

Causes: ① poor function of vacuum pump; ② The sealing rubber ring and air pipe of the printing machine leak; ③ Aging and deformation of sealing rubber ring; ④ The rubber air cushion of the printing machine is not leveled or aged; ⑤ There is a problem with the vacuum pumping indicator, and the pointer ends but the actual pumping is not solid; ⑥ The film or PS version has creases, etc; ⑦ When Newton ring, large air retention area, dust and sundries are found, secondary air extraction shall be carried out in time.

4. Virtual plate caused by overexposure and development

Reason: ① exposure time is too long; ② Before exposure (during punching) or before development after exposure; ③ The developer temperature transition is too high and the concentration is too high; ④ Development time is too long; ⑤ Excessive developer supplement.

Tom (oversea manager) Phone:0086 13303078975 / 17772697357(whatsapp,wechat,line)

Email :cartonmachine.tomwang@aliyun.com

https://www.wdcartonmachine.com