Clean the table top and body of the printer. Printing machine is a kind of contact exposure imaging equipment used to make printing plates. Using pressure (including atmospheric pressure and mechanical pressure), the original plate is closely attached to the photosensitive plate, and the image on the original plate is accurately printed on the photosensitive plate through photochemical reaction. Printer is a kind of vacuum imaging equipment, which can complete contact exposure. It mainly consists of a frame, a drying chamber, an air extraction device and a light source device. The printer is mainly composed of frame, vacuum pumping system, lamps and electrical control system. The original light sources of the printer were mainly high-pressure mercury lamp, dysprosium lamp and xenon lamp, which were replaced by metal halogen lamp-iodine gallium lamp in the late 1980s. It is by far the most suitable light source for printing.

Printing machine plays an extremely important role in prepress equipment, its performance directly affects the quality of plate making, and its maintenance plays an important role in printing production. If the required printer is selected correctly and maintained correctly and in time, it can not only improve the service life of the printer, but also improve the quality of the printer. According to the requirements of national specifications for printer technical conditions, the printer to be selected must be produced according to national standards, and the printer with excellent performance should meet the following requirements. PS plate should be kept in complete contact with the glass surface when working. The minimum vacuum adjustment range of the vacuum system is 0-86.6 kPa (0-650 mm Hg); The printer should be able to obtain a vacuum of 80 kPa (650 mm Hg) within 60 seconds; The vacuum degree of the printer should not be reduced by 20kPa( 150mmHg) after turning off the power supply of the printer for 5 minutes. The detection method is as follows: put the printing plate with the largest size corresponding to the machine specification into the printing machine, turn off the vacuum system, turn on the vacuum pump, and measure the time required for the vacuum displayed by the vacuum meter in the vacuum system to reach 80kPa(650mmHg) with a stopwatch; Then turn off the power supply, use a stopwatch for 5 minutes, and observe the sealing performance of the vacuum system displayed by the vacuum meter.