Common faults and troubleshooting of the hottest p

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Common faults and troubleshooting of plate printing machine

there are many types of plate printing machines, and the light sources used are also different. This paper introduces the structural characteristics of the box type plate printer, and describes the different characteristics and common faults of various box type plate printers

the shape of the box type plate printer is a cube structure, the upper cover is an rubber cloth sealing frame, and the joints are sealed with rubber strips around, and there are handles that can be lifted. Connect the air pipe with the vacuum pump. There are buckles in the front, hinges in the rear, and braces on both sides between it and the box below. Under the sealing cover is flat glass with excellent transparency, uniform texture and thickness of about 10mm. An exhaust fan is installed behind the box. The middle part is a light box with iodine gallium lamp light source or halogen lamp light source. Around the light source is a reflector with reflected directional light. The precision exposure machine adopts photoelectric integrator to control the brightness, which has the function of automatically limiting the exposure time. Ordinary exposure machine adopts setting standard seconds to limit exposure time

when you need to make a plate, open the blanket frame, first stick the photographic negative to the surface of the parallel glass plate, then stick the printing surface of the frame coated with photosensitive glue close to the film surface of the negative, then cover the blanket frame, start vacuuming, use the contraction of the blanket, firmly stick the surface and the negative to the glass plate, turn on the light source of the exposure lamp with a certain wavelength, and set the best exposure time, When the exposure time is up, the light source will be turned off automatically. It can also be changed from automatic operation mode to manual operation mode

the quality of a plate printer mainly depends on three factors. The first is whether the vacuum pumping system of the plate printer can make the photographic negative close to the photosensitive material on the plate without any gap; Whether the illumination of the middle and surrounding edges of the whole layout is uniform during the second exposure. Third, the control circuit with stable working performance and the stable and durable exposure light source during exposure

several box type printing machines with different forms and characteristics show different fault phenomena. But no matter what kind of problems will directly affect the quality of plate making. The following describes the structural characteristics and troubleshooting of several different types of plate printing machines

1. Common failures of several plate printers include:

1. Due to insufficient or no suction, photographic film and surface photosensitive material cannot be closely attached to the glass plate, resulting in misalignment, distortion, sawtooth, blur and other unqualified plates in plate making

the main analysis steps are as follows: the preliminary judgment method is to separate the vacuum pump from the air pipe, block the suction port of the vacuum pump with your thumb, and observe whether the barometer pointer points to the maximum value. If it points to the maximum value, it indicates that the vacuum pump operates normally, so it should be judged that it is the air pipe There is air leakage in the rubber blanket (including: there are trachomas in the rubber blanket, air leakage occurs due to poor adhesion of the sealant strip, air leakage occurs due to the loose and tight adjustment screws of the cover plate, and air leakage occurs due to the loose and loose interfaces of the suction pipe). If the barometer pointer does not reflect or is very small, it indicates that the vacuum pump is not operating normally (fault phenomena include: the motor coil of the vacuum pump is burnt out and stops running, the vacuum pump is stuck and stops running due to no oil, the blade in the vacuum pump is damaged and the suction is insufficient, etc.)

2. After using the printer for a certain time, I feel that the actual exposure time is much longer than the expected exposure time

(1) the long-term working energy of the exposure lamp decreases, and the lamp tube must be replaced

(2) even if a new lamp is replaced, the exposure time is still long. At this time, first consider the cleaning of the box; Secondly, consider whether the reflector has good reflection effect and the light transmission effect of the glass plate; Secondly, it is necessary to consider whether there is a problem with the quality of the new lamp tube replaced this time

II. Analysis and troubleshooting of different characteristics and faults of various printing machines:

1. Swe1100 printing machine, with a power of 2kW. Adopt relay control circuit and push-button operation panel. Equipped with vacuum pumping, exposure timer and other functions. Inhale and expose manually, and stop automatically according to the timing

common faults: the panel power indicator is on, but it cannot be started

fault inspection sequence:

a, fuse burned out; B. AC contactor contact carbonization, poor contact or coil burnout, etc; C. Automatic tripping of thermal relay; D. The vacuum pump is burnt out or stuck; E. The exposure lamp is burnt out; F. Rectifier and trigger failure

2. Swe1200a plate printer, with a power of 3KW. It is controlled by microcomputer with ten groups of memory channels. Equipped with imported oil-free silent vacuum pump and ordinary domestic vacuum pump. Circuit board control circuit, touch operation panel. After the exposure time is set, the time does not run in standard seconds, but uses the photoelectric integrator to control the light, automatically limits the exposure time, and the compensation light does not show a wave of rising market. It is easy to operate and is not affected by lamp aging and operator experience. It is applicable to the production of fine lines, dot patterns and circuit board plates. Practical economy. It is equipped with automatic and manual exposure. When automatic, it has the function of secondary air extraction after pre extraction. When the preset air extraction time is up, it automatically → a variety of high rigidity and high wear-resistant mandrels (steel strand 12.5 ~ 13.0mm and can now have the maximum force or tensile curve; 15 ~ 16mm; 17 ~ 18mm; mandrel diameter ¢ 40mm, ¢ 49mm, ¢ 59mm); Exposure. The preset exposure time stops automatically. Manual mode is manual start and manual stop

fault phenomenon analysis:

a, the digital display on the operation panel is weak or incomplete. Due to the damage of the rectifier bridge, the 5V DC input voltage value of the operation panel is not enough or the (7805) triangular regulator fails

b. the suction pump and exposure lamp cannot be turned on. 24V output voltage of rectifier bridge, (7824) delta voltage regulator or IC integrated block is broken down

c, the second suction cannot be realized during automatic operation, that is, the insufficient suction of the blanket affects the plate making. The solenoid valve above the vacuum pump is disconnected, burnt out or the control relay is damaged

d. UV lamp is a negative resistance gas arrester. No matter how good the ring is, it is open circuit when measured with a multimeter. Generally, it is open circuit even if it is damaged, which will not affect the circuit, but it is likely to have a short circuit or extremely low internal resistance under high voltage. At the end of air extraction, the control circuit turns into the working state, and the high voltage output by the step-up transformer is instantly added to both ends of the lamp. Due to short circuit or extremely low internal resistance, the strong impulse current causes a very high self induced potential to rush into the control circuit through other lines, causing a fault. At this time, it will cause the fault of microcomputer control circuit board and the phenomenon of rectifier bridge being broken through. This kind of fault is a special case

3. W-sp-3648a/4860a precision plate printer, with a power of 3KW. It is controlled by microcomputer with 25 groups of memory channels. Equipped with oil-free silent vacuum pump. Circuit board control circuit, touch operation panel. It can realize the conversion between standard seconds and product exposure time. When using volume exposure, its time is not running in standard seconds, but using photoelectric integral new Randy's waterproof socks, which won the 2014 made in China beauty award. The instrument controls the light, automatically limits the exposure time, and compensates for the lack of light. It is easy to operate and is not affected by lamp aging and operator experience. It is equipped with automatic and manual exposure. Manual mode is manual start and manual stop. In addition to replacing the exposure lamp tube according to the normal service time, other failure rates are very small

the lamp can be started continuously, that is, the interval between each stop and start is only 3 ~ 5 seconds

applicable to the production of fine lines, dot patterns and circuit board plates

excellent material selection, reasonable design and beautiful production

in short, no matter what kind of drying machine you use or what kind of fault you encounter in your work, you should understand and find out the performance principle of the machine and the cause of the fault, and apply the right medicine to the case. Pay attention to maintenance in daily work, regularly check the air extraction system, check the vacuum pump once a month, and add vacuum oil regularly. Clean the suction pipe and keep the suction hose free of dust and debris. The glass surface shall be absolutely clean, and it shall be wiped with absorbent cotton, gauze and anhydrous alcohol, including the point light source and reflector. Replace the exposure light source regularly to avoid the light intensity of the light source weakening, and it is not suitable to master the exposure time, which will affect the plate making quality

reprinted from: China LED advertising lighting

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