How to troubleshoot the common problems of printing machine

There are many types of printers and the light sources used are different. Here we introduce the structural features of the box-type printing machine, and describe some of the different features of the box-type printing machine and the common faults.

The shape of the box-type printing machine is a cubic structure. The upper cover is a blanket sealing frame and the seams are sealed with a rubber strip around the seams, and there are handles that can be lifted. The trachea is connected to a vacuum pump. Between the box and the lower one, there is a lock in front, a hinge in the rear, and a strut on both sides. Under the cover is a flat glass with excellent transparency, uniform texture, and a thickness of approximately 10mm. There is an exhaust fan behind the cabinet. The middle is a light box with an iodine lamp light source or a halogen light source. Around the light source is a reflector with reflected parallel light. The precision screen exposure machine uses an optical integrator to control the brightness and has the function of automatically limiting the exposure time. Ordinary Screen Exposure Machines use standard seconds to limit the exposure time.

When making the screen, open the blanket frame, first attach the photographic film to the surface of the parallel glass plate, and then place the printing surface coated with the sensitized adhesive on the film surface of the film, and then cover the rubber. The cloth frame starts to vacuum, and the shrinkage of the blanket is used to firmly attach the mesh surface and the film on the glass plate, and the exposure light source with a certain wavelength is turned on, and the optimal exposure time is set, until the exposure time reaches Then turn off the light automatically. It can also be changed from manual operation mode to manual operation mode.

The quality of a printing machine mainly depends on three factors. The first is whether the squeezing machine system of the printing machine can make the photographic film and the screen sensitive material close together, leaving no gaps and gaps; In the second exposure, the illuminance of the center and the periphery of the entire layout is uniform. The third stable performance of the control circuit and the exposure exposure stable and durable exposure light source.

Several kinds of different types and characteristics of the box-type printing machine revealed the fault phenomenon is also different. But no matter what kind of problems will directly affect the quality of the plate. The following sections describe the structural features of several different types of printing machines and the analysis and exclusion of failures.

The common failures that can occur with several printers include:

1, due to suction is not enough or no suction, so that the photographic film and the surface of the photosensitive material can not be closely attached to the glass plate, resulting in plate-making take place, distortion, sawtooth, unclear and other unqualified screen.

Reasons for failures such as insufficient suction or no suction in the printing machine, the main analysis steps are as follows: The initial judgment method is to separate the vacuum pump from the trachea, block the suction port of the vacuum pump with the thumb, and observe whether the barometer pointer points to the maximum value. If the maximum value indicates that the vacuum pump is operating normally, then it should be judged that there is a gas leak in the air pipe and blanket (including: the rubber cloth has a trachoma leak; the sealant is not stuck well; the cover plate is loosely adjusted) Screws do not adjust properly, loose, tight will appear leak; suction pipe interface loose, off leaks, etc.). If the barometer pointer is not reflected or is very small, it means that the vacuum pump is not operating normally (failure phenomena include: vacuum pump motor coil burned out to stop running, vacuum pump oilless to cause stuck operation, vane damage in the vacuum pump, insufficient suction force, etc.) For reasons.)

2. After the printer has been used for a certain period of time, it feels that the actual exposure time has increased a lot more than expected.

(1) The exposure lamp has a reduced working energy for a long time and the lamp must be replaced.

(2) Even if a new lamp is replaced, the exposure time is still long. In this case, first consider the cleaning inside the box; secondly, consider whether the reflector has a good reflection effect and the light transmission effect of the glass plate; secondly, it is necessary to consider whether the quality of the new lamp replaced is problematic.

Second, the various features and failures of the printing machine analysis and elimination:

1, SWE1100 type plate machine, power 2KW.

Uses relay control circuit, push-button operation panel. Vacuum extraction, exposure timer and other functions are available. Manually inhale and expose, stop automatically according to the timing.

Common faults: The panel power indicator is on but it does not start.

Failure inspection order:

A, insurance burnout; B, AC contactor contact carbonization, poor contact or coil burnout; C, thermal relay automatic trip; D, vacuum pump burned or stuck; E, exposure lamp burnout; F, rectifier, Trigger failure.

2. The SWE1200A type printing machine has a power of 3KW. Microcomputer control, with ten sets of memory channels. There are two kinds of imported oil-free silent vacuum pumps and ordinary domestic vacuum pumps. Circuit board control circuit, touch operation panel. After the exposure time is set, the time is not the standard number of seconds to run, but the use of optical integrator to control the light, automatically limit the exposure time, compensation for lack of light. Easy to operate, not affected by lamp aging and operator experience. Applicable to the production of fine lines, dot patterns, circuit board screens. Practical economy. With automatic and manual exposure. The function of the second pumping after the pre-evacuation is provided automatically, the preset pumping time is reached, and the automatic exposure is performed. Preset exposure time to stop automatically. Manual mode starts manually and stops manually.

Fault phenomenon analysis:

A. The number on the operation panel is weak or incomplete. Due to the damage of the rectifier bridge, the 5V DC input voltage of the operation panel is not enough or the (7805) triangular regulator fails;

B. Suction pump and exposure lamp cannot be turned on. The bridge rectifier's 24V output voltage, (7824) triangular regulator, or IC manifold is oscillated and fails;

C. The second inhalation cannot be achieved automatically, that is, the suction of the blanket does not affect the plate making. The solenoid valve above the vacuum pump dropped, burned, or damaged the control relay;

D, UV lamp is a negative resistance type gas discharge device, regardless of good ring, with a multimeter to measure the open state, and under normal circumstances even if the damage is also an open state, will not affect the circuit, but is likely to be under high pressure Short circuit or extremely low internal resistance may occur. At the end of pumping, the control circuit is transferred to the working state. The high voltage of the boosting transformer output is instantaneously applied to both ends of the lamp. Due to the short circuit or extremely low internal resistance, a strong inrush current causes a very high self-sensing potential to enter through other lines. Control loops cause failures. This will cause the failure of the microcomputer control circuit board and the phenomenon of the rectifier bridge being excited. Such a fault is a special case.

3, W-SP-3648A/4860A precision screen printing machine, power 3KW. Microcomputer control with twenty-five groups of memory channels. With oil-free silent vacuum pump. Circuit board control circuit, touch operation panel. The conversion of standard seconds and cumulative exposure time can be achieved. With cumulative exposure, the time is not the standard number of seconds to run, but the use of optical integrator to control the light, automatically limit the exposure time, compensation for lack of light. Easy to operate, not affected by lamp aging and operator experience. With automatic and manual exposure. Manual mode starts manually and stops manually. Except for changing the exposure lamp according to the normal use time, the other failure rate is very small.

The lamp can be started continuously, that is, it takes only 3 to 5 seconds for each stop and start interval.

Applicable to the production of fine lines, dot patterns, circuit board screens.

Good material selection, reasonable design and beautiful appearance.

In short, regardless of the use of that drying machine, or the kind of failure encountered in the work, we must understand, understand the principle of the machine performance and cause of the malfunction, the right medicine. Daily work should pay attention to maintenance, maintenance, often check the exhaust system, vacuum pump inspection once a month, regularly add vacuum oil. The suction pipe is cleaned to keep the suction hose free of dust and debris. The surface of the glass plate should be absolutely clean. Wipe it with absorbent cotton, gauze, and anhydrous alcohol to clean it. The point light source and reflector should also be spotless. The exposure light source should be replaced regularly to prevent the light intensity of the light source from weakening. It is not appropriate to grasp the exposure time and affect the quality of the plate.