Awareness of Domestic Printing Card UV Offset Printing Machine (1)

The development time of UV offset printing in the domestic market is not long. Compared with foreign countries, there are many technical problems. There are many differences between paper printing and UV printing. Correct understanding of UV offset printing can save a lot of trouble in the printing process. Let's talk about the author's understanding of UV offset printing at home.

Offset configuration requirements

1. UV curing device

Generally, 2 to 3 UV lamps are installed in the middle part of the delivery chain guide rails, and an exhaust nozzle is installed at the top of the delivery section. A UV curing device can also be connected separately. The conveyor belt is connected to the delivery table section. . Obviously, the latter is limited by the speed of the conveyor belt of the UV curing device, which will affect the printing speed, and is not suitable from the perspective of the space occupied. When the first method is adopted, UV lamps can be set between the unit and the unit, and each unit can be used interchangeably. According to the different requirements of the printing products, the wet and dry printing state can be achieved.

The UV curing device can be equipped with a stepless adjustable power output. When the printer is under pressure, the output power is controlled to connect with the printer. At this time, the output power of the UV lamp is automatically reduced, which can extend the service life of the lamp. The UV curing device is usually air-cooled and water-cooled at the same time. Each UV lamp is equipped with a mirror to ensure that excess heat is effectively removed during printing. At present, the service life of general UV lamps is from 1000 to 1500 hours. If it is used well, it can reach 1500 to 2000 hours. Business card UV lamp. At present, domestic imports are still the mainstay, among which the German elthch company and the Japanese GSM company are more typical.

2. Special ink roller

UV inks use special ink rollers. The special ink roller's acid resistance, alkali resistance, oil resistance, and swelling resistance are all superior to those of the ordinary ink roller. Its excellent performance is specially applied to UV inks. The service life of the special ink roller is usually within 2 years, and the dampening roller is within 1 year.

In addition, it is preferable to install the ink cooling device of the ink fountain roller, which can effectively control the temperature of the ink roller and ensure that the print quality problem is not caused by the temperature change after the rubbing of the UV ink in the continuous rapid printing.

3. roller

(1) The impression cylinder

The impression roller uses a double-diameter cylinder (two revolutions of the plate cylinder correspond to one revolution of the impression cylinder) to ensure smooth and smooth transfer of the plastic film. Sheets after imprinting cylinders are imprinted. Only when it is transferred to the next roller, when the printer runs at a high speed, it is not easy to produce a fault, and the pressure and impulses that the printed sheet bears are kept at a minimum.

(2) transfer roller

The skeleton type transfer roller replaces the conventional transfer roller. A type of air blowing is adopted, and a row of air blows is installed on the transfer roller. During the transfer process, the tail of the printed sheet is blown down, and a cushion is blown to lift the printed sheet to prevent the dirty or scratched phenomenon. The other is to replace the air blow with a slide bar. Place the two slide bars on the two sides of the printed sheet to avoid contact with the printing graphic part in the middle. The slide bar can move freely and can be adjusted according to different printing formats.

4. Gripper, Feeder, Take-up

All the grippers, delivery teeth, and tines of the delivery teeth must be treated with special steel (such as chrome plating) to ensure their wear resistance, ensure the accuracy of the delivery, and prevent overprinting caused by slipping. Since the feed tooth row needs to be circulated from the UV lamp, its own metal structure must be resistant to high temperatures, otherwise once it is deformed, it will seriously affect the printing transfer.

5. Main motor

The main motor of the printing press is an AC motor. Because of the large viscosity and poor fluidity of UV inks, the friction between the UV ink rollers is large and the load on the printer is large. Therefore, a motor that is one step higher than the main motor of an ordinary offset press of the same specification must be selected to ensure normal printing.

6. In addition to static electricity, dust removal device

Since the static electricity of PVC and other sheets is large and there is a lot of dust, it is recommended to install a static electricity removing device at the paper feeding portion and the paper receiving portion. If the conditions permit, the dust removing device may be installed at the paper feeding portion.