Sheet-fed gravure printing machine technology and structural features

I. Overview Gravure printing has a large printing market at home and abroad because of its excellent printing quality and high printing durability. It is particularly prominent in the packaging of tobacco, food, and textiles.
At present, the vast majority of gravure printing in China is web printing. Although the printing efficiency is extremely high, it takes a lot of paper to adjust the machine before the official printing. High-grade web gravure printing machines are expensive (200-3000 million yuan per machine) and are suitable for high-volume product printing. Compared to web gravure printing machines, single-sheet gravure printing machines are more suitable for small and medium-volume products. print.
Sheet-fed gravure printers have flexible printing operations, short setup times, and short product turnaround times. In theory, the accuracy of sheet-fed gravure printing machines is exactly the same as that of offset printing machines; due to the simple adjustment, paper waste is minimal before the formal printing; the configuration of sheet-fed gravure printing machines is flexible, and even a monochrome machine can be used to Several prints can print multicolor prints.
Second, the sheet-foil gravure printing machine process characteristic analysis The advantage of the sheet-fed gravure printing machine in terms of technological characteristics is as follows:
1) Non-wet and wet printing, so there is no danger of ghosting, there is no ink-ink balance problem, there is no problem of ink emulsification.
2) No dusting, no ink build-up, almost no ink fluctuations.
3) Printable Nearly all difficult-to-handle printing materials for offset presses, such as vacuum aluminized paper (gold cardboard, silver cardboard), metal foil, etc.
4) Can print gold, silver, fluorescent ink, cover white, pearlescent ink, UV glazing, waterborne glazing...
5) The ink film and varnish dry quickly, so it can be processed immediately afterwards, such as cutting, embossing, die cutting and so on.
6) The printed ink color can almost always reach the desired thickness, while the offset printing is generally printed twice. Gravure passes paint four times more than offset printing.
7) Can print 0.03mm (80g/m2) to 0.04mm thick paper jam.
8) In the case of large-area color printing, gravure printing does not suffer from ink drop and no ghosting occurs.
9) Ink correction is reliable because gravure does not have ink shades caused by ink penetration that are common in offset printing. But the premise is that color inks should be painted immediately, and gravure printing is generally done.
10) With millions of impressions, gravure only requires a set of plates.
11) The structure of the gravure printer is simple and no ink transfer roller and ink fountain screws are needed.
12) Gravure printing can print imitation metal etching printing, pearlescent ink and so on.
Disadvantages:
1) The outlets and levels of printed materials are not as good as offset printing.
2) Thin line printing is better than offset printing.
3) The gravure plate making cost is expensive, and it is not suitable to print the short version live.
It can be seen that for the sake of high quality, high efficiency and low price, the ideal combination method is offset printing and gravure printing.
Incidentally, for the contamination of environmental products with benzene, toluene, and xylene in the gravure printing process, a water-based ink diluted with alcohol has been gradually used instead of the conventional gravure benzene ink.
Third, single-convex machine structural characteristics Beijing Cheng Henry Printing Machinery Co., Ltd. manufactured YAIAI-type sheet-fed gravure printing machine (referred to as Chen Henry single-cone machine) is to achieve gravure printing process an ideal device, it is given by Paper device, paper delivery mechanism, embossing mechanism, ink supply and squeegee mechanism, gravure cylinder, paper transmission mechanism, paper positioning system, drying system, delivery device and electrical control system, etc., have the following structural features:
1. The paper feeding device can continuously feed paper without stopping at a high speed, and the speed of the paper feeding machine can reach 12,000 sheets/hour.
2, the paper machine adopts aluminum alloy material for paperboard, and tape type for paper feeding belt.
3, the paper feeding head uses four delivery nozzles and four suction nozzles to adapt to high speed.
4, the separation head adopts rotary gas valve, both ends are supported by ball bearings, the gap between the valve body and the valve sleeve is small, has good sealing, and can avoid directly wearing the valve body, at the same time, easy to remove the cleaning paper hair, Dirt, has a long service life.
5, the paper feeder is all bearing, no oil pool, timely oil pump by hand, quantitative, fixed-point oil.
6. The power transmitted from the main machine to the paper feeder adopts the chain drive, which simplifies the structure and improves the reliability compared with the previous universal joint transmission.
7. The delivery system adopts the advanced technology of advanced offset printing presses to ensure accurate overprinting.
8. The main drive system adopts 7.5kW frequency-conversion speed-adjusting motor, which can stably save power and PLC control whole machine operation and fault monitoring.
9, the host uses rain lubrication, timing, quantitative, fixed-point oil supply. The whole machine uses an oil pump to supply oil on both sides of the operating surface and transmission surface.
10. The scraper system is the key to this machine. The squeegee pressure is driven by two cylinders. The squeegee angle is arbitrarily selected from 45 degrees to 85 degrees, and various products can be printed. At the same time, the squeegee can quickly install the card. The squeegee oscillates laterally for stepless adjustment.
11, ink fountain structure in the high-speed state (8000 / h) printing does not throw off ink, no ink leakage.
12, gravure cylinder structure, two-end support rigidity, pressure. The gravure cylinder structure can use a hollow version gravure cylinder, a shaft gravure cylinder.
13. After the paper is printed, it is conveyed to the delivery table via the delivery chain. Usually, the wind and infrared rays are heated in the conveying path to dry the printed surface. The length of the conveying channel can be selected according to the actual printing of an economic length, to ensure that the printed product is completely dry.
14, the machine is equipped with IR infrared light box, waterborne varnish can be printed on a sheet of gravure printing machine. At the same time can be equipped with UV drying system, printing UV UV light polishing oil.
15. The dentition of the collection tooth row is a special lengthening (abbreviated as "shadowless teething"). When it is dry, it guarantees that the whole layout of the printed product can be dried.
16. The paper delivery device can realize non-stop paper delivery (abbreviated as attached paper) under high-speed printing status, which saves auxiliary time.
17. The ink supply pump controls the ink volume for a special mixing special ink pump.
18, the machine is equipped with a safety lifting device, a very light replacement roller.
19. The electrostatic ink-absorbing device developed further improves the effect of gravure printing.
With the rapid changes in the market, packaging printing tends to be less marketable, variety, and high quality. This single-sheet gravure printing machine will play an important role in high-end packaging printing. (Beijing Zheng Henry Printing Machinery Co., Ltd. Feng Yan)