JPH09327903A - Printing system and its web-stabilizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the web stabilizing device of a printing system for efficiently drying images on a web, which is sent from a printing device under the state being accompanied by fluttering or wrinkles. SOLUTION: In this web stabilizing device, compressed air blowing nozzle for spraying compressed air against a web 4 are arranged above and below the web at the inlet of a drying passage 21, which is provided within a drying device 2 for passing threethrough. By giving tension to the web 4 by the compressed air blowing off the compressed air blowing nozzles, the web 4 is provented from entering the drying device under the state being accompanied by fluttering or wrinkles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stabilizer for a moving web in a printing system, and more particularly to a stabilizer for a web which prevents a web before drying from contacting an inlet fitting of a dryer or a hot air nozzle.

[0002]

2. Description of the Related Art In a multi-color printing system of this type, a web is sent to a series of printing units consisting of a plate cylinder and an impression cylinder (blanket cylinder), and the impression cylinder sequentially contacts the web to form a large number of prints on the web. Apply different color inks to form a color printed image. When the web exits the printing section, the ink is still wet and smudges. Therefore, prior to the subsequent processing, the image is dried by heating the web with a drying device to evaporate various solvents contained in the ink, and then the web is cooled with a cooling device to fix the ink. It is common to go through a process.

By the way, in the dryer, it is usually 250 ° C.
The solvent contained in the ink is evaporated by blowing the above hot air from the hot air nozzle onto the web. Since the evaporated solvent has a bad odor, it is necessary to keep the inside of the dryer at a negative pressure so as not to leak outside from the web inlet / outlet of the dryer. If the opening of the web entrance is unnecessarily widened, a large amount of outside room temperature air will be sucked into the dryer, so a large amount of fuel will be used to raise the hot air up to 250 ° C, and fuel consumption will deteriorate.

Therefore, conventionally, a metal fitting having a narrow opening is attached to the web entrance of the drying device, and the web is passed through the opening of the entrance fitting to solve the above problem. However, in the final printing unit, the web after printing flutters and wrinkles easily occur on the web, so the undried web may contact the inlet metal fittings of the dryer or the hot air nozzles in the dryer and rub the printed matter. was there.

That is, when the web leaves the printing apparatus, the contact between the web and the final impression cylinder causes the web to pitch for the following reasons. The ink applied to the web by the impression cylinder is tacky when it contains water, and adheres the web to the outer peripheral surface of the impression cylinder. The adhesiveness is relatively low in the area where the image density is high. Local variations in web tension as the web is pulled away from the surface of the impression cylinder cause the web in contact with the final impression cylinder to wobble.

Therefore, conventionally, when the web comes into contact with the entrance fitting of the dryer, it is necessary to widen the opening of the entrance fitting more than necessary so as not to come into contact with the entrance fitting, which results in an increase in fuel consumption. Further, when the web comes into contact with the hot air nozzles in the drying device, the blowing pressure of the hot air nozzles on the opposite side to which the hot air nozzles arranged in the staggered arrangement are lowered until they no longer come into contact. Therefore, it has been a cause of defective drying of the image applied on the web.

As described above, there has been no fundamental solution to efficiently dry the image on the web sent from the printing device to the drying device with fluttering or wrinkles.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide a web before drying on an inlet fitting of a dryer or a hot air nozzle in the dryer. The fuel consumption can be reduced without any contact with each other and the opening of the inlet fitting is not unnecessarily widened, and sufficient drying can be performed in the drying device to obtain a good product. Printing system and its web stabilizer.

[0009]

A web stabilizer for a printing system according to the present invention comprises a compressed air blowing nozzle for blowing compressed air toward the web at the entrance of a drying passage through which the web provided in the dryer can pass. They are arranged one above the other, which achieves the above object.

In a preferred embodiment, the slit provided in the compressed air blowing nozzle opens toward the web, and the compressed air blown out from the slits of the upper and lower nozzles are located at different positions in the longitudinal direction of the web. Spraying is preferred.

Further, the printing system of the present invention has a printing device, a drying device, and a web stabilizing device disposed between the printing device and the drying device, and the web stabilizing device includes the printing device. The above object is achieved by having at least a pair of upper and lower compressed air blowing nozzles for blowing compressed air toward the upper and lower surfaces of the web fed from the device to the drying device.

In the present invention, before the web is printed in the final printing unit and enters the drying device, compressed air is blown from the upper and lower surfaces of the web to exert a tension on the web, thereby causing the web to flap and wrinkle itself. It is intended to solve the fundamental problem by eliminating.

[0013]

1 shows a schematic diagram of a multicolor printing system, which comprises a printing device 1, a drying device 2 and a cooling device 3. Printer 1
Has a blanket cylinder 11 and a plate cylinder 12, and the web 4 is passed between both blanket cylinders 11 to apply ink onto the web 4. Next, the ink-coated web 4 is dried by a drying device 2 to evaporate the solvent contained in the ink.
Be led to. Here, the web means a paper, a film, a composite product of these, a processed product, or the like.

The drying device 2 has a drying path 21 through which the web 4 can pass, and a large number of nozzles for ejecting hot air are arranged in a staggered pattern in the drying path 21. A web stabilizer 5 for preventing or suppressing flapping of the web is attached to the drying path 21 at the web entrance side.

As shown in FIGS. 2 to 6, the web stabilizer 5 has compressed air blowing nozzles 6a and 6b which are arranged above and below the moving web 4, respectively. The nozzles 6 a and 6 b are arranged above and below the drying passage 21 over the entire width of the drying passage 21. As shown in FIGS. 4 and 10, the upper and lower nozzles 6b are connected to a cold air pipe 8 so that air is sent from a blower 7. The compressed air blowing nozzles 6a and 6b are provided with slits 9, and the compressed air is jetted from the slits 9 of the upper and lower nozzles 6b toward the upper and lower surfaces of the web 4, respectively, to prevent the flapping of the web 4. It is designed to prevent or suppress.

The compressed air blowing nozzle 6 will be described below.
The configurations of a and 6b will be described in detail.

As shown in FIG. 6, the compressed air blowing nozzles 6a and 6b may have a cylindrical cross section. The following advantages can be obtained by making the cross-sectional shape of the nozzles 6a and 6b cylindrical.

The lengths of the nozzles 6a and 6b are usually formed to be slightly longer than the width of the maximum web 4 for printing. Therefore, even when the width of the printing web 4 becomes narrow, the nozzles 6a, 6
There is a portion where the compressed air ejected from b does not hit the web 4. Nozzle 6 on the side facing the compressed air in this part
Since it may hit b and 6a, a part of the compressed air is blown to the final printing unit, which causes adverse effects such as curing of ink. However, by forming the round nozzles 6a and 6b, the compressed air blown out from the nozzles 6a and 6b on the opposite side passes through the curved side surfaces of the nozzles 6b and 6a and thus can be prevented from being blown to the printing unit.

As shown in FIGS. 5 and 6, the drying device 2
A lower bracket 22 and an upper bracket 23 are fixed to the wall surface 2a on the inlet side of the web 4 so as to sandwich the inlet of the drying path 21. The lower bracket 23 is provided with a vertically long slot 24, and the upper bracket 22 is provided with a horizontally long slot 25. The contact plates 26 fixed to both ends of the lower nozzle 6b are attached to the lower bracket 23 so as to be vertically movable. Similarly, the contact plates 27 fixed to both ends of the upper nozzle 6a are attached to the upper bracket 22 so as to be movable horizontally (close to and away from the wall surface 2a of the drying device 2). A cylinder bracket 28 is fixed to the lower surface of the lower nozzle 6b, a bracket 29 is fixed to the wall surface 2a of the drying device 2, and the rod 3 of the air cylinder 30 fixed to the bracket 29 is fixed.
1 is fixed to the cylinder bracket 28 of the lower nozzle 6b. Therefore, by driving the air cylinder 30, the lower nozzle 6b can be moved up and down to adjust the distance between the lower nozzle 6b and the upper nozzle 6a. The distance between the upper nozzle 6a and the web 4, and the lower nozzle 6b
The distance between the web 4 and the web 4 is usually about 10 mm to 40 mm.

The moving distance of the upper nozzle 6a in the horizontal direction can be about 50 mm. Similarly, the lower nozzle 6b may be movable in the horizontal direction.

After the adjustment, the upper bracket 22 and the contact plate 27 are fixed in the elongated hole 25 with bolts and nuts.
After the adjustment, the lower bracket 23 and the backing plate 26 are
Although it may be fixed with bolts and nuts in the long hole 24,
The air cylinder 30 may be vertically movable without being fixed.

The temperature of the compressed air blown out from the nozzles 6a and 6b may be adjusted depending on the purpose, but it is usually room temperature. However, the compression heat of the blower 7 causes a slight increase in temperature. The blowing air velocity of the compressed air is determined by the upper and lower nozzles 6.
A and 6b alone are preferably 0 m / sec to 40 m / sec, and can be adjusted within that range.

Next, the shape of the slit 9 portion of the upper nozzle 6a will be described in detail.

As shown in FIGS. 7 and 8, the upper nozzle 6a includes a nozzle barrel 33, a branch pipe 34 connected to the nozzle barrel 33, and a backing plate 27 for closing both ends of the nozzle barrel 33. , 27 and.

An opening 35 is formed at the lower end of the nozzle body 33 over substantially the entire width of the nozzle body 33. At the opening 35, a lip 36 is fixed to the nozzle body 33, and a sliding metal fitting 37 is provided at a position facing the lip 36.
Are fixed slidably in the direction of the lip 36. The slit 9 is formed between the lip 36 and the sliding fitting 37. The distance between the slits 9 can be adjusted by moving the sliding fittings 37, and generally the distance between the slits is preferably about 2 to 4 mm.

The lower nozzle 6b can have the same structure as the upper nozzle 6a.

The cooling device 3 arranged on the downstream side of the drying device 2 can be constructed by using a conventional cooling roll.

Next, the operation will be described.

The web 4 coated with the ink is the drying device 2
When being conveyed in, the compressed air blown out from the slits 9, 9 of the compressed air blowing nozzles 6a, 6b of the web stabilizer 5 presses the upper and lower surfaces of the web 4. for that reason,
The web 4 is curved in an S shape and receives tension. Therefore, fluttering and wrinkling caused in the final printing unit of the printing device are here prevented or reduced. The position where the compressed air from the slits 9, 9 acts on the web 4 may be different depending on the moving direction of the web 4. The web 4 thus prevented from fluttering and the like is dried by receiving hot air from the hot air nozzle in the drying device 2.

In the above embodiment, the web stabilizer 5 is used.
Is fixed to the wall surface 2a on the web entrance side of the drying device 2 so as to effectively prevent flapping or wrinkling of the web entering the drying device 2 between the drying device 2 and the final printing unit. A web stabilizer may be provided in the. In this case, it is effective that the distance between the web stabilizer and the dryer is short, and it is particularly preferably 50 to 70 mm. Further, the web stabilizer may be configured by staggering the nozzles vertically. In this case, the compressed air from the nozzle is blown to the web to give tension to the web and further prevent flapping, wrinkles and the like.

[0031]

According to the present invention, since the compressed air blowing nozzles for blowing the compressed air toward the web are arranged at the entrance of the drying passage of the drying device, the tension is applied to the web. You can eliminate the flapping and wrinkling of the web. Therefore, there are the following effects.

(1) Since it is not necessary to unnecessarily widen the opening of the drying device inlet fitting, it is possible to suppress the inflow of external air and improve fuel efficiency.

(2) As described above, in order to keep the inside of the drying device at a negative pressure, exhaust gas accompanied by a bad odor is drawn to the outside by a fan. However, according to the present invention, the opening of the web can be narrowed, Even if the same amount of exhaust gas is drawn by the fan, the wind speed at the opening becomes faster, so that exhaust gas leakage to the outside can be reduced.

(3) The higher the hot air nozzle blowout pressure from the hot air nozzle, the better the heat transfer efficiency to the web, and the temperature of the web can be effectively raised to perform drying. According to the present invention,
Since the blowing pressure from the hot air nozzle is not lowered, the web temperature can be raised and dried with the highest efficiency of the apparatus.

(4) Since flapping and wrinkles of the web, which could not be solved by the conventional solutions, can be eliminated, rubbing of the web in the drying device can be prevented, and a good finished product can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a multicolor printing system of the present invention.

FIG. 2 is a front view of the printing apparatus of the multicolor printing system of the present invention shown in FIG.

FIG. 3 is a plan view of the printing apparatus shown in FIG.

FIG. 4 is a side view of the printing apparatus shown in FIG.

FIG. 5 is a front view of one embodiment of the web stabilizer of the present invention.

FIG. 6 is a view taken along the line AA ′ of FIG.

7A and 7B are diagrams showing an upper nozzle of the web stabilizer shown in FIG. 5, FIG. 7A being a front view thereof, and FIG. 7B being a sectional view thereof.

8 is an enlarged cross-sectional view of a B part in FIG.

9 is a cross-sectional view showing a lower nozzle of the web stabilizer shown in FIG.

FIG. 10 is a schematic view showing a pipe for compressed air.

[Explanation of symbols]

 1 Printing Device 2 Drying Device 3 Cooling Device 4 Web 5 Web Stabilizing Device 6a, 6b Compressed Air Blowing Nozzle 7 Blower 8 Piping 9 Slit 21 Drying Path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Sakae Mino, Osaka Prefecture Osaka City, Yodogawa-ku, 4-1-1-14, Sumitomo Life Shin-Osaka Kita Building, 7th floor, Osaka Oxygen Industry Co., Ltd. (72) Inventor, Takayu Murakami, Osaka Prefecture 2-2469, 2-2, Minamiki, Yao-shi

Claims (3)

[Claims] 1. A web stabilizing device for a printing system, wherein a compressed air blowing nozzle for blowing compressed air toward the web is vertically arranged at an entrance of a drying passage through which the web provided in the drying device can pass. 2. The compressed air blowing nozzle has slits that open toward the web, and compressed air blown from the slits of the upper and lower nozzles blows at different positions in the web conveying direction. A web stabilizer for the described printing system. 3. A printing device, a drying device, and a web stabilizing device disposed between the printing device and the drying device, the web stabilizing device feeding from the printing device to the drying device. A printing system having at least a pair of upper and lower compressed air blowing nozzles for blowing compressed air toward the upper and lower surfaces of a web to be compressed.