JPH0952351A - Printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make optional adjustment of moistening amount possible in accordance with grades of printing paper, to make uniform moistening extending from end to end of the printing paper possible so that the printing paper in the state of dryness becomes to be in equilibrium moisture content, and to make a moistening device installable to any of existing printing apparatuses at any time without requiring much consideration for installation spaces. SOLUTION: In a printing apparatus that is equipped with a drying device 11 for drying printing ink at the outlet side of printing paper 27 of a printing roll, a moistening device 18 composed of a moistening roll 12, a plurality of nozzles 14 arranged in the axial direction of the moistening roll 12 with their orifices 13 facing the circumferential face of the moistening roll 12, and a gauge plate 17 with its edge 16 for adjusting water screen ejected out of the nozzles 14 and formed on the circumferential face of the moistening roll 12 facing the circumferential face of the moistening roll 12 is provided at the outlet side of the printing paper 27 of the drying device 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to printing paper (hereinafter also simply referred to as "ink") printed on a printing paper (hereinafter simply referred to as "paper") by a printing roll. The present invention relates to a printing apparatus having a drying device on the ejection port side, which dries the ink printed on the paper.

[0002]

2. Description of the Related Art The moisture content of a sheet taken out through this drying device is extremely low at 2% or less, and since the sheet is heated and has residual heat, the sheet absorbs moisture and has an equilibrium moisture content (about 7%).
%), It takes a considerable time to recover the moisture content, and various troubles occur during that time.

The main problems are: (1) Since static electricity is easily generated on the sheets, when the sheets cut by the cutting device are piled up, the slipping of the sheets is bad and the edges of the piled sheets are uneven. . (2) Shrinkage unevenness occurs in the paper that is taken out of the printing apparatus and is in a tensionless state (so-called no tension), the surfaces of the paper are not evenly aligned, and the dimensions of the paper are uneven. (3) Since the paper is stiff and extremely dry, cracks are likely to occur at the folds of the paper that can be passed through the folding device. (4) Since the paper adheres to the guide roll on the paper outlet side of the drying device due to static electricity and becomes difficult to separate, it is not possible to increase the transport speed of the paper, and the main body of the printing machine in the previous process that continues to the drying device. Printing speed cannot be increased. (5) When a cooling roll is attached to the paper outlet side of the dryer, residual ink causes adhesive ink to transfer from the printing surface of the paper to the cooling roll and adhere to it, which then returns to the paper. Transfer and pollute the printed surface.

[0004]

Therefore, a plate surface humidifying device attached to the main body of the offset printing machine is used, and the humidifying device is directed toward the cooling roll installed on the paper outlet side of the drying device, and the paper of the drying device is used. An attempt was made to humidify the paper passing through the peripheral surface of the cooling roll with the humidifier attached to the outlet side.

However, since the conventional plate surface humidifying device used in the offset printing press main body humidifies the plate surface which is a non-hygroscopic material, when it is diverted to humidify a highly hygroscopic paper, It is not possible to properly humidify the paper by strictly controlling the amount of humidification so as to reach the equilibrium moisture content of the paper. In particular, the hygroscopicity of the paper differs depending on the type of paper such as thickness and material, the presence or absence of solid printing (ground coating), the drying method in the drying device following the printing process, the time to pass through the drying device (that is, The conveyance speed of the paper, which is both the printing speed and the drying speed), the ratio of the area of the printed area with ink to the area of the non-printed area without ink, or the area ratio of the paper. The hygroscopicity of the paper changes slightly, such as the hygroscopicity of the paper being partially different depending on the distribution state of the printed area and the non-printed area.Therefore, if it is not humidified according to the change of the hygroscopicity of the paper, excessive humidification Problem arises.

To moisten the entire width of the paper,
The length of the cooling roll and the humidifying roll must be longer than the width of the paper.In that case, the water film on the left and right ends of the peripheral surface of the humidifying roll that protrudes from the left and right edges of the paper. , It will be accumulated between the end of the humidifying roll and the end of the cooling roll that do not touch the paper, forming a water pool,
It permeates into the edges of the paper, and only the edges of the paper become excessively humidified, and the water for humidification in the water pool sometimes infiltrates between the cooling roll and the paper that are in close contact, and spreads over the entire surface of the paper. Generate moisturizing spots.

Of course, the lengths of the cooling roll and the humidifying roll can be made equal to the width of the paper, but for that purpose, the cooling roll and the humidifying roll are changed in accordance with the width every time the printing paper whose width changes is changed. Will have to be replaced. However, it is practically impossible to align the lengths of the cooling roll and the humidifying roll with the width of the paper.

Most of the plate surface humidifiers of the main body of the offset printing machine are of a pumping system in which water lifted up by a water roll immersed in a water tank (that is, a water tank) is supplied to the plate surface. Since the mounting location is limited to the lower side of the water source roll, when diverting the plate surface humidifier to humidify the paper, it is not possible to attach the humidifier to the upper side of the cooling roll that cannot pump water toward the cooling roll. No, the mounting location is limited to the lower side of the cooling roll, and the plate surface humidifier of the offset printing machine body cannot be diverted to the existing printing device that does not have a large space under the cooling roll. .

There is also a spray type humidifier for the plate surface of the offset printing machine main body, which is suitable for humidifying a non-hygroscopic plate surface, but wipes off excess water scattered from the spray. Not suitable for humidifying paper that does not have it.

[0010]

SUMMARY OF THE INVENTION Therefore, according to the present invention, the amount of humidification can be freely adjusted according to the standard of the paper, and the moistening of the paper in an absolutely dry state reaches the equilibrium moisture content evenly from end to end. It is also an object of the present invention to provide a paper humidifying device which can be mounted on an existing printing device at any time without any particular difficulty in finding a mounting space.

[0011]

A printing device according to the present invention has a drying device (11) for drying printing ink on a printing paper outlet side of a printing roll, and a humidifying roll (12).
And a plurality of nozzles (14) arranged in the axial direction of the humidifying roll with the mouth (13) facing the peripheral surface of the humidifying roll.
And a gauge plate (17) having a rim (16) for adjusting a water film (15) formed on the peripheral surface of the humidifying roll ejected from the nozzle and directed toward the peripheral surface of the humidifying roll. The first feature is that (18) is provided on the printing paper exit side of the drying device (11).

A second feature of the present invention is that, in addition to the first feature described above, the mouth end (13) of the nozzle (14) has a flat shape which is elongated in the axial direction of the humidifying roll. To be there.

A third feature of the present invention is that, in addition to the first feature described above, a plurality of partition plates (19) whose planes are oriented at right angles to the axial direction of the humidifying rolls include a nozzle (14) and a gauge. The plates (17) are arranged in the axial direction of the humidifying rolls (12).

A fourth feature of the present invention is that, in addition to the above first feature, each of the plurality of nozzles (14) is provided with a cock (20) for adjusting the discharge amount.

A fifth feature of the present invention is that, in addition to the above first feature, a water supply source (21) is provided to each of the plurality of nozzles (14).
The water supply passage continuing from is provided with a filter (23) for purifying the humidifying water (22).

The sixth feature of the present invention is that, in addition to the above first feature, it has a doctor (24) in contact with the peripheral surface of the humidifying roll (12).

A seventh feature of the present invention is that, in addition to the above first feature, a cooling roll (25) is provided on the printing paper outlet side of the drying device (11) and a humidification roll (12) is provided. A cooling paper (27) which is a metal roll, and a rubber roll (26) is interposed between the cooling roll (25) and the metal roll (12), and passes closely to the peripheral surface of the cooling roll (25).
In addition, the water film (28) formed on the peripheral surface of the metal roll (12) is transferred and supplied through the rubber roll (26).

An eighth feature of the present invention is that, in addition to the first feature described above, any two or more of the second, third, fourth, fifth, sixth and seventh features described above are included. Features humidifier (18)
Has both.

[0019]

The moisturizing roll 12, a plurality of nozzles 14 arranged in the axial direction of the moisturizing roll with the tips 13 facing the peripheral surface of the moisturizing roll, and the peripheral surface of the moisturizing roll discharged from the nozzles. The edge 16 for adjusting the water film 15 formed on the surface of the gauge plate 17 is oriented to the peripheral surface of the humidifying roll.
In the humidifying device 18 composed of, the mouth end 13 of the nozzle 14 is not elongated in the axial direction of the humidifying roll, and even if there is a gap between the consecutive nozzles, the nozzle 14 discharges the humidifying roll. Humidification water 22 attached to the peripheral surface of 12
Moves toward the gauge plate side (17), spreading like a fan along the peripheral surface of the rotating humidifying roll 12 toward the gauge plate side (17), like smoke coming out from the chimney and blowing in the wind, and the gauge plate 17 and the humidifying roll 12 In the meantime, a water pool 35 is formed which continues in a straight line in the axial direction of the humidifying roll.

Such a water pool 35 can be naturally formed when the nozzle 14 is installed so that the mouth 13 is directed downwards and the humidifying water 22 flows down the humidifying roll 12. But,
Such a water pool 35 can be formed even when the nozzle 14 is installed on the lower side of the moisturizing roll 12 with the mouth end 13 facing upward like the water splash that the wheels splash (FIGS. 1 and 3).
Therefore, the humidifying device 18 is not limited to the lower side of the cooling roll capable of pumping water toward the cooling roll, as in the case of a pumping type plate surface humidifying device including a water boat and a water source roll.
It can be installed on the upper side of the cooling roll that cannot pump water toward the cooling roll, and when installing it on an existing printing device, it is not necessary to find a mounting space for it.

The supply amount of the humidifying water can be adjusted by the valve 38 and the cock 20, which cock 20 is used for each nozzle 14.
Since it is attached to the paper 27, the length of the water puddle 35 can be changed according to the change of the width of the paper 27, and the non-printing portion where the ink is not printed and the water is easily absorbed is biased. When the sheet is continuous in the length direction, it is possible to make the moisture content of the sheet uniform over the entire width by reducing the discharge amount from the nozzle 14 corresponding to the continuous portion.

In this case, when a plurality of partition plates 19 whose planes are oriented at right angles to the axial direction of the humidifying roll are arranged in the axial direction of the humidifying roll 12 between the nozzle 14 and the gauge plate 17, those partition plates 19 are arranged. Since the water pool 35 is partially partitioned by the partition plate 19, the movement of the humidifying water 22 from a portion having a large discharge amount to a portion having a small discharge amount is suppressed. That is, paper 2
That is, it is possible to apply the humidifying water 22 to only a limited part of the width direction 7.

As the humidifying water 22, not ordinary water but dust-free water that has passed through the filter 23 is used.
By the doctor 24 in contact with the peripheral surface of the humidifying roll 12, the paper dust and other dust transferred from the paper 27 to the peripheral surface of the humidifying roll 12 is scraped off from the peripheral surface of the humidifying roll 12, so that the humidifying water supplied to the paper is supplied. 22 is always kept in a dust-free state, the humidifying device 18 does not contaminate the paper, and the printing surface is finished neatly.

A metal roll is used as the humidifying roll 12,
A cooling roll 25 is installed on the printing paper outlet side of the drying device 11, and a rubber roll 26 is interposed between the cooling roll 25 and the metal roll 12 so that the cooling paper 27 comes into close contact with the peripheral surface of the cooling roll 25 and passes through. When transferring and supplying the water film 15 formed on the peripheral surface of the metal roll 12 via the rubber roll 26, the supply amount of the humidifying water 22 is reduced as much as possible so that the moisture content of the paper 27 approaches the equilibrium moisture content. It is possible to press the small amount of humidifying water 22 and press the paper 27.
Can be absorbed by.

In the present invention, since the humidifying water 22 is applied to the paper 27 while being cooled by the cooling roll 25, the applied humidifying water 22 is suppressed from evaporating, and the applied humidifying water 22 is stored inside the paper ( 27) so that the supply amount of the humidifying water 22 is easily controlled so that the entire sheet (27) reaches the equilibrium moisture content uniformly.

[0026]

The present invention will be described below with reference to the illustrated embodiments. FIG. 5 is a flow chart of a printing process by the printing apparatus of the present invention. The paper 27 pulled out from the winding roll is adjusted to a certain tension state by the tension roll 29 and guided to the main body 30 of the printing machine. After the ink is printed, the ink is dried by passing through the heating / drying device 11 and then cooled by passing through the cooling roll 25, and then passed through the cutting device 31 to be cut into a predetermined size and piled up, or through the folding machine 32. It is designed to be folded.

FIGS. 1 to 4 show a humidifying device 18 attached to the cooling roll 25. The humidifying roll 12 and the shaft of the humidifying roll with the tip 13 facing the peripheral surface of the humidifying roll. A gauge plate in which a plurality of nozzles 14 arranged in the core direction and an edge 16 for adjusting a water film 15 formed on the peripheral surface of the humidifying roll discharged from the nozzle are directed to the peripheral surface of the humidifying roll. And the humidifying water 22 applied to the peripheral surface of the humidifying roll 12
Is transferred to the paper 27 on the peripheral surface of the cooling roll 25 via the intermediate roll 26.

Reference numeral 33 is a gutter for receiving water dripping from the nozzle, and one side edge thereof also serves as the gauge plate 17.
Reference numeral 34 denotes a water supply pipe, and each nozzle 14 penetrates the water supply pipe 34 through the trough (33) and projects vertically to the peripheral surface of the humidifying roll 12. A discharge amount adjusting cock 20 is operated by a computer so that the discharge amount is adjusted for each nozzle.

The mouth end 13 of each nozzle has a flat shape elongated in the axial direction of the moisturizing roll 12, and the moisturizing water 22 discharged from each nozzle 14 is surrounded by the mouth end of the nozzle and the moisturizing roll 12. A water vein that follows equilibrium is formed between the surfaces in the axial direction of the humidifying roll 12.

From the gage plate side of the inner surface of the gutter, a plurality of partition plates 19 whose planes are oriented at right angles to the axial direction of the humidifying rolls.
Lie between the nozzle 14 and the gauge plate 17 in the axial direction of the humidifying roll 12 so as to partition the space between the nozzle 14 and the nozzle 14, and are ejected from each nozzle and adhere to the peripheral surface of the humidifying roll. The humidifying water 22 is regulated by the partition plates 19 and moves in parallel to the gauge plate side (17) with the rotation of the humidifying roll 12, and between the edge 16 of the gauge plate 17 and the peripheral surface of the humidifying roll 12. The water pool 35 is formed, and is stroked by the edge 16 of the gauge plate to adjust the amount of the water film 15 attached to the peripheral surface of the humidifying roll to a predetermined amount. The partition plate 19 may be continuous from the gauge plate side to the opposite side so as to cross the gutter 33, that is, to divide the gutter 33 into nozzles.

When the distance between the humidifying roll 12 and the nozzle tip 13 is set to 0.5 to 5.0 mm, and the gauge between the gauge plate 17 and the humidifying roll 12 is set to 0.05 to 0.5 mm. Good. 37 is a squeeze roll, by which the water film 15 is smoothed. Reference numeral 21 is a water supply tank for supplying humidifying water to the nozzle. There is a filter 23 and a valve 38 between the water tank 21 and the nozzle 14,
The humidifying water 22 is purified by a filter to be dust-free, and a required amount thereof is supplied. The surplus humidifying water 22 received by the gutter 33 may be filtered by the filter (23) and circulated to the nozzle 14 again. The nozzle 1
No. 4 is not a spray nozzle of the conventional spray type plate surface humidifier of the offset printing machine body, but discharges (spouts) water like a water faucet. A thin pipe (14) is connected to the water supply pipe 34. It may be only the state of the branched pipe. The gutter 33 is not for preventing the humidifying water 22 from scattering, but is for collecting the excess humidifying water 22. 41 is a shaft of the squeeze roll 37,
Is a rubber surface layer. Reference numeral 43 is a saucer for receiving the water dripping from the squeeze roll 37.

The humidifying water 22 contains silicon, amine compounds such as quaternary amines and polyamines, ammonium compounds, cationic surfactants, anionic surfactants,
An antistatic agent such as a nonionic surfactant or a polyhydric alcohol derivative is added in an amount of 0.1 to 1000 P. P. It is preferable to add M, which suppresses the generation of static electricity on the surface of the paper, and at the same time accelerates the attachment, absorption, and permeation of the humidifying water into the paper to increase the paper transport speed (printing speed, drying speed). Good.

The humidifying roll 12 is constituted by a chrome-plating roll in which a cylinder (steel pipe) 39 plated with chrome is supported by a shaft 40, and a rubber roll is used as the intermediate roll 26. The thickness of the chrome plating is preferably 30 μm or more and 100 to 300 μm. For the surface layer of the rubber roll (mediating roll) 26, NBR (nitrile butyl rubber), PVC / NBR (blend rubber of polyvinyl chloride and nitrile butyl rubber), or acrylic rubber may be used. The hardness is preferably 30 to 50 degrees.

Reference numeral 24 denotes a doctor which is in contact with the peripheral surface of the chrome plating roll (humidifying roll) 12, and is moved from the paper 27 to the peripheral surface of the chrome plating roll (humidifying roll) 12 via a rubber roll (mediating roll) 26. The paper dust and other dust are scraped off by the doctor 24. The peripheral surface speed of the rubber roll (mediating roll) 26 in contact with the paper 27 is the same as the peripheral speed of the cooling roll 25, that is, the same as the transport speed of the paper 27, but not in contact with the paper 27. ) 12 and the squeeze roll 37 are slower than the peripheral surface speed of the rubber roll (mediating roll) 26 (it is preferable to be 1 to 80% slower than the peripheral surface speed of the rubber roll 26), and slip between those rolls to make them rolls. The dust removal effect of the doctor 24 is enhanced by scraping off the dust adhering to the peripheral surface of the.
Further, when the peripheral speed of the chrome plating roll 12 is slowed in this way, the water film 15 does not scatter from the peripheral surface of the chrome plating roll 12 which is smooth and difficult to wet, so that the water film 15 on the peripheral surface of the chrome plating roll 12 is prevented. Since the thin water film 15 allows the humidifying water 22 to be gradually and uniformly supplied to the paper 27, the paper 2 can be made thin and uniform.
It becomes easier to control the amount of water supplied to 7. Squeeze roll 3
7 is a water film 15 that is evenly struck by the gauge plate 17
Therefore, the peripheral speed of the squeezing roll 37 may be slower than that of the chrome plating roll 12, and a doctor blade can be used instead of the squeezing roll 37.

[0035]

As described above, the paper moisturizing device according to the present invention can freely adjust the moisturizing amount according to the standard (width and hygroscopicity) of the paper, and the paper is in an absolutely dry state via the drying device. Can be humidified evenly and quickly from edge to edge to reach the equilibrium moisture content, and it can be attached to existing printing equipment at any time without any particular difficulty in finding its installation space. , When cutting through a cutting device and stacking, the edges of the paper do not become uneven, printing defects due to shrinkage unevenness and paper dimensions are not uniform, creases in the paper, printing surface with ink sticky due to residual heat The problems such as contamination of the paper can be solved, and the paper does not come into close contact with the guide roll due to static electricity to make it difficult to separate. Therefore, the paper can be conveyed at a high speed to perform high-speed printing. As described above, according to the present invention, an elaborate printing apparatus can be obtained by attaching the paper humidifier to the paper exit of the dryer.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of a paper humidifying device according to the present invention.

FIG. 2 is a perspective view of an essential part of the paper humidifying device according to the present invention.

FIG. 3 is a cross-sectional view of an essential part of the paper humidifying device according to the present invention.

FIG. 4 is a side view of the sheet humidifying device according to the present invention.

FIG. 5 is a schematic side view of the printing apparatus according to the present invention.

[Explanation of symbols]

 11 Drying Device 12 Humidifying Roll 13 Tip 14 Nozzle 15 Water Rolling 16 Edge 17 Gauge Plate 18 Humidifying Device 19 Partition Plate 20 Cock 21 Water Supply Tank 22 Humidifying Water 23 Filter 24 Doctor 25 Cooling Roll 26 Rubber Roll (Media Roll) 27 Paper 29 Tension Roll 30 Printing Machine Main Body 31 Cutting Device 32 Folding Machine 33 Gutter 34 Water Supply Pipe 35 Water Pool 36 Gauge 37 Squeezing Roll 38 Valve 39 Cylinder 40 Shaft 41 Shaft 42 Rubber Surface Layer 43 Saucer

Claims (7)

[Claims] 1. A printing apparatus having a drying device (11) for drying printing ink on the printing paper outlet side of the printing roll, wherein a humidifying roll (12) and a mouth (13) are provided on the peripheral surface of the humidifying roll. A plurality of nozzles (14) aligned in the axial direction of the humidifying roll, and a water film (1) formed on the peripheral surface of the humidifying roll discharged from the nozzle.
Humidification device (1) whose edge (16) for adjusting 5) comprises a gauge plate (17) directed to the peripheral surface of the humidification roll.
The printing device 8) is provided on the printing paper outlet side of the drying device (11). 2. The nozzle (14) according to claim 1, wherein the mouth (13) of the nozzle (14) has a flat shape elongated in the axial direction of the humidifying roll.
A printing device according to claim 1. 3. A plurality of partition plates (19) having the plane according to claim 1 oriented at right angles to the axial direction of the humidifying roll,
The printing device according to claim 1, wherein the printing device is arranged between the nozzle (14) and the gauge plate (17) in the axial direction of the humidifying roll (12). 4. The printing apparatus according to claim 1, wherein each of the plurality of nozzles (14) according to claim 1 has a cock (20) for adjusting a discharge amount. 5. A filter (23) for purifying the humidifying water (22) is provided in a water supply passage extending from the water supply source (21) to each of the plurality of nozzles (14) according to claim 1 above. The printing apparatus according to claim 1, wherein the printing apparatus is a printing apparatus. 6. The humidifying roll (1) according to claim 1 above.
The printing apparatus according to claim 1, further comprising a doctor (24) contacting the peripheral surface of 2). 7. The drying device (11) according to claim 1 above.
A cooling roll (25) is provided on the printing paper outlet side of the sheet, the humidifying roll (12) is a metal roll, and a rubber roll (26) is provided between the cooling roll (25) and the metal roll (12). And the cooling roll (25)
The water film (28) formed on the peripheral surface of the metal roll (12) is transferred and supplied to the cooling paper (27) passing through in close contact with the peripheral surface of the metal roll (12) via the rubber roll (26). The printing apparatus according to claim 1, wherein the printing apparatus is a printing apparatus.