JP4071888B2 - Humidifier for offset printing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a humidifier for an offset printing machine.
[0002]
[Background Art and Problems to be Solved by the Invention]
As shown in FIG. 3, the plate cylinder 12 of the offset printing machine 11 is provided with an ink device 13 for supplying printing ink to the plate cylinder 12 and a humidifier 14 for applying water to the surface of the plate cylinder 12. It has been. The inking device 13 takes out the ink in the ink fountain 15 from between the bottom plates 16 by the fountain roller 17, and sends the ink adhering to the fountain roller 17 to the ink form roller 20 through the many roller groups 19 by the ink transfer roller 18. Ink is supplied to the plate cylinder 12. The humidifier 14 is for forming a minimum water film on the surface of the plate cylinder 12 so that ink does not adhere to the non-image area of the plate cylinder 12, and a part of the humidifier 14 is immersed in the humidified water tank 21. The water source roller 22 that rotates in turn, the water application roller 23 that rotates by rolling contact with the plate cylinder 12, and the two waters that feed the water adhering to the surface of the water source roller 22 to the water application roller 23 by rolling contact. It consists of transfer rollers 24 and 25. The water transfer roller 25 that is in rolling contact with the swim roller 23 is often oscillated in the axial direction in order to uniformly adhere water to the swim roller 23.
[0003]
In the humidifier 14, water is sent in the order of the water source roller 22, the water transfer rollers 24 and 25, and the water application roller 23, but in the reverse order, the water supply roller 23 makes contact with the plate cylinder 12 from the water application roller 23. Ink is transferred to the roller 22 side. As a means for coping with the transfer of ink from the swim roller 23, two types of methods are employed. One is a method in which the surface of the water source roller 22 and the water transfer roller 24 that is in rolling contact with the water source roller 22 is made of a material and a structure in which only water adheres and ink does not adhere. The ink allows the ink to adhere to the surface of the water source roller 22 and the water transfer roller 24 and uses the ink film attached to the surface of the roller to emulsify the water and the ink. Is sent from the water source roller 22 to the swim roller 23.
[0004]
The latter method can be easily realized by using a lipophilic material for the surface of the water source roller 22 and the water transfer roller 24, and has an advantage that the humidifier 14 can be manufactured at low cost. As a method of making the roller surface oleophilic, a method of lining oleophilic NBR (nitrile butadiene rubber) or the like on the roller surface is often employed. Hereinafter, this type of humidifier is referred to as a simple type.
[0005]
As shown in FIG. 4, the body length of the water source roller 22 is usually longer than the water transfer roller 24 that is in rolling contact with the water source roller 22. In the above-described simple humidifier, water and emulsified ink spread to the roller barrel end side while being transferred by each roller, and the ink spread to the roller barrel end side is transferred to the barrel end of the water transfer roller 24. As shown by a two-dot chain line in FIG. 4, it sticks to the body end portion of the water source roller 22 that does not make rolling contact with the water transfer roller 24 and hardens. When the ink is deposited in this way and the surface of the water source roller 22 is uneven, the water in the water supply tank 21 jumps around by the rotation of the water source roller 22 partially immersed in the water supply water tank 21. There is a problem of scattering and soiling printed matter.
[0006]
Accordingly, an object of the present invention is to provide a simple type humidifier for an offset printing press that can prevent water splashing in a humidified water tank.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a water source roller that is rotated by being partially immersed in a humidifying water tank, a swim roller that rotates by rolling against a plate cylinder, and the water source roller In the humidifier for an offset printing press, comprising the one or more water transfer rollers disposed between the rollers and sending the water adhering to the surface of the water source roller to the swim roller by rolling contact, the water source roller Alternatively, at least one of the water transfer rollers is provided with means for making it difficult for water and oil to adhere to the surface of the cylinder end, and the cylinder central surface layer between the cylinder end surfaces is made an oleophilic material. The structure formed by was adopted.
[0008]
That is, by making it difficult for water and oil to adhere to the surface of the body end of at least one of the water source roller or the water transfer roller, the water and the emulsified ink transferred from the swim roller, The surface of the cylinder end portion is prevented from being transferred to the cylinder end side at the position of the roller where water and oil are difficult to adhere, so that ink is not deposited on the cylinder end portion of the water source roller.
[0009]
As a means for making it difficult for water and oil to adhere to the surface of the barrel end, a method of forming the surface layer of the barrel end with rubber that is difficult to adhere to water and oil can be employed. Silicone rubber or fluoro rubber can be used as the rubber that is difficult for water and oil to adhere to.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The basic structure of the humidifier of this offset printing press is the same as that of the humidifier 14 shown in FIG. 3, and as shown in FIG. A roller 2, a swim roller 4 that rolls in contact with the plate cylinder 3, and two water transfer rollers 5, 6 that feed water adhering to the surface of the water source roller 2 to the swim roller 4 by rolling. The water transfer roller 6 that is in contact with the swim roller 4 is oscillated in the axial direction.
[0011]
As shown in FIG. 2, the water source roller 2 is formed so that its trunk length is longer than that of the water transfer roller 5, and the surface of the cylinder end portion from slightly inside to the both side cylinder ends of the water transfer roller 5. No. 7 is lined with fluoro rubber which is hard to adhere to water and oil. The cylinder center surface 8 between the cylinder end surfaces 7 lined with this fluoro rubber is lined with lipophilic NBR. Therefore, the water and the emulsified ink transferred from the swim roller 4 do not adhere to the end surface 7 of the water source roller 2, and no ink is deposited on this portion.
[0012]
In the above-described embodiment, the trunk end of the water source roller is lined with fluoro rubber, which is difficult for water and oil to adhere to, but means for making it difficult for water and oil to adhere to the surface of the trunk end of the water transfer roller may be applied. Of course, this means may be applied to both. Even when there are one or more water transfer rollers, this means may be applied to at least one of the water source roller or the water transfer roller. As a means of making water and oil difficult to adhere, in addition to a method of lining fluoro rubber or silicone rubber, a method of coating the surface of the body end of the roller with a material that is difficult to attach water or oil may be adopted. it can.
[0013]
【The invention's effect】
As described above, the simplified humidifier for an offset printing press according to the present invention makes it difficult for water and oil to adhere to the surface of the body end of at least one of the water source roller or the water transfer roller, The water and emulsified ink transferred from the swim roller are prevented from being transferred to the barrel end at this roller position, so water splash due to ink accumulation on the barrel end of the water source roller is eliminated. be able to.
[Brief description of the drawings]
FIG. 1 is an external perspective view showing an embodiment of a humidifier. FIG. 2 is a partially omitted cutaway plan view of FIG. 1. FIG. 3 is a partially omitted vertical sectional view of a conventional offset printing machine. 3 main part enlarged plan view [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Humidification water tank 2 Water source roller 3 Plate cylinder 4 Swim roller 5, 6 Water transfer roller 7 Cylinder end surface 8 Cylinder center surface 11 Offset printing machine 12 Plate cylinder 13 Inking device 14 Humidifier 15 Ink fountain 16 Bottom plate 17 Vat Roller 18 Ink Transfer Roller 19 Roller Group 20 Ink Forming Roller 21 Humidity Water Tank 22 Water Source Roller 23 Water Forming Rollers 24 and 25 Water Transfer Roller

Claims (2)

A water source roller that is rotated by being partially immersed in a humidifying water tank, a swim roller that rotates by rolling against a plate cylinder, and is disposed between the water roller and the swim roller, and is disposed on the surface of the water roller. An offset formed by one or more water transfer rollers that send the adhered water to the swim roller by rolling contact, and the body length of the water source roller is formed longer than the body length of the water transfer roller that contacts the water roller In the humidifier for a printing press, at least one of the water source roller and the water transfer roller is provided with means for making it difficult for water and oil to adhere to the surface of the cylinder end, A humidity supply device for an offset printing machine, characterized in that the surface layer in the middle of the cylinder is made of a lipophilic material. 2. The moisture supply device for an offset printing press according to claim 1, wherein the means for preventing water and oil from adhering to the surface of the cylinder end is formed of a rubber that is difficult for water and oil to adhere to the surface of the cylinder end. .

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