JP5380101B2 - Water supply roll - Google Patents

Description

  The present invention relates to a water supply roll such as a water kneading roll, a water rider roll, or a water source roll used in a water supply mechanism of a printing apparatus.

  As is well known, offset printing is a printing method that utilizes the property of repelling oil (ink) and water. This printing method is the current mainstream printing technology, and is often used for printing newspapers, magazines, textbooks, flyers and the like.

  In the offset printing, after an image portion (an ink-philic resin layer) and a non-image portion (hydrophilic aluminum layer) are formed on a plate in advance, water is first applied to the non-image portion by a dampening device, and then Ink is applied to the image area by an inking device, and the ink image is transferred to a rubber blanket that rotates in contact with the plate. Further, a printed material such as paper is passed between an impression cylinder rotating in contact with the rubber blanket, and an ink image on the rubber blanket is transferred for printing.

  By the way, in offset printing, a water supply roll is used as a water supply mechanism of a printing press. As the water supply roll, for example, a water kneading roll, a water rider roll, and a water source roll are known. These water supply rolls have the functions of dampening water supply, water retention, history elimination, and cylinder ink winding (ink stain) elimination, and are very important from the viewpoint of speeding up the printing press and improving the quality of printed matter. Have a role to play.

A printing apparatus using a conventional water source roller (water supply roll) will be described with reference to FIG. A water supply device for accommodating the numbering 1 1 dampening water in the figure, are disposed close to each dip roller 2 0 as a water roller in the water supply apparatus 1 1. Here, the water fountain roller 2 0, grooves or irregularities and has a rather smooth surface to the surface. The water fountain roller 2 0, the metal cylinder 12 which has been subjected to chrome plating on the surface are arranged in proximity. Dip roller 2 0 contacts at a point of a single nip the metal cylinder 12, and rotates the rotated together not through gears or the like. Here, the metal cylinder 12 is configured to reciprocate in the axial direction in order to spread the dampening water film uniformly. A rubber watering roller 14 is disposed on the metal cylinder 12 . The watering roller 14 is configured to rotate in contact with the plate cylinder 15 . The plate cylinder 1 5, plate cylinder 1 mounted on a 5 the editions supplying ink to an image portion (not shown) ink roll 1 6a, 1 6b, 1 6c are arranged close .

The operation of the printing apparatus having such a configuration is as follows.
First, dampening water of the water supply apparatus 1 1 is supplied to the water fountain roller 2 0 and transferred to the metal cylinder 12. Next, the fountain solution is transferred to a rubber dampening roller 14 and supplied to the non-image portion of the plate mounted on the plate cylinder 15 that is also rotating in contact with the plate, thereby moistening the plate surface. Thereafter, the ink is supplied to the image portion by the ink roller 1. 6a to 1 6c, basic printing image is formed. After this step, it is essential that the image is transferred from the rubber blanket to the paper to be printed and that the image formation on the plate is accurate. If ink adheres to the non-image area of the plate, it will also be printed on the printing medium and will become dirty and become defective. Further, if the fountain solution is excessive, it will also adhere to the image-receiving portion, resulting in insufficient ink transfer and insufficient ink density of the printed matter.

  Note that Patent Document 1 is known as a printing roller used in a printing press. In Patent Document 1, the roller surface is roughened into a lattice-type groove shape with an angle of 20 ° to 160 ° or a diagonal groove shape with an angle with the axial direction of 10 ° to 80 ° to form continuous recesses, This is an attempt to solve the problem of unevenness and the problem of ink amount or coating amount at the same time.

JP-A-6-23965

  However, in the conventional water supply roll, even if an appropriate nip is ensured, the roll surface is smooth and is not driven by itself but is rotated by the rotation of the opposing cylinder roll. For this reason, as the rotation of the cylinder roll increases, the rotation of the water source roll may drop and eventually stop. This is considered to be caused by slipping due to a “water film” existing between the roll and the nip (that is, similar to the hydroplaning phenomenon during high-speed driving of the vehicle). In addition, since the phenomenon of the trouble mentioned above also occurs at the time of cleaning the roll, the cleaning becomes insufficient, and conversely, it may cause a stain on the printing medium.

  In addition, as described above, the water source roller (water supply roller) has been required to have a smooth rubber surface from the past for the purpose of supplying a uniform dampening water film to the watering roller by the metal cylinder in contact therewith, From the background of manufacturing and using with a general surface roughness (Rz less than 10 μm), it has been considered that the formation of grooves and irregularities on the surface impairs the uniformity of the water film. The above-mentioned Patent Document 1 is an invention related to an ink mechanism (ink supply to an image portion), and development with a water mechanism (water supply to a non-image portion) is unthinkable in conventional common sense. .

  The present invention has been made in consideration of such circumstances, and creates a water escape route by forming irregular irregularities roughened to a roughness of 120 to 300 μm on the rubber layer surface of the core metal. An object of the present invention is to provide a water supply roll that can prevent the rotation from dropping or stopping even when the metal cylinder roll speed increases, and can stably supply dampening water.

The water supply roll according to the present invention includes a water supply device containing dampening water, a plate cylinder, a watering roller for supplying the dampening water to the plate cylinder, and the dampening water supplied from the water supply device. A water supply roll comprising a water rider roll disposed close to the metal cylinder, and used in a printing apparatus including a metal cylinder for supplying the dampening water to the watering roller, and a core metal peripheral surface formed rubber layer, characterized in that the formation of the irregular unevenness roughened to roughness 1 7 0~300μm to the rubber layer surface.

  According to the present invention, even if the metal cylinder roll is increased in speed, the rotation falls off by forming the irregular irregularities roughened to a roughness of 120 to 300 μm on the surface of the rubber layer of the metal core. Stopping can be avoided and dampening water can be supplied stably.

Explanatory drawing of the printing apparatus using the water supply roll which concerns on Example 1 of this invention. Explanatory drawing of the water supply roll used for the printing apparatus of FIG. Explanatory drawing of the printing apparatus using the conventional water supply roll.

Hereinafter, the present invention will be described in more detail.
In the present invention, as the material of the rubber layer, for example, any rubber such as silicone rubber, acrylonitrile butadiene rubber, ethylene propylene rubber, fluorine rubber, urethane rubber, chloroprene rubber, epichlorohydrin rubber, natural rubber, etc. can be used. Desirably, acrylonitrile butadiene rubber is the main component. In addition, a known compounding agent such as a vulcanizing agent, a vulcanization aid, a vulcanization accelerator, an antiaging agent, a plasticizer, and a filler can be used as the material for the rubber layer.

  In the present invention, the surface roughness (Rzjis) of the rubber layer is 120 to 300 μm. The surface roughness (Rzjis) is defined in JIS B0601-2001. The reason for limiting the surface roughness to the above numerical range is as follows. That is, when the roughness is less than 120 μm, the depth of the concave and convex portions becomes shallow, and slipping is likely to occur as in the case of a roll having a smooth surface. On the other hand, if the roughness exceeds 300 μm, the dampening water is cut too much, and ink stains due to dampening water shortage tend to occur. The roughness of the rubber layer surface is preferably 150 to 250 μm.

  In the present invention, “irregular irregularities” means that fine grooves are discontinuously formed. “Discontinuous” means that the concave portion (groove) is not formed in a spiral shape or a ring shape along the circumferential direction of the rubber layer surface, but is formed to be blocked by the convex portion in the middle. means. Irregular irregularities can be obtained by polishing a disk-shaped polishing stone by placing the disk surface on the roll surface, not on the circumferential side surface that is normally used. The groove is preferably formed at an angle of 20 ° to 70 ° with respect to the axial direction of the roll. Further, the length of the groove is preferably 1 to 10 mm. Here, when the length of the groove is less than 1 mm, the effect of forming the groove is small, and slipping is likely to occur as in a conventional roll having a smooth surface. If the length of the groove exceeds 10 mm, there is no problem in the water supply performance, but the manufacturing cost becomes excessive in consideration of cost effectiveness.

In the present invention, a layer made of ebonite or the like may be provided as an intermediate layer between the cored bar and the rubber layer. As the core metal, a core material made of an arbitrary material that keeps the necessary synthesis, such as a carbon core, in addition to an iron core can be used.
In this invention, it is preferable that the hardness of the roll surface is JISA20-45. Here, if the hardness is less than 20, the physical properties of the rubber are deteriorated and the life is shortened. On the other hand, if the hardness exceeds 45, since the hardness is high when pressed against the metal cylinder, the nip amount becomes small and the uniform supply of water is hindered. The rubber layer may be a single layer or a multilayer of two or more layers. For example, the hardness or the thickness of both can be adjusted so that the surface layer is hardened, the inner layer is softened, and the total hardness is the same as that of the rubber single layer.

  Next, a printing apparatus using the water supply roll of the present invention will be described with reference to the drawings.

(1) When used as a water kneading (water rider) roll
Please refer to FIG. 1 and FIG. Reference numeral 11 in FIG. 1 is a water supply device which accommodates the dampening water, the metal cylinder 12 is disposed in close proximity subjected to chrome plating on the surface in the water supply apparatus 1 1. Here, the metal cylinder 12 is configured to reciprocate in the axial direction in order to spread the dampening water film uniformly. A water kneading (water rider) roll 13 serving as a water supply roller is disposed adjacent to the metal cylinder 12. The metal cylinder 12 is provided with a rubber watering roller 14. The watering roller 14 is configured to rotate in contact with the plate cylinder 15. In the plate cylinder 15, ink rolls 16 a, 16 b, and 16 c that supply ink to an image portion of a plate (not shown) mounted on the plate cylinder 15 are disposed in proximity to each other.

  The water kneading roll 13 has a configuration shown in FIGS. 2A is a sectional view of the water kneading roll 13, FIG. 2B is a partial explanatory view of the plan view of FIG. 2A, and FIG. Sectional drawing which follows a X-ray is shown. The water kneading roll 13 has a configuration in which a rubber layer 18 as a surface layer is formed on the peripheral surface of a cored bar 17 as shown in FIG. Irregular irregularities roughened to a roughness of 120 to 300 μm are formed on the surface of the rubber layer 18 as shown in FIGS. Note that reference numeral 19 in FIGS. 2B and 2C indicates a discontinuous groove.

  2C shows that the lower surface (bottom surface) in the discontinuous groove 19 in FIG. 2C is flat (planar). However, the lower surface in the discontinuous groove 19 is not necessarily flat. Although not shown, for example, the lower surface (bottom surface) in the discontinuous groove may be an acute surface such as a V shape. The example of the shape of FIG. 2C is only an example.

(2) When used as a water source roll
Please refer to FIG. However, the same members as those in FIG. Reference numeral 20 in the figure indicates a water source roll as a water supply roll. The water source roll 20 is disposed close to the water supply device 11. Here, the water source roll 20 has the same configuration as the water kneading roll of FIG.

Next, specific examples of the present invention will be described.
Example 1
First, a roll having an inner diameter of 100 mm, an outer diameter of 120 mm, a surface length of 1648 mm, and a hardness of 25 ° is made of acrylonitrile-butadiene rubber (NBR), and this roll is mounted on a grinding machine of the roll, and the surface of the rubber layer has a roughness (Rzjis) of 170 to Irregular irregularities roughened to 190 μm were formed.

  The water supply roll which concerns on the said Example 1 has the structure which formed the irregular unevenness | corrugation roughened to the roughness 170-190 micrometers on the rubber layer surface of a metal core. When a water supply roll having such a configuration is used as a water mixing roll for an offset rotary press with a nip width of 7 mm setting with a metal cylinder, no slip occurs between the metal cylinder and the ink even after 6 months. There were no problems such as insufficient density or stains on the printed matter.

(Example 2)
First, a roll having an inner diameter of 100 mm, an outer diameter of 120 mm, a surface length of 1648 mm, and a hardness of 30 ° is made of NBR, and this is mounted on a grinding machine of the roll, and the surface of the rubber layer is roughened to a roughness of 170 to 190 μm. Unevenness was formed.

  As in the case of Example 1, the water supply roll according to Example 2 was used as a water kneading roll for an offset rotary press with a nip width of 7 mm set with a metal cylinder. There was no slip with the cylinder, and there were no problems such as insufficient ink density or smudges on the printed matter.

(Comparative example)
A water supply roll was produced in the same manner as in Example 1 except that the surface roughness was Rz 8 μm. When the same test as Example 1 was performed using the water supply roll which concerns on a comparative example, slip generate | occur | produced between the metal cylinders and the printed matter generate | occur | produced three months after use.

Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment. Specifically, an intermediate layer made of ebonite, for example, may be provided between the metal core and the rubber layer, and the grooves for forming the irregularities of the rubber layer are not limited to those having the configuration described in the above embodiment.
Hereinafter, the invention described in the scope of claims of the present application will be appended.
A water supply roll that rotates in contact with a metal or resin roll for supplying dampening water in a printing apparatus, comprising a cored bar and a rubber layer formed on a peripheral surface of the cored bar, the rubber layer A water supply roll characterized in that irregular irregularities roughened to a surface of 120 to 300 μm are formed on the surface.

  DESCRIPTION OF SYMBOLS 11 ... Water supply apparatus, 12 ... Metal cylinder, 13 ... Water kneading roll, 14 ... Watering roll, 15 ... Plate cylinder, 16a, 16b, 16c ... Ink roll, 17 ... Core metal, 18 ... Rubber layer, 19 ... Groove, 20 ... Mizumoto roll.

Claims (3)

A dampening solution containing a dampening water; a plate cylinder; a watering roller for supplying the dampening water to the plate cylinder; and the dampening water supplied from the water supply device; A water supply roll comprising a water rider roll used in a printing apparatus including a metal cylinder for supplying to a watering roller, and disposed close to the metal cylinder,
Water roll comprising a metal core and a core metal peripheral surface formed rubber layer, characterized in that the formation of the irregular unevenness roughened to roughness 1 7 0~300μm to the rubber layer surface . The water supply roll according to claim 1, wherein an intermediate layer is provided between the core metal and the rubber layer. The water supply roll according to claim 1 or 2, wherein the roll surface has a hardness of JIS A20 to 45.

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