JPH0531949U - Ink delivery roll for keyless printing machine - Google Patents

Abstract

(57) [Summary] [Purpose] The free water ejected between the ink source roll and the ink delivery roll can be discharged smoothly. [Structure] The ink source roll 106 and the ink delivery roll 107 are rotated at different peripheral speeds with a minute gap, and the surface of the ink delivery roll 107 is formed into a grid pattern 3 consisting of continuous groove portions 2 and independent mountain portions 1. It is characterized by being formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an ink delivery roll in a keyless printing machine.

[0002]

[Prior Art]

 As shown in FIG. 6, the ink 102 in the ink fountain 101 is pressure-fed to the nozzle 104 by the ink pump 103, ejected from the nozzle 104 toward the ink source roll 106 rotating at a low speed, and adheres to the ink source roll 106. The ink is passed through the gap between the ink source roll 106 and the supply doctor 105, which is located in parallel with the ink source roll 106, to obtain a uniform film thickness, and the gap is narrower than the gap between the ink source roll 106 and the supply doctor 105. The ink is transferred to the ink delivery roll 107 which is positioned parallel to the ink source roll 106 and rotates at high speed.

The surface of the ink delivery roll 107 has a smooth or uneven surface with continuous peaks and independent valleys. The ink transferred to the ink delivery roll 107 is transferred to the printing paper 115 through the doctor roll 108, the first inking roll 110, the second inking roll 109, the plate cylinder 113, and the blanket cylinder 114. The dampening water is supplied to the plate cylinder 113 by the dampening water supply device 112. The difference in the ink film thickness caused by the ink consumption part and the non-consumption part of the ink corresponding to the image area and the non-image area of the plate cylinder 113 is reversed to the doctor roll 108 via the first and second inking rolls 110 and 109. Although transferred, it is scraped off by the docker blade 111 to form a uniform film thickness. The ink scraped off by the doctor blade 111 falls on the ink fountain 101 and is recirculated.

[0004]

[Problems to be solved by the device]

 Since the ink scraped off by the doctor blade 111 contains about 20% dampening water, the water content of the ink in the ink fountain 101 gradually increases and becomes equilibrium at about 10 to 30%. Therefore, the ink on the ink source roll 106 measured by the supply doctor 105 contains about 10 to 30% of fountain solution, and the low speed (peripheral speed of about 1 m / s or less) ink source roll 106 and the high speed (5 to 5%). (15 m / s) The ink in the gap with the ink delivery roll 107 is sheared by 4 to 14 m / s. When the water-containing ink on the ink source roll 106 is sheared, water is ejected. When the surface of the ink delivery roll 107 is smooth, there is no escape area for the free water, so the free water adheres to the surface of the ink delivery roll 107 in a layered manner, which hinders the transfer of the ink. If the surface of the ink delivery roll 107 has an uneven shape with continuous peaks and independent valleys, free water accumulates in the recesses, and since there is no escape area, it is saturated in a short time and the peaks are also free. A water film is formed and the transfer of ink is hindered.

The present invention was developed to address such problems, and an object thereof is to facilitate the discharge of free water.

[0006]

[Means for Solving the Problems]

 The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 to 7 corresponding to the embodiments. The present invention is directed to a low speed rotating ink source roll 106, a high speed rotating ink delivery roll 107 and a doctor blade. In a keyless printing machine having a doctor roll 108 rotating at a high speed adjacent to 111, the ink source roll 106 and the ink delivery roll 107 are rotated at different peripheral speeds with a minute gap, and the surface of the ink delivery roll 107 is Are formed in a grid pattern 3 consisting of continuous groove portions 2 and independent mountain portions 1.

Further, it is characterized in that the mountain portion 1 has a trapezoidal cross section and a top portion thereof is a curved surface forming an outer peripheral surface of the ink delivery roll 107. Further, the surface of the curved surface forming the top of the peak portion 1 is the lipophilic material 4 and the surface of the valley portion is the hydrophilic material 5.

[0008]

[Action]

 According to the present invention, the free water in the water-containing ink released by high shear due to the above means has a significantly lower viscosity than the ink and has good fluidity, and since the groove is continuous, the pressure in the groove becomes atmospheric pressure, The free water selectively flows into the groove from the high pressure mountain portion, and the ink having a low water content, which is the expulsion of the free water, remains near the mountain portion. The ink attached to the ridges has a reduced water content and recovers elasticity, so it easily transfers to a doctor roll. The free water that has flowed into the groove is not covered with the ink film and is consumed by the centrifugal force for misting and evaporation into the atmosphere.

On the other hand, by flattening the top of the mountain part, the low water content ink exuding the free water is attached, and the effective area for transferring to the downstream roll can be widened, and the mountain part is made to be lipophilic. By doing so, the outer surface ink of the emulsified ink from which the free water is ejected preferentially adheres to the ridges, and by making the groove hydrophilic, the free water preferentially flows into the groove and the ink is extruded.

The cross-sectional shape of the groove is V-shaped when the water content of the ink is relatively low, and U-shaped when the water content is relatively high, so that the cross-sectional area of the groove is changed without changing the area of the flat portion of the crest. Can be obtained. Therefore, the shape should be selected according to the equilibrium water content determined by the operating conditions and the emulsification limit of the ink used. If the depth and width of the groove are too small, the separating and collecting action of free water will be insufficient, and if it is too large, not only free water but also the emulsified ink will flow into the groove and be transferred to the doctor roll as a lump. As a result, spotted high density areas are produced on the paper surface.

Furthermore, the maximum pitch of the lattice pitch is determined from the effective range in which one groove can collect free water ejected from the emulsified ink, and the minimum pitch maximizes the area of the flat top of the mountain peak that is responsible for the transfer action of the emulsified ink. It depends on what you do. Therefore, there is an optimum value from both, which is about 0.3 to 3 mm.

[0012]

【Example】

 An embodiment of the present invention will now be described with reference to the drawings. In the present invention, as shown in FIG. 6, the ink source roll 106 that rotates at a low speed, the ink delivery roll 107 that rotates at a high speed, and the doctor blade 111 rotate at a high speed. In a keyless printing machine having a doctor roll 108, the ink source roll 106 and the ink delivery roll 107 are rotated at different peripheral speeds with a minute gap, and the surface of the ink delivery roll 107 is shown in FIGS. As shown in the figure, a grid-like pattern 3 consisting of continuous groove portions 2 and independent mountain portions 1 was formed. The pitch of the grid pattern 3 is 0. The top of the mountain portion 1 is flat and has a curved surface that forms the outer peripheral surface of the ink delivery roll 107.

FIG. 3 shows another embodiment in which the surface of the curved surface forming the top of the mountain portion 1 is coated with the lipophilic material 4. FIG. 4 shows another embodiment in which the surface of the groove 2 is coated with the hydrophilic material 5. 5 shows a V-shaped groove having a V-shaped cross-sectional shape, and FIG. 6 shows a U-shaped groove having a U-shaped cross-sectional shape, and the depth of each groove. Is 0. 04 to 0.3 mm, and the opening width at the top of the groove is 0.03 to 0.30 mm.

Thus, when the water-containing ink filled in the narrow gap between the ink source roll 106 and the ink delivery roll 107 is subjected to high shear due to the speed difference between the both rolls, the water-containing ink releases free water and free water. Divided into emulsified ink with water content. If this free water is left as it is, the ink transfer will be hindered. Therefore, it is separated and collected in the groove that does not participate in the ink transfer to prevent the ink transfer from being hindered.

Further, since the water in the ink that is involved in the ink transfer adhered to the mountain portion becomes an emulsified ink containing only thin and uniform water droplets from which free water is removed, elasticity is improved and transferability is improved.

[0016]

[Effect of the device]

 As described above, according to the present invention, the ink source roll and the delivery roll are rotated at different peripheral speeds with a minute gap, and the surface of the ink delivery roll is formed in a grid pattern having continuous grooves and ridges independent of each other. Therefore, the water-containing ink between the ink source roll and the delivery roll is separated into free water and low water content emulsified ink extruding free water, and the free water is collected in the groove and ink transfer is not hindered. Have an effect.

[Brief description of drawings]

FIG. 1 is an enlarged view of an ink delivery roll showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view showing another embodiment of FIG.

FIG. 4 is a sectional view showing still another embodiment of FIG.

FIG. 5 is a cross-sectional view of a groove portion.

FIG. 6 is a cross-sectional view showing another embodiment of the groove portion.

FIG. 7 is an overall view of a keyless printing machine.

[Explanation of symbols]

 1 Mountain part 2 Groove part 3 Lattice pattern 4 Lipophilic material 5 Hydrophilic material 106 Ink source roll 107 Ink delivery roll 108 Doctor roll 111 Doctor blade

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuaki Makino 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Research Laboratory (72) Kenji Iwasaki 4-chome, Kannon Shinmachi, Nishi-ku, Hiroshima Prefecture 6-22 No. 22 Hiroshima Research Institute, Mitsubishi Heavy Industries, Ltd. (72) Inventor Hiromitsu Soeda 4-6-22 Kannon-Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Prefecture 72-6 Inside Hiroshima Research Institute, Mitsubishi Heavy Industries (72) Masataka Hirota Nishi-ku, Hiroshima-shi, Hiroshima 4-8-4 Kannon Shinmachi Ryomei Giken Co., Ltd. (72) Inventor, Kazufumi Sueoka 4-8-4 Kannon Shinmachi Nishi-ku, Hiroshima City, Hiroshima Inside Ryomei Giken Co., Ltd.

Claims (3)

[Scope of utility model registration request] 1. A keyless printing machine comprising: an ink roll that rotates at a low speed; an ink delivery roll that rotates at a high speed; and a doctor roll that rotates at a high speed in contact with a doctor blade. An ink delivery roll in a keyless printing machine, wherein the ink delivery roll is rotated at different peripheral speeds with a gap and the surface of the ink delivery roll is formed in a grid pattern composed of continuous grooves and independent ridges. 2. The ink delivery roll for a keyless printing machine according to claim 1, wherein the mountain portion has a trapezoidal cross section, and a top portion thereof is a curved surface forming an outer peripheral surface of the ink delivery roll. 3. The ink delivery roll in a keyless printing machine according to claim 2, wherein the surface of the curved surface forming the top of the mountain portion is an oleophilic material and the surface of the groove portion is a hydrophilic surface. .