Scraping unit, printing apparatus and coating apparatus

Abstract

To provide a scraping unit, printing apparatus, and coating apparatus that can suppress chipping of the doctor blade on the scraping unit side without making any structural changes to the gravure roll side. [Solution] The scraping unit 10 has a blade 1, an auxiliary member 2 attached to the blade 1, and a holder 3 for the blade 1. The auxiliary member 2 is configured to reduce the pressing force applied to a part of the blade 1, and by bringing the blade 1 into contact with the roll member 101, it removes the material adhering to the roll member 101.

Description

Technical Field

[0001] The present invention relates to a scraping unit, a printing apparatus, and a coating apparatus. relates to.

Background Art

[0002] Conventionally, in a gravure coater or a gravure printer that transfers ink or paint onto a flexible substrate that is continuously conveyed, a doctor blade such as a "spatula" is used so that only the required amount of the liquid lifted by the gravure roll is transferred onto the substrate and no excess ink or paint is transferred. A doctor blade is a long strip-shaped member mainly used in gravure printing, flexographic printing, special coating, and painting. It directly contacts a roll material of an intaglio plate (engraved roll, gravure roll, etc.) to which ink or paint adheres, and is a scraping blade for removing excess ink, paint, etc. adhering to parts other than the intaglio part (concave part) of the roll material.

[0003] This doctor blade is generally used by being integrally fixed to a holder together with an auxiliary member (see, for example, Patent Document 1). The auxiliary member, also called a backing plate or a backup blade, is a strip-shaped member having the same length as the doctor blade, and by overlapping it on a part other than the cutting edge of the doctor blade, excessive "bending" of the doctor blade can be suppressed, and the scraping performance can be improved.

Prior Art Documents

Patent Documents

[0004]

Patent Document

Summary of the Invention

Problems to be Solved by the Invention

[0005] <关于 However, by providing an auxiliary member overlapping the doctor blade, there has been a problem that blade spillage occurs particularly at the longitudinal end portions of the doctor blade.

[0006] The following provides a detailed explanation. Figure 13 is a photograph showing a conventional doctor blade 301. Figure 13(A) is a photograph of the doctor blade 301, Figure 13(B) is a close-up photograph of the doctor blade 301 and backing plate 302 fixed to the blade holder 303, and Figure 13(C) is an overall photograph of Figure 13(B).

[0007] The doctor blade 301 is made of thin metal or resin plates and is secured by being sandwiched in the blade holder 303. In addition, a backing plate 302 is often placed between the doctor blade 301 and the blade holder 303 in order to precisely adjust the pressure. The backing plate 302 may be placed on one side or both sides of the doctor blade 301.

[0008] Figure 14 shows the cross-sectional structure of a typical gravure roll 200 used in printing and coating equipment. Figure 15 is a plan view of the gravure roll 200. Figure 16 is a schematic plan view showing how the doctor blade 301 is brought into contact with the gravure roll 200 to perform scraping.

[0009] As shown in Figure 14, the gravure roll 200 is coated with nickel plating 202, copper plating 203, hard chrome plating 204, etc., on the iron core 201 so that it is resistant to wear even when rubbed by the doctor blade. When a plating layer M is formed by such a multi-layer plating treatment, as shown in Figure 15, a plating protrusion PL is often formed where the plating layer M is applied thicker in some areas, creating a raised portion of an arbitrary shape. The plating protrusion PL is formed along the circumferential direction at the corner portion connecting the end faces (bottom faces) 200S (both end faces in the direction of extension of the iron core 201 axis) of the cylindrical gravure roll to the circumferential surface of the cylinder. The shape of the plating protrusion PL is arbitrary, but for example, it may protrude outward in the axial direction from the end faces 200S and / or outward in the diametrical direction in the circumferential direction.

[0010] As shown in Figure 16, the doctor blade 301 is a long, strip-shaped member in the axial direction of the gravure roll 200. The main body portion, excluding the cutting edge 301T (see Figure 13(A)), is superimposed on an auxiliary member (backing plate) 302 of the same length, and both are integrally fixed to the blade holder 303 by bolts 305 or the like. The cutting edge 301T of the doctor blade 301 is brought into contact with the circumferential surface of the gravure roll 200 (plated layer M) to scrape off excess ink, etc.

[0011] However, if a plated protrusion PL is present on the gravure roll 200, especially if the plated protrusion PL is present in such a way that the diameter of the gravure roll 200 is locally increased, contact with the doctor blade 301 will cause partial lifting, hindering uniform pressure distribution on the gravure roll 200. Furthermore, if the auxiliary member 302 is superimposed over the entire longitudinal direction of the doctor blade 301 and is fixed to the blade holder 303, the flexibility of the doctor blade 301 is suppressed, causing the pressing force of the doctor blade 301 to concentrate near the axial end face of the gravure roll 200 (near the plated protrusion PL). Often, burrs and irregularities exist at the end of the gravure roll 200, and as a result, the cutting edge 301T near the end in the longitudinal direction of the doctor blade 301 (pressure concentration point 306) may be damaged during coating or printing. If chipping progresses at the pressure concentration point 306 of the doctor blade 301, the doctor blade 301 becomes more prone to vibration, resulting in problems such as unstable overall scraping and the mixing of wear particles into the liquid, causing foreign matter problems.

[0012] To address these problems, for example, as shown in Figure 17, one could consider tapering the axial ends 211 of the gravure roll 210 so that they gradually become smaller in diameter than the main body 211. However, using such a gravure roll 210 would not allow for different printing widths or coating widths. Furthermore, it would require processing from an iron core, making it impossible to utilize existing gravure rolls and thus incurring costs.

[0013] Furthermore, as shown in Figure 18, it is conceivable to make the ends 221 of the gravure roll 220 in the axial direction smaller in diameter than the main body 222 by giving them a stepped end structure, but this is difficult to implement for the same reasons as described above.

[0014] In view of these circumstances, the present invention aims to provide a scraping unit, a printing apparatus, and a coating apparatus that can suppress chipping of the doctor blade on the scraping unit side without making any structural changes to the gravure roll side. [Means for solving the problem]

[0015] The present invention relates to a printing apparatus that presses a doctor blade against a gravure roll to scrape off a portion of the printing ink transferred from the gravure roll to a substrate, and comprises a blade holder that holds and secures the doctor blade, wherein a backing plate is provided between one or both sides of the doctor blade and the blade holder, and the backing plate of The width end of the aforementioned gravure roll From the width position corresponding to the outer edge of the gravure roll, the material has a lower modulus of elasticity than the central part of the plate. This invention relates to a printing apparatus characterized by the deployment of a [specific feature / feature]. Furthermore, the present invention relates to a coating apparatus that presses a doctor blade onto a gravure roll to scrape off a portion of the coating liquid transferred from the gravure roll to a substrate, the apparatus comprising a blade holder that holds and secures the doctor blade, and a backing plate being positioned between one or both sides of the doctor blade and the blade holder, wherein a material with a lower modulus of elasticity than the central part of the backing plate is positioned at a width position on the backing plate corresponding to the outside of the gravure roll from the width end of the gravure roll.

[0016] Furthermore, the present invention relates to a printing apparatus that presses a doctor blade onto a gravure roll to scrape off a portion of the printing ink transferred from the gravure roll to a substrate, the apparatus comprising a blade holder that holds and secures the doctor blade, wherein a backing plate is provided between one or both sides of the doctor blade and the blade holder, the width of the backing plate being equal to the width of the doctor blade, a notch being provided in the area of ​​the backing plate at a width position corresponding to the width end of the gravure roll and inside the edge of the backing plate, and the edge of the backing plate being provided with a non-notched portion. Furthermore, the present invention relates to a coating apparatus that presses a doctor blade against a gravure roll to scrape off a portion of the coating liquid transferred from the gravure roll to the substrate, and comprises a blade holder that holds and secures the doctor blade. In a device in which a backing plate is provided between one or both sides of the doctor blade and the blade holder, the widthwise length of the backing plate is equal to the widthwise length of the doctor blade, and the backing plate The width end of the aforementioned gravure roll The present invention relates to a coating apparatus characterized in that a notch is provided in a region corresponding to a width position and inside the edge of the plate in question, and the edge of the plate in question is provided with a non-notched portion.

[0017] Furthermore, the present invention includes a blade and a holder for the blade. , provided between the blade and the holder, An auxiliary member attached to the blade and , comprising a roll member, A scraping unit that removes deposits from the roll member by contacting the blade, wherein the auxiliary member It includes a low-elasticity section and a high-elasticity section, and the low-elasticity section is positioned at a width position corresponding to the outside of the roll member from the width end of the roll member. This invention relates to a scraping unit characterized by the following features. Furthermore, the present invention relates to a scraping unit comprising a blade, a holder for the blade, an auxiliary member provided between the blade and the holder and attached to the blade, and a roll member, wherein the scraping unit removes deposits from the roll member by bringing the blade into contact with it, characterized in that the widthwise length of the auxiliary member is equal to the widthwise length of the blade, the auxiliary member includes a notch and an unnotched portion, the notch is positioned at a width position corresponding to the width end of the roll member, and the unnotched portion is positioned at a width position outside the notch.

Advantages of the Invention

[0018] According to the present invention, it is possible to provide a scraping unit, a printing apparatus, and a coating apparatus that can suppress blade dripping of a doctor blade on the scraping unit side without changing the structure on the gravure roll side, and can achieve excellent effects.

Brief Description of the Drawings

[0019] [Figure 1] It is a schematic diagram for explaining the classification of the gravure method. [Figure 2] It is a schematic diagram for explaining the flow of the gravure method and the balance of the film thickness. [Figure 3] It is a schematic diagram for explaining the classification of doctor blades. [Figure 4] It is a schematic diagram for explaining the filling state of liquid in the cells of a gravure roll. [Figure 5] It is a graph showing the correlation between the Ca number dependence of the filling state and the influence of the thickness of the doctor blade. [Figure 6] It is a schematic plan view showing the scraping unit and the printing apparatus of the present embodiment. [Figure 7] It is a photograph of the auxiliary member of the present embodiment. [Figure 8] It is a schematic plan view showing another example of the scraping unit and the printing apparatus of the present embodiment. [Figure 9] It is a schematic plan view showing another example of the scraping unit and the printing apparatus of the present embodiment. [Figure 10] It is a schematic plan view showing another example of the scraping unit and the printing apparatus of the present embodiment. [Figure 11] It is a photograph showing another example of the auxiliary member of the present embodiment. [Figure 12] It is a table for explaining the present embodiment and the comparative example. [Figure 13] It is a photograph showing a conventional doctor blade. [Figure 14] This is a schematic cross-sectional diagram illustrating the structure of a gravure roll. [Figure 15] This is a schematic plan view illustrating the plated protrusions of a gravure roll. [Figure 16] This is a schematic plan view showing a conventional printing apparatus. [Figure 17] This is a schematic plan view showing a conventional gravure roll. [Figure 18] This is a schematic plan view showing a conventional gravure roll. [Modes for carrying out the invention]

[0020] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0021] Figure 1 is a schematic diagram showing the gravure method of a printing apparatus (or coating apparatus) 100 having a gravure roll 101. The scraping unit 10 in this embodiment has a blade (doctor blade 1) and is incorporated into the printing apparatus (or coating apparatus) 100, or used together with the printing apparatus (or coating apparatus) 100.

[0022] The printing apparatus (or coating apparatus) 100 has a gravure roll 101. The scraping unit 10 presses the doctor blade 1 against the gravure roll 101 to scrape off a portion of the printing ink (or coating liquid) that is transferred from the gravure roll 101 to the substrate 102.

[0023] In gravure printing, the liquid (printing ink or coating liquid) scraped up by the gravure roll 101 is transferred to the substrate 102 according to the pattern of the gravure plate. Therefore, the backup roll 103 that pulls the gravure roll 101 and the substrate 102 rotates forward at the same speed in sync (referred to as forward rotation, forward method, etc.; Figure 1(A)).

[0024] When using the gravure method for coating, the speeds of the gravure roll 101 and the substrate 102 are not necessarily the same (when the speeds are different, this is called different peripheral speeds), and they may be rotated in opposite directions (this is called the reverse method; Figure 1(B)). Different peripheral speeds in forward rotation and reverse rotation are mainly used when a thin coating is desired. Further examples include the kiss reverse method without backup (Figure 1(C)), the small-diameter gravure method with gravure rolls 101 mainly of Φ20~50mm which is space-saving and excellent for high-speed coating while avoiding coating streaks (Figure 1(D)), and the doctor chamber method in which the coating liquid is contained in a sealed chamber 120 (Figure 1(E)).

[0025] Figure 2 shows the flow and film thickness balance for different gravure printing methods. Figure 2(A) shows the flow and film thickness balance for the forward rotation method, and Figure 2(B) shows the flow and film thickness balance for the reverse rotation method.

[0026] In both cases, the liquid scooped up by the gravure roll 101 is transferred to a continuously moving flexible substrate 102. Therefore, ensuring that the transfer amount remains stable over time in both the longitudinal and width directions is a crucial challenge in the gravure industry. In the forward rotation method, as shown in Figure 2(A), the liquid is measured in the narrow gap between the gravure roll 101 and the substrate 102, and then divided onto the substrate 102 and the gravure roll 101. In the reverse rotation method, as shown in Figure 2(B), the liquid scooped up by the gravure roll 101 that did not pass through the narrow gap between the substrate 102 and the gravure roll 101 is transferred to the substrate 102. In both forward and reverse rotation, the amount of liquid transferred depends on the amount scooped up, so the challenge can be rephrased as "ensuring that the scooped-up amount remains stable over time in both the longitudinal and width directions."

[0027] The liquid scooped up from the receiving pan 104 onto the gravure roll is partially scraped off by the doctor blade 1 before being transferred to the substrate 102 (see Figure 1).

[0028] Figure 3 shows the classification of doctor blades 1. The amount of liquid scraped off by the doctor blade 1 depends on the pressure Po. With a hard metal doctor blade 1, the state becomes stiff (also called bevel or tip) as shown in Figure 3(B), and the stronger the pressure Po, the more liquid is scraped off, reducing the amount of liquid passing through the gap between the doctor blade 1 and the gravure roll 101. On the other hand, with a resin or thin metal doctor blade 1, the state becomes vented as shown in Figure 3(C), and the stronger the pressure Po, the more the doctor blade 1 floats due to the liquid pressure, widening the gap with the gravure roll 101 and increasing the amount of liquid that passes through.

[0029] The surface of the gravure roll 101 is provided with a grid-like pattern of bumps and diagonal grooves called "cells." Figure 4 shows the state of liquid filling in the cells 105. As shown in Figure 4, when the liquid surface completely covers the cells 105, it is called "overfilling," and when the liquid surface is lower than the top of the cells 105, it is called "partial filling." In gravure printing, partial filling is the basic method to prevent plate staining. In gravure coating, overfilling is used when applying a thick coat, and partial filling is used when applying a thin coat.

[0030] Figure 5 shows the dependence of the Ca number on the packed state and the effect of the thickness of the doctor blade 1, with the vertical axis representing the liquid level position [μm] and the horizontal axis representing the Ca number.

[0031] The filling state, such as overfilling or partial filling, is adjusted by the degree of scraping by the doctor blade 1. As shown in Figure 5, scraping progresses more and partial filling is more likely when the doctor blade 1 is 300 μm thick than when it is 85 μm thick. Here, the Ca number (=η·Ugravure / σ [-]) is a dimensionless number called the capillary number, where η is viscosity, Ugravure is gravure rate, and σ is surface tension.

[0032] Thus, the amount of scraping, which affects the transfer amount, depends on the state in which the liquid is filled into the cell 105 of the doctor blade 1. Therefore, controlling the scraping by the doctor blade 1 leads to the stabilization of gravure printing and gravure coating.

[0033] The scraping unit 10 of this embodiment can easily and inexpensively adjust the pressing force at the end of the doctor blade 1, thereby stabilizing gravure printing or gravure coating. This will be described in detail below.

[0034] The following describes a scraping unit 10 used with a printing apparatus 100 having a gravure roll 101 as an example. Figure 6 is a schematic plan view showing the scraping unit 10 of this embodiment and a part of the printing apparatus 100 equipped therewith. Figure 6(A) is a plan view showing the scraping unit 10 and the gravure roll 101, and Figure 6(B) is a partially enlarged view of the gravure roll 101.

[0035] The scraping unit 10 of this embodiment has a blade (doctor blade 1), an auxiliary member 2, and a holder (blade holder) 3, and is incorporated into the printing device 100 or used together with the printing device 100. Herein, as an example, we will describe the case in which the scraping unit 10 is integrally attached to the printing device 100.

[0036] Furthermore, in the description of this embodiment, the direction is defined as follows: the axial direction of the gravure roll 101 is called the printing width direction W, and the direction that intersects the printing width direction W and causes the doctor blade 1 to come into contact with the gravure roll 101 is called the contact direction P. Note that the contact direction P defines only the direction and does not distinguish between positive and negative (direction toward or away from the gravure roll 101).

[0037] The gravure roll has a plating layer M on its surface. The composition of the plating layer M is, for example, the same as in Figure 14, but may be different.

[0038] The doctor blade 1 is a long, strip-shaped member in the axial direction (printing width direction W) of the gravure roll 101, and the member is made of a thin sheet of metal or resin. The doctor blade 1 is an ink scraping blade mainly used in gravure printing, flexographic printing, and special coating processes. The doctor blade 1 moves along the circumference of the roll member (gravure roll 101), which has engraved (recessed) areas on its cylindrical circumference, scraping off excess printing ink from areas other than the recessed areas. The configuration of the doctor blade 1 is similar to that shown in Figure 13, for example.

[0039] The auxiliary member (also called a backing plate or backup blade) 102 is a long, strip-shaped member in the axial direction (printing width direction W) of the gravure roll 101, and in the example shown in Figure 6, it has the same length as the doctor blade 1. In the printing width direction W, the length L1 of the doctor blade 1 and the length L2 of the auxiliary member 2 are longer than the length L3 of the gravure roll 101.

[0040] The auxiliary member 2 is made of a thin plate of metal or resin and is provided overlapping the main body of the doctor blade 1, except for the cutting edge 1T (the part that contacts the gravure roll 101) of the doctor blade 1. In other words, in the contact direction P, the tip edge 2S of the auxiliary member 2 is located further away from the gravure roll 101 than the tip (cutting edge 1T) of the doctor blade 1. As a result, the doctor blade 1 contacts the gravure roll 101 with its cutting edge 1T protruding beyond the auxiliary member 2, while the auxiliary member 2 does not contact the gravure roll 101. The auxiliary member 2 overlaps a part of the doctor blade 1, but it may be provided so as to cover both the front and back surfaces of the doctor blade 1, or it may be provided so as to cover only one surface. The doctor blade 1 and the auxiliary member 2 are integrally fixed to the blade holder 3. Specifically, the blade holder 3 is provided with one or more elongated holes 31, and the doctor blade 1 and the auxiliary member 2 are provided with bolt insertion holes (not shown) corresponding to the elongated holes 31. By inserting bolts 4 through the elongated holes 31 in the blade holder 3 and the bolt insertion holes in the doctor blade 1 and auxiliary member 2, a scraping unit 10 is formed in which the doctor blade 1, auxiliary member 2, and blade holder 3 are integrally fixed. By changing the fastening position of the bolts 4 in the elongated holes 31, the amount of contact (pressing force) of the doctor blade 1 with the gravure roll 101 can be adjusted.

[0041] The scraping unit 10 of this embodiment is configured so that the pressing force applied to a part of the doctor blade 1 can be reduced by the auxiliary member 2. In other words, the auxiliary member 2 has a pressing force reduction function.

[0042] Specifically, in the example shown in Figure 6, the auxiliary member 2 is equipped with a pressure relief portion 21. The pressure relief portion 21 is, for example, a notch 21A provided near both ends in the longitudinal direction (printing width direction W) of the auxiliary member 2.

[0043] The shape of the notch 21A is roughly U-shaped, as shown in the plan view in Figure 6, where a portion of the area including the tip edge 2S in the contact direction P of the auxiliary member 2 is removed in a roughly rectangular shape inward from both ends in the printing width direction W. The shape of the notch 21A is not limited to this example; it may also be roughly U(C)-shaped, with a roughly semicircular (or elliptical) cutout inward from both ends in the printing width direction W (at least a portion of which may be a curve in the plan view).

[0044] The position of the pressure relief portion 21 (notch 21A) corresponds to the end faces 101S (both bottom faces of the cylinder) in the direction of extension of the axis of the cylindrical gravure roll 101 (printing width direction W).

[0045] As already mentioned, the corner portions connecting the end faces 101S of the gravure roll 101 to the cylindrical surface are often thicker in the circumferential direction, forming plated protrusions PL that rise up in any shape. The shape of the plated protrusions PL is arbitrary, but for example, they may protrude axially from the end faces 101S and / or protrude in a direction that increases the diameter of the gravure roll 101 in the circumferential direction.

[0046] Furthermore, when a plated protrusion PL is created that protrudes in the diametrical direction of the gravure roll 101, and the doctor blade 1 comes into contact with it, the pressing force of the doctor blade 1 is concentrated in and around the contact area. Hereinafter, the part of the doctor blade 1 that comes into contact with the plated protrusion PL will be referred to as the protrusion contact area 11.

[0047] In other words, in this embodiment, a portion of the auxiliary member 2 that supports the doctor blade 1 near the contact area 11 of the protruding portion of the doctor blade 1 is missing along the contact direction P to partially allow the doctor blade 1 to bend. This makes it possible to alleviate the concentration of pressing force (pressing force against the gravure roll 101) in the contact area 11 of the protruding portion of the doctor blade 1.

[0048] Referring to Figure 6(B), when the length of the auxiliary member 2 in the short direction (length along the contact direction P) is defined as the short direction length, the region without the notch 21A has the maximum short direction length S1, and the region with the notch 21A has a short direction length S2 that is smaller than the short direction length S1.

[0049] In other words, in the example shown in Figure 6, the auxiliary member 2 has notches 21A in the protruding contact area 11 (two locations) of the doctor blade 1, and a non-notched portion 21N having a length S1 in the short direction is provided inside the notches 21A in the longitudinal direction (printing width direction W). The position of the notches 21A is behind the protruding contact area 11 (away from the gravure roll 101) in the contact direction P.

[0050] The shape and size of the notch 21A should preferably be such that, for example, if the notch 21A and the plated protrusion P are butted together, at least the plated protrusion PL can be accommodated. Specifically, the depth Cd of the notch 21A in the contact direction P should preferably be greater than or equal to the expected radial protrusion amount Pd (expected maximum value) of the plated protrusion PL. Furthermore, the length Cw of the notch 21A in the printing width direction W should preferably be greater than or equal to the expected axial protrusion amount Pw (expected maximum value) of the plated protrusion PL.

[0051] In this way, even if a plated protrusion PL is formed on the gravure roll 101 and the doctor blade 1 comes into contact with it, the deformation (bending) of the protrusion contact area 11 of the doctor blade 1 is permitted by the notch 21A. Specifically, a notch 21A is provided behind the protrusion contact area 11 (in the direction away from the gravure roll 101) where the auxiliary member 2 is missing. In other words, the protrusion contact area 11 and its vicinity can be deformed in the opposite direction to the direction in which the pressing force of the doctor blade 1 is applied (the direction toward the gravure roll 101 in the contact direction P).

[0052] In other words, the pressure (concentration of pressure) on the gravure roll 101 (plated protrusion PL) in the contact area 11 of the protruding portion of the doctor blade 1 can be mitigated by the notch 21A. Therefore, partial lifting of the doctor blade 1 is reduced, and uniform pressure is applied to the entire area that is intended to be pressurized, enabling optimal doctoring.

[0053] Furthermore, the concentration of pressure from the doctor blade 1 near the plated protrusion PL can be mitigated, preventing chipping of the doctor blade 1's cutting edge during printing. As a result, vibrations caused by chipping at the end of the doctor blade 1 can be suppressed, the overall scraping is stabilized, and problems caused by wear particles mixing into the liquid and hard foreign matter (wear particles) from the doctor blade and gravure roll surface being mixed in can be avoided.

[0054] Furthermore, even if the depth Cd of the notch 21A is smaller than the assumed radial protrusion amount Pd (maximum value) of the plated protrusion PL, the notch 21A can mitigate to some extent the concentration of pressing force on the gravure roll 101 (plated protrusion PL) of the doctor blade 1. Similarly, even if the length Cw of the notch 21A is smaller than the assumed axial protrusion amount Pw (maximum value) of the plated protrusion PL, the concentration of pressing force on the gravure roll 101 (plated protrusion PL) of the doctor blade 1 can mitigate to some extent. Furthermore, this example shows a notch where the edge of the notch 21A along the printing width direction W (edge ​​with length Cw) is cut parallel to the tip edge 2S. However, the notch may also be cut in a way that is inclined with respect to the longitudinal edge (tip edge 2S) (in the plan view shown, the inside is higher and the outside is lower / or the outside is higher and the inside is lower). Similarly, this example shows a notch where the edge of the notch 21A along the contact direction P (edge ​​with depth Cd) is cut parallel to the short edge. However, the notch may also be cut in a way that is inclined with respect to the short edge (in the plan view shown, the upper side is located outside the printing width direction W and the lower side is located inside / or the lower side is located outside the printing width direction W and the upper side is located inside).

[0055] In other words, the shape and size of the notch 21A are appropriately selected according to the shape and size of the plated protrusion PL (maximum value, average value, etc.) that is expected to occur, the material of the doctor blade 1 and auxiliary member 2, etc.

[0056] Figure 7 is a photograph showing an example of an actual auxiliary member 2. In this example, the auxiliary member 2 was precisely finished using spring steel. The four corners of the auxiliary member 2 were rounded to prevent damage even when in contact with the doctor blade 1 or gravure roll 101.

[0057] In this case, the length Cw of the notch 21A was set to 10mm to 20mm as an example, and the depth Cd of the notch 21A was set to 2mm to 5mm. However, as stated above, the size of the notch 21A is not limited to the above, as long as it can reduce the pressing force against the gravure roll 101 in the contact area 11 of the protruding part of the doctor blade 1.

[0058] Alternatively, the scraping unit 10 of this embodiment, its base mechanism, and control means (control mechanism) for the scraping unit 10 may constitute a doctor blade device. In this case, the doctor blade device may be provided on the printing device 100, or it may be configured separately from the printing device 100.

[0059] Furthermore, this embodiment may also be a printing apparatus 100 equipped with the above-described scraping unit 10 (or doctor device). That is, the printing apparatus 100 is a printing apparatus 100 that presses a doctor blade 1 onto a gravure roll 101 to scrape off a portion of the printing ink transferred from the gravure roll 101 to the substrate 102, and is equipped with a blade holder 3 that holds and fixes the doctor blade 1, and an auxiliary member (backing plate) 2 is provided between one or both sides of the doctor blade 1 and the blade holder 3 so that the doctor blade 1 is pressed uniformly against the gravure roll 101. The auxiliary member 2 has a pressing force reduction function so that the pressing force of the doctor blade 1 near the end of the gravure roll 101 in the printing width direction W (protruding part contact area 11) is weaker than the pressing force of the doctor blade 1 outside the protruding part contact area 11.

[0060] As an example of a pressure relief function, the auxiliary member 2 has a pressure relief section 21. The pressure relief section 21 is, for example, a notch 21A located near the end of the gravure roll 101 in the printing width direction W (the part where the occurrence of plated protrusions PL is expected). When the doctor blade 1 is brought into contact with the gravure roll 101, if plated protrusions PL are present, the pressure of the doctor blade 1 near the end of the doctor blade 1 in the printing width direction W (protrusion contact area 11) that contacts them will be greater than the pressure of the doctor blade 1 outside the protrusion contact area 11. In this embodiment, the notch 21A allows for deformation of a part of the doctor blade 1, so that the pressure of the doctor blade 1 near the protrusion contact area 11 is weaker than the pressure of the doctor blade 1 outside the protrusion contact area 11.

[0061] According to this embodiment, the scraping unit 10 is configured to absorb the effects of the plated protrusion PL (mitigating the concentration of pressing force of the doctor blade 1 against the gravure roll 101), thus suppressing chipping of the doctor blade 1 without changing the configuration of the gravure roll 101 (printing device 100). Changing the configuration of the gravure roll 101 would require modifications for each printing device 100, which would be costly, but in this embodiment, chipping of the doctor blade 1 can be suppressed simply by changing the shape of the auxiliary member 2 on the scraping unit 10 side (forming the notch 21A).

[0062] In other words, even if the gravure roll 101 changes (such as a change in the shape or size of the plated protrusion PL, or the distance between the plated protrusion PLs), multiple auxiliary members 2 with corresponding notches 21A are prepared, and by simply replacing the auxiliary members 2, it is possible to accommodate various printing devices 100. This means that it offers high versatility and allows for inexpensive and easy prevention of chipping of the doctor blade 1.

[0063] The pressure-relieving portion 21 of the auxiliary member 2 is not limited to the example described above. Figure 8 shows another example of the pressure-relieving portion 21. The configuration other than the auxiliary member 2 is the same as in the embodiment shown in Figure 6, so its explanation is omitted.

[0064] In this case, the pressure relief portion 21 is also composed of a notch 21B, but its shape differs from that of the example in Figure 6. Specifically, the shape of the notch 21B is approximately L-shaped, in which a portion of the area including the tip edge 2S in the contact direction P of the auxiliary member 2 in the plan view shown in Figure 8 is removed in a roughly rectangular shape, including both ends in the printing width direction W. Note that the plan view shape of the notch 21B may include at least a curve. Furthermore, this example shows a notch where the edge of the notch 21B along the printing width direction W (edge ​​with length Cw) is cut parallel to the tip edge 2S. However, the notch may also be cut in a way that is inclined with respect to the longitudinal edge (tip edge 2S) (in the illustrated plan view, the inside is higher and the outside is lower / or the outside is higher and the inside is lower). Similarly, this example shows a notch where the edge of the notch 21B along the contact direction P (edge ​​with depth Cd) is cut parallel to the short edge. However, the notch may also be cut in a way that is inclined with respect to the short edge (in the illustrated plan view, the upper side is located outside the printing width direction W and the lower side is located inside / or the lower side is located outside the printing width direction W and the upper side is located inside).

[0065] The position of the notch 21B is behind the protruding contact area 11 (away from the gravure roll 101) in the contact direction P.

[0066] In this case as well, in the printing width direction W, the length L1 of the doctor blade 1 and the length L2 of the auxiliary member 2 are longer than the length L3 of the gravure roll 101. Notches 21B are provided at both ends of the auxiliary member 2 in the longitudinal direction, and in the printing width direction W, the notches 21B are provided at the corresponding positions of the expected plated protrusions PL and on both sides thereafter, and the notches 21B reach both ends of the auxiliary member in the printing width direction W.

[0067] In other words, notches 21B having a length S2 in the short direction are provided at both ends in the longitudinal direction of the auxiliary member 2, and non-notched portions 21N having a length S1 in the short direction are provided inside them. The length S2 in the short direction is shorter than the length S1 in the short direction. The shape and size of the notches 21B are preferably such that, for example, if the notches 21A and the plated protrusions PL are butted together, at least the plated protrusions PL can be accommodated.

[0068] In this case as well, the notch 21B partially allows for flexing near the protruding contact area 11 of the doctor blade 1, thereby mitigating the concentration of pressing force in the protruding contact area 11.

[0069] Thus, the auxiliary member 2 outside the print width direction W may be shortened (cut to be shortened) in its shorter direction (contact direction P) (in the direction from the blade holder 3 toward the gravure roll 101) so that the pressing force of the doctor blade 1 at the print width direction W end of the gravure roll 101 is weaker than the pressing force of the doctor blade 1 at other points in the print width direction W.

[0070] Figure 9 shows another example of the pressure relief portion 21. In this case, the pressure relief portion 21 is a low-elasticity portion 21C provided on a part of the auxiliary member 2. The low-elasticity portion 21 is made of a metal or resin with lower elasticity than the auxiliary member 2 (e.g., spring steel). For example, the auxiliary member 2, which is made of spring steel, is provided in a region inside the end of the gravure roll 101 in the printing width direction W, and pressure relief portions 21 (low-elasticity portions 21C) are provided at both ends thereof. The low-elasticity portion 21C extends outside the end of the gravure roll 101 in the printing width direction W. The position and shape of the low-elasticity portion 21 may be such that it fills in the notches 21A and 21B shown in Figure 6 or Figure 8. In this case as well, the position of the low-elasticity portion 21C is behind the protruding portion contact area 11 (away from the gravure roll 101) in the contact direction P.

[0071] Thus, in the printing width direction W, the auxiliary member 2 inside the end of the gravure roll 101 may be made of a material with a relatively high modulus of elasticity, such as spring steel, and the auxiliary member 2 outside the end of the gravure roll 101 may be made of a material with a relatively low modulus of elasticity, forming a low-elasticity section 21C. This allows the pressing force of the doctor blade 1 at the end of the gravure roll 101 in the printing width direction W to be weaker than the pressing force of the doctor blade 1 at other points in the printing width direction W.

[0072] FIG. 10 shows another example of the auxiliary member 2 having a pressing force relaxation function. In the printing width direction W, the length L2 of the auxiliary member 2 is made shorter than the length L1 of the doctor blade 1 and the length L3 of the gravure roll 101 (L1 > L3 < L2), and the auxiliary member 2 may be disposed inside both ends (entire width) in the printing width direction W of the gravure roll 101.

[0073] The auxiliary member 2 is provided at a position inside in the printing width direction W rather than behind the protruding portion contact region 11 so as not to exist behind the protruding portion contact region 11 in the contact direction P (the direction away from the gravure roll 101).

[0074] In this case, the auxiliary member 2 having a shorter length in the printing width direction W than the doctor blade 1 allows the bending portion to be partially tolerated in the vicinity of the protruding portion contact region 11 of the doctor blade 1, and the concentration of the pressing force in the protruding portion contact region 11 can be alleviated.

[0075] Thereby, the pressing force at the end in the printing width direction W of the gravure roll 101 (the protruding portion contact region 11 of the doctor blade 1) can be made weaker than the pressing force of the doctor blade 1 other than the protruding portion contact region 11.

[0076] FIG. 11 is a photograph of another example of the auxiliary member (pad) 2 of the present embodiment. FIG. 11(A) is an overall photograph, and FIG. 11(B) is an enlarged photograph of the vicinity of the end. These are examples in which the notch 21A shown in FIG. 6 is provided as the pressing force relaxation portion 21, and the notch 21A is disposed on the leading edge 2S of the auxiliary member 2 and the other leading edge 2D facing the same. The leading edges 2S and 2D are opposing long sides of the auxiliary member 2. The leading edge S2 is the side close to the cutting edge 1T of the doctor blade 1 described in FIG. 6 and the like.

[0077] In this case, it is preferable to make the shape and / or size of the notches 21A and 21A' different on the tip edge 2S side and the tip edge 2D side. This allows for fine adjustment of the pressing force (relaxation) of the doctor blade 1 by switching the auxiliary member 2 so that the notches 21A and 21A' closest to the blade tip 1T are swapped when the printing conditions (speed, doctor blade 1 thickness, ink type, etc.) are different.

[0078] The above explanation mainly described the case where the gravure roll 101 is installed in the printing device 100, but the same method can be used and the same effect can be obtained even if the gravure roll 101 is installed in a coating device (roll coater). In other words, "printing device" in the above explanation can be replaced with "coating device," and "(printing) ink" can be replaced with "coating liquid." Furthermore, the auxiliary member 2 is not limited to the above example, as long as it is configured to alleviate the pressing force on the protruding portion contact area 11 of the doctor blade 1 when it comes into contact with the plated protruding portion PL. For example, it is sufficient if the configuration allows for deformation, bending, and flexing of the protruding portion contact area 11 when it comes into contact with the plated protruding portion PL.

[0079] According to the printing apparatus 100 or coating apparatus of the present invention, even if a plated protrusion PL is formed at the end of the gravure roll 101 in the printing width direction, the pressing force of the doctor blade 1 can be suppressed from concentrating on the end of the gravure roll 101. As a result, lifting and vibration of the doctor blade 1 relative to the gravure roll 101 are suppressed, the operation is stabilized, and uniform printing or coating can be performed, leading to a reduction in streaks, doctor blade marks, and smudges. [Examples]

[0080] Next, embodiments and comparative examples of the present invention are shown. Printing was performed using a printing apparatus 100 equipped with the scraping unit 10 of this embodiment and a printing apparatus of the comparative example, and a comparison was made. The auxiliary member 2 in the scraping unit 10 of this embodiment is shown in Figure 11, and the size of the notch 21A is such that the length Cw in the printing width direction W is 20 mm and the depth Cd is 3 mm. On the other hand, the printing apparatus of the comparative example is equipped with a scraping unit that integrates an auxiliary member, which is the same size and material as the auxiliary member 2 shown in Figure 11, except that it does not have a pressing force relief function (notch 21A), and a doctor blade. The printing results of both are summarized in the table shown in Figure 12.

[0081] As shown in Figure 12, according to this embodiment (the example in the table in Figure 12), the image could be printed without unevenness. Furthermore, there was no chipping of the doctor blade at the end of the gravure roll, and no lifting of the doctor blade at the end of the gravure roll was observed. In addition, no hard foreign matter was found to be mixed into the ink. In contrast, in the comparative example (the comparative example in the table in Figure 12), chipping occurred in the doctor blade at the end of the gravure roll, and foreign matter was found to be mixed into the ink. Furthermore, lifting of the doctor blade at the end of the gravure roll occurred, and unevenness in the image became apparent.

[0082] As stated above, the scraping unit 10 and the printing apparatus (or coating apparatus) 100 of the present invention are not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention. [Industrial applicability]

[0083] This invention can be used in scraping units, doctor blade devices, printing devices, or coating devices. [Explanation of Symbols]

[0084] 1 Doctor Blade 1T cutting edge 2. Auxiliary members 2S, 2D tip edge 3. Holder (Blade Holder) 10 scraping units 11 Projection contact area 21 Pressure relief part 21A, 21B Notches 21C Low elastic force section 100 Coating Equipment) 100 Printing equipment (coating equipment) 101 Gravure Roll 102 Base material 200 Gravure Rolls M Plating layer M Gravure Roll 200 (Plating Layer) P Contact direction PL plated protruding part

Claims

1. In a printing apparatus that presses a doctor blade against a gravure roll to scrape off a portion of the printing ink transferred from the gravure roll to the substrate, the apparatus is equipped with a blade holder that holds and secures the doctor blade, and a backing plate is provided between one or both sides of the doctor blade and the blade holder, A printing apparatus characterized in that a material with a lower modulus of elasticity than the central part of the plate is placed at a width position corresponding to the outer edge of the gravure roll, from the width end of the gravure roll on the backing plate.

2. A coating apparatus for which a doctor blade is pressed against a gravure roll to scrape off a portion of the coating liquid transferred from the gravure roll to a substrate, the apparatus comprising a blade holder for holding and fixing the doctor blade, wherein a backing plate is provided between one or both sides of the doctor blade and the blade holder, A material with a lower modulus of elasticity than the central part of the plate is placed at a width position corresponding to the outer edge of the gravure roll, from the width end of the gravure roll to the outer edge of the gravure roll. A coating apparatus characterized by the following features.

3. A printing apparatus that presses a doctor blade against a gravure roll to scrape off a portion of the printing ink transferred from the gravure roll to a substrate, the apparatus comprising a blade holder that holds and secures the doctor blade, wherein a backing plate is provided between one or both sides of the doctor blade and the blade holder, The widthwise length of the backing plate is equivalent to the widthwise length of the doctor blade. A notch is provided in the area of ​​the backing plate at a width position corresponding to the width end of the gravure roll, and the end of the backing plate is provided with a non-notched portion. A printing apparatus characterized by the following features.

4. A coating apparatus for which a doctor blade is pressed against a gravure roll to scrape off a portion of the coating liquid transferred from the gravure roll to a substrate, the apparatus comprising a blade holder for holding and fixing the doctor blade, wherein a backing plate is provided between one or both sides of the doctor blade and the blade holder, The widthwise length of the backing plate is equivalent to the widthwise length of the doctor blade. A notch is provided in the area of ​​the backing plate at a width position corresponding to the width end of the gravure roll, and the end of the backing plate is provided with a non-notched portion. A coating apparatus characterized by the following features.

5. The blade and The holder of the aforementioned blade, An auxiliary member provided between the blade and the holder and attached to the blade, It has a roll member, A scraping unit that removes deposits from the roll member by contacting the blade, The auxiliary member includes a low-elasticity portion and a high-elasticity portion. The low-elasticity portion is positioned at a width corresponding to the outer edge of the roll member, from the width end of the roll member. A scraping unit characterized by the following.

6. The blade and The holder of the aforementioned blade, An auxiliary member provided between the blade and the holder and attached to the blade, It has a roll member, A scraping unit that removes deposits from the roll member by contacting the blade, The widthwise length of the auxiliary member is equivalent to the widthwise length of the blade. The auxiliary member includes a notch and an unnotched portion. The notch is positioned at a width position corresponding to the width end of the roll member, and the non-notched portion is positioned at a width position outside the notch. A scraping unit characterized by the following.

Images