JP2013111499A - Coating apparatus, coating method, and sleeve body produced by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a highly-smooth uniformly-thick coating layer around the external circumferential surface of a sleeve efficiently without the use of a mandrel.SOLUTION: The coating apparatus comprises: a rotation drive means for rotating a sleeve; and a scraping blade for scraping off the surface side of a primary coating layer applied to the external circumferential surface of the rotating sleeve. The rotation drive means comprises: a pair of holding tools, which holds the sleeve while straddling the sleeve between the first and second holding rollers; and a driving tool having a driving roller which holds the sleeve between it and the corresponding first holding roller. The edge of the scraping blade is located on the first reference lines passing through the centers of the drive rollers and the center of the first rollers.

Description

  The present invention relates to a coating apparatus, a coating method, and a sleeve body manufactured by the coating apparatus that apply a liquid coating material to the outer peripheral surface of a cylindrical sleeve to form a coating layer having a predetermined thickness with high accuracy.

  In recent years, a sleeve body in which a coating layer having a seamless and smooth surface is formed on the outer peripheral surface of a cylindrical sleeve has been used in various applications by setting various coating materials. For example, toner transfer members in electrophotographic copying machines using photoconductors, fax machines, printers, etc., and blankets for ink transfer in offset printing machines are known.

  The important points in the sleeve body for these applications are the surface smoothness and thickness uniformity of the coating layer. The required accuracy of the surface smoothness and thickness uniformity varies depending on the application, but the surface smoothness of the sleeve body used as the most demanding electrophotographic transfer member has an average roughness of 10 points. It is required to be 1 μm or less, more preferably 0.5 μm or less. The thickness uniformity also depends on the size, but a high accuracy of in-plane ± 10 μm or less is required.

  And the thing of the following patent document 1 is proposed as an apparatus which forms the coating layer h which has a highly smooth surface without a joint on the outer peripheral surface of a sleeve. As shown in FIG. 6 (A), this apparatus supplies a liquid coating agent g to the outer peripheral surface of a rotating body a comprising a sleeve a1 while rotating it to form a primary coating layer h1, and A scraping blade c fixed below the rotating body a with a gap is provided below the rotating body a. By scraping the surface side of the primary coating layer h1 with the scraping blade c, the coating thickness is increased. The thickness is formed to a predetermined thickness. The coating material g that has been scraped is dropped and removed along the scraping blade c.

  However, in the apparatus, the scraping blade c is fixed so that the distance of the tip of the scraping blade c is constant with respect to the axis of the rotating body a. Therefore, as in the conventional case, when the sleeve a1 is rotatably supported using a cored bar d as shown in FIG. 6B, if the roundness of the cored bar d is low, the outer peripheral surface of the sleeve a1 The gap between the tip of the scraping blade c varies, and the thickness uniformity of the coating layer h cannot be obtained.

  For this reason, each time the inner diameter of the sleeve a1 changes, it is necessary to prepare a high-precision cored bar d having a high production cost, resulting in an increase in production cost.

JP 2002-59065 A

  Therefore, the present invention provides a coating apparatus, a coating method, and a sleeve manufactured by the method, which can form a coating layer on the outer peripheral surface of the sleeve with high accuracy while eliminating the need for a mandrel and suppressing an increase in production cost. It is aimed.

In order to solve the above-mentioned problem, the invention of claim 1 of the present application is a coating apparatus for applying a liquid coating material to the outer peripheral surface of a cylindrical sleeve to form a coating layer having a predetermined thickness.
Rotational drive means for rotating the sleeve;
Application means for applying the coating material to the outer peripheral surface of the rotating sleeve to form a primary coating layer,
And a tip is disposed apart from the outer peripheral surface of the sleeve, and comprises a scraping blade that forms a coating layer of a predetermined thickness by scraping the surface side of the applied primary coating layer with the tip.
The rotation driving means includes one rotation driving tool disposed on one end side in the axial direction of the sleeve and the other rotation driving tool disposed on the other end side in the axial direction.
In addition, the one and the other rotational drive tools are
A holding tool having first and second holding rollers parallel to the sleeve and rotatably holding the sleeve between the first and second holding rollers;
A driving tool having a driving roller inscribed in the inner peripheral surface of the sleeve, and rotating the sleeve held by the holding tool by sandwiching the sleeve between the driving roller and the first holding roller. And
In addition, the scraping blade is disposed between the first holding roller of one of the rotary driving tools and the first holding roller of the other rotary driving tool, and the tip thereof is first from the center of the driving roller. Is located on a first reference line that passes through the center of the holding roller, and is at least 0 degree and less than 90 degrees with respect to a vertical second reference line that hangs down from the contact point between the first holding roller and the sleeve. It is characterized in that the sleeve is arranged on the front side in the rotational direction of the sleeve at an angle θ.

  A second aspect of the present invention is a coating method invention, wherein the coating apparatus according to the first aspect is used to rotate the sleeve by a rotation driving means, and the outer peripheral surface of the rotating sleeve is coated by an application means. An application step of applying a material to form a primary coating layer; and a scraping step of forming a coating layer of a predetermined thickness by scraping the surface side of the applied primary coating layer with a tip of a scraping blade; It is characterized by performing.

  A third aspect of the present invention is a sleeve invention, wherein a coating layer is formed on the outer peripheral surface using the coating method according to the third aspect.

As described above, the present invention has first and second holding rollers parallel to the sleeve. Therefore, the sleeve can be rotatably held across the first and second holding rollers without using a cored bar, but in a hollow cylindrical shape. However, in this case, since the sleeve is held in a hollow cylindrical shape, it is difficult to maintain a perfect circular state, for example, it can be easily deformed into an elliptical shape by its own weight, etc. As a result, the thickness of the coating layer becomes non-uniform.
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Therefore, in the present invention, a driving roller that is in contact with the inner peripheral surface of the sleeve is used, and the sleeve is sandwiched between the driving roller and the first holding roller to be driven to rotate, and the tip of the scraping blade is connected to the driving roller. And the first reference line passing through the center of the first holding roller. As a result, even when the sleeve is deformed into an oval shape, the gap between the sleeve and the scraping blade can be kept constant, and the coating layer can be formed with high quality and high accuracy.

It is a perspective view which simplifies and shows the principal part of one Example of the coating apparatus of this invention. It is sectional drawing which further simplifies and shows the principal part of the said coating apparatus. It is a schematic sectional view exaggeratingly showing the effect of the present application. It is a schematic sectional view showing a problem when the tip of the scraping blade is not on the first reference line. It is a conceptual diagram which shows schematically the relationship between the width | variety of the scraping blade 7, the space | interval of the 1st holding | maintenance roller 12a, 12a, and the formation width of the primary coating layer 5a. (A) is a schematic cross-sectional view illustrating a conventional coating apparatus, and (B) is a cross-sectional view illustrating a conventional holding method of a sleeve.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIGS. 1 and 2, the coating apparatus 1 of the present embodiment applies a rotation driving means 3 for rotating a cylindrical sleeve 2, and a liquid coating material 4 is applied to the outer peripheral surface 2S of the rotating sleeve 2. Coating means 6 for forming the primary coating layer 5a, and a scraping blade 7 for forming the coating layer 5 having a predetermined thickness by scraping the surface side of the applied primary coating layer 5a.

  In this example, the sleeve 2 is a resin sleeve, and a sleeve body used as a blanket for ink transfer in an offset printing machine may be formed by forming a coating layer 5 of silicon rubber on the outer peripheral surface thereof. Illustrated.

  The rotation driving means 3 is composed of one rotation driving tool 9A disposed on one end side in the axial direction of the sleeve 2 and the other rotation driving tool 9B disposed on the other end side in the axial center direction. The one and other rotational driving tools 9A and 9B include a holding tool 10 that rotatably holds the sleeve 2 and a driving tool 11 that rotationally drives the sleeve 2 held by the holding tool 10.

  The holder 10 has first and second holding rollers 12a and 12b parallel to the sleeve 2, and the sleeve 2 is straddled between the first and second holding rollers 12a and 12b. It can be held rotatably. The first holding rollers 12a and 12a on both sides in the axial direction are arranged concentrically with each other, and the second holding rollers 12b and 12b on both sides in the axial direction are also arranged concentrically with each other.

  Reference numeral 13 in the drawing denotes a roller holder that pivotally supports the first and second holding rollers 12 a and 12 b and is supported by the frame F of the coating apparatus 1. In order to prevent the sleeve 2 from being displaced in the axial direction during rotation, the holder 10 is provided with, for example, a positional deviation preventing means (not shown) that can come into contact with the end surface of the sleeve 2 in the axial direction. Can be provided.

  The driving tool 11 has a driving roller 14 that is inscribed in the inner peripheral surface of the sleeve 2, and the holding tool 14 is sandwiched between the driving roller 14 and the first holding roller 12 a to hold the holding roller 14. The sleeve 2 held by the tool 10 can be driven to rotate. In this example, the drive rollers 14 and 14 on both sides in the axial direction are supported by a single drive shaft 15 and the drive shaft 15 is rotationally driven by a motor M connected to one end thereof. The drive shaft 15 can be moved parallel to the shaft center of the first holding roller 12a by appropriate support means (not shown) so that the sleeve 2 can be moved close to the drive roller 14 and the first holding roller. The sleeve 2 can be sandwiched between the sleeve 12a and the sleeve 2 by being separated.

  Next, the coating means 6 has a supply blade 16 in this example. The supply blade 16 has a flat plate shape with a sharp tip attached to the outer peripheral surface 2S of the sleeve 2 with a downward slope, and the tip 16e terminates from the outer peripheral surface 2S of the sleeve 2 with a gap Da. . Therefore, by supplying the coating material 4 to the upper surface of the supply blade 16, the coating material 4 is applied to the outer surface 2S of the rotating sleeve 2 through the upper surface of the supply blade 16 and the gap Da, and the gap A primary coating layer 5a having a thickness substantially equal to Da is formed.

  In addition, the code | symbol 17 in a figure is a coating material supply tool, and in this example, the supply path 17A and the accommodating part 17B which accommodates the coating material 4 for one coating supplied from this supply path 17A temporarily. Have. The accommodating portion 17B of the present example has a horizontally open container shape in which both sides in the axial direction of the L-shaped cross-section with the back plate portion 18b raised from the rear edge of the lower plate portion 18a are closed by the side plate portions 18c. The accommodating portion 17B is supported so as to be tiltable around the axis j in the vicinity of the rear edge, and the back plate portion 18b is inclined rearward to receive the coating material 4 from the supply path 17A, and a lower state Y1. The plate portion 18a can be tilted between the supply state Y2 in which the coating material 4 for one application accommodated in the plate portion 18a is horizontal or forward inclined and is delivered to the supply blade 16.

  Next, the scraping blade 7 has a plate shape with a sharp tip disposed between the first holding rollers 12a and 12a on both sides in the axial direction. The tip 7e of the scraping blade 7 is separated from the outer peripheral surface 2S of the sleeve 2 by a gap Db that is narrower than the gap Da. It is arranged on the first reference line X1 passing through the center. Further, the scraping blade 7 has an angle θ of 0 ° or more and less than 90 ° with respect to a vertical second reference line X2 hanging from the contact point P between the first holding roller 12a and the sleeve 2. 2 is arranged on the front side in the rotational direction.

  The scraping blade 7 scrapes off the surface side of the primary coating layer 5a by making the gap Db smaller than the gap Da of the supply blade 16, and has a thickness substantially equal to the gap Db. The coating layer 5 is formed. Further, the scraped coating material 4 falls down along the side surface 7S of the scraping blade 7.

  Here, the sleeve 2 is held between the first and second holding rollers 12a and 12b in a hollow cylindrical shape without using a cored bar. Although depending on the thickness of the sleeve 2, the sleeve 2 is slightly deformed into an elliptical shape as shown exaggeratedly in FIGS. 3A and 3B due to its own weight. At this time, the sleeve is sandwiched between the driving roller 14 and the first holding roller 12a, and the scraping blade is placed on the first reference line X1 passing through the center of the driving roller 14 and the center of the first holding roller 12a. 7, the distance L between the tip 7e and the outer peripheral surface 2S of the sleeve 2 can be kept equal to the gap Db even in the case of an ellipse, and the thickness is uniform. The coating layer 5 can be formed. On the other hand, as shown in FIG. 4, when the tip 7e is not located on the first reference line X1, the distance L varies depending on the position of the sleeve 2, and a uniform thickness cannot be obtained.

  Further, the scraping blade 7 needs to have the angle θ of 0 degree or more and less than 90 degrees, and if it is out of the range, the scraped coating material 4 returns to the sleeve 2 side and reattaches. Then, the surface property of the coating layer 5 may be adversely affected. Therefore, the lower limit of the angle θ is more preferably 30 degrees or more, and the upper limit is more preferably 60 degrees or less.

  In this example, as shown in FIG. 5, the width W1 of the scraping blade 7 is smaller than the interval W2 between the first holding rollers 12a and 12a and larger than the formation width W3 of the primary coating layer 5a. Set to

Next, a coating method for forming the coating layer 5 on the outer peripheral surface 2S of the sleeve 2 using the coating apparatus 1 will be described. In this coating method,
(A) a rotation step in which the sleeve 2 is rotated by the rotation drive means 3;
(A) an application step of applying the coating material 4 to the outer peripheral surface 2S of the rotating sleeve 2 by the application means 6 to form the primary coating layer 5a;
(C) a scraping step of forming the coating layer 5 having a predetermined thickness by scraping the surface side of the applied primary coating layer 5a with the tip 7e of the scraping blade 7,
With In the present example, after the scraping step, a self-leveling step of smoothing the surface of the coating layer 5 by rotating for a predetermined time is configured.

  In the rotation process, the sleeve 2 is rotated from the start of the application process to the end of the self-leveling process.

  In the application step, the liquid coating material 4 is supplied from the gap Da to the outer peripheral surface 2S of the sleeve 2 to form the primary coating layer 5a having a thickness matching the gap Da. The supply amount of the coating material 4 is an amount necessary for the coating layer 5 to have a predetermined thickness, and excessive supply causes problems such as waste of the coating material 4 and adhesion to unnecessary portions. .

  Further, when the primary coating layer 5a applied in the application step reaches the position of the scraping blade 7, the surface side is sequentially scraped by the scraping blade 7, and this is repeated by continuous rotation of the sleeve 2. The coating layer 5 having a uniform thickness is formed (scraping process). The rotation speed and rotation time of the sleeve 2 in the coating process and the scraping process are not particularly limited, but the rotation speed is preferably about 3 to 60 rotations / minute, and the rotation time is preferably about 30 seconds to 5 minutes. In this example, it is rotated for 3 minutes at a rotation speed of 10 times / minute.

  Thereafter, the supply blade 16 and the scraping blade 7 are removed in this order, and then the self-leveling process is performed. In this self-leveling step, the sleeve 2 is continuously rotated after the coating layer 5 is formed, and is cured while smoothing the surface by utilizing the self-leveling property of the coating material 4. The rotational speed in this self-leveling process is not particularly restricted, but it is necessary that the thickness of the coating layer 5 is not made uneven by centrifugal force, and is preferably slower than the rotational speed in the coating process and the scraping process, In this example, it is rotated at 30 times / minute. Further, the self-leveling process time is until the coating layer 5 is cured, and in this example, it is performed for about 5 hours. In order to accelerate the curing time, it is also preferable to heat the coating layer 5 during the self-leveling process, and the heating temperature at this time is preferably 45 ° C. or less, for example, so as not to adversely affect the coating layer 5.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

In order to confirm the effect of the present invention, the coating apparatus 1 having the structure shown in FIG. 1 is used to form an offset by forming a coating layer 5 made of silicon rubber and having a thickness of 0.5 mm on the outer surface of the sleeve 2 made of synthetic resin. A blanket for ink transfer in a printing press was formed. The sleeve 2 has an outer diameter of 100 mm, a length of 300 mm, and a thickness of 2 mm. As the coating material 4, silicon rubber (RT601, viscosity 3500 mPa · s) manufactured by Asahi Kasei Wacker Silicone Co., Ltd. was used. The forming conditions are as follows.
・ Gap Da of supply blade 16 --- 1.0 mm,
-Gap Db of scraping blade 7 --- 0.5 mm,
・ An angle θ of the scraping blade 7 −−− 45 degrees,
・ Coating process and scraping process Number of rotations --- 10 times / minute,
Process time ---- 3 minutes,
-Self-leveling process Number of rotations --- 30 times / min Process time ---- 5 hours Heating temperature --- 40 ° C

  The coated sleeve 2 was removed from the coating apparatus 1 and the thickness of the coating layer 5 was measured. In the measurement method, the coated sleeve 2 was mounted on a metal core, and the layer thickness was measured using an electromagnetic film thickness meter. The measurement positions were measured at a total of 40 positions of 5 locations at intervals of 5 cm in the axial direction and 8 locations at intervals of 45 degrees in the circumferential direction. As a result, the thickness variation is within a range of 0.50 mm ± 0.01 mm, and it can be confirmed that a uniform coating layer having high smoothness can be efficiently formed without using a cored bar. It was.

DESCRIPTION OF SYMBOLS 1 Coating apparatus 2 Sleeve 2S Outer peripheral surface 3 Rotation drive means 4 Coating material 5 Coating layer 5a Primary coating layer 6 Application means 7 Scraping blade 7e Tip 9A, 9B Rotation drive tool 10 Holding tool 11 Driving tool 12a First holding roller 12b Second holding roller 14 Driving roller X1 First reference line X2 Second reference line

Claims (3)

A coating apparatus that forms a coating layer of a predetermined thickness by applying a liquid coating material on the outer peripheral surface of a cylindrical sleeve,
Rotational drive means for rotating the sleeve;
Application means for applying the coating material to the outer peripheral surface of the rotating sleeve to form a primary coating layer,
And a tip is disposed apart from the outer peripheral surface of the sleeve, and comprises a scraping blade that forms a coating layer of a predetermined thickness by scraping the surface side of the applied primary coating layer with the tip.
The rotation driving means includes one rotation driving tool disposed on one end side in the axial direction of the sleeve and the other rotation driving tool disposed on the other end side in the axial direction.
In addition, the one and the other rotational drive tools are
A holding tool having first and second holding rollers parallel to the sleeve and rotatably holding the sleeve between the first and second holding rollers;
A driving tool having a driving roller inscribed in the inner peripheral surface of the sleeve, and rotating the sleeve held by the holding tool by sandwiching the sleeve between the driving roller and the first holding roller. And
In addition, the scraping blade is disposed between the first holding roller of one of the rotary driving tools and the first holding roller of the other rotary driving tool, and the tip thereof is first from the center of the driving roller. Is located on a first reference line that passes through the center of the holding roller, and is at least 0 degree and less than 90 degrees with respect to a vertical second reference line that hangs down from the contact point between the first holding roller and the sleeve. A coating apparatus characterized by being disposed at a forward angle in the rotational direction of the sleeve at an angle θ. Using the coating apparatus according to claim 1,
A rotation step of rotating the sleeve by a rotation driving means;
An application step of applying a coating material to the outer peripheral surface of the rotating sleeve by an application means to form a primary coating layer;
And a scraping step of forming a coating layer having a predetermined thickness by scraping the surface side of the applied primary coating layer with a tip of a scraping blade.   A sleeve body, wherein a coating layer is formed on the outer peripheral surface of the sleeve using the coating method according to claim 3.

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