JP2004167310A - Coating stopping method for coater and coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating stopping method for a coater for swinging either one of the rolls provided to the left and right regions of the coater to separate a web from the coater and a coating apparatus for applying a coating solution to the web during feed in a contact state, and to prevent the coating solution from adhering to a pass roll held as it is even if either one of upsteam and downstream pass rolls is raised from the other pass roll. <P>SOLUTION: When the web 9 is separated from the coater, air is sprayed on the web 9 from above to bend the web downward. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coater coating stopping method in which one of the rolls placed on the left and right sides of the coater swings to separate the web from the coater, and a coating apparatus that coats the coating solution in contact with the web being transported.
[0002]
[Prior art]
Many webs used for photographic film supports, magnetic recording tape supports, etc. are coated with a coating solution such as a primer or emulsion on both sides in the form of a long strip, and then It is obtained by cutting into length and width. Here, it is well known that the coating liquid is applied one side at a time using a coating apparatus called a bar coater as shown in FIG. 1 while conveying a belt-like web.
[0003]
FIG. 1 is a diagram schematically showing a conventional coating apparatus called a bar coater.
[0004]
The coating apparatus 1 shown in FIG. 1 includes a coating head 10, a gantry 20, and two pass rolls 81 and 82. The long web 9 is conveyed so as to be wound around these pass rolls 81 and 82. In FIG. 1, the web 9 is conveyed from the lower right to the upper left as indicated by an arrow S in the drawing, and is applied between the upstream pass roll 81 and the downstream pass roll 82. A head 10 is provided.
[0005]
The coating head 10 is placed on the upper surface 20 a of the gantry 20. The coating head 10 includes a bar 11 and a Giesa block 12. The bar 11 is formed by winding a wire 111 having a circular cross section in a coil shape without a gap. The Giesa block 12 is provided with a liquid reservoir 121 for storing the coating liquid, and a receiving seat 13 is provided at the bottom of the liquid reservoir 121. The bar 11 is placed on the receiving seat 13 so that the lower part of the bar 11 is immersed in the coating liquid stored in the liquid reservoir 12. The receiving seat 13 is provided with a through-hole 131 that connects a portion of the liquid reservoir 12 upstream and downstream of the receiving seat 13. Further, the coating liquid overflows from the portion of the liquid reservoir 12 downstream of the bar 11, and the receiving tray 14 for receiving the overflowed coating liquid is attached to the Giesa block 12. The bar 11 is rotated in the direction of the arrow R by a motor (not shown) while in contact with the receiving seat 13. The coating liquid is carried in the space formed by the arc portion of the adjacent wire 111 on the circumferential surface of the bar 11. The web 9 being conveyed is conveyed in contact with the bar 11 of the coating apparatus 1. A space B sandwiched between the application surface of the web 9 and the peripheral surface of the bar 91 is formed on each of the upstream side and the downstream side of the web 9 in contact with the bar 11. The coating liquid carried on the peripheral surface of the bar is supplied to the space B on the upstream side to form a bead. The bead coating liquid is applied to the application surface 9b of the web 9 that has been conveyed. In addition, in the space B on the downstream side, a surplus coating liquid is accumulated.
[0006]
By the way, in the line in which the coating apparatus 1 as shown in FIG. 1 is provided, the line is compactly gathered and the coating liquid is applied to both surfaces 9a and 9b of the web 9, so that the pass rolls 81 and 82 as shown in FIG. And the application head 10 in many cases. In such a line, even when an abnormality occurs in the coating head, the web conveyance is usually continued. When an abnormality occurs in the application head, the application head is lowered or only the downstream pass roll of the two pass rolls is raised so that the web being transported is not in contact with the bar. Thus, a work space is secured between the coating head 10 and the portion of the web 9 positioned above the coating head 10, and an operation for checking an abnormality occurring in the coating head and a recovery operation for the coating head are performed. The height of the downstream pass roll 82 shown by the solid line in FIG. 2 is the same as the height of the upstream pass roll 81, and when the downstream pass roll 82 is at this height, the web 9 is Then, it is conveyed in contact with the bar 11 of the coating apparatus 1. On the other hand, the height of the downstream pass roll 82 indicated by a two-dot chain line in FIG. 2 is higher than the height of the upstream pass roll 81, and when the downstream pass roll 82 is at this height, the web 9 is Then, it is conveyed in a non-contact state to the bar 11 of the coating apparatus 1, and a sufficient working space is ensured between the coating head 10 and the web 9.
[0007]
Patent Document 1 describes a coating apparatus that includes an upstream pass roll and a downstream pass roll that are in contact with the upper surface of the web, and that coats the lower surface of the web with a coating head.
[0008]
[Patent Document 1]
JP-A-9-108614 [0009]
[Problems to be solved by the invention]
However, in the coating apparatus 1 shown in FIG. 1, when the downstream pass roll 82 rises, the web 9 is inclined downward from the downstream side toward the upstream side, as indicated by a two-dot chain line. The application liquid is applied to the application surface 9b of the web 9 by the application device 1 shown in FIG. 1 until immediately before the downstream pass roll 82 is raised. For this reason, when the downstream pass roll 82 rises and the web 9 is inclined, the coating liquid applied until immediately before flows down to the peripheral surface of the upstream pass roll 81 along the web application surface 9b. Come. When the coating liquid adheres to the peripheral surface of the upstream pass roll 81 and hardens, the solidified shape of the coating liquid is transferred to the coating surface 9b of the web 9, and the coating surface 9b of the web 9 is applied after the coating head is restored. A planar defect will occur.
[0010]
Further, the widths of the upstream and downstream pass rolls provided in the coating apparatus described in Patent Document 1 are both larger than the width of the web, and when one pass roll is swung upward, the other pass roll has a web Even the pass roll that comes into contact with the upper surface of the web may be soiled.
[0011]
In view of the above circumstances, the present invention provides a coater capable of preventing the coating liquid from adhering to the other pass roll even if one of the upstream pass roll and the downstream pass roll is raised from the other pass roll. An object of the present invention is to provide a coating stopping method and a coating apparatus.
[0012]
[Means for Solving the Problems]
The coater coating stop method of the present invention that achieves the above object is a coater coating stop method in which either one of the rolls placed on the left and right of the coater swings to separate the web from the coater.
When the web is separated from the coater, air is blown from above the web toward the web, and the web is bent downward.
[0013]
According to the coating application stopping method of the present invention, even if one roll swings and the web tilts downward from the swing roll toward the other roll, the web bends downward. The liquid flowing down along the upper surface or the lower surface of the liquid does not flow down from the portion bent downward. Therefore, it is possible to prevent the coating liquid from reaching the other roll and the coating liquid from adhering to the other roll.
[0014]
The coating apparatus of the present invention that achieves the above object includes a coating head that coats the coating liquid in contact with the web being transported,
An upstream pass roll provided upstream of the coating head and around which a web being conveyed is wound;
A downstream pass roll provided on the downstream side of the coating head and around which the web being conveyed is wound;
The web is arranged so as to be sandwiched between the coating heads, and includes an air blowing device that blows air toward the web.
One of the upstream pass roll and the downstream pass roll is lifted to a manufacturing position where the web is in contact with the coating head and a position where the web is in a non-contact state with the coating head. Move up and down
The air blowing device blows out air that bends a web downward between the upstream pass roll and the downstream pass roll when any one of the pass rolls is in the retracted position.
[0015]
According to the coating apparatus of the present invention, the liquid flowing down along the upper surface or the lower surface of the web does not flow first from the portion bent downward. Therefore, the coating liquid does not reach the pass roll, and it is possible to prevent the coating liquid from adhering to the pass roll.
[0016]
Moreover, in the coating apparatus of the present invention, any one of the above-described pass rolls is more than a retreat position where the air blowing device blows out air that causes the web between the upstream pass roll and the downstream pass roll to bend downward. It is preferable that it can be raised to a higher position.
[0017]
In such a coating apparatus, the retracted position as described above is kept high enough to allow an operator's hand to enter between the web and the bar, so that the coating applied to the coating surface of the web is performed. The liquid is less likely to flow down, and the application liquid applied to the application surface of the web can be wiped from between the web and the bar. Further, when any one of the above-described pass rolls is raised from the retreat position as described above to a higher position, a sufficient working space of the coating head can be secured.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the coating apparatus of the present invention will be described.
[0019]
The coating apparatus according to the present embodiment is a so-called bar coater, which is a device that applies a coating solution to a long web serving as a support for a photographic film. The general configuration of the coating apparatus of the present embodiment is the same as that of the coating apparatus 1 shown in FIG. Here, the characteristic part of the coating device of this embodiment is demonstrated using the same code | symbol as the code | symbol used by description of the coating device 1 shown in FIG.
[0020]
FIG. 2 is a diagram schematically showing a coating apparatus according to an embodiment of the present invention.
[0021]
Similar to the coating apparatus shown in FIG. 1, the coating apparatus 1 shown in FIG. 2 includes a coating head 10, a gantry 20, and two pass rolls 81 and 82, and the coating apparatus 1 includes an air blowing device 40. It also has. Also in FIG. 2, the web 9 is conveyed from the lower right to the upper left as indicated by the arrow S in the figure, and between the upstream pass roll 81 and the downstream pass roll 82. A coating head 10 is provided. The coating head 10 is placed on the upper surface 20 a of the gantry 20. The upper surface 20a of the gantry 20 is formed horizontally, and the coating head 10 is disposed horizontally. Further, weirs 23 extend in the width direction of the web (in the direction perpendicular to the paper surface in FIG. 2) at both the upstream edge and the downstream edge of the gantry 20 in the web conveyance direction. ing. Further, the coating apparatus 1 shown in FIG. The save-all 30 has a box shape opened upward, and has a horizontal plane 30a and a vertical plane 30b rising from the periphery of the horizontal plane 30a. The gantry 20 is not shown in FIG. 3 and only two are shown in FIG. 2, but has four support legs 21 on the bottom surface. The gantry 20 is placed on the horizontal surface 30 a of the saveall 30 by these four support legs 21. When the coating liquid is applied to the web 9 by the coating apparatus 1 shown in FIG. 2, the coating liquid is scattered not only to the upper surface 20 a of the gantry 20 and the horizontal surface 30 a of the saveall 30. Water continuously flows on the upper surface 20a of the gantry 20 and the horizontal surface 30a of the save-all 30, and the scattered coating liquid is carried out of the coating apparatus 1 together with the flowing water.
[0022]
Of the two pass rolls 81 and 82, the upstream pass roll 81 has a fixed arrangement position, and the downstream pass roll 82 is indicated by a manufacturing position indicated by a solid line and a two-dot chain line in FIG. Swing type that can move up and down between different working positions. When the downstream pass roll 82 is in the manufacturing position, the web 9 is conveyed in contact with the bar 11 rotating in the direction of the arrow R. However, when the downstream pass roll 82 rises above the manufacturing position, the web 9 Is transported to the bar 11 in a non-contact state. When the downstream pass roll 82 is in the working position, a sufficient working space is secured between the coating head 10 and the portion of the web 9 positioned above the coating head 10.
[0023]
The air blowing device 40 blows air toward the web 9, has a width longer than the width of the web 9, and spans the bar 11 from the upstream side to the downstream side in the conveyance direction of the web 9. Deployed. A plurality of blow holes (not shown) are arranged at a uniform pitch in the width direction of the web on the blow surface 40a of the air blow device 40 facing the web 9, and the blow holes at both ends are at both ends of the web. It is deployed to be directly above. Further, a plurality of such widthwise blowing holes are arranged in the web conveyance direction. Further, the air blown from the blowing holes is efficiently blown to the web 9 by the guide plates 41 provided at the upstream end and the downstream end of the air blowing device 40, respectively. The air blowing device 40 moves up and down as the pass roll 82 on the downstream side moves up and down.
[0024]
In the coating apparatus 1 shown in FIG. 2, the coating operation is performed while the web 9 is being transported in a state where the downstream pass roll 82 is disposed at the manufacturing position. During the coating operation, air is blown out from all the blowing holes of the air blowing device 40, and the web 9 being conveyed is pressed against the peripheral surface of the bar 11.
[0025]
Further, the coating apparatus 1 shown in FIG. 2 employs an embodiment of the coating stop method of the coater of the present invention. In this coating apparatus 1, an abnormality occurs in the coating head 10 during the coating operation. When it is necessary to stop the application, the downstream pass roll 82 is first raised to the retracted position indicated by the dotted line between the manufacturing position and the working position while the web 9 continues to be conveyed. While the downstream pass roll 82 rises from the manufacturing position to the retracted position, the air blowing device 40 continues to blow air from the blowing holes located upstream of the bar 11 and from the blowing holes located downstream. The air blowing is stopped. When the downstream pass roll 82 rises, the web 9 is inclined downward from the downstream side toward the upstream side as indicated by the dotted line in the figure, but the air blown from the upstream side of the air blowing device 40 A portion of the web 9 upstream of the bar 11 bends downward. Here, the greater the inclination of the web 9 that is inclined downward from the downstream side toward the upstream side, the easier it is for the coating liquid that has been applied just before to flow down along the application surface 9b of the web. Compared to the case where the downstream pass roll 82 is raised to the working position indicated by the two-dot chain line in the drawing, the coating liquid is less likely to flow down when it is only raised to the retracted position indicated by the dotted line, but the web application surface The coating liquid that is about to flow down even though a little passes through 9b does not flow down from the downwardly bent portion of the web 9 indicated by the dotted line, and drops on the upper surface 20a of the gantry 20 and the horizontal surface 30a of the saveall 30 To do. For this reason, according to the coating apparatus 1 shown in FIG. 2, even if the downstream pass roll 82 is raised above the upstream pass roll 81, the coating liquid that flows down along the coating surface 9b of the web 9 flows upstream. It is possible to prevent the application liquid from adhering to the upstream pass roll 81 without reaching the pass roll 81. The coating liquid dropped on the upper surface 20a of the gantry 20 and the horizontal surface 30a of the saveall 30 is carried to the outside of the coating apparatus 1 together with water flowing therethrough. When the downstream pass roll 82 rises to the retracted position indicated by the dotted line, the rise of the pass roll is once stopped. When the downstream pass roll 82 rises to the retracted position, a gap is formed between the coating head 10 and the portion of the web 9 that is positioned above the coating head 10 so that an operator's hand can enter. The operator wipes the coating solution applied to the coating surface 9b of the web 9 from this gap. By this wiping operation, the coating liquid does not flow down along the coating surface 9b of the web 9, and the blowing of air blown from the upstream side of the air blowing device 40 is stopped. Subsequently, the downstream pass roll 82 is raised to a work position indicated by a two-dot chain line in the drawing to secure a sufficient work space above the coating head 10. The operator uses this work space to check for an abnormality that has occurred in the coating head 10 and to restore the coating head 10. When these operations are completed, the downstream pass roll 82 is lowered to the manufacturing position, and the coating operation is resumed.
[0026]
In the description here, the rise of the downstream pass roll 82 is temporarily stopped at the retracted position between the manufacturing position and the work position, and the wiping operation of the coating liquid is performed. However, the work position indicated by the two-dot chain line is The downstream pass roll 82 may be raised to the working position at a stretch while the web 9 is bent by the air at the retreat / work position. In the description here, a device capable of blowing air also to the downstream side of the bar 11 is used as the air blowing device, and such an air blowing device is used to apply the web 9 to the peripheral surface of the bar 11 during coating work. However, the air blowing device may blow air only to the upstream side of the bar 11. Here, the web serving as the support for the photographic film has been described as an example of the member to be coated, but the member to be coated may be a web serving as the support for the magnetic recording tape. Furthermore, in the description here, the present invention is applied to a coating apparatus called a bar coater. However, the present invention is not limited to a bar coater and can also be applied to a gravure coating machine, an extrusion coating machine, and the like. Furthermore, the present invention is not limited to a coating apparatus in which the upstream pass roll 81 is in contact with the web application surface, but is a coating apparatus in which the downstream pass roll is in contact with the web application surface, or the upstream pass roll is the web application. The present invention can be applied not only to a coating apparatus that contacts a surface opposite to the surface, but also to a coating apparatus in which the upstream pass roll 81 rises higher than the downstream pass roll 82.
[0027]
【The invention's effect】
As described above, according to the present invention, even if one of the upstream and downstream pass rolls is raised from the other pass roll, the coating liquid is prevented from adhering to the other pass roll. be able to.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a conventional coating apparatus called a bar coater.
FIG. 2 is a diagram schematically showing a coating apparatus according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Application | coating apparatus 10 Application | coating head 11 Bar 12 Giesa block 20 Mounting base 20a Upper surface 21 Support leg 23 Weir 30 Save all 30a Horizontal surface 30b Vertical surface 40 Air blowing device 40a Blowing surface 81, 82 Path roll 9 Web 9b Application surface

Claims (3)

In the coating application stopping method in which one of the rolls placed on the left and right of the coater swings to separate the web from the coater,
A coater coating stopping method, characterized in that, when a web is separated from a coater, air is blown toward the web from above the web, and the web is bent downward. An application head for applying the application liquid in contact with the web being conveyed;
An upstream pass roll provided on the upstream side of the coating head, on which a web being conveyed is wound;
A downstream pass roll provided on the downstream side of the coating head, around which a web being conveyed is wound;
An air blowing device that is arranged so as to sandwich the web between the coating head and blows air toward the web; and
One of the upstream pass roll and the downstream pass roll is lifted up to a manufacturing position where the web is in contact with the coating head and to a position where the web is not in contact with the coating head. Move up and down
The air blowing device blows out air that bends a web downward between the upstream pass roll and the downstream pass roll when any one of the pass rolls is in the retracted position. apparatus. Any one of the pass rolls can be raised to a position higher than a retreat position where the air blowing device blows out air that bends the web between the upstream pass roll and the downstream pass roll downward. The coating apparatus according to claim 2.

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