JP2002282765A - Method and apparatus for removing coating liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for surely removing a thick coated part with the suction treatment for a coated layer end part and a coated tip part without soiling a web and a pass roller in order to obtain thinly coated layer. SOLUTION: (1) Liquid coating composition is removed by sucking the liquid coating composition while blowing a gas to the liquid coating composition applied on the continuously traveling web. (2) The apparatus for removing the liquid applied on the continuously traveling web has at least a suction nozzle and a gas blowing nozzle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photographic film
Photosensitive materials such as photographic paper and photoengraving materials, magnetic recording materials such as magnetic recording tape, materials such as pressure-sensitive recording paper and heat-sensitive recording paper,
A liquid coating composition applied to a web in a process of applying a liquid coating composition (hereinafter, also referred to as a coating liquid) to a continuously running long flexible support (hereinafter, referred to as a "web") in the production of an ink jet recording sheet In particular, the present invention relates to a method and an apparatus for removing a thick-coated portion at both ends in a coating width direction and a thick-coated portion at the start or end of coating.

[0002]

2. Description of the Related Art In the above-mentioned coating process, both ends in the width direction of the web and the tip of the coating depend on the surface tension, specific gravity and viscosity of the coating solution, or the water absorption, surface roughness and flatness of the web. In addition, a thick-coated portion is generated at the rear end, and this thick-coated portion may cause uneven drying in a subsequent drying process. Therefore, it is desirable to remove the thick-coated portion before the drying process. US Patent No. 2,8
No. 99,339 discloses that in such a process, nozzles for sucking a coating liquid are provided at both ends in the width direction of the web, and the nozzles have an L-shaped double-pipe structure. Discloses a device for supplying a spray liquid or a jet stream of a diluent / solvent from a substrate and sucking a coating liquid together with the diluent / solvent from a central portion.

Further, Japanese Patent Publication No. 52-38407 discloses a method in which a coating solution at the edge of a coating layer is sucked only by a suction nozzle heated from the surroundings.
Japanese Patent Application Laid-Open No. 579/1992 is also characterized in that a liquid is ejected from the central portion of a suction nozzle having a double-tube structure to the thick coating portion, and the liquid and the coating solution in the thick coating portion are sucked together by the suction nozzle. A method for producing a coating has been proposed. Furthermore, Japanese Utility Model Application Laid-Open No. Sho 60-49949 discloses a suction nozzle having a double pipe structure having a cleaning liquid jet port and a suction port at the tip end, wherein the jet port is positioned off the axis of the double pipe. The suction nozzle is provided so as to form an angle of 30 ° to 85 ° with the shaft core, and the suction port is provided at a central shaft portion of the double pipe. However, these suction removal methods are insufficient to reliably remove the thickly coated portion without causing contamination of the web and the pass roller.

On the other hand, in recent years, the spread of curtain coating methods which have enabled higher-speed coating has been remarkable. This curtain coating method enables high-speed coating of 200 m / min or more,
On the other hand, the degree of thick coating at the initial stage of coating is several steps larger than the slide bead coating method, both in terms of quantity and area (thick coating length). Quantitatively, the regular application amount of 5
Ten times as thick, the length of the thick part extends to several tens of meters. With such a thick coating, it is difficult to sufficiently dry the coating equipment.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to apply a thinner layer with a smaller amount of coating to the end of the coating layer and the tip of the coating layer by suction treatment of the web and the coating. It is an object of the present invention to provide a novel removal method and a novel removal device for reliably removing a thick coating portion without causing contamination of a pass roller.

[0006]

The objects of the present invention have been attained by the following inventions. 1) A method for removing a liquid coating composition, which comprises suctioning and removing the liquid coating composition while blowing gas onto the liquid coating composition applied to a continuously running web. 2) Of the liquid coating composition applied to the continuously running web, while blowing gas to the thick coating portions at both ends in the web width direction, the thick coating portions at both ends of the liquid coating composition are sucked and removed. A method of removing a liquid coating composition. 3) Removing the liquid coating composition, wherein the liquid coating composition is suctioned and removed over the entire width of the web while spraying gas over the entire width of the liquid coating composition applied to the continuously running web. Method. 4) A device for removing a liquid coating composition applied to a continuously running web, the device having at least a suction nozzle and a gas blowing nozzle.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The method of suction-removing a coating solution of the present invention mainly involves blowing off and suctioning with a gas. Less than,
The method of the present invention will be described in detail with reference to the accompanying drawings. Figure 1
FIG. 4 is a side cross-sectional view of an embodiment in which a thick coating portion at an end of a web is removed using a suction removal device of the present invention. FIG. 2 is a plan view of FIG.

In FIG. 1, a liquid coating composition 1 is applied on a web 2 running continuously in a direction of an arrow 6, and a thick coating portion 3 is generated at an end thereof. FIG.
This shows a mode in which the thick coating section 3 is suction-removed by the suction-removal device 8 of the present invention. The suction removing device 8 of the present invention includes a suction nozzle 4 and a gas blowing nozzle 5.

The suction nozzle 4 and the blowing nozzle 5 may be provided integrally as shown in FIG. 1, or may be provided separately and close to each other. The thick coating portion 3 is peeled off from the web 2 by the wind blown from the blowing nozzle 5, is sucked from the tip of the suction nozzle 4, and is discharged to the outside by a pump and piping (not shown). Although not shown, a compressor or the like for sending compressed air is also attached to the gas blowing nozzle 5 through a pipe.

The mounting angle of the suction nozzle 4 is not particularly limited, but it is preferable that the suction nozzle 4 is installed perpendicular to the web 2. The gas blowing nozzle 5 is preferably installed so as to be inclined in the opposite direction to the transporting direction (progressing direction) 6 of the web 2, and the angle θ between the gas blowing nozzle 5 and the web 2 shown in FIG. It is preferably about 70 degrees, particularly preferably 20 to 60 degrees.

In FIG. 1, the tips of the suction nozzle 4 and the gas blowing nozzle 5 are set at a distance A from the web 2 so as not to directly hit the web 2, the liquid coating composition 1, and the thick coating portion 3. The distance A needs to be changed slightly depending on the amount of the liquid coating composition 1 applied, but is about 0.1 mm to 2 mm, preferably about 0.2 mm to 1 mm.

FIG. 2 is a plan view of the state of FIG. 1 as viewed from above. On the web 2 conveyed in the direction of arrow 6,
The liquid coating composition 1 is applied, and thick coating portions 3 are generated at both ends. The thick coating portions 3 at both ends are removed by suction by the suction removing device 8. Here, the blowing nozzle 5 may blow from the inside of the web 2 to the outside. Therefore, the angle α shown in FIG. 2 is about 0 to 70 degrees, preferably 1
It is about 0 to 60 degrees.

FIG. 3 is a cross-sectional view showing another embodiment in which the thick coating portion 3 at the end in FIG. 1 is removed by using the suction removing device 8 of the present invention. Only one end is shown for convenience of explanation. The liquid coating composition 1 is applied on a web 2 that advances forward, and a thick coating portion 3 is generated at the end. The thick coating portion 3 is suction-removed by the suction-removal device 8. In FIG. 3, the gas blowing nozzles 5 and 7 are provided on the left and right sides of the suction nozzle 4 for convenience of description, but the effect of the present invention can be sufficiently obtained by installing one of the gas blowing nozzles. Of course, gas blowing nozzles may be provided on both sides. In this case, the angle γ between the gas blowing nozzles 5 and 7 and the web 2 is
It is preferably about 10 to 70 degrees, particularly preferably 20 to 60 degrees. In FIG. 3, a scattering prevention plate 9 for the liquid coating composition may be attached at a position facing the gas blowing nozzle 5 for blowing gas from the inside to the outside of the web 2. Although not shown in FIG. 1, a scattering prevention member may be provided at a position facing the gas blowing nozzle 5 for the same purpose. In this case, the height is set so as not to contact the liquid coating composition.

FIGS. 1 and 3 described above each show a mode in which the mounting position of the gas blowing nozzle is changed with respect to the thick coating portion at the end. Preferably, the gas blowing nozzle is mounted as shown in FIG. It is to install.

Next, an embodiment for removing the liquid coating composition over the entire width of the web will be described. A thick coating often occurs at the initial stage or the final stage where the coating is started, or at the joint of the web. At such times, it is necessary to remove the liquid coating composition over the entire width of the web. FIG. 4 is a side cross-sectional view when the thick coating portion generated over the entire width at the start of coating is removed.

In FIG. 4, a continuously running web 2 is shown.
A liquid coating composition 1 is applied on the top of the substrate, and a thick coating portion 3 is generated at the tip. This thick coating portion 3 has been removed by the suction removing device 8 of the present invention. The structure of the suction removing device 8 is the same as that of FIG. However, the suction nozzle 4 and the gas blowing nozzle 5 are provided over the entire width.

The mounting angle of the suction nozzle 4 is not particularly limited, but is preferably set perpendicular to the web 2. The gas blowing nozzle 5 is preferably installed so as to be inclined in the opposite direction to the transport direction (progressing direction) 6 of the web 2, and the angle θ shown in FIG.
Particularly, 20 to 60 degrees is preferable. Thereby, the thick coating part 3
Is drawn off by the suction nozzle 4 while being stripped off by the gas blown out from the gas blowing nozzle 5, and is discharged from a pipe attached above the suction nozzle 4 by an exhaust device (not shown).

The tips of the suction nozzle 4 and the gas blowing nozzle 5 spread in the coating width direction are set at a distance A from the web 2 so as not to directly hit the web 2, the liquid coating composition 1, and the coating thick coating portion 3. You. This distance A corresponds to the liquid coating composition 1
It is necessary to change it slightly depending on the amount of
m to 2 mm is appropriate, and preferably 0.2 mm to
It is about 1 mm.

Since the suction and removal device 8 of the present invention cannot perform reliable suction and removal if the web 2 flaps, it is desirable to process the web 2 on a surface held by a roll.

[0020]

According to the above-described method for sucking and removing a coating liquid of the present invention, even when a relatively thin layer having a relatively thick coating is applied, the thick coating can be reliably removed without contaminating the web and the pass roller. , The coating rate can be further reduced, the high-speed coating and the thin-layer coating can be performed, and the productivity and quality can be improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment in which a thick coating portion at an end of a web is removed using a suction removing device of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a side sectional view of another embodiment for removing a thick coating portion at an end of a web using the suction removing device of the present invention.

FIG. 4 is a side sectional view of an embodiment in which a thick coating portion having the entire width of the web is removed using the suction removing device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid coating composition 2 Web 3 Thick coating part 4 Suction nozzle 5, 7 Gas blowing nozzle 8 Suction removing device 9 Shatter prevention plate

Continued on the front page F term (reference) 4D075 AC84 AC93 BB20Z BB56Z BB57Z CA47 DA04 DA33 DA34 DB18 DB31 DC27 EA07 4F042 AA22 BA10 BA25 CC03 CC09 DD04 DD33 5D112 CC03 CC08 CC10 HH09

Claims (7)

[Claims] 1. A method for removing a liquid coating composition, comprising suctioning and removing the liquid coating composition while blowing gas onto the liquid coating composition applied to a continuously running web. 2. Among the liquid coating compositions applied to a continuously running web, the thick coating sections at both ends of the liquid coating composition are sucked while blowing gas to the thick coating sections at both ends in the web width direction. And removing the liquid coating composition. 3. A liquid coating composition, wherein the liquid coating composition is sucked and removed over the entire width of the coating while spraying gas over the entire width of the liquid coating composition applied to the continuously running web. How to remove things. 4. An apparatus for removing a liquid coating composition applied to a continuously running web, the apparatus comprising at least a suction nozzle and a gas blowing nozzle. 5. The liquid coating composition removing apparatus according to claim 4, wherein the gas blowing nozzle is installed to be inclined in a direction opposite to the traveling direction of the web. 6. The apparatus for removing a liquid coating composition according to claim 5, wherein an inclination angle (an angle with the web) of the gas blowing nozzle is 10 to 70 degrees. 7. The apparatus for removing a liquid coating composition according to claim 4, wherein a scattering prevention plate is provided at a position facing the gas blowing nozzle.