JP2004066031A - Coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus which prevents the irregularity of coating due to vibrations of conveyed base material and air blowing. <P>SOLUTION: The coating apparatus coating the base material S travelling on the surface of a backup roller 11 with coating liquid by using a die head 12 is constituted in such a manner that an air blowing case 13 having a blowing surface 14 of a width larger than the width of the base material is disposed on the non-coated surface side of the base material S on the downstream side of the backup roller 11, and air is supplied from both side surfaces on the air blowing case 13. The coated surface is not disturbed because the air is not blown onto the coated surface of the base material S and the distribution of flow rate of the blow air is made to be a concave shape in the width direction of base material and the base material is uniformly floated. Hence the base material S is allowed to stably travel during the half surface blowing to the non-coated surface. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention belongs to the technical field of applying a coating liquid to a surface of a sheet-like base material to be conveyed by a die head, and more particularly to a die-coating type coating apparatus using a backup roll for running the base material.
[0002]
[Prior art]
Conventionally, in a die-coating type coating apparatus using a backup roll, as a method for preventing the vibration of the base material due to the air flow from the drying furnace inlet and the twist of the base material between the guide rolls from affecting the coating part, The following method is adopted.
[0003]
(A) Single-sided air blowing method (Fig. 1)
A plurality of slits 1a for blowing air in the width direction are provided on the surface of the backup roll 1, and the air supplied from the blower 3 is directed from these slits 1a to the non-coated surface of the substrate S during coating by the die head 2. A method in which the base material S is lifted from the surface of the backup roll 1 by the static pressure of air by blowing, thereby preventing the vibration of the base material S. In FIG. 1, reference numeral 4 denotes an air blow-through prevention member attached to the backup roll 1.
[0004]
(B) Double-sided air blowing method (Fig. 2)
Immediately after the coating portion of the backup roll 1, a box-shaped air blowing case 5 is installed so as to sandwich the substrate S, and the air supplied from the blower 3 is applied during coating by the die head 2. To prevent vibration of the base material S by blowing out from both sides of the base material S.
[0005]
[Problems to be solved by the invention]
The above conventional method has the following problems. That is, in the single-sided air blowing method shown in FIG. 1, since the air outlet is on the non-coated side, the coating surface is not disturbed by the direct contact of the blown air, but the pressure of the air blown out from the slit is locally increased. When a great variation occurs, the distance between the die head and the base material changes, so that the film thickness in the width direction of the base material and in the flow direction becomes uneven. Further, in the double-sided air blowing method shown in FIG. 2, since air is blown onto the coating surface, the coating surface is disturbed, particularly in the case of a low-viscosity coating liquid, and coating unevenness occurs.
[0006]
The present invention has been made in view of such problems, and an object of the present invention is to prevent coating unevenness due to vibration or air spray of a conveyed base material. It is to provide a device.
[0007]
[Means for Solving the Problems]
The coating device according to the first aspect of the present invention is a coating device that applies a coating liquid to a substrate traveling on the surface of a backup roll by a die head, wherein the substrate is not coated downstream of the backup roll. An air blowing case having a blowing surface having a width equal to or larger than the base material width is arranged on the surface side, and air is supplied from both side surfaces of the air blowing case.
[0008]
A coating apparatus according to a second aspect of the present invention is the coating apparatus according to the first aspect, wherein a porous sintered body material is used for a blowing surface of an air blowing case.
[0009]
A coating apparatus according to a third aspect of the present invention is the coating apparatus according to the first or second aspect, wherein a punching plate is provided in the air blowing case in parallel with the blowing surface.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to specific examples.
[0011]
FIG. 3 is a side view showing an outline of the coating apparatus according to the present invention in use, and FIG. 4 is a front view of the same.
[0012]
The coating device shown in these figures is of a type in which a coating liquid is applied to a substrate S traveling on the surface of the backup roll 11 by a die head 12, and the substrate S on the downstream side of the backup roll 11 is not coated. An air blowing case 13 is provided on the application surface side. The air blowing case 13 used here is a box shape having a triangular prism shape in appearance, has a blowing surface 14 having a width equal to or larger than the width of the base material, and piping from the blower 16 is provided to the air inlets 15 on both sides. It is connected. The blowing surface 14 of the air blowing case 13 is formed using a porous sintered body material.
[0013]
In this coating apparatus, during the coating by the die head 12, the air supplied from the blower 16 is blown from the blowing surface 14 of the air blowing case 13 toward the non-coated surface of the base material S, and the base pressure is generated by the static pressure of the air. The material S is levitated to prevent the vibration of the base material S.
[0014]
At this time, since air is supplied from both side surfaces of the air blowing case 13, the flow rate distribution of the blowing air from the blowing surface 14 becomes concave in the width direction of the base material, so that the base material S can float uniformly. In addition, the base material S can be stably run even when the single-sided blowing is performed to the non-coated surface. That is, if an air inlet is provided at the center of the air blowing case 13, the air leaking from both sides of the blowing surface increases the air blowing flow rate at the center of the blowing surface, and the base material in the base material width direction and the flow direction. In this case, the base material floats in a bowl shape and the influence on the coating unevenness is increased. However, such a situation can be prevented by supplying air from both sides of the air blowing case 13. .
[0015]
Further, in the above-described coating apparatus, since the porous sintered body material is used for the blowing surface 14, air is blown from the entire blowing surface to increase the blowing area, and the blowing surface 14 and the base material S And a stable air thin film is formed. Therefore, generation of vibration of the substrate S due to the blown air is prevented, and the substrate S is supported in a stable state and the vibration is absorbed.
[0016]
In the above-mentioned coating apparatus, it is preferable to install a punching plate 17 as shown in FIG. 6 in the air blowing case 13 in parallel with the blowing surface 14 as shown in FIG. In this case, in order to uniformly blow air from the punching plate 17 to the blowing surface 14, the punching plate 17 is provided with a round hole 17a having a diameter of about φ1 mm to φ2 mm so as to have an opening ratio determined by the following equation (1). It is preferable to open at the pitch determined by equation (2).
Opening ratio = (air intake cross-sectional area / 2) / air blow-out case cross-sectional area ... (1)
Pitch = (90 × diameter of hole / opening ratio) ^1/2 (2)
[0017]
As described above, the embodiments of the present invention have been described in detail. However, the coating apparatus according to the present invention is not limited to the above embodiments, and various changes may be made without departing from the spirit of the present invention. What is possible is obvious.
[0018]
【The invention's effect】
The coating device according to the first aspect of the present invention is a coating device that applies a coating liquid to a substrate traveling on the surface of a backup roll by a die head, wherein the substrate is not coated downstream of the backup roll. On the surface side, an air blowing case having a blowing surface with a width equal to or larger than the base material width is arranged, and air is supplied from both side surfaces of the air blowing case, so that the air is applied to the coating surface of the base material. The coating surface is not disturbed because it is not sprayed onto the surface, and the flow rate distribution of the blowing air is concave in the width direction of the base material so that the base material can be uniformly floated. Can be run stably.
[0019]
The coating apparatus according to the second aspect of the present invention is characterized in that, in the coating apparatus according to the first aspect, a porous sintered body material is used for a blowing surface of an air blowing case. In addition, since the air thin film formed between the blowing surface and the base material is stable, it prevents vibration of the base material caused by the blown air, and supports the base material in a stable state and absorbs vibration. Becomes possible.
[0020]
The coating apparatus according to a third aspect of the present invention is characterized in that, in the coating apparatus according to the first or second aspect, a punching plate is installed in the air blowing case in parallel with the blowing surface. In addition to the effect described above, an effect that the air blowing in the blowing surface becomes more uniform is exhibited.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a single-sided air blowing method for preventing a base member from affecting a coating portion in a die coating method using a backup roll.
FIG. 2 is an explanatory diagram of a double-sided air blowing method for preventing a base material from affecting a coating portion in a die coating method using a backup roll.
FIG. 3 is a side view schematically showing a coating apparatus according to the present invention in a used state.
FIG. 4 is a front view showing an outline of a coating apparatus according to the present invention in a used state.
FIG. 5 is a cross-sectional view showing a state in which a punching plate is installed in an air blowing case in the coating apparatus shown in FIGS. 3 and 4.
FIG. 6 is a plan view of a punching plate.
[Explanation of symbols]
S base material 11 backup roll 12 die head 13 blowing case 14 blowing surface 15 air intake 16 blower 17 punching plate 17a round hole

Claims (3)

In a coating apparatus for applying a coating liquid to a substrate traveling on the surface of a backup roll by a die head, a blowing surface having a width equal to or larger than the substrate width is provided on the non-application surface side of the substrate on the downstream side of the backup roll. A coating apparatus, wherein an air blow case having the air blow case is disposed, and air is supplied from both side surfaces of the air blow case. The coating apparatus according to claim 1, wherein a porous sintered body material is used for a blowing surface of the air blowing case. The coating apparatus according to claim 1, wherein a punching plate is provided in the air blowing case in parallel with the blowing surface.

Images