JP2002143742A - Viscous material supplying device and applicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an applicator which prevents air bubbles from being included in a coating film when a web is coated, thereby keeping the durability and characteristics of the coating film excellent, and providing high maintainability. SOLUTION: In order to stick a coating material to a web W by supplying the coating material from a liquid storage bed while feeding the web W along a back roll 21 in the lengthwise direction, the tip of a liquid storage pan 24 comprising the liquid storage bed is curved inward, or an angle α between a tangent to the top end 24a of the liquid storage pan 24 and a tangent to the outer peripheral surface of the back roll 21 is adjusted to >=90 deg. and <=180 deg. at a position where the liquid storage pan 24 and the back roll 21 are most close.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for applying a viscous material to a long strip web.

[0002]

2. Description of the Related Art FIG. 22 shows an example of a coating apparatus for applying a viscous material such as a paint or an adhesive to one surface of a web such as paper, cloth or film cut into a long strip. The drawing shows a paint supply device which constitutes a part of the coating device. Reference numeral 1 denotes a back roll for feeding out a web W to be coated, and 2 denotes a thickness of a coating film formed on the web W. Is a liquid storage bed for storing the paint C, which is a viscous material, and supplying it to one surface of the web W as needed.

The back roll 1 is rotatably supported by driving means (not shown). The application roll 2 is supported in parallel to the back roll 1 but does not rotate, and is fixed with a slight gap provided between the coating roll 2 and the back roll 1. The liquid storage bed 3 is inclined obliquely downward, and has a liquid storage pan 4 whose tip abuts against the outer peripheral surface of the back roll 1, and side plates raised on both sides of the liquid storage pan 4 (front and rear in a direction perpendicular to the paper surface). (Not shown) and the outer peripheral surface of the back roll 1. Actually, in order to enable the web W to be sent out, the tip of the reservoir pan 4 and the back roll 1
A small gap is provided between the web W and the web W, and a leakage prevention film 5 is adhered to the tip of the liquid reservoir pan 4 from the inside in order to prevent the paint C from leaking from the gap.

In this coating apparatus, a back roll 1
When the web W enters the reservoir 3 due to the rotation of, the paint C adheres to one surface by the web W going under the paint C. When the web W to which the coating material C is attached is pulled up from the liquid storage bed 3, a coating film having a thickness corresponding to the gap between the back roll 1 and the application roll 2 is formed and sent out. The thickness of the coating film can be adjusted by changing the distance between the back roll 1 and the coating roll 2.

[0005] The following problems have been pointed out in the coating apparatus constructed as described above. The problem is that when the web W is sent out, a pressure reduction occurs in the paint near the tip of the reservoir pan 4, and the paint is drawn from the gap between the tip of the reservoir pan 4 and the web W wound on the back roll 1. That is, air is entrained in C to generate fine bubbles, and these bubbles are mixed into the coating film.

When the web is processed while air bubbles are mixed in the coating film, the smoothness of the coating film is impaired due to the remaining air bubbles in the coating film, or the desired state and properties (airtight sealing property, adhesive strength, etc.) ) Is not fully exhibited. These phenomena become remarkable when the feeding speed of the web W is increased, so that the feeding speed of the web W cannot be increased in the coating process, which is a factor that hinders an improvement in productivity.

Several techniques have been proposed to solve the above problems. For example, as described in JP-A-6-254478, a method of preventing air bubbles from being mixed into paint by sucking the vicinity of a contact point between a liquid storage bed and a back roll from outside the liquid storage tank. As described in JP-A-5-49996, a method of separately installing a partition plate in contact with the back roll in the paint and removing bubbles from the web surface by flowing bubbles mixed in the paint along the partition plate,
And so on.

[0008]

When the above technique is adopted, a certain effect can be expected in terms of speeding up the feeding speed, but the structure of the coating apparatus becomes complicated, and the apparatus is required when changing the web type. It has been pointed out that there is a new problem that the maintenance property is remarkably reduced, for example, it is difficult to wipe off the adhered paint.

The present invention has been made in view of the above circumstances, and when coating a web, aims at improving the coating speed, and preventing the incorporation of air bubbles into the coating film to improve the durability of the coating film. It is an object of the present invention to provide a coating apparatus having good maintainability and characteristics and having high maintainability.

[0010]

Means for Solving the Problems As means for solving the above-mentioned problems, the following configuration is adopted. That is, the viscous material supply device according to the present invention supplies a liquid viscous material from a liquid reservoir provided adjacent to the back roll while feeding the long belt-shaped web in the length direction along the back roll. A viscous material supply device that adheres to one surface of the web, wherein the liquid reservoir has a liquid reservoir pan whose tip is arranged close to the outer peripheral surface of the back roll, The tip is curved inside the liquid reservoir.

The generation of bubbles is caused by the point of contact between the tip of the liquid storage pan and the outer peripheral surface of the back roll as the web is fed (this point is considered to be a contact point because it does not strictly take into account the web thickness). This is due to decompression occurring nearby. It has been found that a circulating flow is generated in the viscous material stored in the liquid storage part as the web is sent out.However, the decompression causing bubbles causes the circulating flow to change its direction rapidly. It is generally explained from the fact that a pressure reduction state occurs at the point of change when acceleration or acceleration is performed.

The circulating flow of the viscous material flows along the surface of the reservoir pan toward the contact point between the tip of the reservoir pan and the outer peripheral surface of the back roll. Therefore, by bending the tip of the liquid reservoir pan to the inside of the liquid reservoir, a viscous body flowing along the liquid reservoir pan does not undergo a sudden change in direction or acceleration, and a reduced pressure state is less likely to occur. This prevents air from being caught in the viscous material from the gap between the tip of the liquid storage pan and the web wound around the back roll and sent out, thereby preventing generation of bubbles.

In order to make the flow of the viscous material smaller in the direction and the speed, the tip of the reservoir pan is preferably curved with a predetermined radius of curvature. However, if the radius of curvature is too small, the flow of the flow is reduced. The change in the direction is large, and the pressure is likely to be reduced. Therefore, the radius of curvature is preferably 3 mm or more.

As described above, the decompression causing bubbles causes a decompression state at the change point when the circulating flow rapidly changes or accelerates the direction of the flow.
Therefore, the angle between the tangent of the tip of the reservoir pan and the tangent of the outer peripheral surface of the back roll is set to 9 inside the reservoir.
By setting the angle to be 0 ° or more and 180 ° or less, even when the viscous material that has moved along the reservoir pan is accelerated in contact with the web, a rapid change in the flow direction does not occur, and the pressure is reduced. Is less likely to occur.

When the liquid storage pan is formed of a rigid body, it is impossible to apply the liquid while keeping its tip pressed against the web. This is because it is impossible to absorb the vibration generated in the back roll and the change in the thickness of the web due to the feeding of the web. Therefore, at present, a gap is actually provided between the tip of the reservoir pan and the web wound on the back roll.

While the web is being fed, the viscous material is pulled in the web feeding direction, so that the viscous material does not flow into the gap between the tip of the liquid storage pan and the web wound around the back roll and fed. . However,
When the feeding of the web is stopped or terminated, the viscous material flows into the gap and leaks out of the liquid reservoir, and the surroundings of the apparatus become dirty or cause a failure.

Therefore, in the viscous material supply device according to the present invention, the elastic member is protruded from the tip of the liquid storage pan toward the back roll side so that leakage can be prevented even when the web feeding is stopped. Is preferably attached. As a result, the elastic member is pressed against the outer peripheral surface of the back roll by the viscous body to close the gap,
Leakage of viscous material can be prevented.

The decompression generated in the viscous material appears remarkably even if the flow direction and speed are slightly changed. Therefore, in the viscous material supply device according to the present invention, it is preferable that the distal end of the elastic member be formed in a wedge-shaped cross section. As a result, when the tip of the reservoir pan is viewed locally, the viscous body flowing along the elastic member does not suddenly change direction or accelerate,
A reduced pressure state hardly occurs.

Regarding the elastic member, even if the elastic member is too thick, the viscous body may cause a change in the direction and speed of the flow to cause a reduced pressure state. Therefore, in the viscous material supply device according to the present invention, it is preferable that the thickness of the elastic member be 0.3 mm or less. If you look at the tip of the reservoir pan locally,
The viscous body flowing along the elastic member does not suddenly change direction or accelerate, and is less likely to be decompressed.

The elastic member is required to have appropriate elasticity and sufficient durability even if it is thin, but since it is inexpensive and easily available, a film-like elastic member is used. Is preferred.

In addition to attaching a film-like elastic member to the tip of the reservoir pan, in order to prevent the leakage of the viscous material, it is conceivable to form at least the tip of the reservoir pan with an elastic material. Thereby, even if the tip of the reservoir pan is brought into contact with the web, it elastically deforms itself and absorbs the vibration of the back roll and the change in the thickness of the web. This can also prevent the viscous body from leaking.

If the coating device is provided with the viscous material supply device having the above-described configuration, even when the coating speed on the web is increased or when the coating film is thickly coated, bubbles are not applied to the coating film. The smoothness and characteristics of the coating film can be kept good by preventing the mixture. Further, the maintainability of the coating device is improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a coating apparatus. In the drawing, reference numeral 10 denotes an unwinding unit that sends out the web W while holding the roll, 11 denotes an application unit that applies paint to one surface of the web W, 12 denotes a drying unit that dries the paint applied to the web W, 13 Is a winding section for winding up the web W after drying of the paint. Coating part 1 of these
1 is provided with a viscous material supply device according to the present invention.

FIG. 2 shows a schematic configuration of the viscous material supply device constituting the coating unit 11. In the drawing, reference numeral 21 is a web W
A roll for adjusting the thickness of a coating film formed on the web W; and 23, a reservoir bed for storing the paint C and supplying it to one surface of the web W as needed. Part). The paint C is supplied to the liquid storage bed 23 from a nozzle (not shown) provided directly above according to the consumption situation, or is appropriately added according to the consumption amount.

The back roll 21 is rotatably supported by driving means (not shown). The application roll 22 is supported in parallel to the back roll 21 but does not rotate, and is fixed with a slight gap provided between the coating roll 22 and the back roll 21. As the application roll 22, a comma roll, a doctor roll, or the like, which is generally called, is used. Although different in shape from these, a doctor knife or the like is also used.

The liquid storage bed 23 is inclined obliquely downward, and has a liquid storage pan 24 whose tip abuts against the outer peripheral surface of the back roll 21, and is raised on both sides of the liquid storage pan 24 (front and rear in a direction perpendicular to the paper surface). Side plate (not shown) and back roll 21
. Actually, a small gap is provided between the tip of the liquid storage pan 24 and the web W wound around the back roll 21 to enable the web W to be sent out, and the paint C leaks from this gap. A leakage prevention film (elastic member) 25 is attached to the tip of the liquid reservoir pan 24 from inside to prevent the leakage. In addition, polyethylene retephthalate (P.
It is preferable to select a material having excellent durability such as a polyethylene resin such as ET), a polypropylene resin, nylon, Teflon, and polyethylene laminated paper.

The tip of the liquid storage pan 24 is a back roll 2
It is curved with a predetermined radius of curvature R just before it abuts on 1. If the radius of curvature R is too small, the change in the flow direction of the paint C in the reservoir bed 23 becomes large, and the pressure tends to be reduced.
Is preferably 3 mm or more, more preferably in the range of 10 mm to 30 mm.

Also, the liquid storage pan 24 and the back roll 21
At the position where is closest, as shown in FIG.
The angle α between the tangent 1 of the tip 24 a of the reservoir pan 24 and the tangent m of the outer peripheral surface of the back roll 21 is set to be equal to or larger than a predetermined size inside the reservoir bed 23. If the angle α is too small, the change in the direction of the flow of the paint C in the reservoir bed 23 becomes large and the pressure is likely to be reduced, so that the angle α is included in the range of 90 ° or more and 180 ° or less. Is preferred.

The leak prevention film 25 is provided in the reservoir pan 24.
Are stuck out to the back roll 21 side from the tip of a certain amount. Further, the tip of the leakage prevention film 25 which is always in sliding contact with the back roll 21 is cut into a rectangular cross section (see FIG. 4A). Note that the thickness t of the leakage prevention film 25 should be 0.3 mm or less because the paint C may cause a change in the direction and speed of the flow even if the leakage prevention film 25 is too thick, which may cause a reduced pressure state. Is more preferable, and it is more preferable that it is included in the range of 0.05 mm to 0.2 mm.

The flow of a coating operation performed by the coating apparatus configured as described above will be described. The web W is held in a roll state by the unwinding unit 10, and is sequentially sent out from the roll by the operation of the back roll 21 and the winding unit 13.

When the web W reaches the application section 11 and enters the reservoir 3, the web W goes under the coating material C, so that the coating material C adheres to one surface in the same manner as when immersed. When the web W to which the coating material C is adhered is lifted from the reservoir bed 3, the back roll 21 and the application roll 22
And a coating film having a thickness corresponding to the gap between them is formed and sent out.

The web W having a predetermined coating film formed thereon is heated in the course of passing through the drying section 12 to dry the coating film. The web W after the drying of the paint C is taken up and rolled in the take-up section 13.

According to the above-mentioned coating apparatus, the angle α between the tangent of the top end 24a of the reservoir pan 24 and the tangent of the outer peripheral surface of the back roll 21 is set to a predetermined value or more. Even when the paint C that has moved along the pan 24 is accelerated in contact with the web W, a sudden change in the flow direction does not occur, and a reduced pressure state is less likely to occur.

Further, since the tip of the reservoir pan 24 is curved inside the reservoir bed 23 with a predetermined radius of curvature R, the paint C flowing along the reservoir pan 24 may have a sudden change in direction or direction. Acceleration does not occur, which also makes it difficult for a reduced pressure state to occur. Therefore, according to the above-described coating apparatus, air is not caught in the coating material C from the gap between the tip of the liquid storage pan 24 and the web W wound around the back roll 21 and sent out, thereby preventing generation of bubbles.

Further, the leakage preventing film 25 is protruded from the tip of the liquid storage pan 24 to the back roll 21 side, and the leakage preventing film 25 is adhered. 2
Since the gap is closed by being pressed against the outer peripheral surface of the first member, leakage from the gap does not occur. This prevents dirt around the device and failure of the device due to the leaked paint.

In this embodiment, the tip of the leakage prevention film 25 is cut into a rectangular shape as shown in FIG. 4A. However, the reduced pressure generated in the paint C can be obtained even if the flow direction and speed are slightly changed. Appears prominently. Therefore, as shown in FIG. 4B, by cutting the tip of the leakage prevention film 25 into a wedge shape, the paint C flowing along the leakage prevention film 25 when the tip of the reservoir pan 24 is viewed locally. Sudden direction change and acceleration do not occur, and a reduced pressure state is less likely to occur, so that further reduction in reduced pressure can be achieved.

In the present invention, the following embodiment can be adopted in addition to the above embodiment. FIG.
In the embodiment shown in (I), the liquid reservoir pan 24 is inclined obliquely downward at a certain angle toward the back roll 21, is bent at a certain position to be horizontal, and the tip is the outer periphery of the back roll 21 at the same angle. Face to face. The angle α between the tangent of the top end 24a of the reservoir pan 24 and the tangent of the outer peripheral surface of the back roll is set to 90 °, but other angles within the range of 90 ° to 180 °. You may choose. Further, it is preferable to attach a leakage prevention film in consideration of the leakage of the paint C.

In the embodiment shown in FIG. 5 (II), the liquid storage pan 24 is inclined obliquely downward at a certain angle toward the back roll 21, is bent at a certain position, and is inclined obliquely upward 45 °. The tip is abutted against the outer peripheral surface of the back roll 21 at an angle of. Although the angle α is set to 135 °, another angle may be selected as long as it is in the range of 90 ° to 180 °. In addition, paint C
It is preferable to attach a leakage prevention film in consideration of the leakage of the film.

In the embodiment shown in FIG. 5 (III), the reservoir pan 24 is inclined obliquely downward at a fixed angle toward the back roll 21 and is bent at a certain position to become vertical.
The leading end is in contact with the outer peripheral surface of the back roll 21. Angle α is set to 180 °. Also in this embodiment, it is preferable to attach a leakage prevention film in consideration of the leakage of the paint C.

In the embodiment shown in FIG. 5 (IV), the shape of the liquid storage pan 24 is the same as that of FIG. 2, but the whole pan is formed of an elastic body. It is in direct contact with the wound web W. In the present embodiment, even if the tip of the liquid storage pan 24 is brought into contact with the web W, it is elastically deformed to absorb the vibration of the back roll 21 and the change in the thickness of the web W. The leakage of the paint C can be prevented without sticking. Note that, in the present embodiment, the liquid reservoir pan 24 other than the tip may be formed of a rigid body as in the other embodiments, and only the tip may be formed of a resin or the like having excellent durability.

The liquid reservoir pan 24 in each of the embodiments shown in FIGS. 1 to 5 is assumed to be formed by bending a steel plate. However, the present invention is not limited to this. The liquid storage pan may be formed by performing the processing. In addition, not only a steel plate and a steel material but also a resin reservoir may be formed by resin molding or resin shaving.

[0042]

EXAMPLE A coating test was carried out using several types of reservoir pans 24 having different shapes ((A) to (F)), and the degree of air bubble generation in the reservoir bed 23 and the drying section 12 were examined.
The degree of bubble generation in the coating film after passing through was observed. The characteristics of each of the shapes (A) to (F) of the liquid reservoir pan 24 are as follows. (A): a flat plate that is provided in a conventional coating apparatus and that is inclined obliquely downward at a certain angle from the paint input side,
The tip is abutted against the outer peripheral surface of the back roll 21 at the same angle. The angle α is 70 °, and a leak prevention film having a thickness t: 0.05 mm is attached to the tip. (B): It is a flat plate obliquely inclined downward at a certain angle from the paint input side, and its tip is curved inside the liquid reservoir bed 23 with a radius of curvature R; The angle α is 135 °, and a leak prevention film having a thickness t of 0.05 mm is attached to the tip. (C): A flat plate that is inclined obliquely downward at a certain angle from the paint input side, and its tip is curved inside the reservoir bed 23 with a radius of curvature R: 20 mm. The angle α is 90 °, and a leakage prevention film having a thickness t of 0.05 mm is attached to the tip. (D): A flat plate that is inclined obliquely downward at a certain angle from the paint input side, and its tip is curved inside the reservoir bed 23 with a radius of curvature R: 20 mm. The angle α is 135 °, and a leak prevention film having a thickness t of 0.3 mm is attached to the tip. (E): A flat plate that is inclined obliquely downward at a certain angle from the paint input side, and its tip is curved inside the liquid reservoir bed 23 with a radius of curvature R: 20 mm. The angle α is 135 °, and a leakage prevention film having a thickness t of 0.2 mm is attached to the tip. (F): It is a flat plate inclined obliquely downward at a certain angle from the paint input side, and its tip is curved inside the liquid reservoir bed 23 with a radius of curvature R: 20 mm. The angle α is 135 °, and a leak prevention film having a thickness t of 0.05 mm is attached to the tip.

The specifications of the structural components other than the reservoir pan are as follows. Diameter of back roll 21; 300 mm; diameter of application roll 22 150 mm; angle of discharge of adhesive from liquid storage bed 23; 50 °; gap between back roll 21 and application roll 22;

FIG. 6 shows that, for each of the liquid storage pans (A) to (F), a paint having a viscosity of 8 Pa · s was used and the web W was fed at a feed speed of 25 m / min, 27 m / min, and 30 m / min. The results of a coating test performed with various values are shown. In addition, the degree of bubble generation was evaluated on four scales of × (; unacceptable), Δ (; acceptable, but close to the limit, which can be practically used), （(good), and ◎ (excellent).

As can be seen from FIG.
At m / min, almost no air bubbles were generated in both the conventional sump pan and the sump pan according to the present invention, and the state of the coating film was stable and good results were obtained. At a feeding speed of 27 m / min, a large amount of air bubbles were generated in the conventional type and the state became unsuitable for practical use. However, in the type according to the present invention, the state of the coating film was stable and good results were maintained. I was dripping. At a feeding speed of 30 m / min, some of the molds in which the present invention was carried out generated bubbles and the state of the coating film became slightly unstable, but generally good results were maintained.

FIG. 7 is a photograph of the state of the coating film (after passing through the drying unit 12) at a feeding speed of 30 m / min using the conventional liquid reservoir pan (A). FIG. 8 is a photograph of the state of the coating film (after passing through the drying unit 12) at a feeding speed of 30 m / min using the liquid pan (F) embodying the present invention. As is apparent from a comparison between FIG. 7 and FIG. 8, even if the feeding speed is increased to a level that was difficult to implement in the conventional type, the generation of air bubbles is remarkably suppressed according to the present invention.

REFERENCE EXAMPLE In the present invention, the present inventors have devised several analytical models of reservoir pans having different shapes, and have analyzed the flow of viscous material in the reservoir bed using a computer. In the analysis, a two-dimensional analysis model shown in FIG. 9 was adopted, and a part surrounded by a broken line in the figure was set as a calculation area. Conditions common to all analysis models include the diameter of the back roll 21 as in the embodiment;
0 mm, diameter of application roll 22 150 mm, liquid storage bed 2
The discharge angle β of the viscous material from 3; 50 °, the back roll 2
The gap between 1 and the application roll 22 was set to 0.15 mm. Further, since the viscous material is consumed by being applied, a virtual supply port for the viscous material is set at the rear end of the reservoir bed 23. In addition, in order to minimize the influence on the flow of the viscous material, the position of the virtual supply port is set at the rear end of the liquid storage pan 23 farthest from the back roll 21, and the flow rate of the viscous material in the virtual supply port is further reduced. Therefore, the size of the virtual supply port is set to 5 mm, which is larger than the gap.

As the analysis software, the general-purpose fluid analysis software “FLUNET version 5.3” manufactured by FLUNET was used. The parameters used for the calculation were the shape of the reservoir pan, the speed of feeding the web, the viscosity of the viscous material, and the finite volume. Numerical analysis was performed by the method. For the boundary conditions necessary for using the software, see the virtual supply port; PressureIn
let, viscous (coating) outlet; Pressure Outlet, open air surface; Symmetry. The RSM model was used as a turbulence model.

FIG. 10 shows the shape of the analysis model of the liquid storage pan 24 analyzed. In the figure, (a) is a model of a standard shape of a liquid storage pan 24 provided in a conventional coating apparatus, and the liquid storage pan 24 is inclined obliquely downward at a certain angle from a virtual supply port. It is a flat plate, and its tip is abutted on the outer peripheral surface of the back roll 21 at the same angle. The angle between the tangent at the tip of the reservoir pan 24 and the tangent at the outer peripheral surface of the back roll 21 is 70 °.

The reservoir pan 24 shown in FIG. 5B is a flat plate inclined obliquely downward at a predetermined angle from the virtual supply port, and its tip is curved inside the reservoir bed 23 with a radius of curvature: 20 mm. I have. The angle formed by the tangent at the forefront of the reservoir pan 24 and the tangent at the outer peripheral surface of the back roll 21 is 180 ° (the tangents coincide).

The liquid storage pan 24 shown in FIG. 3C is inclined obliquely downward at a certain angle from the virtual supply port, is bent at a certain position to be horizontal, and has its tip attached to the outer peripheral surface of the back roll 21 at the same angle. Butt. The angle between the tangent at the tip of the reservoir pan 24 and the tangent at the outer peripheral surface of the back roll 21 is 90 °.

The liquid storage pan 24 shown in (d) in the figure inclines obliquely downward at a certain angle from the virtual supply port, is bent at a certain position and inclines obliquely upward 45 °, and the tip is back rolled at the same angle. 21 against the outer peripheral surface. The angle between the tangent at the tip of the reservoir pan 24 and the tangent at the outer peripheral surface of the back roll 21 is 135 °.

The analysis was performed on each of the above analytical models, with the web feeding speed; 20 m / min, and the viscosity of the viscous material: 7 Pa · s. The pressure distribution in the viscous body in each of the analysis models of FIGS. 10 (a), (b), (c), and (d) is shown in FIGS. 11, 12, 13, and 14, respectively. The state of streamlines in the body is shown in FIGS.
These are shown in FIGS. 17 and 18, respectively. Each figure showing the pressure distribution is an enlarged view of the vicinity of the contact point between the tip of the liquid pan 24 and the back roll 21.
Gauge pressure display.

Looking at the pressure distributions in FIGS.
In the analysis model (a) representing the conventional sump pan,
It can be seen that extreme decompression occurs near the contact point between the tip of the reservoir pan and the web wound on the back roll. In other analysis models, the degree of decompression is suppressed as compared with (a). Arranging each analysis model in descending order of degree of decompression,
(A), (c), (d), and (b). From this analysis result, it is expected that the smaller the angle between the tangent of the top of the reservoir pan and the tangent of the outer peripheral surface of the back roll, the higher the degree of decompression will be. The effect of the present invention of preventing the generation of bubbles by suppressing the degree of pressure reduction by increasing the angle formed by the tangent to the outer peripheral surface of the roll is confirmed.

Looking at the state of the streamlines in FIGS. 15 to 18, in the analysis model (a) representing the conventional reservoir pan, the viscous material suddenly drops at the boundary between the tip of the reservoir pan and the back roll. It can be seen that the direction of the flow changes. In other analysis models, the flow direction does not change abruptly as compared with (a), and especially in (b), the arc drawn by the streamline is smooth. From this, it is expected that (b) is the best among the analysis models.

Although the leak prevention film is not considered in each analysis model of FIG. 10, when the leak prevention film is attached to the tip of the reservoir pan, the degree of pressure reduction is higher than in the case where this is not considered. It is expected to be.
This is because a flow similar to the boundary of the analysis model (c) is considered to be generated in this portion by forming the tip of the leakage prevention film cut vertically when viewed locally. .

Therefore, a new analysis model in which a leakage prevention film was attached to the analysis model (b) was newly set, and the same analysis was performed by changing the thickness of the leakage prevention film and the shape of the tip. FIG. 19 shows the pressure distribution when a leak prevention film having a thickness t of 0.2 mm is attached to (b), and FIG. 20 shows the pressure distribution of the leak prevention film having a thickness t; The pressure distribution when the tip is cut into a wedge-shaped cross section at an angle of 45 ° is shown. FIG. 21 (b) shows the pressure distribution when a leak prevention film having a thickness t of 0.05 mm is attached to (b). Each of the drawings is a local view centered on the tip of the leakage prevention film.

Looking at the pressure distributions in FIGS.
It is expected that the degree of decompression near the tip of the leakage prevention film will be reduced by cutting the tip of the leakage prevention film into a wedge shape or by making the leakage prevention film thinner. The effect of the present invention in which the degree of decompression is suppressed low and the generation of bubbles is prevented by cutting into a wedge shape is supported.

[0059]

As described above, according to the present invention,
When coating on the web, the coating speed can be improved, and the incorporation of bubbles into the coating film can be prevented, so that the durability and properties of the coating film can be kept good. Further, the maintainability of the coating device is improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a coating apparatus according to the present invention.

FIG. 2 is a schematic view showing a viscous material supply device constituting the application unit of FIG. 1;

FIG. 3 is an explanatory diagram showing a relationship between a back roll and a liquid storage pan.

FIG. 4 is a cross-sectional view showing a tip shape of the leakage prevention film.

FIG. 5 is a schematic diagram showing another embodiment of a viscous material supply device constituting a coating unit.

FIG. 6 shows a result of a coating test performed on each of the liquid storage pans having different shapes (A) to (F) by using a paint having a viscosity of 8 Pa · s and changing a web sending speed in three stages. FIG.

FIG. 7 is a view showing a state of a coating film when the feeding speed is 30 m / min using a conventional liquid reservoir pan (A).

FIG. 8 is a view showing a state of a coating film when a feeding speed is set to 30 m / min using a liquid storage pan (F) embodying the present invention.

FIG. 9 is a diagram showing an outline of an analysis model adopted in performing a flow analysis of a viscous body in a liquid storage bed.

FIG. 10 is a diagram showing the shape of each analysis model of (a) to (d).

FIG. 11 is a diagram showing a pressure distribution in a viscous body in the analysis model (a).

FIG. 12 is a diagram showing a pressure distribution in a viscous body in the analysis model (b).

FIG. 13 is a diagram showing a pressure distribution in a viscous body in the analysis model (c).

FIG. 14 is a diagram showing a pressure distribution in a viscous body in the analysis model (d).

FIG. 15 is a diagram showing streamlines of a viscous body in the analysis model (a).

FIG. 16 is a diagram showing streamlines of a viscous body in the analysis model (b).

FIG. 17 is a diagram showing streamlines of a viscous body in the analysis model (c).

FIG. 18 is a diagram showing streamlines of a viscous body in the analysis model (d).

FIG. 19 is a diagram showing a pressure distribution when a leakage prevention film having a thickness of t: 0.2 mm is attached to the analysis model (b).

FIG. 20 is a diagram showing a pressure distribution when the tip of a leak prevention film having a thickness t of 0.2 mm is cut into a wedge-shaped cross section at an angle of 45 ° in the analysis model (b).

FIG. 21 is a view showing a pressure distribution when a leakage prevention film having a thickness t of 0.05 mm is attached to the analysis model (b).

FIG. 22 is a schematic configuration diagram illustrating an example of a conventional paint supply device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 unwinding part 11 coating part 12 drying part 13 winding part 21 back roll 22 coating roll 23 liquid storage bed (liquid storage part) 24 liquid storage pan 25 leakage prevention film (elastic member)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuo Ashita 3-37-15 Bessho, Urawa-shi, Saitama (72) Inventor Hiroyasu Udagawa 278 Koizumi, Ageo-shi, Saitama (72) Inventor Masayuki Nakamura Kita, Omiya-shi, Saitama 1-299-8-609 Fukuromachi F term (reference) 4F040 AA22 AC01 BA47 CC12 4F042 AA22 DD03 DD09 DD46

Claims (9)

[Claims] 1. While feeding a long belt-shaped web in a length direction along a back roll, a liquid viscous body is supplied from a liquid reservoir provided adjacent to the back roll to provide one surface of the web. A viscous material supply device that adheres to the liquid reservoir, wherein the liquid reservoir has a liquid reservoir pan whose tip is disposed close to the outer peripheral surface of the back roll, and the liquid reservoir pan has a liquid reservoir that has a tip. A viscous body supply device characterized by being curved inward. 2. The viscous material supply according to claim 1, wherein the tip of the liquid storage pan is curved with a predetermined radius of curvature, and the predetermined radius of curvature is set to 3 mm or more. apparatus. 3. A liquid viscous material is supplied from a liquid reservoir provided adjacent to the back roll while feeding the long belt-like web in the length direction along the back roll, and one surface of the web is provided. A viscous material supply device that adheres to the liquid reservoir, wherein the liquid reservoir has a liquid reservoir pan whose tip is arranged close to the outer peripheral surface of the back roll, and the liquid reservoir pan and the back roll are most attached. At the close position, the angle between the tangent of the top of the reservoir pan and the tangent of the outer peripheral surface of the back roll is 90 degrees inside the reservoir.
A viscous material supply device characterized by being set to {not less than 180 °}. 4. The viscous material supply device according to claim 1, wherein an elastic member is attached so as to protrude from the tip of the liquid storage pan toward the back roll side. 5. The viscous body supply device according to claim 4, wherein a tip of said elastic member is formed in a wedge-shaped cross section. 6. The viscous body supply device according to claim 4, wherein the thickness of the elastic member is 0.3 mm or less. 7. The viscous material supply device according to claim 4, wherein the elastic member is in the form of a film. 8. The liquid storage device according to claim 1, wherein at least a tip of the liquid storage pan is formed of an elastic body.
4. The viscous material supply device according to 2 or 3. 9. A coating apparatus comprising the viscous body supply device according to claim 1, 2, 3, 4, 5, 6, 7, or 8.