Curtain shape spray coating device and method

Abstract

To provide a curtain shape spray coating device and method capable of coating to a correct region, when performing intermittent coating of a hot melt adhesive agent.SOLUTION: A curtain shape spray coating device A comprises: a compressed air supply part 2 for supplying compressed air K to an air injection hole 36; and an electromagnetic valve 1 which is provided on a channel 4 for supplying the compressed air K to the air injection hole 36 from the compressed air supply part 2, and switching a communication state of the channel 4. When a state where a hot melt adhesive agent h is discharged from a coating nozzle hole group 32, is an on state, a state where discharge of the hot melt adhesive agent h is stopped from the coating nozzle hole group 32, is an off state, when switching is performed from the on state to the off state, the electromagnetic valve 1 causes the channel 4 to become in an interruption state, so that injection of the compressed air K from the air injection hole 36, is stopped.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a curtain spray coating apparatus and method. [Background technology]

[0002] 2. Description of the Related Art A known technique involves spraying pressurized air at hot melt adhesive that is discharged from an application nozzle hole and falls, thereby forming the hot melt adhesive into long, thin fibers and applying the adhesive to an object.

[0003] Patent Documents 1 and 2 disclose a curtain-like spray coating device as a technique for coating a fibrous hot melt adhesive in a wide thin film on an object to be coated. In the curtain-like spray coating device in these documents, pressurized air is sprayed from an air injection hole onto the hot melt adhesive discharged from a group of coating nozzle holes in which a large number of coating nozzle holes are arranged in a row, and the hot melt adhesive in the form of elongated fibers falls in a row, performing "curtain-like spray coating." Specifically, as shown in FIG. 6, the hot melt adhesive h' sprayed in a curtain shape falls toward the object to be coated 100, and the object to be coated 100 is transported in a constant transport direction X by a transport device C, so that a thin-film coating surface H can be formed on the object to be coated 100.

[0004] Such a curtain-type spray coating device has advantages such as being able to shorten the bonding process of the hot melt adhesive, not needing a pretreatment process such as a primer, and not needing a drying process after the adhesive is applied. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3278664 [Patent Document 2] Patent No. 3661019 Summary of the Invention [Problem to be solved by the invention]

[0006] For the purpose of continuously manufacturing articles having a thin-film coating surface H of a hot melt adhesive, intermittent coating has been conventionally performed by intermittently performing curtain-like spray coating on a coating object 100 as shown in Figures 3 and 5. By performing intermittent coating, a coating surface H can be formed on the coating object 100 at predetermined intervals.

[0007] However, in the conventional curtain-type spray application device A' as exemplified in FIG. 4, there is a problem that the application surface H onto which the hot melt adhesive is actually applied extends backward in the conveying direction X with respect to the target area T to be applied, as shown in FIG.

[0008] The present disclosure has been made in consideration of the above-mentioned circumstances regarding curtain-type spray application devices, and aims to provide a curtain-type spray application device and application method that can apply hot melt adhesive to precise areas when intermittently applying the adhesive. [Means for solving the problem]

[0009] In order to solve the above problems, the curtain-type spray coating device disclosed herein is a curtain-type spray coating device that sprays pressurized air from an air injection hole at hot melt adhesive discharged from a coating nozzle hole group in which a plurality of coating nozzle holes are arranged in a row, thereby applying the adhesive in a fibrous form onto an object to be coated, and is characterized in that it is equipped with a pressurized air supply unit that supplies pressurized air to the air injection hole, and an electromagnetic valve that is provided in a flow path that supplies pressurized air from the pressurized air supply unit to the air injection hole and switches the open state of the flow path, and when the adhesive is being discharged from the coating nozzle hole group, it is in an on state, and when the discharge of the adhesive from the coating nozzle hole group is stopped, it is in an off state, and when switched from the on state to the off state, the electromagnetic valve closes the flow path, thereby stopping the spray of pressurized air from the air injection hole.

[0010] In the above curtain-type spray coating device, the solenoid valve may be a three-port valve, and in the off state, the pressurized air supplied from the pressurized air supply unit may be exhausted from the solenoid valve.

[0011] In order to solve the above problems, the coating method disclosed herein is a coating method using a curtain-type spray coating device in which hot melt adhesive is discharged from a coating nozzle hole group in which a plurality of coating nozzle holes are arranged in a row, and pressurized air is sprayed from an air injection hole to apply the fibrous adhesive onto an object to be coated, and is characterized in that when the adhesive is being discharged from the coating nozzle hole group, an on state is defined as a state when the adhesive is being discharged from the coating nozzle hole group, and when the discharge of the adhesive from the coating nozzle hole group is stopped, the spray of pressurized air from the air injection hole is stopped when the on state is switched to the off state. Effect of the Invention

[0012] The curtain-like spray coating device and coating method of the present disclosure provide excellent effects, such as the ability to coat hot melt adhesive in precise areas when intermittently coating the adhesive. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic diagram of a curtain-like spray coating apparatus according to an embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view showing a schematic view of a coating device body according to the present embodiment, taken along the depth direction of FIG. 1. [Diagram 3] 1 is a plan view showing a schematic diagram of a coating surface H being formed on a target area T to be coated in this embodiment. [Figure 4] FIG. 1 is a cross-sectional view showing a schematic example of a conventional curtain-type spray coating device. [Diagram 5] FIG. 1 is a plan view showing a conventional curtain-type spray coating device in which a coating surface H is formed extending beyond a target area T to be coated. [Figure 6]FIG. 1 is a perspective view showing a schematic diagram of a curtain-like spray coating device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the curtain-like spray coating apparatus and coating method of the present disclosure will be described.

[0015] Fig. 1 is a cross-sectional view showing a curtain-type spray coating apparatus A according to this embodiment, and Fig. 2 is a cross-sectional view showing a coating apparatus main body 3 according to this embodiment, cut along the depth direction of Fig. 1. Note that W in Fig. 1 indicates the coating width of a coating surface H formed on a coating target 100. The direction perpendicular to this width direction is the conveying direction X in Fig. 2.

[0016] As shown in Fig. 1, the curtain-like spray coating apparatus A according to this embodiment includes a pressurized air supply unit 2 and a flow path 4. The air injection holes 36 and the pressurized air supply unit 2 included in the coating apparatus main body 3 shown in Fig. 2 are connected by the flow path 4, and the pressurized air K flows through the flow path 4, whereby the pressurized air K is supplied from the pressurized air supply unit 2 to the air injection holes 36. The structure of the flow path 4 is not particularly limited as long as it is a structure that can send the pressurized air K to the air injection holes 36. For example, by providing a pipe that connects the pressurized air supply unit 2 and the coating apparatus main body 3 (air injection holes 36), this pipe can be used as the flow path 4.

[0017] As shown in Figures 1 and 2, in the coating device main body 3, pressurized air K is sprayed from air injection holes 36 onto hot melt adhesive h discharged from a coating nozzle hole group 32 in which a plurality of coating nozzle holes are arranged in a row. This causes the hot melt adhesive h to become elongated fibers, which are sprayed in a curtain shape as indicated by the symbol "h'" in Figure 1 and applied onto the coating object 100. Since the coating object 100 is transported in a constant transport direction X as shown in Figure 2, a coating surface H is formed on the coating object 100 on which the hot melt adhesive is applied in a thin film form.

[0018] The applicator body 3 includes a nozzle unit 31 having a coating nozzle hole group 32, and an adhesive supply unit 33 that supplies the hot melt adhesive h to be discharged from the coating nozzle hole group 32. The applicator body 3 also includes a valve chamber 35 and a valve body 34 that is provided so as to be able to move up and down within the valve chamber 35. As shown in FIG. 2, the valve body 34 can be moved up and down by feeding valve operating air K1 or K2 into the valve chamber 35. The up and down movement of the valve body 34 can switch between a state in which the hot melt adhesive h is supplied from the adhesive supply unit 33 to the coating nozzle hole group 32 and a state in which the supply is stopped, and further, can switch between a state in which the hot melt adhesive h is discharged from the coating nozzle hole group 32 (ON state) and a state in which the discharge is stopped (OFF state).

[0019] 4 is a cross-sectional view showing a schematic example of a conventional curtain-type spray coating apparatus A'. The conventional curtain-type spray coating apparatus A' also includes a pressurized air supply unit 2, a coating apparatus main body 3, and a flow path 4, and is designed so that the discharge of the hot melt adhesive h by the coating apparatus main body 3 is automatically switched between an on state and an off state.

[0020] When performing intermittent application of the hot melt adhesive h using the conventional curtain-like spray application device A', the application device main body 3 alternately switches between an on state and an off state of the hot melt adhesive h discharge. As a result, as shown in FIG. 5, a coating surface H can be formed on the coating target 100 at predetermined intervals. However, in the conventional curtain-like spray application device A', even if the discharge of the hot melt adhesive h is turned off (even if the discharge of the hot melt adhesive h from the application nozzle hole group 32 is stopped), the pressurized air K is always supplied to the air injection hole 36 from the pressurized air supply unit 2. In other words, even if the discharge of the hot melt adhesive h is turned off, the pressurized air K continues to be injected from the air injection hole 36. Due to this, as shown in FIG. 5, there is a problem that the application surface H of the hot melt adhesive protrudes backward in the conveying direction X from the target area T to be coated when intermittent application is performed.

[0021] In contrast, the curtain-shaped spray coating device A according to this embodiment includes an electromagnetic valve 1 that switches the open state of the flow path 4, as shown in FIG. 1. The electromagnetic valve 1 is in an on state when the hot melt adhesive h is being discharged from the coating nozzle hole group 32, and in an off state when the discharge of the hot melt adhesive h from the coating nozzle hole group 32 is stopped. When the electromagnetic valve 1 is switched from the on state to the off state, the flow path 4 is closed. Therefore, when the electromagnetic valve 1 is switched from the on state to the off state, the supply of the pressurized air K to the air injection hole 36 is stopped, and the injection of the pressurized air K is also stopped. This makes it possible to suppress the occurrence of a phenomenon (so-called tailing) in which the coating surface H continues to be formed on the coating target 100 even after the discharge of the hot melt adhesive h is switched to the off state. As a result, as shown in FIG. 3, the coating surface H can be accurately formed on the target area T to be coated when intermittent coating is performed.

[0022] In intermittent application, after the discharge of the hot melt adhesive h is turned off, the discharge is turned on again, so that it is necessary to resume the injection of the pressurized air K from the air injection hole 36 in accordance with the switching from the off state to the on state. Therefore, in the curtain-shaped spray application device A according to this embodiment, when the discharge of the hot melt adhesive h is switched from the off state to the on state, the solenoid valve 1 opens the flow path 4. Note that the solenoid valve 1 may open the flow path 4 at the same time as the discharge of the hot melt adhesive h is switched to the on state, or the solenoid valve 1 may open the flow path 4 before the switching to the on state, and the pressurized air K may be injected from the air injection hole 36 when the discharge of the hot melt adhesive h is started.

[0023] The means for controlling the timing of switching the open state of the flow path 4 by the solenoid valve 1 is not particularly limited, but examples include a method of electrically connecting the solenoid valve 1 and the application device main body 3 so as to be linked to the switching on and off state of the discharge of the hot melt adhesive h from the application device main body 3, and a method of providing a control unit that automatically controls the timing of switching the open state of the flow path 4 by the solenoid valve 1 and the timing of switching the on and off state of the discharge of the hot melt adhesive h from the application device main body 3 in a unified manner.

[0024] In the curtain-type spray coating device A according to this embodiment, the solenoid valve 1 is a three-port valve. By using the solenoid valve 1 as a three-port valve, when the discharge of the hot melt adhesive h from the coating device main body 3 is in an off state, the pressurized air K supplied from the pressurized air supply unit 2 to the flow path 4 can be exhausted from the solenoid valve 1 as shown in FIG.

[0025] According to the curtain-type spray applicator A of this embodiment, the hot melt adhesive h can be applied to a precise area when it is applied intermittently. As a result, the quality of the product (the object 100 to be applied having the application surface H) can be improved. In addition, the loss of the hot melt adhesive h can be reduced, and the number of maintenance steps such as cleaning the production line can be drastically reduced, resulting in excellent cost performance.

[0026] The hot melt adhesive h used in the curtain-shaped spray coating device A of this embodiment is not particularly limited, but a urethane-based reactive hot melt adhesive (PUR) and an olefin-based reactive hot melt adhesive (POR) can be used, making it possible to manufacture products with excellent adhesion, heat resistance, and weather resistance.

[0027] According to the curtain-type spray coating device A of this embodiment, a coating method can be implemented in which the spraying of pressurized air K from the air injection hole 36 is stopped when the discharge of hot melt adhesive h from the coating nozzle hole group 32 is switched from an on state to an off state.

[0028] It should be noted that the embodiments disclosed herein are illustrative in all respects and are not intended to be a basis for a restrictive interpretation. Therefore, the technical scope of the present disclosure is not interpreted solely by the above-described embodiments, but is defined based on the claims. Also, all modifications within the scope and meaning equivalent to the claims are included.

[0029] For example, in the curtain-type spray coating apparatus A shown in FIG. 1, the solenoid valve 1 is provided independently between the pressurized air supply unit 2 and the coating apparatus main body 3, but the solenoid valve 1 may be included in the pressurized air supply device serving as the pressurized air supply unit 2. [Explanation of symbols]

[0030] 1 Solenoid valve 2. Pressurized air supply 3 Coating device body 31 Nozzle unit 32 Coating nozzle hole group 33 Adhesive supply section 34 Valve body 35 Valve chamber 36 Air Jet Hole 4 Flow Path 100 Coating object A Curtain-type spray coating device C. Conveyor device h Hot melt adhesive h' Hot melt adhesive sprayed in a curtain shape H Hot melt adhesive coating surface K. Compressed air K1 Valve operation air K2 Valve operation air T Target area to be coated X conveying direction W Coating width

Claims

1. A curtain-type spray coating device that applies a fibrous hot melt adhesive onto an object to be coated by injecting pressurized air from an air injection hole onto the hot melt adhesive discharged from a coating nozzle hole group in which a plurality of coating nozzle holes are arranged in a row, a pressurized air supply unit that supplies pressurized air to the air injection hole; an electromagnetic valve that is provided in a flow path for supplying pressurized air from the pressurized air supply unit to the air injection hole and switches an open state of the flow path; When the adhesive is being discharged from the application nozzle hole group, the state is set to be on, and when the discharge of the adhesive from the application nozzle hole group is stopped, the state is set to be off. A curtain-type spray coating device characterized in that when the on state is switched to the off state, the solenoid valve closes the flow path, thereby stopping the spray of pressurized air from the air injection hole.

2. 2. The curtain spray coating apparatus of claim 1, The solenoid valve is a three-port valve, The curtain-type spray coating device, wherein in the off state, the pressurized air supplied from the pressurized air supply unit is exhausted from the solenoid valve.

3. A coating method using a curtain-type spray coating device, in which pressurized air is sprayed from an air injection hole onto a hot melt adhesive discharged from a coating nozzle hole group in which a plurality of coating nozzle holes are arranged in a row, so that the adhesive becomes fibrous and is applied onto an object to be coated, When the adhesive is being discharged from the application nozzle hole group, the state is set to be on, and when the discharge of the adhesive from the application nozzle hole group is stopped, the state is set to be off. a coating method comprising: stopping the injection of pressurized air from the air injection hole when the on state is switched to the off state.

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