Coating method and coating apparatus

Abstract

To provide a technology which can prevent a hot melt adhesive from being applied to a designed non-application range.SOLUTION: In an application method, a hot melt adhesive is intermittently applied from a coating gun to an object to be coated (coated object) transported in a given direction. The coating gun has a discharge port which discharges the hot melt adhesive. The application method includes: a first step in which the discharge port is placed in contact with the coated object in an application state where the hot melt adhesive is applied to the coated object; and a second step in which a pressure is applied to the coated object from below to filter the hot melt adhesive accumulated at the downstream side of the discharge port when the application state is switched to a non-application state where the hot melt adhesive is not applied to the coated object.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a coating method and a coating apparatus.

Background Art

[0002] In the manufacturing process of absorbent articles such as disposable diapers, urine pads, and sanitary products, a hot melt adhesive is intermittently applied to an object to be coated, such as a sheet material, which is conveyed in a certain direction (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The hot melt adhesive is applied from a coating gun to the object to be coated in a state where the solid raw material is heated and melted. The hot melt adhesive is applied with the discharge port of the coating gun in contact with the object to be coated. Since the hot melt adhesive has a high viscosity even in a melted state, there is a risk that the hot melt adhesive that cannot completely cover the sheet material will accumulate on the downstream side of the discharge port of the coating gun in the conveyance direction. When attempting to apply the hot melt adhesive intermittently, if the hot melt adhesive accumulates on the downstream side of the discharge port in the conveyance direction, a trailing phenomenon will occur where the coating gun drags the accumulated hot melt adhesive, and in terms of design, the hot melt adhesive will be applied even to the non-application range where the hot melt adhesive is not supposed to be applied.

[0005] An object of the present invention is to provide a technique that can prevent the hot melt adhesive from being applied to the non-application range in terms of design.

Means for Solving the Problems

[0006] In order to solve the above problems, in the present invention, when switching the hot melt adhesive from the applied state to the non-applied state, the hot melt adhesive accumulated on the downstream side of the discharge port is filtered off.

[0007] Specifically, the present invention is a coating method for intermittently coating a workpiece conveyed in a certain direction with a hot melt adhesive from a coating gun. The coating gun has a discharge port for discharging the hot melt adhesive. In the coating state where the hot melt adhesive is applied to the workpiece, a first step of bringing the discharge port into contact with the workpiece, and when switching from the coating state to a non-coating state where the hot melt adhesive is not applied to the workpiece, applying pressure from below to the workpiece to filter off the hot melt adhesive accumulated on the downstream side of the discharge port, and a second step.

[0008] In the above coating method, a roller that is movable up and down is provided below the workpiece and on the downstream side of the discharge port, and the roller rotates in the conveyance direction of the workpiece in synchronization with the conveyance speed of the workpiece. In the first step, the roller is in contact with the workpiece at a predetermined position. In the second step, the roller contacts the workpiece above the predetermined position to apply pressure to the workpiece, and the hot melt adhesive accumulated on the downstream side of the discharge port is filtered off. The coating method may further include a third step of separating the workpiece from the discharge port by lowering the roller after filtering off the hot melt adhesive.

[0009] In the above coating method, a roller that rotates in the conveyance direction of the workpiece to be coated in synchronization with the conveyance speed of the workpiece to be coated is disposed below the workpiece to be coated and on the downstream side of the discharge port. The roller has a circumferential portion corresponding to the length of the application range of the hot melt adhesive to the workpiece to be coated, an enlarged diameter portion having a diameter larger than that of the circumferential portion, which applies pressure to the workpiece to be coated and filters the hot melt adhesive accumulated on the downstream side of the discharge port, and a reduced diameter portion having a diameter smaller than that of the circumferential portion, which is disposed so as to face the workpiece to be coated after the enlarged diameter portion. In the first step, the discharge port is brought into contact with the workpiece to be coated by causing the workpiece to be coated to follow the circumferential portion. In the second step, pressure is applied to the workpiece to be coated by the enlarged diameter portion to filter the hot melt adhesive accumulated on the downstream side of the discharge port. The coating method may include a third step of separating the discharge port from the workpiece to be coated by directing the reduced diameter portion toward the workpiece to be coated after filtering the hot melt adhesive.

[0010] In the above coating method, in the second step, the hot melt adhesive may be filtered by applying compressed air to the workpiece to be coated from below the workpiece to be coated.

[0011] In the above coating method, the workpiece to be coated is a sheet material for absorbent articles, and the hot melt adhesive may be blended with a material that changes color when it comes into contact with excrement.

[0012] In addition, the present invention can be grasped from the side of the coating apparatus. For example, the present invention is a coating apparatus that intermittently applies a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, the coating gun having a discharge port for discharging the hot melt adhesive, the coating gun being configured to bring the discharge port into contact with the workpiece in a coating state in which the hot melt adhesive is applied to the workpiece, and a filtering means for filtering the hot melt adhesive accumulated on the downstream side of the discharge port by applying pressure to the workpiece from below when switching from the coating state to a non-coating state in which the hot melt adhesive is not applied to the workpiece.

Advantages of the Invention

[0013] According to the present invention, it is possible to prevent the hot melt adhesive from being applied to the non-coating range in the design.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

[0016] <Outline of the Coating Method> The coating method according to this embodiment is a method of intermittently applying a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction. Examples of the workpiece to be coated include sheet materials used for absorbent articles such as disposable diapers, urine pads, and sanitary products. In a manufacturing line for manufacturing absorbent articles, a hot melt adhesive is applied to a sheet material for absorbent articles that is conveyed in a certain direction. The hot melt adhesive is applied to the designed coating range (hereinafter referred to as the "coating range") and may be intermittently applied to the sheet material so as not to be applied to the designed non - coating range (hereinafter referred to as the "non - coating range"). The coating range and the non - coating range are continuous in the conveying direction of the sheet material. When the coating range of the sheet material passes under the coating gun, the hot melt adhesive is discharged from the coating gun, and when the non - coating range of the sheet material passes under the coating gun, the hot melt adhesive is not discharged from the coating gun. Thereby, the hot melt adhesive is intermittently applied to the sheet material conveyed in a certain direction. It may be intermittently applied to the sheet material so that it is applied to the designed coating range (hereinafter referred to as the "coating range") and not applied to the designed non - coating range (hereinafter referred to as the "non - coating range"). The coating range and the non - coating range are continuous in the conveying direction of the sheet material. When the coating range of the sheet material passes under the coating gun, the hot melt adhesive is discharged from the coating gun, and when the non - coating range of the sheet material passes under the coating gun, the hot melt adhesive is not discharged from the coating gun. Thereby, the hot melt adhesive is intermittently applied to the sheet material conveyed in a certain direction.

[0017] Also, in the coating method according to this embodiment, the discharge port of the coating gun is brought into contact with the sheet material in the coating state where the hot melt adhesive is applied to the sheet material. Different from this, when the hot melt adhesive is applied without bringing the discharge port of the coating gun into contact with the sheet material, the hot melt adhesive is applied by spraying, and when the hot melt adhesive is intermittently applied, the hot melt adhesive cannot be cleanly applied at the end portion. Therefore, when it is necessary to intermittently apply the hot melt adhesive (such as when it is necessary to provide a non - adhesive area or when applying a hot melt adhesive containing a coloring substance for forming an indicator), it is preferable to bring the coating gun into contact with the sheet material as in the coating method according to this embodiment.

[0018] In addition, in the coating method according to the present embodiment, the hot melt adhesive is applied from a coating gun to a sheet material in a state where a solid raw material is heated to about 140°C to 160°C and melted. Since the hot melt adhesive has a high viscosity even in a melted state, there is a risk that the hot melt adhesive that cannot be completely loaded onto the sheet material will accumulate on the downstream side in the conveyance direction of the discharge port of the coating gun.

[0019] FIG. 1 is a schematic diagram showing a coating method according to a comparative example. The upper part of FIG. 1 is a schematic diagram of a sheet material S, which is the object to be coated, viewed from above, and the lower part of FIG. 1 is a schematic diagram of the sheet material S viewed from the side. The sheet material S is conveyed in the direction indicated by arrow A1 in FIG. 1 by a roller R100 that rotates in the direction indicated by arrow A2 in FIG. 1. The coating gun G is supplied with a raw material of the hot melt adhesive H heated to about 140°C to 160°C from a supply device (not shown) by a pump, and the coating gun G can discharge the hot melt adhesive H from a discharge port N provided at the tip. Further, by switching the pump of the supply device between an operating state and a non-operating state, it is possible to switch between a discharge state in which the hot melt adhesive H is discharged from the discharge port N and a non-discharge state in which the hot melt adhesive H is not discharged from the discharge port N. In the comparative example, a contact-type coating gun G that constantly contacts the discharge port N with the sheet material is employed.

[0020] In this comparative example, the range B shown in FIG. 1 is the designed application range of the hot melt adhesive H. When the rear end of the application range B passes through the discharge port N, the hot melt adhesive H is in a non-discharging state. However, there is a trailing phenomenon in which the coating gun G drags the hot melt adhesive H accumulated on the downstream side in the conveyance direction of the discharge port N, and the hot melt adhesive H is also applied to the non-application range. Thus, when the hot melt adhesive H is intermittently applied with the discharge port N of the coating gun G always in contact with the sheet material, a trailing phenomenon occurs where the coating gun G drags the hot melt adhesive H, and the hot melt adhesive H is also applied to the non-application range. In an absorbent article, it is not preferable that adhesiveness is exhibited in the non-application range where non-adhesion is desired. Although it is conceivable to lower the viscosity of the hot melt adhesive H by raising the temperature of the hot melt adhesive H above 160°C to suppress the occurrence of trailing, if the hot melt adhesive H is heated above 160°C, there is a risk that the performance will change, which is not preferable.

[0021] Therefore, in the coating method according to the present embodiment, at the start of the non-application state where the hot melt adhesive is not applied to the sheet material S, the hot melt adhesive accumulated on the downstream side of the discharge port is filtered off. As a result, it is possible to prevent the coating gun from dragging the hot melt adhesive accumulated on the downstream side in the conveyance direction of the discharge port, and to prevent the hot melt adhesive from being applied to the non-application range in design. This can prevent the hot melt adhesive from being dragged and prevent the hot melt adhesive from being applied to the non-application range in design.

[0022] FIG. 2 is a flowchart showing an outline of the coating method according to the present embodiment. In the coating method according to the present embodiment, first, a hot melt adhesive is applied to a sheet material (step S101, an example of the "first step" in the present application). Next, when switching from the applied state of the hot melt adhesive to the non-applied state where the hot melt adhesive is not applied to the workpiece, by applying pressure to the sheet material from below, the hot melt adhesive accumulated on the downstream side of the discharge port is filtered out (step S102, an example of the "second step" in the present application). Next, after filtering out the hot melt adhesive, the sheet material is separated from the discharge port (step S103, an example of the "third step" in the present application). The coating method according to the present embodiment can intermittently apply the hot melt adhesive to the sheet material conveyed in a certain direction by repeatedly executing steps S101 to S103. Note that step S103 can be omitted.

[0023] Next, based on FIGS. 3 to 5, the coating method according to the present embodiment will be described in more detail. In the present embodiment, three specific examples of Examples 1 to 3 are illustrated. As shown in FIGS. 3 to 5, in the present embodiment, the coating gun G has a discharge port N for discharging the hot melt adhesive H. The coating gun G is supplied with the raw material of the hot melt adhesive H heated to about 140°C to 160°C from a supply device (not shown) by a pump. Also, similar to the above-described comparative example, by switching the pump of the supply device between the operating state and the non-operating state, the discharge state and the non-discharge state of the hot melt adhesive H can be switched. Further, in the present embodiment, a contact-type coating gun G that brings the discharge port N into contact with the sheet material S in the discharge state is adopted. Also, in each of the examples shown in FIGS. 3 to 5, the sheet material is conveyed in the direction indicated by the arrow A1 in each figure.

[0024] <Example 1> Based on FIGS. 3(a) to 3(c), the coating method according to Example 1 will be described. FIGS. 3(a) to 3(c) are schematic diagrams for explaining the coating method according to this example. The upper parts of FIGS. 3(a) to 3(c) are schematic diagrams of the sheet material S viewed from above, and the lower parts of FIGS. 3(a) to 3(c) are schematic diagrams of the sheet material S viewed from the side. The coating apparatus used in the coating method according to this example includes a coating gun G and a roller R10 (an example of the "filtering means" referred to in the present application). The roller R10 is located below the sheet material S, and the center of rotation O is arranged on the downstream side of the discharge port N and is movable up and down. Further, the roller R10 rotates in the conveying direction of the sheet material S (the direction indicated by the arrow A2) in synchronization with the conveying speed of the sheet material S.

[0025] FIG. 3(a) shows the step of applying the hot melt adhesive H. In this step, the roller R10 is in contact with the sheet material S at a predetermined position, and the discharge port N is in contact with the sheet material S. The sheet material S is conveyed downstream in the tangential direction of the circumference of the roller R10 while being in contact with the discharge port N. Note that the predetermined position of the roller R10 in this step is the height at which the sheet material S is suitable for the discharge port N in the applied state of the hot melt adhesive H.

[0026] FIG. 3(b) shows the step of filtering the hot melt adhesive H. In this step, the roller R10 applies pressure to the sheet material S by contacting the sheet material S above a predetermined position, and filters the hot melt adhesive H accumulated on the downstream side of the discharge port N. Thereby, when switching the hot melt adhesive H from the applied state to the non-applied state, the hot melt adhesive H accumulated on the downstream side of the discharge port N can be filtered. Therefore, it is possible to prevent the coating gun G from dragging the hot melt adhesive H in the non-applied state and prevent the hot melt adhesive H from being applied to the non-applied range in the design.

[0027] FIG. 3(c) shows the separation of the sheet material S from the discharge port N after filtering the hot melt adhesive H This shows the step of causing. In this step, the roller R10 is lowered to separate the sheet material S from the discharge port N. By this step, even when the hot melt adhesive H could not be completely filtered out in the previous step, it is possible to prevent the coating gun G from dragging the hot melt adhesive H and prevent the hot melt adhesive H from being applied to the non - coating range in the design.

[0028] <Example 2> Based on FIGS. 4(a) to 4(c), the coating method according to Example 2 will be described. FIGS. 4(a) to 4(c) are schematic views for explaining the coating method according to this example. The upper part of FIGS. 4(a) to 4(c) is a schematic view of the sheet material S seen from above, and the lower part of FIGS. 4(a) to 4(c) is a schematic view of the sheet material S seen from the side. The coating apparatus used in the coating method according to this example includes a coating gun G and a roller R20 (an example of the "filtering means" referred to in the present application). The roller R20 is located below the sheet material S, and the rotation center O is arranged on the downstream side of the discharge port N. Also, the roller 20 rotates in the conveyance direction of the sheet material S (the direction indicated by the arrow A2) in synchronization with the conveyance speed of the sheet material S.

[0029] The roller R20 has a circumferential portion R21 corresponding to the length of the application range of the hot melt adhesive H on the sheet material S, an enlarged diameter portion R22 with a diameter larger than that of the circumferential portion R21, and a reduced diameter portion R23 with a diameter smaller than that of the circumferential portion R21. The enlarged diameter portion R22 applies pressure to the sheet material S by contacting the sheet material S and filters the hot melt adhesive H accumulated on the downstream side of the discharge port N. The distance between the outer circumference of the enlarged diameter portion R22 and the rotation center of the roller R20 is set to a length at which sufficient pressure is applied to the sheet material S. The reduced diameter portion R23 is arranged so as to face the sheet material S side after the enlarged diameter portion R23. The distance between the outer circumference of the reduced diameter portion R23 and the rotation center of the roller R20 is set to a length at which the sheet material S can be separated from the nozzle N in a state where the reduced diameter portion R23 faces the sheet material S side.

[0030] FIG. 4(a) shows the step of applying the hot melt adhesive H. In this step, the discharge port N is brought into contact with the sheet material S by aligning the sheet material S along the circumferential portion R21 of the roller R20. The sheet material S is conveyed downstream in the tangential direction of the circumferential portion R21 while being in contact with the discharge port N.

[0031] FIG. 4(b) shows the step of filtering off the hot melt adhesive H. In this step, the enlarged diameter portion R22 is in contact with the sheet material S, and by applying pressure to the sheet material S with the enlarged diameter portion R22, the hot melt adhesive H accumulated on the downstream side of the discharge port N can be filtered off. Thereby, when switching the hot melt adhesive H from the applied state to the non-applied state, the hot melt adhesive H accumulated on the downstream side of the discharge port N can be filtered off. Therefore, it is possible to prevent the coating gun G from dragging the hot melt adhesive H in the non-applied state and prevent the hot melt adhesive H from being applied to the non-applied range in terms of design.

[0032] FIG. 4(c) shows the step of separating the sheet material S from the discharge port N after filtering off the hot melt adhesive H. In this step, the reduced diameter portion R23 is directed towards the sheet material S to separate the sheet material S from the discharge port N. By this step, even if the hot melt adhesive H could not be completely filtered off in the previous step, it is possible to prevent the coating gun G from dragging the hot melt adhesive H and prevent the hot melt adhesive H from being applied to the non-applied range in terms of design.

[0033] <Example 3> Based on FIGS. 5(a) to (b), the coating method according to Example 3 will be described. FIGS. 5(a) to (b) are schematic diagrams for explaining the coating method according to this example. The upper part of FIGS. 5(a) to (b) is a schematic view of the sheet material S seen from above, and the lower part of FIGS. 5(a) to (b) is a schematic view of the sheet material S seen from the side. The coating device used in the coating method according to this example includes a coating gun G and a blower device M (an example of the "filtering means" referred to in the present application). The blower device M is arranged below the sheet material S and blows compressed air towards the downstream side of the discharge port N.

[0034] FIG. 5(a) shows the step of applying the hot melt adhesive H. In this step, the discharge port N is in contact with the sheet material S.

[0035] FIG. 5(b) shows the step of filtering off the hot melt adhesive H. In this step, by applying compressed air from the air blower M3 to the sheet material S from the lower side of the sheet material S, the hot melt adhesive H accumulated on the downstream side of the discharge port N can be filtered off. Thereby, when switching the hot melt adhesive H from the applied state to the non-applied state, the hot melt adhesive H accumulated on the downstream side of the discharge port N can be filtered off. Therefore, it is possible to prevent the coating gun G from dragging the hot melt adhesive H in the non-applied state, and to prevent the hot melt adhesive H from being applied to the non-applied range in design.

[0036] The coating method according to the present embodiment can adopt any one of the above Examples 1 to 3. Further, in the present embodiment, the hot melt adhesive H may be blended with a material for an indicator that changes color when coming into contact with excrement. In the absorbent article, the portion where the material for the indicator is applied functions as an indicator showing the presence or absence of excrement such as urination to the outside. The indicator is provided, for example, by applying the hot melt adhesive H containing the material for the indicator to the skin surface side of the back sheet. Note that, as the material for the indicator, a moisture detection material, a pH reaction material, or the like is used. According to the coating method according to the present embodiment, the hot melt adhesive H containing this material can be applied to the arrangement area of the indicator, and the hot melt adhesive H can be prevented from being applied to the non-arrangement area of the indicator, so that the indicator can be arranged within the designed range. Thereby, since the indicator can be arranged within the range as designed for the absorbent article, it is possible to prevent the indicator from becoming an obstacle to the design of the absorbent article.

[0037] <Other Embodiments> The embodiments of the present invention have been described above. However, the various embodiments described above can be combined as much as possible.

Explanation of Reference Numerals

[0038] A1, A2 ··· Arrows G ··· Coating gun H ··· Hot melt adhesive M ··· Blower N ··· Nozzle R10, R20, R100 ··· Rollers S ··· Sheet material

Claims

1. A coating method for intermittently applying a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, wherein the coating gun has a discharge port for discharging the hot melt adhesive, in a coating state where the hot melt adhesive is applied to the workpiece, a first step of bringing the discharge port into contact with the workpiece, a second step of filtering the hot melt adhesive accumulated between the coating gun and the workpiece by applying pressure from below the workpiece and on the downstream side of the coating gun when switching from the coating state to a non - coating state where the hot melt adhesive is not applied to the workpiece, A coating method comprising the above.

2. A coating method for intermittently applying a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, wherein the coating gun has a discharge port for discharging the hot melt adhesive, in a coating state where the hot melt adhesive is applied to the workpiece, a first step of bringing the discharge port into contact with the workpiece, a second step of filtering the hot melt adhesive accumulated on the downstream side of the discharge port by applying pressure from below the workpiece when switching from the coating state to a non - coating state where the hot melt adhesive is not applied to the workpiece, including, a roller that is movable up and down below the workpiece and on the downstream side of the discharge port, and the roller rotates in the conveying direction of the workpiece in synchronization with the conveying speed of the workpiece, in the first step, the roller is in contact with the workpiece at a predetermined position, in the second step, the roller contacts the workpiece above the predetermined position to apply pressure to the workpiece, and filters the hot melt adhesive accumulated on the downstream side of the discharge port, the coating method includes a third step of separating the discharge port from the workpiece by lowering the roller after filtering the hot melt adhesive. Coating method.

3. A coating method for intermittently applying a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, wherein the coating gun has a discharge port for discharging the hot melt adhesive, in a coating state where the hot melt adhesive is applied to the workpiece, a first step of bringing the discharge port into contact with the workpiece, When switching from the coating state to a non - coating state where the hot - melt adhesive is not applied to the workpiece, a second step of filtering out the hot - melt adhesive accumulated on the downstream side of the discharge port by applying pressure to the workpiece from below. Including Below the workpiece, and a roller that rotates in the conveyance direction of the workpiece in synchronization with the conveyance speed of the workpiece is arranged on the downstream side of the discharge port. The roller A circumferential portion corresponding to the length of the application range of the hot - melt adhesive to the workpiece, An enlarged - diameter portion having a diameter larger than that of the circumferential portion, which applies pressure to the workpiece and filters out the hot - melt adhesive accumulated on the downstream side of the discharge port. A reduced - diameter portion having a diameter smaller than that of the circumferential portion, which is arranged to face the workpiece side after the enlarged - diameter portion. Has In the first step, the discharge port is brought into contact with the workpiece by causing the workpiece to follow along the circumferential portion. In the second step, by applying pressure to the workpiece by the enlarged - diameter portion, the hot - melt adhesive accumulated on the downstream side of the discharge port is filtered out. The coating method includes a third step of separating the workpiece from the discharge port by turning the reduced - diameter portion toward the workpiece after filtering out the hot - melt adhesive. Coating method.

4. A coating method for intermittently applying a hot - melt adhesive from a coating gun to a workpiece conveyed in a certain direction, The coating gun has a discharge port for discharging the hot - melt adhesive. A first step of bringing the discharge port into contact with the workpiece in a coating state where the hot - melt adhesive is applied to the workpiece. A second step of filtering out the hot - melt adhesive accumulated on the downstream side of the discharge port by applying pressure to the workpiece from below when switching from the coating state to a non - coating state where the hot - melt adhesive is not applied to the workpiece. Including In the second step, by applying compressed air to the workpiece from below the workpiece, the hot - melt adhesive is filtered out. Coating method.

5. The workpiece is a sheet material for absorbent articles. The hot - melt adhesive is blended with a material that changes color when coming into contact with excrement. The coating method according to any one of Claims 1 to 4.

6. A coating device for intermittently applying a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, The coating gun having a discharge port for discharging the hot melt adhesive, the coating gun that brings the discharge port into contact with the workpiece in a coating state where the hot melt adhesive is applied to the workpiece, Filtering means for filtering the hot melt adhesive accumulated between the coating gun and the workpiece by applying pressure from below the workpiece and on the downstream side of the coating gun when switching from the coating state to a non-coating state where the hot melt adhesive is not applied to the workpiece, A coating device comprising the above.

7. A coating device for intermittently applying a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, The coating gun having a discharge port for discharging the hot melt adhesive, the coating gun that brings the discharge port into contact with the workpiece in a coating state where the hot melt adhesive is applied to the workpiece, Filtering means for filtering the hot melt adhesive accumulated on the downstream side of the discharge port by applying pressure from below the workpiece when switching from the coating state to a non-coating state where the hot melt adhesive is not applied to the workpiece, Comprising, The filtering means is a roller that is movable up and down and is disposed below the workpiece and on the downstream side of the discharge port, and the roller rotates in the conveying direction of the workpiece in synchronization with the conveying speed of the workpiece, In the coating state, the roller is in contact with the workpiece at a predetermined position, When switching to the non-coating state, the roller contacts the workpiece above the predetermined position to apply pressure to the workpiece, filtering the hot melt adhesive accumulated on the downstream side of the discharge port, After filtering the hot melt adhesive, the roller descends to separate the workpiece from the discharge port, A coating device.

8. A coating device for intermittently applying a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, The coating gun having a discharge port for discharging the hot melt adhesive, the coating gun that brings the discharge port into contact with the workpiece in a coating state where the hot melt adhesive is applied to the workpiece, When switching from the coating state to a non - coating state where the hot - melt adhesive is not applied to the workpiece to be coated, filtering means for filtering the hot - melt adhesive accumulated on the downstream side of the discharge port by applying pressure to the workpiece from below. Comprising: The filtering means is a roller that is located below the workpiece to be coated and on the downstream side of the discharge port, and rotates in the conveying direction of the workpiece to be coated in synchronization with the conveying speed of the workpiece to be coated. The roller is: A circumferential portion corresponding to the length of the coating range of the hot - melt adhesive on the workpiece to be coated; An enlarged - diameter portion whose diameter is larger than that of the circumferential portion, which applies pressure to the workpiece to be coated and filters the hot - melt adhesive accumulated on the downstream side of the discharge port; A reduced - diameter portion whose diameter is smaller than that of the circumferential portion, which is arranged so as to face the workpiece to be coated side after the enlarged - diameter portion; Having: In the coating state, the roller brings the discharge port into contact with the workpiece to be coated by causing the workpiece to be coated to follow along the circumferential portion. When switching to the non - coating state, the roller filters the hot - melt adhesive accumulated on the downstream side of the discharge port by applying pressure to the workpiece to be coated with the enlarged - diameter portion. After filtering the hot - melt adhesive, the roller separates the workpiece to be coated from the discharge port by turning the reduced - diameter portion towards the workpiece to be coated. Coating device. **Claim 9** A coating device for intermittently applying a hot - melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, The coating gun having a discharge port for discharging the hot - melt adhesive, the coating gun that brings the discharge port into contact with the workpiece to be coated in a coating state where the hot - melt adhesive is applied to the workpiece to be coated; When switching from the coating state to a non - coating state where the hot - melt adhesive is not applied to the workpiece to be coated, filtering means for filtering the hot - melt adhesive accumulated on the downstream side of the discharge port by applying pressure to the workpiece to be coated from below. Comprising: The filtering means is a blower device that applies compressed air to the workpiece to be coated from below the workpiece to be coated. When switching to the non - coating state, the blower device filters the hot - melt adhesive by applying compressed air to the workpiece to be coated from below the workpiece to be coated. Coating device.

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