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 the downstream side of the discharge port is heated 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, that 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 to the object to be coated from a coating gun 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 be completely placed on the sheet material will accumulate on the downstream side in the conveyance direction of the discharge port of the coating gun. When attempting to apply the hot melt adhesive intermittently, if the hot melt adhesive accumulates on the downstream side in the conveyance direction of the discharge port, a phenomenon called trailing will occur, where the coating gun drags the accumulated hot melt adhesive, and as a result, the hot melt adhesive will be applied to the non-coating range where it is not designed 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-coating range in terms of design.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention provides a step of heating the downstream side of the discharge port when switching from the applied state to the non-applied state of the hot melt adhesive.

[0007] Specifically, the present invention is 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. 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 to be coated, a first step of bringing the discharge port into contact with the workpiece to be coated, and a second step of heating the downstream side of the discharge port 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.

[0008] In the above coating method, a roller that rotates in the conveying direction of the workpiece to be coated in synchronization with the conveying 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 coating range of the hot melt adhesive on the workpiece to be coated and a heating portion for heating the workpiece to be coated. 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 along the circumferential portion, and in the second step, the downstream side of the discharge port may be heated by bringing the heating portion into contact with the workpiece to be coated.

[0009] In the above coating method, a roller that rotates in the conveying direction of the workpiece to be coated in synchronization with the conveying speed of the workpiece to be coated is disposed below the workpiece to be coated and on the downstream side of the discharge port and the roller has a circumferential portion corresponding to the length of the coating range of the hot melt adhesive on the workpiece to be coated and a heating portion for heating the workpiece to be coated, the heating portion being convex outward from the circumferential portion. In the first step, the circumferential portion and the workpiece to be coated are in a non-contact state, and in the second step, the downstream side of the discharge port may be heated by bringing the heating portion into contact with the workpiece to be coated.

[0010] In the above coating method, a heating device that can move up and down is disposed below the workpiece to be coated and on the downstream side of the discharge port. In the first step, the heating device and the workpiece to be coated are in a non-contact state. In the second step, the heating device may be lifted and the downstream side of the discharge port may be heated by bringing the heating device into contact with the workpiece to be coated.

[0011] In the above coating method, in the second step, the downstream side of the discharge port may be heated by raising the temperature in the vicinity of the discharge port of the coating gun.

[0012] In the above coating method, a hot air supply device that blows hot air to the downstream side of the discharge port is disposed. In the second step, the downstream side of the discharge port may be heated by blowing hot air to the downstream side of the discharge port.

[0013] In the above coating method, a laser irradiation device that irradiates a laser to the downstream side of the discharge port is disposed. In the second step, the downstream side of the discharge port may be heated by irradiating a laser to the downstream side of the discharge port.

[0014] Further, the present invention can be grasped from the side of the coating device. For example, the present invention is a coating device that intermittently applies a hot melt adhesive from a coating gun to a workpiece to be coated that is conveyed in a certain direction, and the coating gun having a discharge port that discharges 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, and heating means for heating the downstream side of the discharge port 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 may be provided.

Advantages of the Invention

[0015] 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

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0017] 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.

[0018] <Outline of Coating Method> The coating method according to the present embodiment applies hot melt from a coating gun to a workpiece conveyed in a certain direction. It is a method of intermittently applying a hot melt adhesive. Examples of the object to be coated include sheet materials used for absorbent articles such as disposable diapers, urine pads, and sanitary products. In a manufacturing line for producing 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 may be intermittently applied to the sheet material so as not to be applied to the designed non-application range (hereinafter referred to as the "non-application range") but only to the designed application range (hereinafter referred to as the "application range"). The application range and the non-application range are continuous in the conveyance direction of the sheet material. When the application range of the sheet material passes under the application gun, the hot melt adhesive is discharged from the application gun, and when the non-application range of the sheet material passes under the application gun, the hot melt adhesive is not discharged from the application gun. Thereby, the hot melt adhesive is intermittently applied to the sheet material conveyed in a certain direction.

[0019] Also, in the coating method according to the present embodiment, the discharge port of the application gun is brought into contact with the sheet material in the state of applying the hot melt adhesive to the sheet material. Different from this, when applying the hot melt adhesive without bringing the discharge port of the application gun into contact with the sheet material, the hot melt adhesive is applied by spraying, and when intermittently applying the hot melt adhesive, 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 application gun into contact with the sheet material as in the coating method according to the present embodiment.

[0020] Also, in the coating method according to the present embodiment, the hot melt adhesive is applied from the application gun to the sheet material in a state where the 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 the melted state, there is a risk that the hot melt adhesive that could not completely cover the sheet material will accumulate on the downstream side in the conveyance direction of the discharge port of the application gun.

[0021] 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 an 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 a 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. Also, 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. Further, in the comparative example, a contact-type coating gun G that constantly contacts the discharge port N with the sheet material is employed.

[0022] In this comparative example, the range B shown in FIG. 1 is the designed coating range of the hot melt adhesive H. When the rear end of the coating range B passes through the discharge port N, the hot melt adhesive H is in a non-discharge 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-coating range. Thus, when the hot melt adhesive H is intermittently applied with the discharge port N of the coating gun G constantly in contact with the sheet material S, a trailing phenomenon occurs in which the coating gun G drags the hot melt adhesive H, and the hot melt adhesive H is also applied to the non-coating range. In absorbent articles, it is not preferable that adhesiveness is exhibited in the non-coating range where non-adhesion is desired. It is also conceivable to suppress the occurrence of trailing by lowering the viscosity of the hot melt adhesive H by raising the temperature of the hot melt adhesive H above 160°C, but if the hot melt adhesive H is raised above 160°C, there is a risk that the performance will change, which is not preferable.

[0023] Therefore, in the coating method according to the present embodiment, when switching from the coating state of the hot melt adhesive to the non-coating state where the hot melt adhesive is not applied to the workpiece to be coated, the downstream side of the discharge port is heated. Thereby, by temporarily reducing the viscosity of the hot melt adhesive accumulated on the downstream side in the conveyance direction of the discharge port, the accumulated hot melt adhesive can be separated from the coating gun, and it is possible to prevent the hot melt adhesive from being applied to the non-coating range in the design.

[0024] Figure 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, in the coating state where the hot melt adhesive is applied to the sheet material, the discharge port is brought into contact with the sheet material (step S101, an example of the "first step" referred to in the present application). Next, when switching from the coating state of the hot melt adhesive to the non-coating state where the hot melt adhesive is not applied to the workpiece to be coated, the downstream side of the discharge port is heated (step S102, an example of the "second step" referred to in the present application). The coating method according to the present embodiment executes step S101 and step S102, and by providing a non-coating period of the hot melt adhesive after step S102, the hot melt adhesive can be intermittently applied to the sheet material conveyed in a certain direction.

[0025] Next, based on FIGS. 3 to 8, the coating method according to the present embodiment will be described in more detail. In the present embodiment, six specific examples of Examples 1 to 6 are exemplified. As shown in FIGS. 3 to 8, in the present embodiment, the coating gun G has a discharge port N for discharging the hot melt adhesive H. The raw material of the hot melt adhesive H heated to about 140°C to 160°C is supplied to the coating gun G by a pump from a supply device (not shown). Also, similar to the above-described comparative example, the discharge state and the non-discharge state of the hot melt adhesive H can be switched by switching the pump of the supply device between the operating state and the non-operating state. 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 8, the sheet material is conveyed in the direction indicated by the arrow A1 in each figure.

[0026] <Example 1> Based on FIGS. 3(a) and 3(b), the coating method according to Example 1 will be described. FIGS. 3(a) and 3(b) are schematic diagrams for explaining the coating method according to this example. The coating apparatus used in the coating method according to this example includes a coating gun G and a roller R30. The roller R30 is located below the sheet material S, and the rotation center O is disposed downstream of the discharge port N. The roller R30 rotates in the transport direction (the direction indicated by arrow A2) in synchronization with the transport speed of the sheet material S.

[0027] The roller R30 has a circumferential portion R31 corresponding to the length of the application range of the hot melt adhesive H on the sheet material S, and a heating portion R32 (an example of the "heating means" referred to in this application) disposed on the same circumference as the circumferential portion R31 for heating the sheet material S. A heater is used for the heating portion R32. In the coating method according to this example, the discharge port N is brought into contact with the sheet material S by bringing the circumferential portion R31 along the sheet material S in the coating state, and the downstream side of the discharge port is heated by bringing the heating portion R32 into contact with the sheet material S when switching from the coating state to the non-coating state of the hot melt adhesive H. Thereby, by heating the hot melt adhesive H accumulated on the downstream side in the transport direction of the discharge port N, the viscosity of the accumulated hot melt adhesive H is temporarily reduced, the hot melt adhesive H can be separated from the coating gun, and the hot melt adhesive H can be prevented from being applied to the non-application range in the design.

[0028] <Example 2> Based on FIGS. 4(a) and 4(b), the coating method according to Example 2 will be described. Based on FIGS. 4(a) and 4(b), the coating method according to Example 2 will be described. FIGS. 4(a) and 4(b) are schematic diagrams for explaining the coating method according to this example. The coating apparatus used in the coating method according to this example includes a coating gun G and a roller R40. The roller R40 is located below the sheet material S, and the rotation center O is disposed downstream of the discharge port N. The roller R40 rotates in the transport direction (the direction indicated by arrow A2) in synchronization with the transport speed of the sheet material S.

[0029] The roller R40 has a circumferential portion R41 corresponding to the length of the application range of the hot melt adhesive H on the sheet material S, and a heating portion R42 (an example of the "heating means" in the present application) for heating the sheet material S. A heater is used for the heating portion R42. The length (radius) between the circumferential portion R41 and the rotation center O of the roller R40 is set shorter than the distance between the rotation center O and the sheet material S. For this reason, in the process of the application state of the hot melt adhesive H, the circumferential portion R42 and the sheet material S are in a non-contact state. The heating portion R42 protrudes outward from the circumferential portion R42, and the distance between the tip of the heating portion R42 and the rotation center O is set to be the same as or longer than the distance between the rotation center O and the sheet material S. When switching to the non-application state of the hot melt adhesive H, the roller R40 heats the downstream side of the discharge port N by bringing the heating portion R42 into contact with the sheet material S. Thereby, by heating the hot melt adhesive H accumulated on the downstream side in the conveyance direction of the discharge port N, the viscosity of the accumulated hot melt adhesive H is temporarily reduced, and the hot melt adhesive H can be separated from the application gun, preventing the hot melt adhesive H from being applied to the non-application range in the design.

[0030] <Example 3> Based on FIGS. 5(a) and (b), the application method according to Example 3 will be described. FIGS. 5(a) and (b) are schematic diagrams for explaining the application method according to the present embodiment. The application apparatus used in the application method according to the present embodiment includes an application gun G and a heating apparatus M1 (an example of the "heating means" in the present application). The heating apparatus M1 is disposed below the sheet material S and on the downstream side of the discharge port N. The heating apparatus M1 has a lifting apparatus M11 and a heating portion M12 having a heater disposed at the tip. The lifting apparatus M11 has a drive mechanism and two guide rails L disposed opposite to each other so as to extend vertically, and the heating portion M12 can be driven up and down along the guide rails L by the drive mechanism. The drive mechanism may be configured to include, for example, a motor or a hydraulic device. Thereby, the heating apparatus M1 can move up and down.

[0031] In the process of the application state of the hot melt adhesive H, the heating device and the sheet material S are in a non-contact state. When switching to the non-application state of the hot melt adhesive H, by raising the heating part M12 of the heating device M1, the downstream side of the discharge port N is heated by bringing the heating part M12 into contact with the sheet material S. Thereby, by heating the hot melt adhesive H accumulated on the downstream side in the conveyance direction of the discharge port N, the viscosity of the accumulated hot melt adhesive H is temporarily decreased, the hot melt adhesive H can be separated from the coating gun, and it is possible to prevent the hot melt adhesive H from being applied to the non-application range in the design.

[0032] <Example 4> Based on FIG. 6, the coating method according to Example 4 will be described. FIG. 6 is a schematic diagram for explaining the coating method according to the present embodiment. The coating device used in the coating method according to the present embodiment includes a coating gun G and a heater K (an example of the "heating means" in the present application). The heater K is disposed near the discharge port N of the coating gun G and heats the discharge port N. In the present embodiment, when switching to the non-application state of the hot melt adhesive H, the downstream side of the discharge port N is heated by raising the temperature near the discharge port N of the coating gun G. Thereby, by heating the hot melt adhesive H accumulated on the downstream side in the conveyance direction of the discharge port N, the viscosity of the accumulated hot melt adhesive H is temporarily decreased, the hot melt adhesive H can be separated from the coating gun, and it is possible to prevent the hot melt adhesive H from being applied to the non-application range in the design.

[0033] <Example 5> Based on FIG. 7, the coating method according to Example 5 will be described. The coating apparatus used in the coating method according to this example includes a coating gun G and a hot air supply device M2. The hot air supply device M2 blows hot air to the downstream side of the discharge port N when switching from the coating state to the non - coating state of the hot melt adhesive H. The temperature of the hot air is set lower than the melting point of the sheet material S so as not to melt the sheet material S, and higher than the softening point of the hot melt adhesive H in order to melt the hot melt adhesive H. Also, the hot air is blown so as to hit the mass of the hot melt adhesive. Thereby, by heating the hot melt adhesive H accumulated on the downstream side in the transport direction of the discharge port N, the viscosity of this hot melt adhesive H is temporarily reduced, the hot melt adhesive H can be separated from the coating gun, and it is possible to prevent the hot melt adhesive H from being applied to the non - coating range in the design.

[0034] <Example 6> Based on FIG. 8, the coating method according to Example 6 will be described. The coating apparatus used in the coating method according to this example includes a coating gun G and a laser device M3. The laser device M3 irradiates laser light to the downstream side of the discharge port N when switching from the coating state to the non - coating state of the hot melt adhesive H. The wavelength of the laser light is preferably set within a wavelength range suitable for melting the hot melt adhesive H without the influence of melting the sheet material S and the like. Also, the laser light is irradiated so as to hit the mass of the hot melt adhesive. Thereby, by heating the hot melt adhesive H accumulated on the downstream side in the transport direction of the discharge port N, the viscosity of this hot melt adhesive H is temporarily reduced, the hot melt adhesive H can be separated from the coating gun, and it is possible to prevent the hot melt adhesive H from being applied to the non - coating range in the design.

[0035] The coating method according to this embodiment can adopt any one of the above Examples 1 to 6. Further, in this embodiment, the hot melt adhesive H may be blended with a material for an indicator that changes color when it comes into contact with excrement. In the absorbent article, the portion where the material for the indicator is applied functions as an indicator that indicates 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 this embodiment, the hot melt adhesive H containing this material can be applied to the arrangement region of the indicator, and the hot melt adhesive H can be prevented from being applied to the non-arrangement region 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.

[0036] <Other Embodiments> As described above, the embodiments of the present invention have been described, but the various embodiments described above can be combined as much as possible.

Description of Reference Numerals

[0037] A1, A2 ··· Arrows C1, C3, C4 ··· Circumferential portions C2 ··· Flattened portion G ··· Coating gun H ··· Hot melt adhesive M1 ··· Heating device M2 ··· Hot air supply device M3 ··· Laser irradiation device N ··· Nozzle R30, R40 ··· 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 to be coated, a first step of bringing the discharge port into contact with the workpiece to be coated; a second step of heating the downstream side of the discharge port 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; comprising: below the workpiece to be coated and on the downstream side of the discharge port, 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 arranged, 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, and a heating portion for heating the workpiece to be coated, and has: in the first step, bringing the discharge port into contact with the workpiece to be coated by causing the workpiece to be coated to follow along the circumferential portion; in the second step, heating the downstream side of the discharge port by bringing the heating portion into contact with the workpiece to be coated, coating method.

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 to be coated, a first step of bringing the discharge port into contact with the workpiece to be coated; a second step of heating the downstream side of the discharge port 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; comprising: below the workpiece to be coated and on the downstream side of the discharge port, 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 arranged, 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, and a heating portion for heating the workpiece to be coated, the heating portion being convex outward from the circumferential portion, and has: in the first step, the circumferential portion and the workpiece to be coated are in a non - contact state, in the second step, heating the downstream side of the discharge port by bringing the heating portion into contact with the workpiece to be coated, 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 the coating state of applying the hot melt adhesive to the object to be coated, a first step of bringing the discharge port into contact with the object to be coated; A second step of heating the downstream side of the discharge port when switching from the coating state to a non-coating state where the hot melt adhesive is not applied to the object to be coated; comprising Below the object to be coated, and a heating device movable up and down is arranged on the downstream side of the discharge port, In the first step, the heating device and the object to be coated are in a non-contact state, In the second step, the heating device is raised and the heating device is brought into contact with the object to be coated to heat the downstream side of the discharge port, Coating method.

4. A coating method for intermittently applying a hot melt adhesive from a coating gun to an object to be coated conveyed in a certain direction, The coating gun has a discharge port for discharging the hot melt adhesive, In the coating state of applying the hot melt adhesive to the object to be coated, a first step of bringing the discharge port into contact with the object to be coated without heating the downstream side of the discharge port; A second step of heating the downstream side of the discharge port when switching from the coating state to a non-coating state where the hot melt adhesive is not applied to the object to be coated; comprising a coating method.

5. In the second step, the downstream side of the discharge port is heated by raising the temperature in the vicinity of the discharge port of the coating gun, The coating method according to claim 4.

6. A laser irradiation device for irradiating a laser to the downstream side of the discharge port is arranged, In the second step, the downstream side of the discharge port is heated by irradiating a laser to the downstream side of the discharge port, The coating method according to claim 4.

7. A coating device for intermittently applying a hot melt adhesive from a coating gun to an object to be coated conveyed in a certain direction, The coating gun having a discharge port for discharging the hot melt adhesive, the coating gun for bringing the discharge port into contact with the object to be coated in the coating state of applying the hot melt adhesive to the object to be coated; When switching from the coating state to a non-coating state where the hot melt adhesive is not applied to the object to be coated Heating means for heating the downstream side of the discharge port; comprising Below the object to be coated, and a roller rotating in the conveying direction of the object to be coated in synchronization with the conveying speed of the object to be coated is arranged on the downstream side of the discharge port, The roller is A circumferential portion corresponding to the length of the application range of the hot melt adhesive to the workpiece, A heating portion for heating the workpiece, having, In the application state, the discharge port is brought into contact with the workpiece by causing the workpiece to follow the circumferential portion, When switching to the non-application state, the downstream side of the discharge port is heated by bringing the heating portion into contact with the workpiece, Coating device.

8. A coating device for intermittently applying a hot melt adhesive from a coating gun to a workpiece 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, Heating means for heating the downstream side of the discharge port when switching from the coating state to a non-coating state where the hot melt adhesive is not applied to the workpiece, comprising, Below the workpiece and on the downstream side of the discharge port, a roller that rotates in the conveyance direction of the workpiece in synchronization with the conveyance speed of the workpiece is arranged, The roller, A circumferential portion corresponding to the length of the application range of the hot melt adhesive to the workpiece, A heating portion for heating the workpiece, the heating portion being convex outward from the circumferential portion, having, In the coating state, the circumferential portion and the workpiece are in a non-contact state, When switching to the non-application state, the downstream side of the discharge port is heated by bringing the heating portion into contact with the workpiece, Coating device.

9. A coating device for intermittently applying a hot melt adhesive from a coating gun to a workpiece 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, Heating means for heating the downstream side of the discharge port when switching from the coating state to a non-coating state where the hot melt adhesive is not applied to the workpiece, comprising, Below the workpiece and on the downstream side of the discharge port, a heating device that can move up and down is arranged, In the coating state, the heating device and the workpiece are in a non-contact state, When switching to the non-application state, the heating device is raised and the heating device is brought into contact with the workpiece to heat the downstream side of the discharge port, Coating device.

10. A coating apparatus for intermittently applying a hot melt adhesive from a coating gun to a workpiece being conveyed in a certain direction, wherein the coating gun has a discharge port for discharging the hot melt adhesive, and in a coating state where the hot melt adhesive is applied to the workpiece, the coating gun contacts the discharge port with the workpiece without heating the downstream side of the discharge port; and heating means for heating the downstream side of the discharge port when switching from the coating state to a non - coating state where the hot melt adhesive is not applied to the workpiece. The coating apparatus is provided with the above components.

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