JP7803603B2 - Manufacturing method of spout - Google Patents

Description

The present invention relates to a method for manufacturing a synthetic resin spout that can be attached to the opening of a container that contains a fluid.

A spout is known that is attached to the opening of a container such as a packaging bag. The spout is configured to prevent outside air from entering the container through a flow path formed inside the spout.
For example, Patent Document 1 discloses a spout including a spout that forms a fluid flow path therein and a cap that is detachably attached by screwing onto the spout's inner cylindrical body. The spout and cap have the following structures: The spout has a cylindrical inner cylindrical body and a container connecting tube that is integrally connected to the lower part of the inner cylindrical body. The container connecting tube has a cylindrical base that is integrally connected to the inner cylindrical body and a protruding piece that protrudes radially from the outer surface of the cylindrical base. The cap has a bottomed cylindrical plug that is inserted into the spout's inner cylindrical body and cylindrical base to close the flow path inside the spout.

In the spout device described in Patent Document 1, the outer surface of the cap's stopper body adheres to the inner surface of the spout's cylindrical base, blocking the flow path inside the spout. This is said to prevent oxygen that has permeated through the outer surface of the inner cylindrical main body from flowing axially inside the inner cylindrical main body and into the container.

JP 2018-90271 A

However, it is not possible to block the flow of oxygen inside the inner cylindrical main body and the cylindrical base. Therefore, even if it is possible to limit the amount of oxygen flowing inside the cylindrical base, there is a limit to how far this can be limited. From the perspective of oxygen barrier properties, there is still room for improvement.

The present invention was made in consideration of these conventional circumstances, and its purpose is to provide a method for manufacturing a spout with excellent oxygen barrier properties.

To solve the above problems, a method for manufacturing a spout device made of synthetic resin that is attached to the opening of a container that contains a fluid includes an attachment step of inserting a bottomed, cylindrical lid main body into the inside of a cylindrical spout that forms a flow path for the fluid, and a heating step of heating the underside of the spout and the bottom of the lid main body. In the heating step, the inner periphery of the underside of the spout and the outer periphery of the bottom of the lid main body are welded together, and a gas barrier sheet is attached to the underside of the spout and the bottom of the lid main body.

To solve the above problem, the heating step further involves placing the gas barrier sheet between the spout and a crimping jig equipped with thermal welding means, and then performing thermal welding. This welds and integrates the inner periphery of the underside of the spout and the outer periphery of the bottom surface of the lid body, and also adheres the gas barrier sheet to the underside of the spout and the bottom surface of the lid body.

The present invention provides a spout with excellent oxygen barrier properties.

FIG. 2 is a perspective view of the spout device of the present embodiment. FIG. 3A to 3C are explanatory diagrams showing the steps of manufacturing the spout device of the present embodiment in order.

The synthetic resin spout 1 shown in Figure 1 is attached to the opening of a synthetic resin bag-shaped container. This forms a flow path for pouring out the fluid contained inside the bag-shaped container. The spout 1 is adhesively fixed to the opening of the bag-shaped container by heat sealing. The bag-shaped container is formed from a multi-layered sheet in which an aluminum foil layer is laminated between multiple thin polyethylene sheets. In the following explanation, the top, bottom, left, and right in Figure 1 will be referred to as the top, bottom, left, and right of the spout 1.

As shown in Figures 1 and 2, the synthetic resin spout 1 includes a spout portion 2 that forms a fluid flow path C therein, a lid portion 4 that is removably attached to the spout portion 2 by screwing it into place, and a sheet body 5 that serves as a gas barrier layer.

(Configuration of the pouring portion 2)
As shown in Fig. 2, the outlet portion 2 has a flow path C formed therein. The outlet portion 2 has a cylindrical tube main body 20 formed over the entire length of the outlet portion 2, and an attachment portion 30 formed integrally with the tube main body 20 at the bottom of the tube main body 20.

The inner peripheral surface of the tube main body 20 is formed in a straight shape with no change in diameter in the vertical direction, and is formed as a flat surface with no irregularities. This prevents the fluid from adhering to or remaining on the inner peripheral surface of the tube main body 20, which forms the flow path C, when the fluid is poured out from inside the bag-shaped container.

A male screw 21 is formed on the outer peripheral surface of the upper part of the tube main body 20, extending circumferentially. Furthermore, a radially protruding annular protrusion 22 is formed on the outer peripheral surface of the vertically middle part of the tube main body 20, extending all the way around the circumference. Furthermore, a number of ratchets 23 are formed on the upper part of the annular protrusion 22.

As shown in Figures 1 and 2, the mounting portion 30 is formed at the bottom of the tube main body 20 in a shape that protrudes radially outward from the outer peripheral surface of the tube main body 20. The mounting portion 30 is formed by multiple ribs that are elongated in the left-right direction when viewed from above. The multiple ribs are composed of an upper wall 31 provided on the upper side, a lower wall 32 provided on the lower side, and multiple intermediate walls 33 provided between the upper wall 31 and the lower wall 32. The upper wall 31, lower wall 32, and intermediate wall 33 are the same shape and size, extend parallel to each other, and each side surface is flush in the vertical direction. The side surfaces of the upper wall 31, lower wall 32, and intermediate wall 33 are the parts to which the opening of the bag-shaped container is adhesively fixed by heat sealing, and are formed as flat surfaces without any irregularities. The lower surface 32a of the lower wall 32 and the bottom surface 45a of the lid body 41 of the lid 4 are surfaces to which the sheet 5 is attached in the gas barrier layer formation process described below, and are each formed as a flat surface that is horizontal and has no irregularities in the left-right direction. The upper wall 31, lower wall 32, and intermediate wall 33 are connected together by a connecting wall 34 that extends left-right between the upper wall 31, lower wall 32, and intermediate wall 33.

(Configuration of lid portion 4)
As shown in Figures 1 and 2, the lid portion 4 includes a cylindrical lid main body portion 41 with a bottom that is inserted into the inside of the pouring portion 2, a flange portion 42 that extends radially outward from the upper end of the lid main body portion 41, and an outer tube portion 43 that extends downward from the outer end of the flange portion 42.

As shown in FIG. 2, the lid main body 41 is formed as a hollow body having a cylindrical peripheral wall 44 and a bottom wall 45 attached to the lower edge of the peripheral wall 44. The top surface of the lid main body 41 is open. By inserting the lid main body 41 inside the tube main body 20 of the spout 2, the bottom wall 45 of the lid main body 41 closes the flow path C of the tube main body 20.

The inner peripheral surface of the peripheral wall 44 of the lid main body 41 is formed in a straight shape with a diameter that does not change in the vertical direction. Furthermore, a radially protruding protrusion 46 is formed around the entire circumference at the top of the outer peripheral surface of the peripheral wall 44, and the lower end of the protrusion 46 is formed as a tapered surface 46a that decreases in diameter as it goes downward. In areas where no protrusion 46 is formed, the outer peripheral surface of the peripheral wall 44 is formed in a straight shape with a diameter that does not change in the vertical direction, and its inner peripheral surface is formed as a flat surface with no irregularities. The bottom surface 45a of the bottom wall 45 is formed as a flat surface that is horizontal in the left-right direction and has no irregularities.

The outer diameter of the peripheral wall 44 of the lid main body 41 is slightly smaller than the inner diameter of the tube main body 20 of the pouring part 2. As a result, when the lid 4 is attached to the pouring part 2 through the attachment process described below, a gap of width L1 is formed between the outer surface of the peripheral wall 44 of the lid main body 41 and the inner surface of the tube main body 20 of the pouring part 2. Width L1 is approximately 0.3 to 0.5 mm. The protrusion 46 formed on the upper part of the peripheral wall 44 has a protruding length equal to width L1. Note that width L1 can be changed as appropriate.

The vertical length of the lid main body 41 is set slightly shorter than the vertical length of the tube main body 20 of the pouring portion 2. Specifically, in the lid main body 41, the length from the underside of the flange 42 to the bottom surface 45a of the bottom wall 45 is shorter than the length from the upper end surface of the tube main body 20 to the lower surface 32a of the lower wall 32 of the mounting portion 30. As a result, when the lid 4 is attached to the pouring portion 2, the upper end surface of the tube main body 20 of the pouring portion 2 abuts against the lower surface of the flange 42 of the lid 4, and the bottom surface 45a of the bottom wall 45 of the lid main body 41 is positioned higher than the lower surface 32a of the lower wall 32 of the tube main body 20. The difference in vertical distance between the bottom surface 45a and the lower surface 32a is approximately 0.1 to 0.7 mm, and preferably 0.5 mm.

The outer tube portion 43 is formed in a shape that surrounds the lid main body portion 41, with a predetermined gap formed between it and the outer peripheral surface of the lid main body portion 41. The outer tube portion 43 is cylindrical and concentric with the lid main body portion 41. A female screw 47 that screws into the male screw 21 of the tube main body portion 20 of the spout portion 2 is provided on the inner peripheral surface of the outer tube portion 43 so as to extend circumferentially.

As shown in Figures 1 and 2, a cap ring 48, which provides a known tamper-evident function that verifies the opening and closing history of the lid 4, is connected to the lower end of the outer tube 43. The cap ring 48 is attached to a position between the lower edge of the outer tube 43 and the annular protrusion 22 of the tube main body 20, corresponding to the position of the ratchet 23 provided on the tube main body 20 of the spout 2, and is broken when the lid 4 is rotated in the opening direction to open it. This indicates that the bag-shaped container is in an opened state.

The spout 2 and lid 4 are molded from a conventionally known synthetic resin material. Examples of known synthetic resin materials include thermoplastic resins such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, and ethylene-propylene copolymer.

(Configuration of welded portion 6)
2, the welded portion 6 is formed so as to fill a gap of width L1 between the lower surface 32a of the spout 2 and the bottom surface 45a of the lid main body 41. In other words, the lower surface 32a of the spout 2 and the bottom surface 45a of the lid main body 41 are integrated by the welded portion 6, and there is no gap between them. The welded portion 6 is formed by thermally welding the inner periphery of the lower surface 32a of the spout 2 and the outer periphery of the bottom surface 45a of the lid main body 41 through a heating process described later.

(Configuration of sheet body 5)
2, the sheet body 5 serving as the gas barrier layer is attached to the surface where the lower surface 32a of the spout 2 and the bottom surface 45a of the lid main body 41 are integrated by the welding portion 6. The shape and size of the sheet body 5 are the same as those of the lower wall 32 of the attachment portion 30, and the sheet body 5 is attached in a manner that covers the entire lower surface of the spout 1.

The sheet body 5 is composed of a multilayer structure sheet consisting of multiple thin-film layers. The sheet body 5 includes a base layer, a gas barrier layer laminated on the underside of the base layer, and a heat-sealing layer laminated on the upper side of the base layer. The material of the sheet body 5 is not particularly limited, but examples of the material that can be used include a multilayer structure sheet laminated with thermoplastic resin layers such as polyethylene layers, polypropylene layers, polyethylene terephthalate layers, ethylene vinyl alcohol copolymer layers, and acrylic layers, as well as aluminum foil layers and ceramic vapor deposition film layers. Note that the thickness of the sheet body 5 is exaggerated in Figure 2.

Next, a specific example of a method for manufacturing the spout 1 of this embodiment will be described below with reference to the drawings.
The manufacturing method of the spout 1 of this embodiment includes an attachment step, a heating step, and a gas barrier layer forming step. Figures 3(a) to 3(c), which explain the manufacturing method, show the state of the spout 1 in the attachment step and the heating step.

(Installation process)
In the attachment step, the lid main body 41 is inserted into the inside of the spout 2 to attach the spout 2 and the lid 4 .

As shown in Figure 3(a), during the installation process, multiple spouts 2 are arranged in a line with their undersides 32a facing downward. The lids 4 are placed in a tightening machine that can hold the outer tube 43 by gripping them, with the bottom surface 45a of the lid body 41 facing downward. The tightening machine positions the line connecting the center of the underside 32a of the spout 2 and the center of the bottom surface 45a of the lid body 41 perpendicular to the underside 32a. From this state, the tightening machine moves the lids 4 it is holding vertically downward and rotates them in the closing direction, resulting in the spouts 2 and lids 4 being tightened together as shown in Figure 3(b). At this time, the upper end surface of the tube body 20 of the spout 2 abuts against the lower surface of the flange 42 of the lid 4, and the bottom surface 45a of the lid body 41 is positioned above the lower surface 32a of the tube body 20.

(Heating process)
As shown in FIG. 3( b ), after the mounting process, i.e., before the heating process, a gap of width L1 is formed between the inner periphery of the lower surface 32 a of the spout 2 and the outer periphery of the bottom surface 45 a of the lid main body 41.

In the heating process, a receiving jig is placed that can hold the underside 32a of the spout 2 and the bottom surface 45a of the lid main body 41 facing upward, and multiple spout devices 1 are held in the receiving jig. A crimping jig equipped with a thermal welding means is placed above the receiving jig. The crimping jig is then lowered and pressed against the underside 32a of the spout 2 and the bottom surface 45a of the lid main body 41. As a result, as shown in Figure 3(c), the inner periphery of the underside 32a of the spout 2 and the outer periphery of the bottom surface 45a of the lid main body 41 are thermally welded to form a welded portion 6. This welded portion 6 unites the underside 32a of the spout 2 and the bottom surface 45a of the lid main body 41. When pressing the heat-sealing means against the underside 32a of the spout 2 and the bottom surface 45a of the lid main body 41, the pressing temperature and specified pressing time are selected so that these surfaces are thermally fused appropriately.

(Gas barrier layer forming step)
In the gas barrier layer forming step, a sheet member 5 is attached to the underside of the spout 1 to form a gas barrier layer.

The multilayer structure sheet that makes up the sheet body 5 is long and wound into a roll. The multilayer structure sheet unwound from the roll undergoes a bonding process and a cutting process, where it is joined to the underside 32a of the spout portion 2 and the bottom surface 45a of the lid main body portion 41 at the welded portion 6, forming a unified surface.

In the bonding process, the multilayer sheet is first supplied to the production line with the heat-sealed layer facing downward. A receiving jig is placed below the multilayer sheet, capable of holding multiple spouts 1 without the sheet body 5 attached, with the surface where the underside 32a of the spout portion 2 and the bottom surface 45a of the lid body 41 are joined by the welded portion 6 facing upward. The receiving jig holds the multiple spouts 1. A crimping jig equipped with a heat-sealing means is placed above the multilayer sheet. The crimping jig is then lowered to apply pressure to the multilayer sheet against the surface where the underside 32a of the spout portion 2 and the bottom surface 45a of the lid body 41 are joined by the welded portion 6, thereby bonding the multilayer sheet to the surface where the underside 32a of the spout portion 2 and the bottom surface 45a of the lid body 41 are joined by the welded portion 6. It is preferable to perform the crimping using the crimping jig multiple times, for example, twice. This allows for a high sealing pressure to be applied, improving the bonding strength of the multilayer structure sheet.

In the cutting process, a laser is applied to the multilayer sheet, which is heat-welded to the surface where the underside 32a of the spout 2 and the bottom surface 45a of the lid main body 41 are joined by the welded section 6, along the periphery of the mounting section 30 of each spout 1 to cut the outer periphery. After the cutting process, the multilayer sheet is wound up, leaving the spout 1 with the sheet body 5 attached in the receiving jig. This results in a spout 1 in which the sheet body 5 is joined to the surface where the underside 32a of the spout 2 and the bottom surface 45a of the lid main body 41 are joined by the welded section 6.

Next, the effects of this embodiment will be described.
(1) The spout 1 is made of synthetic resin and is attached to the opening of a bag-shaped container that contains a fluid. The spout 1 includes a cylindrical spout portion 2 that forms a flow path C therein, and a lid portion 4 that is detachably attached to the spout portion 2 by threading it into the spout portion 2. The lid portion 4 has a cylindrical lid main body 41 with a bottom that is inserted inside the spout portion 2. The inner periphery of the lower surface 32a of the spout portion 2 and the outer periphery of the bottom surface 45a of the lid main body 41 are integrated by a welded portion 6 formed by welding them together.

With the above configuration, there is no gap between the inner periphery of the underside 32a of the spout 2 and the outer periphery of the bottom surface 45a of the lid main body 41. Therefore, even if oxygen flows into the interior of the spout 2, it is blocked by the welded portion 6, which integrates the inner periphery of the underside 32a of the spout 2 with the outer periphery of the bottom surface 45a of the lid main body 41. In other words, oxygen is prevented from flowing into the container. This results in a spout 1 with excellent oxygen barrier properties, allowing the contents of the bag-shaped container to be well preserved before opening.

(2) The underside 32a of the spout 2 and the bottom surface 45a of the lid body 41 are covered with a sheet 5 that serves as a gas barrier layer. According to the above configuration, the flow of oxygen is blocked by the sheet 5 that is attached to the surface where the underside 32a of the spout 2 and the bottom surface 45a of the lid body 41 are joined together by the welded portion 6. This results in a spout 1 with excellent oxygen barrier properties.

(3) The manufacturing method of the spout 1 includes an attachment step in which a cylindrical lid body 41 with a bottom is inserted into the cylindrical spout 2, which forms a flow path C therein, and a heating step in which the underside 32a of the spout 2 and the bottom surface 45a of the lid body 41 are heated. In the heating step, the inner periphery of the underside 32a of the spout 2 and the outer periphery of the bottom surface 45a of the lid body 41 are welded together.

With the above configuration, the underside 32a of the spout 2 and the bottom surface 45a of the lid main body 41 can be integrated using the simple method of heating. Furthermore, a crimping tool similar to the crimping tool equipped with heat welding means used in the gas barrier layer formation process can also be used in the heating process.

(4) The manufacturing method of the spout 1 includes, after the heating step, a gas barrier layer forming step in which a sheet 5 is attached to the underside 32a of the spout 2 and the bottom surface 45a of the lid body 41 to form a gas barrier layer.

With the above configuration, the flow of oxygen is blocked by the sheet member 5, which is attached to the surface where the underside 32a of the spout 2 and the bottom surface 45a of the lid body 41 are joined together by the welded portion 6. This results in a spout 1 with excellent oxygen barrier properties.

(5) In the manufacturing method of the spout device 1, during the attachment process, the lid main body 41 is attached to the spout portion 2 so that the bottom surface 45a of the lid main body 41 is positioned above the underside 32a of the spout portion 2. This configuration prevents the bottom surface 45a of the lid main body 41 from coming into contact with and rubbing against the line when the spout portion 2 and the lid portion 4 are seamed together during the attachment process.

This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.
In the spout device 1 of the above embodiment, the vertical length of the lid main body 41 is set to be slightly shorter than the vertical length of the tube main body 20 of the spout 2, but this is not limited to this. For example, the vertical length of the lid main body 41 may be set to match the vertical length of the tube main body 20 of the spout 2. Specifically, in the lid main body 41, the length from the lower surface of the flange 42 to the bottom surface 45a of the bottom wall 45 may be set to be equal to the length from the upper end surface of the tube main body 20 to the lower surface 32a of the lower wall 32 of the attachment portion 30. In this case, when the lid 4 is attached to the spout 2, the upper end surface of the tube main body 20 of the spout 2 abuts against the lower surface of the flange 42 of the lid 4, and the lower surface 32a of the attachment portion 30 of the spout 2 is flush with the bottom surface 45a of the bottom wall 45 of the lid main body 41.

- In the above embodiment, the spout 1 is configured to have a sheet body 5 as a gas barrier layer, but this is not limited to this. For example, the gas barrier layer may be formed by applying a gas barrier agent to a predetermined thickness. It is also possible for the spout 1 not to have a gas barrier layer.

The manufacturing method of the spout device 1 in the above embodiment is merely an example, and other methods may be used. For example, the gas barrier layer forming step may be omitted.
In the attachment process, the lid portion 4 may be placed on the line, and the spout portion 2 may be placed on the winding machine.

- During the heating step, a multilayer structure sheet may be placed between the spout 1 and a crimping jig equipped with a thermal welding means, and thermal welding may be performed, thereby simultaneously carrying out the heating step and the bonding step of the gas barrier layer formation step.

- During the heating process, the heat-sealing means does not need to come into contact with the entire underside 32a of the pouring portion 2 and the bottom surface 45a of the lid main body 41. For example, an annular heat-sealing means may be used that comes into contact with the inner periphery of the underside 32a of the pouring portion 2 and the outer periphery of the bottom surface 45a of the lid main body 41.

- The vertical direction during the manufacturing process does not have to conform to the above embodiment. For example, during the heating process, a crimping jig equipped with heat welding means may be pressed from below with the lower surface 32a of the spout 2 and the bottom surface 45a of the lid main body 41 facing downward.

- The spouting part 2 does not have to have the attachment part 30. In this case, the spouting part 2 is formed from a cylindrical tube main body part 20, and the opening of the bag-shaped container is heat-sealed to the lower part of the tube main body part 20. Furthermore, the inner periphery of the lower surface of the tube main body part 20 of the spouting part 2 and the outer periphery of the bottom surface 45a of the lid main body part 41 are integrated by the welded part 6.

- The shape of the attachment portion 30 is not limited to that of the above embodiment. A shape that is elongated in the left-right direction increases the adhesive strength achieved by heat sealing, but it does not necessarily have to be elongated; it may also be circular when viewed from above.

The attachment portion 30 is not limited to being formed by a plurality of ribs. For example, it may be formed as a single surface having a diameter larger than the outer diameter of the tube main body 20.
The upper wall 31, the lower wall 32, and the intermediate wall 33 of the mounting portion 30 do not have to have the same shape and size. For example, the upper wall 31 may be the largest, and the intermediate wall 33 may be the largest. Furthermore, the number of intermediate walls 33 is not particularly limited.

The side surfaces of the upper wall 31, the lower wall 32, and the intermediate wall 33 of the attachment portion 30 are not limited to being flat surfaces. They may be uneven surfaces.
The shape of the annular protrusion 22 formed on the outer peripheral surface of the vertically middle portion of the tube main body 20 of the spout 2 is not particularly limited. For example, it may be circular or hexagonal. Furthermore, the annular protrusion 22 does not have to be formed.

The ratchet 23 does not have to be formed on the cylindrical main body 20. Furthermore, the tamper-evident function as in the above embodiment does not have to be provided.
The lid body 41 of the lid unit 4 may be solid. Alternatively, the lid body 41 may be hollow and have a closed upper end.

- The inner surface of the peripheral wall 44 of the lid main body 41 is formed in a straight shape with a diameter that does not change in the vertical direction, but is not limited to this. The inner diameter may change, for example, by forming a tapered surface on the inner surface of the peripheral wall 44.

- The outer peripheral surface of the peripheral wall 44 of the lid main body 41 is formed in a straight shape with no change in diameter in the vertical direction except for the protrusion 46, but this is not limited to this. The outer diameter may change, for example, by forming a tapered surface on the outer peripheral surface of the peripheral wall 44.

- The protrusion 46 formed on the outer peripheral surface of the peripheral wall 44 of the lid main body 41 has a tapered surface 46a formed at its lower end, but the shape is not limited to this. For example, the upper end may have a tapered surface that narrows in diameter as it goes upward.

- The bottom surface 45a of the bottom wall 45 of the lid main body 41 is formed as a flat surface that is horizontal in the left-right direction and has no irregularities, but is not limited to this. For example, a gate may be provided on the bottom surface 45a, thereby forming irregularities.

The outer tube portion 43 of the lid main body 41 does not have to be cylindrical. For example, the outer peripheral surface may be elliptical or hexagonal in top view.
The shape and size of the sheet body 5 do not have to be the same as the shape and size of the lower wall 32 of the attachment portion 30 and can be changed as appropriate.

The method for attaching the sheet body 5 does not have to be the adhesive step as in the above embodiment. For example, a multi-layered sheet in a sheet form may be attached to each of the spout devices 1.
In the above embodiment, in the cutting step, the multilayer structure sheet is irradiated with a laser along the periphery of the attachment portion 30 of each spout 1, but this is not limiting. For example, cutting may be performed with a blade.

- The bag-shaped container in the above embodiment is formed from a multi-layered sheet in which an aluminum foil layer is laminated between multiple thin polyethylene sheets, but the configuration and materials are not limited to this.

The spout 1 does not have to be adhered and fixed to the opening of the bag-shaped container by heat sealing. The method of fixing the spout 1 can be changed as appropriate to a method other than heat sealing.
Next, the technical ideas that can be understood from the above-described embodiment and modified examples will be described below.

A method for manufacturing a synthetic resin spout to be attached to the opening of a container that holds a fluid inside. The method includes an attachment step in which a bottomed, cylindrical lid body is inserted into the inside of a cylindrical spout that forms a flow path for the fluid, and a heating step in which the underside of the spout and the bottom of the lid body are heated. In the heating step, the inner periphery of the underside of the spout and the outer periphery of the bottom of the lid body are welded together, and a gas barrier sheet is attached to the underside of the spout and the bottom of the lid body. This configuration reduces the number of steps and makes it easy to obtain a spout with excellent oxygen barrier properties.

C... Flow path 1... Spout 2... Spout portion 4... Lid portion 5... Sheet body (gas barrier layer)
6... Welded part 20... Cylinder body part 30... Mounting part 32a... Lower surface 41... Lid main body part 45... Bottom wall 45a... Bottom surface

Claims (2)

A method for manufacturing a synthetic resin spout that is attached to an opening of a container that contains a fluid therein, comprising:
an attachment step of inserting a bottomed cylindrical lid main body into a cylindrical outlet portion that forms a flow path for the fluid;
a heating step of heating a lower surface of the spout portion and a bottom surface of the lid main body portion;
Equipped with
In the heating step, the inner periphery of the lower surface of the pouring portion and the outer periphery of the bottom surface of the lid main body are welded together to form a single unit, and a gas barrier sheet is attached to the lower surface of the pouring portion and the bottom surface of the lid main body. 2. The method for manufacturing a spout according to claim 1, wherein in the heating step, the gas barrier sheet is placed between the spout and a crimping jig equipped with a thermal welding means and thermal welding is performed, thereby welding and integrating the inner periphery of the underside of the spout portion and the outer periphery of the bottom surface of the lid main body portion, and attaching the gas barrier sheet to the underside of the spout portion and the bottom surface of the lid main body portion.