JPH0796262B2 - Method and apparatus for forming tubular body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and apparatus for polymerizing and adhering a flexible belt-shaped body to a plurality of layers to continuously form a tubular body, and particularly excellent in pressure resistance. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous molding method for tubular bodies and an apparatus therefor.

(Prior Art) Conventionally, a method of forming a tubular body proposed in Japanese Patent Publication No. 60-35254 is known as this type.

In this method, a plurality of flexible strips are polymerized by staggering them laterally so that their side edges are stepwise, and then stacking the strips at first on both side edges thereof. Adhesive only in the narrow width region located in the middle of the band, and at the same time gradually bending these strips along the circumference of the mandrel to form a tubular shape and overlapping the width of the adhesive region of the superposed strip until both sides join. The two edges of the strips, which gradually increase toward the edges and are displaced from each other, are joined to form a complete tubular body.

In this way, when the tubular body is molded, the adhesive region is gradually expanded and molded, which is advantageous in that wrinkles and the like can be prevented from occurring in the adhesive region of each strip.

Also, when the adhesive area is gradually expanded, when the adhesive used is a water-soluble adhesive, the adhesive remains liquid for a relatively long time after being adhered, so that the adhesive between the adhered strips is relatively long. Since they can be offset from each other, it is not necessary to give much consideration to the bonding work even if the bonding area is gradually expanded.

However, when such a water-soluble adhesive is used, it takes a long time for the adhesive to dry. Further, when the molded tubular body is used as a container for containing a liquid, it is necessary to provide a waterproof layer on the innermost layer or the outermost layer, and in that case, it is extremely difficult to dry the adhesive. In such a case, it is preferable to use a hot melt adhesive that does not require drying.

However, when a hot melt adhesive is used as an adhesive in such a molding method, since the strips are adhered and at the same time each strip is firmly fixed,
If even bonding is not performed evenly in each band even when partially bonding, wrinkles will occur between each band and unbonded parts will occur, reducing the compressive strength of the tubular body. It is not possible to form a high-quality tubular body simply by gradually expanding.

(Problems to be Solved) The present invention solves such a conventional inconvenience, and manufactures a tubular body excellent in pressure resistance by uniformly adhering each band-shaped body formed into a tubular body using a hot melt adhesive. It is an object of the present invention to provide a continuous molding method and an apparatus therefor.

(Means for Solving the Problems) In order to achieve the above object, the first aspect of the present invention is to provide a plurality of long strips made of a flexible material such that their side edges are stepwise. Are supplied by polymerizing them by shifting their positions relative to each other, gradually bending along the mandrel, and adhering the respective strips with an adhesive interposed between the strips, and joining both side edges which are offset from each other to complete In the method of forming a tubular body, a step of continuously supplying a plurality of long strips provided with a hot-melt adhesive in a molten state on at least one side thereof with a tension applied in the longitudinal direction at intervals, The space between the bodies is maintained until just before they are bonded to each other, and a force for pressing the strip-shaped body is applied to a mandrel arranged in the longitudinal direction of the strip-shaped body at an intermediate position between both side edges of the innermost strip-shaped body. To form a tubular body by continuously transferring to And a process.

A second aspect of the present invention is to supply a plurality of long strips made of a flexible material by shifting the positions of the strips so that their side edges are stepwise and polymerizing them, and gradually feeding them along a mandrel. Bending In a device for adhering each strip by an adhesive interposed between the strips and joining both side edges which are offset from each other to form a complete tubular body, a hot melt adhesive in a molten state on at least one side A plurality of long strips provided with a space between each other to apply tension to the strip in the longitudinal direction, and a longitudinal direction of the strip at an intermediate position of both side edges of the innermost strip. Of the mandrel and a plurality of rollers having a shape along the outer peripheral surface of the mandrel are displaced in the longitudinal direction of the mandrel, and the positions of the rollers are partially overlapped with each other in the circumferential direction of the mandrel with reference to these one roller. Let's go all around continuously A roller device that is disposed and presses the strip-shaped body against the mandrel by each roller, and a heating and holding device that heats and holds the hot-melt adhesive of the strip-shaped body in a molten state at least until it reaches the roller group. Is characterized by.

The flexible strip used in the present invention is made of a material such as paper or plastic metal foil. Also, these materials may be used in combination. In particular, the present invention is suitable when the innermost layer and outermost layer of the band to be polymerized are waterproofed.

The band-shaped body is made of a continuous long sheet material, and the formed tubular body is appropriately cut into a predetermined size before use.

The hot-melt adhesive used in the present invention may be a known conventional one, such as polyethylene simple substance, ethylene and ethylene copolymer, ethylene vinyl acetate copolymer, ethylene methyl methacrylate copolymer, ethylene ethyl acrylate copolymer. Polymer, ethylene methyl acrylate copolymer, ethylene ethyl acrylate maleic anhydride copolymer, ethylene acrylic acid copolymer, ethylene acrylic acid copolymer, ionomer resin, polyamide resin, polyester resin, nylon resin, polypropylene resin A resin, a vinyl acetate copolymer resin, a polymethylmethacrylate resin, or the like may be used alone or in combination.

A hot melt adhesive is applied to at least one surface of the strip to be used. A hot-melt adhesive may be applied on both sides of the strip forming the intermediate layer. This hot melt adhesive may be applied and formed on a strip in advance and reheated immediately before the step of molding the tubular body to bring it into a molten state.
When molding the tubular body, a hot melt adhesive in a molten state may be applied. This hot melt adhesive needs to be heated so as to maintain the molten state until the tubular body forming step.

A plurality of strips provided with the hot-melt adhesive in a molten state were made to be in a state of being polymerized by shifting their positions so that their side edges are stepwise and at intervals to each other, and polymerizing them. Tension is applied in the longitudinal direction to supply continuously. When such tension is applied continuously, it serves to maintain the distance between the strips until just before forming the tubular body.

In this way, a mandrel having an outer shape that defines the shape of the tubular body in the longitudinal direction is arranged at the intermediate position between the both side edges of the innermost layer of the continuously supplied strip, and the mandrel is arranged around the mandrel. Bending along the surface to form a tubular body. At this time, a pressing force applied to the band-shaped body for bending along the mandrel is continuously transferred linearly in the circumferential direction of the mandrel and given over the entire circumference of the mandrel to form the band-shaped body into a tubular body. is important.

(Operation) The present invention holds the hot-melt adhesive applied and formed on each strip in a molten state until each strip is bonded,
A force that applies a tension to each strip in the longitudinal direction so that the strips are kept spaced from each other until just before the strips are bonded, and presses each strip against the mandrel arranged in the longitudinal direction of the innermost layer. Since it is continuously transferred linearly in the circumferential direction of the mandrel and added to form a tubular body, the region where each strip is adhered is gradually observed as the strip progresses as seen in the transverse position where the strip is located. While it expands to the full width, when viewed in the longitudinal direction of the strip, it gradually expands from the peripheral surface position with the mandrel toward the entire peripheral surface, so that the area of each strip that is not bonded is in the width direction of each strip. On the other hand, it gradually decreases from the peripheral surface position where the mandrel exists in the longitudinal direction of the strip toward the entire peripheral surface, and in the meanwhile, it is free from the bonding area.
Then, the band-like bodies are adhered while the wrinkles and the like generated in the band-like bodies when the pressing area is displaced in the circumferential direction of the mandrel by this pressing force is released to the side edges thereof.

Such adhesion is performed by shifting the positions of a plurality of rollers having a shape along the outer peripheral surface of the mandrel in the longitudinal direction of the mandrel and partially overlapping the positions of the rollers with each other in the circumferential direction of the mandrel with reference to these one roller. It is possible to dispose the rollers over the entire circumference and press each roller against the mandrel through the strip-shaped body. In particular, the tubular body to be molded has a circular or elliptical cross-section, and therefore the mandrel has a circular or elliptical cross-sectional shape, the pressure contact surface of each roller is an arc surface along the outer peripheral surface of the mandrel, and the rotation of each roller is The shaft is provided so as to be orthogonal to the axis of the mandrel, and the mandrel is effectively pressed against the mandrel at the intermediate position of the arc surface via the strip.

(Embodiment) The following will describe the embodiment of the present invention in more detail with reference to the drawings.

1 and 2 are schematic views of an example of an apparatus for carrying out the molding method of the present invention.

A is a feeding device for continuously feeding the four paper strips 1,
B is a preheating device that preheats each of the fed strips 1 in order to uniformly dry the strips, and C is a polymer of the strips 1 that are displaced from each other so that their side edges are stepwise. A positioning device for positioning the strip-shaped body 1, D an adhesive coating device for coating and forming a hot-melt adhesive on each strip 1, and E a heating means for keeping the adhesive coated on the strip 1 in a molten state. A heating device, F is a forming device for bending each strip along a mandrel to form a tubular body, G is a drawing device for pulling out the formed tubular body, and H is a drawn tubular body having an appropriate length. It is a cutting device for cutting.

Each strip 1 is tensioned in the longitudinal direction by the drawing device G after forming until it reaches the forming device F.

FIG. 3 shows the heating device E, in which heated air is jetted from the nozzle 2 having a built-in heater into the gaps between the strips 1 to melt the hot melt adhesive applied to the strips 1. Keep on. A plurality of nozzles 2 are provided so that the hot-melt adhesive agent of each band-shaped body 1 bent and molded by the molding apparatus F as shown in FIG. 4 is surely melted immediately before being bonded. It was

FIG. 5 and FIG. 6 show the forming apparatus F, which extends in the longitudinal direction of the strips at the intermediate position of both side edges of the strips located in the innermost layer of the strips (not shown) continuously supplied. , A mandrel 3 having a circular cross section that extends to the drawing device G and the cutting device H.

Around the mandrel 3, a plurality of rollers 4 to 15 for bending each strip along the outer peripheral surface of the mandrel 3 to form a tubular body are provided at different positions in the traveling direction of the strip. The rollers 4 to 15 are basically all mandrels 3
Has an arcuate surface corresponding to a part of the outer circumferential surface of the mandrel 3 in the circumferential direction, and all of the rotation axes are arranged orthogonal to the axis of the mandrel 3.

Then, as shown in FIG. 6 and FIG. 7 which schematically shows the arrangement of the rollers, the rollers 4 to 15 are arranged such that the roller 4 which first presses the belt-shaped member against the mandrel 3 is located at both side edges of the innermost layer-shaped member 1a. It is provided corresponding to the intermediate position. Then, the rollers 5 and 6 downstream of the roller 4 were provided at positions where the respective pressure contact surfaces of the mandrel 3 overlap with the pressure contact surfaces of the roller 4 in both circumferential directions. In addition, the roller 7 located downstream of the rollers 5 and 6
The roller 5 and the roller 8 are provided so that the pressure contact surfaces of the roller 5 and the roller 6 overlap with each other. Furthermore,
The roller 9 downstream of the rollers 7 and 8 is provided with the roller 7, and the roller 10 is provided with the roller 8 so that their pressure contact surfaces partially overlap with each other, and the other rollers 11 to 15 are also similarly formed. The pressure contact surface is provided on each of the rollers 4 to 15 so as to cover the entire circumference of the mandrel 3.

Each of the rollers 4 to 15 includes cylinders 16 to 27 that press the center of each arc-shaped press contact surface toward the mandrel 3. 28
Is a support roller for supporting and guiding the tubular body formed by the forming apparatus F.

With such a configuration, the rollers 4 to 15 can apply a force for pressing each strip-shaped body to the mandrel 3 with the roller 4 as a reference by continuously transferring it linearly in the circumferential direction of the mandrel 3. Becomes

Further, the process of forming the tubular body will be described with reference to FIG.

First, as shown in FIG. 7 (A), each strip 1 is pressure-contacted by the roller 4 to the mandrel 3 and polymerized and adhered by a hot-melt adhesive interposed therebetween. At this time, the pressing force of the central region 4a of the pressure contact surface of the roller 4 is the maximum, and the pressing force becomes weaker toward the side edge of the pressure contact surface. Therefore, the central region 4a
Then, the respective strips 1 are strongly adhered to each other, and the adhesion is gradually insufficient toward the side edges.

Next, as shown in FIG. 7 (B), the strip-shaped bodies 1 are pressed by the rollers 5 and 6 to expand the bonding area while maintaining a distance from each other except for the portions bonded by the rollers 4. . At this time, since the central regions 5a and 6a of the pressure contact surfaces of the rollers 5 and 6 are displaced in both circumferential directions of the mandrel 3,
The area where the adhesion was insufficient by the roller 4 is completely adhered, and the adhesion area is enlarged. Similarly, FIG. 7 (C)
As shown in (E), rollers 8 to 12 gradually transfer the pressing force linearly toward both side edges of each strip 1 to bend each strip 1 to form a shape along the mandrel 3.

At this time, the roller 11 is bent so that one side edge side of each strip 1 is brought into contact with the mandrel 3 earlier than the other side edge, and thereafter, as shown in FIGS. 7 (F) to (H), the rollers 13 to 15 are bent. Thus, the other side edge is polymerized and bonded to form a completely bonded tubular body.

(Effect) According to the present invention, a plurality of long strips provided with a hot-melt adhesive in a molten state on at least one surface thereof are provided at intermediate positions of both side edges of the innermost strip in the longitudinal direction of the strips. When forming a tubular body by gradually bending along a mandrel provided and adhering to each other, the strips are continuously supplied with a tension applied in the longitudinal direction thereof while maintaining an interval between them, and also by hot melt adhesion. To hold the molten state of the agent to the bonding position and gradually bond the bonding area of each band while bonding,
By applying a force to press the strip on the mandrel by continuously transferring it in the circumferential direction of the mandrel, it is possible to form a tubular body without trouble even if a hot met adhesive is used, and the strips are evenly bonded. It is possible to obtain a tubular body having excellent pressure resistance.

Also, a plurality of rollers having a shape along the outer peripheral surface of the mandrel are displaced in the longitudinal direction of the mandrel and
By using a roller device in which the rollers are arranged over the entire circumference while partially overlapping each other in the circumferential direction of the mandrel with one roller as a reference, and each roller is pressed against the mandrel via the strip, It is possible to form a tubular body in which each strip is uniformly adhered with a melt adhesive.

[Brief description of drawings]

1 to 7 show an embodiment of the present invention, in which FIG. 1 is a plan view thereof, FIG. 2 is a front view thereof, FIG. 3 is a plan view of a heating device, and FIG. 4 is heating. For explaining the heating process of the hot melt adhesive by the apparatus, FIG. 5 is a front view of the molding apparatus, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, and FIG.
The figure is a diagram for explaining the molding process. 1 ... band-shaped body, 3 ... mandrel 4-15 ... roller E ... heating device, F ... molding device

Front page continuation (72) Inventor Satoshi 1528-4 Hara City, Ageo City, Saitama Prefecture (72) Inventor Michiya Tamura 7353-6 Iwatsuki City, Iwatsuki City, Saitama Prefecture

Claims (4)

[Claims] 1. A plurality of long strips made of a flexible material,
They are supplied by polymerizing them by shifting their positions so that their side edges are stepwise, and then gradually bending along the mandrel and adhering the strips with an adhesive interposed between the strips and shifting them from each other. In the method of joining both side edges to form a complete tubular body, a plurality of long strips having a hot-melt adhesive in a molten state on at least one surface are tensioned in the longitudinal direction at intervals. The step of giving and continuously supplying, and the interval between the strips is held until just before being bonded to each other, and the strip is provided on the mandrel arranged in the longitudinal direction of the strip at an intermediate position of both side edges of the innermost strip. And a step of continuously transferring linearly the pressing force of the mandrel in the circumferential direction of the mandrel to form a tubular body. 2. A plurality of long strips made of a flexible material,
They are supplied by polymerizing them by shifting their positions so that their side edges are stepwise, and then gradually bending along the mandrel and adhering the strips with an adhesive interposed between the strips and shifting them from each other. In a device for joining both side edges to form a complete tubular body, a plurality of long strips having a molten hot-melt adhesive on at least one surface are tensioned in the longitudinal direction at intervals. A belt-shaped body feeding device for supplying and feeding, a mandrel arranged in the longitudinal direction of the belt-shaped body at an intermediate position of both side edges of the innermost belt-shaped body, and a plurality of rollers having a shape along the outer peripheral surface of the mandrel. In the longitudinal direction of the mandrel and these one roller is used as a reference, and the positions are partially overlapped with each other in the circumferential direction of the mandrel so as to be arranged continuously over the entire circumference, and the belt-shaped body is pressed against the mandrel by each roller. Do Over La apparatus and the molding device of the tubular body, characterized by comprising a heating holding device for heating and maintaining the hot melt adhesive of the strip in the molten state until it reaches at least the rollers. 3. The mandrel has a circular or elliptical cross-sectional shape, the pressure contact surface of the roller is an arcuate surface along the outer peripheral surface of the mandrel, and the rotation axis of the roller is orthogonal to the axis of the mandrel. The tubular body molding apparatus according to claim 2, wherein the strip-shaped body is pressed against the mandrel at the middle position of the arc surface. 4. The mandrel and a roller of the rollers, which first presses the strip-shaped body against the mandrel, are provided at an intermediate position of both side edges of the innermost strip-shaped body of the strip-shaped body. The apparatus for molding a tubular body according to claim 2.