Method for connecting composite sheet materials

Abstract

To provide a method for connecting composite sheet materials while ensuring necessary strength and preventing the thickness of the connecting portion from increasing.SOLUTION: When joining composite sheet materials 60 each including a heat-sealable layer 62 and a functional layer 61 laminated on the heat-sealable layer 62 and having the function required for the product, the ends of the composite sheet materials 60 are butted together. Next, an auxiliary heat-sealable sheet 71 formed of a heat-sealable layer 64 is placed over the ends of the heat-sealable layer 62. By heating the composite sheet material 60 and the auxiliary heat-sealable sheet 71, the heat-sealable layer 62 and the auxiliary heat-sealable sheet 71 are welded together, and the butted ends are also welded together with the auxiliary heat-sealable sheet 71.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for connecting composite sheet materials. [Background technology]

[0002] One example of a case where joining of sheet materials is required is the production of packaging containers. For example, Patent Document 1 discloses a method of manufacturing a packaging container by using a laminated sheet material in which a base film layer and a sealant layer are laminated, and overlapping and joining the base film layers in a gabled shape. Patent Document 1 also discloses that the gabled joint can be folded back toward the laminated film side to increase the joining strength and improve airtightness.

[0003] Furthermore, Patent Document 2 discloses a method of overlapping the ends of two sheet materials, covering the overlapping area with a film sheet, and joining them by heat welding. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-96391 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-14508 Summary of the Invention [Problem to be solved by the invention]

[0005] The mainstream joining method for manufacturing packaging containers is clasp welding, which forms a joint in a folded shape. However, the clasp welding disclosed in Patent Document 1 has the problem of low tensile strength. In addition, it has the problem of the joint becoming thick.

[0006] Furthermore, the method disclosed in Patent Document 2, in which sheet materials are stacked and covered with a film sheet, has the problem of thick joints. In particular, with rubberized sheet materials, the sheet materials themselves are thick, so the joints become thick. Furthermore, there are sheet materials, such as rubber, that cannot be welded.

[0007] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a method for connecting composite sheet materials that ensures the necessary strength and does not increase the thickness of the connecting portion. [Means for solving the problem]

[0008] In order to solve the above problems, the method for connecting composite sheet materials of the present invention comprises: When joining composite sheet materials each including a heat-sealable heat-sealable layer and a functional layer laminated on the heat-sealable layer and having a function required for a product, butting the ends of the composite sheet material together; An auxiliary heat-sealing sheet having a surface formed of a heat-sealing agent is placed across the end of the heat-sealing layer, At least the joint portion between the composite sheet material and the auxiliary heat-sealing sheet is heated, whereby the heat-sealing layer and the heat-sealing agent of the auxiliary heat-sealing sheet are welded together, and the butted ends are also welded together.

[0009] the composite sheet material is composed of a laminate of a thermoplastic polyurethane layer and a rubber layer, It is desirable that at least one surface of the auxiliary heat-welding sheet be made of a thermoplastic polyurethane layer.

[0010] The composite sheet materials may be connected in a circular shape by butting the longitudinal ends together and applying the auxiliary heat-welding sheet to them and heat welding them together, and then the circular composite sheet materials may be folded in the width direction and the composite sheet materials may be overlapped and joined together to connect them in a circular and cylindrical shape. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a method for connecting composite sheet materials that ensures the necessary strength and does not increase the thickness of the connecting portion. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a side view of a composite sheet material according to an embodiment of the present invention. [Figure 2] 1A and 1B are diagrams for explaining a method for connecting composite sheet materials according to an embodiment of the present invention, in which (a) is a plan view of the composite sheet materials to be connected in a butted state, and (b) is a side view of (a). [Figure 3] 1A and 1B are diagrams for explaining a method of connecting composite sheet materials according to an embodiment of the present invention, in which (a) is a plan view showing an auxiliary heat-sealing sheet placed across composite sheet materials that are butted together, and (b) is a side view of (a). [Figure 4] 1A and 1B are diagrams for explaining a method for connecting composite sheet materials according to an embodiment of the present invention, in which (a) is a side view showing a step of heating and pressurizing the joining portions of the composite sheet materials to be connected, and (b) is a side view showing the connected state. [Figure 5] FIG. 10 is a diagram showing the composite sheet material joined together in a cylindrical shape. [Figure 6] 1A and 1B are diagrams for explaining the auxiliary air column frame of a muddy walking board according to an embodiment of the present invention, in which (a) is a schematic oblique view of the air column frame body only, and (b) is a schematic oblique view of the auxiliary air column frame showing the walking board disassembled. [Figure 7] 1A and 1B are diagrams for explaining the auxiliary air column frame of a board for walking on muddy ground according to an embodiment of the present invention, where (a) is a plan view, (b) is a cross-sectional view taken along line AA in (a), and (c) is a cross-sectional view taken along line BB in (a). [Figure 8] 1A to 1D show the first half of a method for manufacturing an auxiliary air column frame for a board for walking on muddy ground according to an embodiment of the present invention. [Figure 9] 1A to 1D are process diagrams of the latter half of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Below, an embodiment of the method for connecting composite sheet materials of the present invention will be described with reference to an example in which multiple composite sheet materials are connected to form a cylindrical air column frame, and this air column frame is used to construct an auxiliary air column frame for a board material for walking on muddy ground.

[0014] In the following description, examples of heat welding include heat sealing (external heating) and high-frequency welding. High-frequency welding applies internal heat only to the welding points of the heated object, allowing welding in a short time and without thermally affecting non-welded areas. Furthermore, because the heated object is heated uniformly from the inside, the welding strength is excellent, and stable welding processing can be performed with a heating time of just a few seconds. Furthermore, it is a clean processing method that does not generate environmentally hazardous substances during or after processing. In order to prevent the heat from affecting non-welded areas, heat welding using a high-frequency welder is more preferable. In the example of constructing a board for walking on muddy terrain, heat welding using a high-frequency welder is shown.

[0015] In this embodiment, the composite sheet material 60 to be connected is a laminate in which a functional layer 61 and a thermal welding layer 62 are laminated, as shown in FIG.

[0016] The functional layer 61 functions as the outer layer of the product manufactured using the composite sheet material 60, and is made of a material that fulfills the functions required for the outer surface of the final product. In this embodiment, since the final product is a walking board that is placed on muddy ground and used, the functional layer 61 is made of a rubber layer 61 that is excellent in airtightness, waterproofness, strength, etc. However, it is not limited to this and can be changed as appropriate depending on the application, etc.

[0017] On the other hand, the thermal welding layer 62 is a layer in which at least the outer surface area is made of a thermal welding agent, which is a material that can be heat-sealed. In this embodiment, the thermal welding layer 62 is a thermoplastic polyurethane layer (TPU layer) 62.

[0018] In this embodiment, the board is for walking on muddy ground and requires strength. For this reason, a reinforcing layer 63 is further provided between the rubber layer 61 and the TPU layer 62. The reinforcing layer 63 is a layer that ensures the strength of the entire composite sheet material 60 and is made of a flexible, high-strength material. In this embodiment, the reinforcing layer 63 is a nylon fabric layer.

[0019] With the above-described configuration, the composite sheet material 60 has the necessary functions such as waterproofness, stain resistance, and strength for use in muddy areas provided by the outer rubber layer 61, the TPU layer 62 ensures heat welding properties, and the nylon fabric layer 63 ensures even greater strength.

[0020] An example of a composite sheet material 60 having the above configuration and functions is HY-450 SP / PU manufactured by Achilles Corporation, which has a rubber layer 61 with a thickness of 0.16 mm, a TPU layer 62 with a thickness of 0.18 mm, and a nylon fabric layer 63 with a thickness of 0.26 mm, with a total thickness of 0.6 mm.

[0021] Next, a process for manufacturing a cylinder by joining a plurality of composite sheet materials 60 having the above-described structure will be described. First, composite sheet materials 60A and 60B, which are approximately rectangular in plan view, are prepared and arranged with their end faces (edges) butted against each other with a gap GA between them, as shown in Figures 2(a) and 2(b). The gap GA is approximately 0 to 5 mm, but is not limited to this. From the perspective of avoiding stress concentration, it is desirable that the edge (opposing edge) of composite sheet materials 60A and 60B be straight and approximately parallel to each other.

[0022] Next, as shown in FIGS. 3(a) and 3(b), an auxiliary heat-sealing sheet 71 is placed over the gap GA, spanning both composite sheet materials 60. The auxiliary heat-sealing sheet 71 has a heat-sealing layer 64. The heat-sealing material is preferably TPU for ease and reliability of welding to the TPU layer 62. Therefore, in the following description, the heat-sealing layer 64 is assumed to be a TPU layer. Furthermore, to ensure the strength of the joint, it is preferable to have a reinforcing layer 65 made of a flexible, high-strength material, such as a nylon fabric layer 65.

[0023] The overlap length L between the auxiliary heat-welding sheet 71 and the composite sheet materials 60A, 60B is preferably 5 mm, and more preferably 10 mm or more, from the viewpoint of ensuring strength and airtightness.

[0024] Next, as shown in Fig. 4(a), the entire joint between the thermal welding layer 64 and the composite sheet materials 60A, 60B is welded using a high-frequency welder, and as shown in Fig. 4(b), the TPU layers 62 and 64 are melted and integrated. After that, the composite sheet materials 60A, 60B are naturally cooled, and the TPU layers 62 and the thermal welding layer 64 are welded together at their surfaces.

[0025] The heating method for welding is not limited, but it is preferable to use a high-frequency welder as described above, since it is possible to heat only the areas to be welded internally and to weld without thermally affecting areas that are not to be welded.

[0026] During welding, as shown in FIG. 4(b), it is desirable that a portion 64a of the molten TPU penetrates into the gap GA, and that the opposing end faces of the TPU layer 62 are also welded together. Furthermore, it is desirable that the opposing end faces of the nylon fabric layer 65 are also welded together. Welding the end faces further increases the adhesive strength. This allows for higher-pressure air to be introduced when applied to the manufacture of the air column frame 10 described below, for example, making damage and air leakage less likely when the air column frame 10 is inflated. Furthermore, the gap GA is partially or entirely filled with molten TPU, reducing the possibility of damage due to snagging from the functional layer.

[0027] If the length of the composite sheet material 60 in the X-axis direction after joining is shorter than the length of the cylinder to be formed, the same joining operation is repeated to ensure the required length in the X-axis direction. Similarly, if the length of the composite sheet material 60 in the Y-axis direction after joining is insufficient for the circumferential length of the cylinder to be formed, the same joining operation is repeated in the Y-axis direction as well to ensure the required length.

[0028] When the joining process forms a composite sheet material 60 of a size that can be formed into a cylinder, for example, as illustrated in Figure 5, the composite sheet material 60 is folded in the Y-axis direction, i.e., the width direction, to shape the composite sheet material 60 into a cylindrical shape, and the strip-shaped end portions (strip portions) 60a extending in the X-axis direction are overlapped with each other. Next, the strip portions 60a are welded using a high-frequency welder to join the TPU layers 62. Note that by not aligning the edges of the strip portions 60a and leaving an end 60aa of the TPU layer 62 of one of the strip portions 60a exposed, it is possible to connect the strip portions 60a to other members by thermal welding.

[0029] In this manner, the composite sheet material 60 can be used to manufacture a cylinder 69 having fin-like bands 60a.

[0030] (Application example) Hereinafter, such a connecting method using the composite sheet material 60 will be used, for example, to manufacture the auxiliary air column frame 1 of the board for walking on muddy ground shown in FIG.

[0031] As shown in Figure 6, the auxiliary air column frame (hereinafter simply referred to as the air column frame) 1 is composed of an air column frame body 10 that surrounds the attached walking board material P and is placed on muddy ground, a strip-shaped portion 20 that protrudes inside the periphery of the air column frame body 10 and prevents mud and water from entering the air column frame body 10 from the bottom, and a support connecting body 30 that connects the strip-shaped portions 20 to support the walking board material P and can drain mud and water from inside the air column frame body 10 when it is retrieved.

[0032] The air column frame 1 is made of prefabricated (unprocessed) boards such as 6x6 boards or plywood (910 x 1820 mm) that are attached as walking boards P during rescue operations, etc., and serves as the frame for the air column to construct a walkway.

[0033] In summary, the above-mentioned connection technology is utilized in the manufacture of the air column frame body 10 of the air column frame 1 in the following ways. First, multiple composite sheet materials 60 are connected with auxiliary heat-welding sheets 71 to form a long piece, as shown in Figures 2 to 4. Next, the longitudinal ends of the long composite sheet materials 60 are butted together, and as shown in Figures 2 to 4, auxiliary heat-welding sheets 71 are applied and welded to connect them, forming a ring shape. Next, the ring-shaped composite sheet materials 60 are folded in the width direction and connected by cross-jointing, as shown in Figure 5, to form an airtight ring-shaped cylinder. High-pressure air is injected into this ring-shaped cylinder to form the air column frame 10. Furthermore, the strip-shaped portion 20 protruding inside the bottom of the air column frame 10 is connected to the strip-shaped support connector 30.

[0034] When the air column frame 10 was covered with a composite sheet material 60 butted with a 25 mm wide auxiliary heat welding sheet 71 and the connecting parts were heat welded using an electrode (high frequency welder processing), the strength and airtightness required in the tensile direction when the internal pressure of the air column frame 10 was set to 100 KPa were ensured. Similarly, it was confirmed that the strength and airtightness required in the circumferential direction when the internal pressure of the air column frame 10 was set to 100 KPa were ensured when the connecting parts in the circumferential direction were heat welded using an electrode. When heat welding was performed by pressing an electrode against the frame, the corners of the electrode tip were scraped off to prevent scratches caused by the electrode itself.

[0035] The air column frame 10 of the air column frame 1 is cylindrical and, as shown in Figures 5 and 6, is placed on muddy ground, surrounding the walking board P, and is inflated with air. The diameter d of the air column frame 10 is set so that, when placed on muddy ground, mud and water do not creep up, and rescued people and objects can be pulled in without being lifted. The diameter d of the air column frame 10 is, for example, 50 mm or more and 300 mm or less. If the diameter d is too small, such as 50 mm or less, it will not function as a protective barrier against mud and water. If the diameter d is larger than 300 mm, rescued people and objects cannot be pulled in from muddy ground into the air column frame 10, and must be lifted. The diameter d of the air column frame 10 is preferably 100 to 200 mm, and more preferably 100 to 150 mm.

[0036] The perimeter of the air column frame 10 is set so that the walking boards P, such as plywood, mounted inside the air column frame 10 will not come off even if the frame is turned upside down. For example, if a 910 x 1820 mm plywood panel has a diameter d of 100 mm, the short sides of the air column frame 10 on the center line are approximately 1020 mm (910 + approximately 100 mm) and the long sides are approximately 2000 mm (1820 + approximately 100 mm). In this case, the perimeter is (approximately 1020 + approximately 2000) x 2 = approximately 6040 mm. This allows the walking boards P to be mounted so that they fit around the perimeter of the expanded air column frame 10 by approximately 20 mm, as shown in Figure 7, and the expansion of the air column frame 10 helps maintain the mounted state.

[0037] As shown in Figures 6 and 7, the air column frame 10 is formed by molding the air column chamber 11 into a rectangular frame shape. The rectangular frame-shaped air column chamber 11 can be formed by any method. For example, one air column chamber 11 can be bent at four corners to form a rectangular frame. Alternatively, two air column chambers 11 bent at their corners can be connected to form a rectangular frame. The number of air column chambers 11 is not limited to the above example and can be set as appropriate. As will be described later, each air column chamber 11 is provided with at least one air valve 12 so that the air column chamber 11 can be inflated or deflated.

[0038] A fin-shaped band-like portion 20 is provided protruding inward from the bottom of the air column frame 10. As shown in FIG. 7, the band-like portion 20 is formed in a sheet shape, for example, with a protrusion amount (protrusion width) of approximately 100 mm from the bottom of the center line of the air column frame 10. This minimizes the infiltration of mud, water, etc. into the inside of the upper surface of the air column frame 10 from the bottom of the air column frame 10. In addition, by attaching a walking board P between the band-like portion 20 and the expanded air column frame 10, the walking board P can be held to the air column frame 10 in cooperation with the support connector 30, which will be described later. The band-like portion 20 corresponds to the heat-welded band-like portion 60a shown in FIG. 5.

[0039] The centers of the band-shaped portions 20 on the short sides of the air column frame 10 and the centers of the band-shaped portions 20 on the long sides are connected in a cross shape by band-shaped support connectors 30. As a result, the inside portions of the band-shaped portions 20 on the bottom of the air column frame 10 are not completely blocked, and four rectangular through-holes 31 partitioned by the support connectors 30 are formed in the bottom.

[0040] As shown in FIGS. 1 and 2, the air-column frame 10 is provided with handles 40 on its short sides. More specifically, metal rings 41, e.g., D-shaped rings, are attached to two locations on the short sides of the air-column frame 10 by gluing them via a fixing sheet material, and the metal rings 41 are connected by handles 40 made of a string-like belt member. The handles 40 allow the air-column frame 10 with the walking board P attached to it to be easily transported. Alternatively, string-like connecting members 50 may be tied to the metal rings 41, and the connecting members 50 may be passed through the metal rings 41 of adjacent air-column frames 10 and connected with rod-like fasteners (duffle buttons: toggle buttons) 51, allowing the air-column frames 10 to be connected to each other. This configuration allows the air-column frames 10 to be connected to each other without being affected by mud getting caught, as compared to when only buckles or string-like connecting members 50 are used.

[0041] When installing a walking board for muddy terrain, a walking board P such as plywood is attached to the inside of the air column frame 10 before inflation. Next, air is pumped into the air column frame 10 through the air valve 12 to inflate it. The walking board P is then held between the band-shaped portion 20 and the inflated air column frame 10.

[0042] Next, the air column frame 1 is lifted by the handles 40, and the air column frame 1 with the walking board P attached is placed on the muddy ground. When placed on the muddy ground, the bottom periphery of the air column frame body 10 is sealed with the strip-shaped portion 20, which prevents mud and water from entering from the bottom, and also prevents mud and water from creeping up from the top of the air column frame body 10.

[0043] This allows a walkway to be constructed in muddy ground using the air column frame 1 and walking planks P. Moreover, the boundary between the muddy ground and the walking planks P is clearly defined by the air column frame body 10, allowing people to walk safely on the walking planks P. If the walkway needs to be extended further, a similar air column frame 1 is carried to an adjacent muddy ground, and the string-like connecting member 50 is passed through the metal ring 41 of the handle 40 and connected with the rod-like fastener 51. In this way, the air column frames 1 can be connected in a line adjacent to each other, allowing the walkway to be extended and constructed.

[0044] When retrieving the air column frame 1, the walking plank P can be lifted together with the air column frame body 10 by lifting the air column frame 1 using the handle 40. Even if mud or water gets inside the walking plank P, it will be expelled through the through holes 31 between the support connecting bodies 30, and it can be retrieved and transported without becoming heavy.

[0045] Next, one embodiment of a method for manufacturing the air column frame 1 of the board for walking on muddy ground having the above-mentioned configuration will be described according to the steps shown in FIGS.

[0046] First step S1: As shown enlarged in Figure 8(a), the air column frame 1 is formed from a composite sheet material 60 in which a surface rubber layer 61, a TPU layer 62, and a nylon fabric layer 63 are laminated.

[0047] The composite sheet material 60 is connected as necessary, and the width is adjusted to the sum of the circumferential length of the air column frame 10 and the length of the strip portion 20, and the length is adjusted to the perimeter of the walking board P. In the illustrated example, two pieces of air column frame 10 each having half the circumferential length required for joining are prepared in the length direction, and these are joined together for use.

[0048] An air valve 12 for supplying and discharging air into the air column chamber 11 is attached to the composite sheet material 60 in advance. Furthermore, reinforcing sheet materials 70 are attached to the composite sheet material 60 at four locations corresponding to the corners of the walking board P. The reinforcing sheet materials 70 may be formed by cutting a composite sheet material 60 made of the same material as the composite sheet material 60 and heat welding the TPU layers 62 together. The reinforcing sheet material 70 has gaps formed at the top and bottom in the width direction so that when the air column frame 10 is joined into a cylindrical shape, the sheets do not overlap and interfere with each other.

[0049] Second step S2: As shown in Figures 8(b) and 8(c), the composite sheet material 60 is joined in the lengthwise direction to form a ring-shaped sheet 80. The composite sheet material 60 is joined in one position in the lengthwise direction to form a single sheet. The two joints are joined by thermal welding using an auxiliary thermal welding sheet 71, as shown in an enlarged partial view in Figure 8(c). The joining method described with reference to Figures 2 to 4 is used. By joining the two positions of the composite sheet material 60, the ring-shaped sheet 80 is formed (see Figure 8(d)).

[0050] Third step S3: As shown in Fig. 9(a), the annular sheet 80 is folded in the width direction and joined together, leaving the band-shaped portion 20, to form the annular air column frame 10. This is the joining method described with reference to Fig. 8.

[0051] Fourth step S4: As shown in Figures 9(b) and (c), triangular corner holding portions 21 that hold the air column frame 10 in its folded shape are formed on the band-shaped portion 20 of the outer portion of the air column frame 10 to which the reinforcing sheet material 70 is attached. More specifically, corner holding portions 21 in the shape of an isosceles right triangle with a corner as the apex are cut out in advance from the band-shaped portion 20 of the portion where the reinforcing sheet material 70 has been attached inside the annular sheet 80, and the two right-angled sides are joined by welding or the like. This forms a right-angled corner with the apex of the corner holding portion 21 as the center. Note that the corner holding portion 21 may also be cut out after the two right-angled sides are joined by welding or the like. Furthermore, although not shown, the inside portion of the air column frame 1 where the two right-angled sides are welded is reinforced by adhesive or welding the reinforcing sheet material 70 or the like across it. Corner holding parts 21 are formed at four places on the annular sheet 80, and when air is pumped into the air column frame 10 from an air valve 12 to inflate it, the corners of the air column frame 10 are restrained and bent at right angles.

[0052] Fifth step S5: As shown in Figure 9(d), support connectors 30 that support the walking planks P are connected between the strips 20. The support connectors 30 connect the opposing center portions of the strips 20 that protrude inward within the air-column frame 10. Composite sheet materials 60 made of the same material as the air-column frame 10 and the strips 20, each approximately 100 mm wide, are arranged in a cross shape, and the strips 20 and the composite sheet materials 60, such as thermoplastic polyurethane layers, are attached by thermal welding. The intersections of the strips 20 are bonded with adhesive or left unbonded. As a result, the inner portions of the bottom strips 20 of the air-column frame 1 are not completely blocked, and four rectangular through-holes 31 separated by the support connectors 30 are formed in the bottom of the air-column frame 10.

[0053] Sixth step S6: Handles 40 are attached to the short sides of the air column frame body 10, and metal rings 41 are attached at two points on the short sides by gluing them via a fixing sheet material, and the two metal rings 41 are connected by the handles 40. In addition, a connecting member 50 is tied to the metal ring 41 of the handle 40, and string-like connecting members 50 are passed through the metal rings 41 of adjacent air column frames 1 and connected with rod-like fasteners (duffle buttons: toggle buttons) 51, so that the air column frames 1 can be connected to each other.

[0054] As described above, according to the manufacturing method of the air column frame for the board material for walking on muddy ground, the air column frame body 10 can be easily manufactured using the composite sheet material 60, and by attaching a board material such as plywood as the walking board material P, rescue operations and walking on muddy ground can be carried out safely. In addition, the joining of the composite sheet material 60 can ensure joint strength and airtightness by combining joining using a cross joint (cross joint) and joining using heat welding in which an auxiliary heat welding sheet 71 is attached to the butt joint.

[0055] As specifically explained in the above embodiments, the air column frame body 10 of the air column frame 1 of the muddy walking board of the present invention comprises the air column frame body 10 that surrounds the attached walking board P and is placed on the muddy ground, the strip-shaped portion 20 that protrudes inside the periphery of the air column frame body 10 and prevents mud and water from entering the air column frame body 10 from the bottom, and the support connecting body 30 that connects the strip-shaped portions 20 to support the walking board P and can drain mud and water from the air column frame body 10 when it is retrieved.

[0056] According to this configuration, by attaching the walking plank P to the inside of the air column frame 10, even when placed on muddy ground, the boundary between the walking plank P and the muddy ground can be clearly defined, allowing people to safely walk on the walking plank P or perform rescue operations. In addition, when retrieving the walking plank P, mud and water can be discharged through the through holes 31 of the support connecting body 30 simply by lifting it up, and it can be easily retrieved and transported without becoming heavy.

[0057] In the muddy walking board of the present invention, the air column frame 10 is formed of one air column chamber 11 or multiple air column chambers 11, and is bent or connected to a shape that corresponds to the outer shape of the walking board P, and is made into a ring shape that holds the attached walking board P. With this configuration, preparation can be easily performed by inflating the air column frame 10 with air, and rescue operations can be started quickly by assembling it with standardized boards such as ready-made plywood as walking boards P. In addition, it is easy to secure the walking boards P in the vicinity of where rescue operations will be carried out, and they are also easy to transport.

[0058] The air column frame 10 of the board for walking on muddy ground of the present invention has a diameter d that allows the object to be pulled in without mud and water creeping up and lifting it from the muddy ground. With this configuration, when carrying out rescue operations in muddy areas, rescuers or large objects do not need to be lifted, but can simply be pulled in, thereby reducing the physical exertion required for the work.

[0059] In the muddy walking board of the present invention, the air column frame 10 is provided with a handle 40 so that it can be carried with the walking board P attached. This configuration allows for easy lifting, transport, and retrieval, allowing for quick use.

[0060] In the muddy terrain walking board of the present invention, the air column frame body 10 is provided with connecting members 50 that connect adjacent air column frame bodies 10. With this configuration, adjacent air column frame bodies 10 can be connected with the connecting members 50, making it easy to extend the walking path and expand the range of rescue operations.

[0061] In the muddy walking board of the present invention, the air column frame 10 is composed of a composite sheet material 60 in which a rubber layer 61 is laminated on the surface of a heat-sealed layer 62, and the composite sheet materials 60 are overlapped and joined together in the circumferential direction, and in the longitudinal direction, the end faces are butted together and heat-sealed via an auxiliary heat-sealed sheet 71 having a TPU layer 64 to form a ring shape. According to this configuration, by using the composite sheet material 60 and combining cross-jointing and butt-jointing of the end faces, it is possible to form an air column frame 10 that is highly airtight and strong.

[0062] In the muddy walking board of the present invention, the walking board P attached to the air column frame 10 is made of standard plywood used for concrete processing that has been treated to be water resistant. According to this configuration, the walking board material P can be procured without prior preparation, and no processing is required, which makes it easier to respond at the scene of rescue operations.

[0063] In addition, the manufacturing method of the air column frame for the muddy walking board of the present invention includes the steps of attaching a reinforcing sheet material 70 to the inner surface of a composite sheet material 60, the composite sheet material 60 having a width approximately equal to the circumferential length of the air column plus the width of the band-shaped portion 20, and having a length approximately equal to the perimeter of the walking board P, so as to correspond to the position of the corners of the walking board P; connecting the ends of the composite sheet material 60 to form an annular sheet 80; folding the annular sheet 80 widthwise to form an annular air column frame body 10, leaving the band-shaped portion 20; forming triangular corner holding portions 21 on the band-shaped portion 20 of the outer portion of the air column frame body 10 to which the reinforcing sheet material 70 is attached, which hold the air column frame body 10 in its folded shape; and connecting support connectors 30 that support the walking board P between the band-shaped portions 20.

[0064] With this configuration, the air column frame 10 can be easily manufactured using the composite sheet material 60, and by attaching a board material such as plywood as a walking board material P, rescue operations and walking in muddy areas can be carried out safely. In addition, the joining of the composite sheet material 60 can ensure joint strength and airtightness by combining joining using a cross joint (cross joint) and joining using heat welding in which an auxiliary heat welding sheet 71 is attached to the butt joint.

[0065] In the method for manufacturing the air column frame of the muddy walking board of the present invention, the composite sheet material 60 and the auxiliary heat-welding sheet 71 are made of a composite sheet material in which a rubber layer is laminated on the surface of a thermoplastic polyurethane layer. With this configuration, the thermoplastic polyurethane layers can be joined together by heat welding, and by combining butt joints and cross joints, it is possible to ensure joint strength and airtightness.

[0066] In the manufacturing method of the air column frame of the muddy walking board of the present invention, the composite sheet material 60 is joined by butting the ends together and overlapping the TPU layer 64 of the auxiliary heat-welding sheet 71 for thermal welding. With this configuration, the auxiliary heat-welding sheet 71 can be used to butt together and weld, keeping the joint flat.

[0067] The present invention is not limited to the above-described embodiments, and each invention can be combined to provide its own effects. [Explanation of symbols]

[0068] 1 Auxiliary air column frame (air column frame) 10 Air column frame 11 Air column chamber 12 Air valve 20 Belt 21 Corner holding part 30 Support connection 31 Through hole 40 Handle 41 Metal Ring 50 Connecting member 51 Rod-shaped fastener 60 Composite Sheet Material 60a Belt 61 Functional layer (outer layer, rubber layer) 62 Heat-sealed layer (thermoplastic polyurethane layer (TPU layer)) 63 Reinforcement layer (nylon fabric layer) 64 Heat welding layer (TPU layer) 65 Reinforcement layer (nylon fabric layer) 70 Reinforcement sheet material 71 Auxiliary heat-sealing sheet 80 Circular Sheet P Walking board d Diameter of the air column frame

Claims

1. When joining composite sheet materials each including a heat-sealable heat-sealable layer and a functional layer laminated on the heat-sealable layer and having a function required for a product, butting the ends of the composite sheet material together; An auxiliary heat-sealing sheet having a surface formed of a heat-sealing agent is placed across the end of the heat-sealing layer, At least the joint portion between the composite sheet material and the auxiliary heat-welding sheet is heated to weld the heat-welding layer and the heat-welding agent of the auxiliary heat-welding sheet, and also weld the butted ends together. A method for connecting composite sheet materials.

2. the composite sheet material is composed of a laminate of a thermoplastic polyurethane layer and a rubber layer, At least one surface of the auxiliary heat-welding sheet is made of a thermoplastic polyurethane layer. The method for connecting composite sheet materials according to claim 1.

3. The longitudinal ends of the composite sheet materials are butted together and the auxiliary heat-welding sheet is applied and heat-welded to connect them into a ring shape, and then the ring-shaped composite sheet materials are folded in the width direction and the composite sheet materials are overlapped and joined together to connect them into a ring and cylindrical shape.

3. The method for connecting composite sheet materials according to claim 1 or 2.

Images