Coreless roll body and method for manufacturing the same

Abstract

To provide a cylindrical coreless roll body which is a winding body of a sheet such as a blue sheet, is sufficiently hard even in a state without a winding core, and keeps a circular shape of an end face, and to provide its manufacturing method.SOLUTION: A coreless roll body is a cylindrical roll body having a circular end face and formed of a wound body of a sheet, wherein the sheet is formed of a laminated sheet in which a synthetic-resin layer is laminated on one surface of a fabric formed of flat yarns, a central hole penetrating from one end face to the other end face is formed in a central portion of the end face of the roll body, a caliber of the central hole is 15 to 25mm, and the central hole has no winding core. The method for manufacturing the coreless roll body includes a step of winding and taking up the sheet around a take-up shaft in which two shaft members having inclined parts are overlapped with each other at the inclined parts, and then pulling the shaft members in the longitudinal direction of the take-up shaft to separate and pull out the shaft members.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a roll body made of a wound sheet, and a method for manufacturing the same. [Background technology]

[0002] Sheets called blue tarps are used for rain cover for materials at construction sites, temporary covering for buildings, rain protection for agricultural crops stored outdoors, and as simple mats for sports days and outings.

[0003] Blue tarps are made by weaving a thread called flat yarn, which is obtained by cutting and stretching a film, and then laminating a synthetic resin layer on the resulting fabric. Blue tarps are typically cut to standard sizes, such as 1.8m x 1.8m, 1.8m x 3.6m, or 3.6m x 5.4m, with the edges of the fabric folded over and metal grommets attached to the edges formed by the folding. They are sold in retail stores, such as home improvement centers, folded to a size of approximately 25cm x 40cm.

[0004] On the other hand, when covering a large area, such as for protection in civil engineering construction work, or as temporary covering for playgrounds or walkways, long tarps are sometimes rolled up into rolls without cutting them to a standard size, folding the edges of the fabric, or attaching grommets. Because these rolls can be rolled to unfold the tarp, they are easier to use than tarps cut to a standard size when covering a large area. Traditionally, rolls have been made by wrapping tarps around a core such as paper.

[0005] Known methods for obtaining a roll without using a core include a method using a core for manufacturing a coreless roll, as described in Patent Document 1. However, the core for manufacturing a coreless roll described in Patent Document 1 was not at all intended to be used to produce a wide roll such as a blue tarp. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-71473 Summary of the Invention [Problem to be solved by the invention]

[0007] The core used in the roll body is no longer needed after the tarp is spread and installed, and must be disposed of. It is desirable to use a coreless roll body that does not use a core, even for wide roll bodies such as tarps.

[0008] One way to obtain a roll without a core is to remove the core after winding. However, when a long tarp is wound with a certain amount of tension, the tarp tightens, making it difficult to remove the core. If the tension applied when winding the tarp is released, the sheet will pop out like a bamboo shoot at the beginning of the winding when the core is removed. Even if the core can be successfully removed, if the roll is soft and easily deformed, the end surface will deform into an oval cylindrical shape, making it difficult to roll and unfold the tarp, and the roll will bend in the middle of the tarp's width.

[0009] To provide a cylindrical coreless roll body, which is a roll of a sheet such as a blue sheet, that has sufficient hardness even without a core and maintains the circular shape of the end face, and a method for manufacturing the same. [Means for solving the problem]

[0010] The above problem can be solved by providing a cylindrical roll body having a circular end face made of a roll of sheet, the sheet being a laminated sheet in which a synthetic resin layer is laminated on one side of a woven fabric made of flat yarn, the roll body end face having a central hole at the center thereof that penetrates from one end face to the other end face, the central hole having a diameter of 15 to 25 mm, and a coreless roll body in which no winding core is provided.

[0011] In this case, the width of the sheet is preferably 75 to 225 cm, and the wound length of the sheet is more preferably 10 to 300 m. As a manufacturing method thereof, it is preferable to wind the sheet around a winding shaft in which two shaft members each having an inclined portion are overlapped with each other with the inclined portions facing each other, and then pull the shaft members in the longitudinal direction of the winding shaft to separate and remove them. [Effects of the Invention]

[0012] The coreless roll of the present invention has a small diameter of the central hole at the end face of the roll, so it is sufficiently hard even without a core, and the circular shape of the end face is maintained, making it easy to roll the roll and unfold the sheet. Since there is no core, there is no need to dispose of it, and the weight is lighter because no core is used. The diameter of the end face of the roll is also reduced, and the roll is sufficiently hard and less flexible, making it easy to carry and transport. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing a coreless roll body of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing a state in which the shaft member of the winding shaft used in the examples is separated. [Figure 3] FIG. 2 is a schematic diagram showing a state in which the shaft members of the winding shaft used in the examples are aligned. DETAILED DESCRIPTION OF THE INVENTION

[0014] Preferred embodiments of the coreless roll of the present invention will be described below. The embodiments described below are merely limited examples of the present invention, and the technical scope of the present invention is not limited to the exemplified embodiments.

[0015] As shown in Figure 1, the coreless roll 1 of the present invention is a rolled body around which a long sheet 2 is wound. The sheet 2 is a laminated sheet 2 in which a synthetic resin layer is laminated on one side of a woven fabric made of flat yarn. The flat yarn is a tape-like thread obtained by cutting a film into strips and stretching it. The laminated sheet 2 can be obtained by weaving the flat yarn and then laminating a synthetic resin layer onto the resulting woven fabric by a method such as extrusion lamination, thermal lamination, coating, or immersion.

[0016] The material of the laminate sheet 2 is selected appropriately depending on the purpose of use, but as a flat yarn, it is preferable to use a polyolefin material such as high-density polyethylene or polypropylene, as it is lightweight and can be made high-strength by stretching, and it is particularly preferable to use a high-density polyethylene material, as it can be finished into a flexible laminate sheet 2.

[0017] The flat yarns constituting the laminate sheet 2 are woven into a woven fabric. The weave is not particularly limited, but a plain weave is preferable. The flat yarns constituting the woven fabric preferably have a fineness of, for example, 100 to 3000 dt (decitex). The flat yarns preferably have a width of, for example, 0.5 to 8 mm. The flat yarns preferably have a thickness of, for example, 15 to 150 μm. When flat yarns are used in both the warp and weft directions, the weave density of the woven flat yarn fabric is preferably 5 to 30 threads / 25.4 mm.

[0018] A thermoplastic resin layer is formed on at least one side of the flat yarn fabric that constitutes the laminate sheet 2. The material of the thermoplastic resin layer may be selected as appropriate, but is preferably one that has good adhesion to the flat yarn fabric. For example, the laminate sheet 2 and the flat yarn fabric may be made of the same synthetic resin material. For example, if the flat yarn is made of a polyolefin material, the thermoplastic resin layer is preferably also made of a polyolefin. If high-density polyethylene is selected as the material for the flat yarn, the material for the thermoplastic resin layer is preferably selected from low-density polyethylene, ethylene-vinyl acetate copolymer, or ethylene-ethyl acrylate copolymer. The thickness of the thermoplastic resin layer is preferably, for example, 10 to 100 μm.

[0019] There is no particular limitation on the basis weight of the laminated sheet 2, and it is 50 to 300 g / m 2 However, when used at construction sites such as civil engineering works, a larger amount of winding is preferable in order to cover as large an area as possible while keeping the weight of the roll body 1 within a range that can be carried by human power. Therefore, a lighter weight per unit area is preferable. However, when used at construction sites such as civil engineering works, it is necessary to ensure a certain level of weight per unit area and to maintain strength. Therefore, the weight per unit area is 70 to 220 g / m. 2 It is preferable that the range is:

[0020] The width W of the laminated sheet 2 forming the coreless roll 1 can be selected as appropriate, but a wide width is preferred from the viewpoint of covering a wide area at a site such as a civil engineering or construction site. On the other hand, in consideration of portability, it is preferable that the width W is not too wide. Therefore, the width W of the laminated sheet 2 is preferably in the range of, for example, 75 to 225 cm.

[0021] The winding length of the laminated sheet 2 constituting the coreless roll 1 is appropriately selected taking into consideration the weight of the coreless roll 1, etc., but is preferably in the range of 10 to 300 m. The winding length is preferably as large as possible so that it can cover a large area at a civil engineering or construction site, and is more preferably 20 m or more. Since the weight per roll increases if the winding length becomes too large, it is more preferable to set the winding length to 250 m or less.

[0022] The coreless roll 1 is a roll of the laminated sheet 2 and can be obtained by winding the laminated sheet 2. A typical sheet winding machine may be used for winding. After winding, the coreless roll 1 has a cylindrical shape with circular end faces. When winding using a winding machine, a winding shaft is used to wind the laminated sheet 2, and a center hole 3 is formed in the center of the end face of the resulting roll 1, penetrating from one end face to the other. In the present invention, the coreless roll 1 is finished so that this center hole 3 does not have a winding core, and the diameter D of this center hole 3 is in the range of 15 to 25 mm. In this specification, the terms "circular" or "cylindrical" do not refer only to a perfect circle or a perfect cylindrical shape that does not allow for any processing errors or distortions. Furthermore, the terms "center" or "central portion" do not refer to a center or central portion that does not allow for any processing errors or distortions. Although not particularly limited, for example, the circularity of the outer circumference of the roll body 1, calculated by [(maximum diameter of the circle (cm) - minimum diameter of the circle (cm)) ÷ 2], is acceptable as long as it is within 1.0 cm. Furthermore, although not particularly limited, for example, when referring to the center or central part, the position of the center hole 3 is acceptable as long as it is shifted by 0 to 10 mm from the center position of the circular end face.

[0023] A typical core-equipped roll uses a cylindrical core such as a paper tube, PVC pipe, or ABS pipe. The core prevents the laminated sheet 2 from tightening when wound on a winding machine, making it easier to pull the roll 1 off the winding shaft, and also prevents the roll 1 from bending or collapsing, thereby maintaining its cylindrical shape. However, the coreless roll 1 does not have a core, and therefore cannot maintain its cylindrical shape with the core. To maintain the cylindrical shape of the coreless roll 1, which does not have a core, it is necessary to form it into a structure that suppresses deformation of the center hole 3.

[0024] A laminated sheet 2 made of flat yarn fabric is wound around the coreless roll 1. Flat yarn fabrics have a coarse weave density and are not uniform in thickness, but layering synthetic resin layers reduces thickness variations. Therefore, the overlapping laminated sheets 2 adhere to each other adequately during winding to prevent blocking, providing rigidity to the wound body. In the present invention, the rigidity of the laminated synthetic resin is utilized to suppress deformation of the central hole 3. Deformation of the central hole 3 can be suppressed by minimizing the diameter D. However, since the central hole 3 is also a hole created by using a winding shaft, if the diameter D is too small, it is difficult to apply sufficient tension during winding, and the laminated sheets 2 are less likely to adhere to each other, resulting in a hard wound body. Therefore, for a coreless roll 1 using a laminated sheet 2 made of flat yarn fabric, it is important that the diameter D of the central hole 3 be 15 to 25 mm.

[0025] There are various methods for forming a coreless roll 1, including winding the sheet onto a dummy core that deforms to facilitate removal after winding is complete, followed by deforming the core and removing it. Another method involves injecting air or other material into the winding shaft, expanding the winding shaft to a larger diameter, and then winding the winding shaft. After winding, the air is removed to narrow the winding shaft and remove it from the roll 1. Because the diameter D of the central hole 3 of the coreless roll 1 is 25 mm or less, a preferred method is to wind the laminated sheet 2 directly onto the winding shaft without using a core, and then reshape the winding shaft before removing it. The winding shaft is preferably thin and strong, and preferably comprises two shaft members with inclined portions stacked together with their inclined portions facing each other. After winding the sheet 2, the stacked winding shaft can be separated by pulling it longitudinally, allowing the two shaft members to be removed from the roll. It is preferable that such a winding shaft be provided with a separation limiting means to prevent the shaft members from accidentally separating from each other from the start of winding until winding is completed. The separation limiting means need only limit movement of the two shaft members in a direction perpendicular to the axis. Movement may be limited by fastening the shaft members together with fasteners such as rings, screws, or pins from the outside of the shaft at a position that does not overlap the winding portion of the sheet, and releasing the fastener before pulling out the shaft members. Movement may also be limited by attaching a magnetic body to the inclined portion of the shaft member. Movement may also be limited by providing a groove and a pin in the inclined portion of the shaft member and engaging the groove and the pin. Movement may also be limited by using a combination of the respective separation limiting means exemplified above.

[0026] Separation between one shaft member and the other shaft member may be restricted at one end and the other end in the longitudinal direction of the winding shaft, as shown in Fig. 2 described later. Separation between one shaft member and the other shaft member is preferably restricted not only at the one end and the other end but also at a middle portion between the one end and the other end. Restricting separation between one shaft member and the other shaft member at the middle portion in addition to the one end and the other end makes it easier to pull out the winding shaft.

[0027] For example, even when the laminated sheet is wound around a shaft member while being cut to a predetermined width, one shaft member can be easily pulled out from the other shaft member. The predetermined width is not particularly limited, but an example is when the laminated sheet is cut at the center in the width direction and then cut to half the width. [Example]

[0028] The present invention will be described in more detail below with reference to examples. The examples shown below are merely limited examples of the present invention, and the technical scope of the present invention is not limited to the exemplified examples.

[0029] A commercially available Tarpee Cloth #3000 (manufactured by Hagiwara Kogyo Co., Ltd.) was prepared as a long sheet. This sheet was made by plain weaving flat yarns made of high-density polyethylene, with low-density polyethylene layers formed on both sides. The basis weight was 150 g / cm. 2 , and the width was 180cm.

[0030] The prepared sheet was placed on a payout machine, and a winding shaft was placed on the drum roll of a drum winding machine. The sheet was wound around the winding shaft while the drum roll was rotated, thereby winding the sheet onto the winding shaft to obtain a wound body. Schematic diagrams of the winding shaft used in this case are shown in Figures 2 and 3.

[0031] The winding shaft 5 shown in FIGS. 2 and 3 is formed by combining a first shaft member 51a and a second shaft member 51b. As shown in FIG. 2, each shaft member 51a has an inclined portion 52a, 52b obliquely arranged relative to the shaft center. The inclined portions 52a, 52b are provided with guide pins 53a, 53b and guide grooves 54a, 54b. The inclined portions 52a, 52b are flat surfaces that slope downward from the base end to the tip end of the shaft member. When the inclined portion 52 of the first shaft member 51a and the inclined portion 52 of the first shaft member 51b are combined, the winding shaft 5 has a circular cross section. The guide pins 53a, 53b and the guide grooves 54a, 54b are separation limiting means that limit movement of the first shaft member 51a and the second shaft member 51b in a direction perpendicular to the shaft center. The guide pin 53 has a larger diameter at its tip end than at its base end. The guide grooves 54a and 54b are wider at their tip end than at their base end. The base end of the shaft is the side where the diameter of the shaft is larger. By sliding and inserting the guide pin 53a of the first shaft member 51a into the guide groove 54b of the second shaft member 51b, and simultaneously, the guide pin 53b of the second shaft member 51b into the guide groove 54a of the first shaft member 51a, the inclined portions 52a and 52b overlap as shown in FIG. 3, and the first shaft member 51a and the second shaft member 51b become a single take-up shaft 5. At this time, the large-diameter tip end of the guide pin 53 engages with the narrow groove at the base end of the guide groove 54, thereby restricting movement in the direction perpendicular to the guide groove 54. Therefore, when the first shaft member 51a and the second shaft member 52b are to be separated again, they are separated by pulling the first shaft member 51a and the second shaft member 52b in a direction that separates them in the longitudinal direction of the winding shaft 5. The length of the winding shaft 5 was 250 cm. A magnetic body (not shown) is attached to the inclined portion 52, which makes it possible to limit movement of the first shaft member 51a and the second shaft member 52b in a direction perpendicular to the axis of the first shaft member 51a and the second shaft member 52b even in the middle portion in the longitudinal direction of the winding shaft 5.

[0032] After winding 100 m of the laminated sheet, the winding body with the winding shaft 5 still attached was removed from the winding machine. The winding shaft 5 was then removed from the winding body by grasping the first shaft member 51 a and the second shaft member 52 b of the winding shaft 5 and pulling it longitudinally. The winding shaft 5 of FIGS. 2 and 3 was easily removed because the first shaft member 51 a and the second shaft member 51 b had inclined portions 52, which gradually changed the thickness of the winding shaft as it was pulled longitudinally. When the first shaft member 51 a and the second shaft member 51 b were combined to form a single winding shaft 5, the diameter of the winding shaft 5 of FIGS. 2 and 3 was 19 mm. The winding shaft 5 of FIGS. 2 and 3 had a relatively simple structure, allowing it to maintain sufficient strength even when made thin and long.

[0033] The coreless roll obtained as described above had a central hole diameter of 19 mm. The coreless roll obtained was sufficiently hard even without a core, and the circular shape of the end faces was maintained, making it easy to roll and the sheet to be easily unrolled. [Explanation of symbols]

[0034] 1. Coreless roll (roll) 2. Laminated sheet (sheet) 3 center hole 5 Winding shaft 51 Shaft member 51a First shaft member 51b Second shaft member 52 Slope 53 Guide pin 54 Guide groove

Claims

1. A cylindrical roll body having a circular end surface made of a roll of sheet, The sheet is a laminated sheet in which a synthetic resin layer is laminated on one side of a woven fabric made of flat yarns, The coreless roll body has a center hole penetrating from one end face to the other end face at the center of the end face of the roll body, the diameter of the center hole is 15 to 25 mm, and the center hole does not have a winding core.

2. 2. The coreless roll according to claim 1, wherein the sheet has a width of 75 to 225 cm.

3. 3. The coreless roll according to claim 2, wherein the wound length of the sheet is 10 to 300 m.

4. A method for producing a coreless roll having the shape according to any one of claims 1 to 3, This method for manufacturing a coreless roll body includes a step of winding a sheet around a winding shaft in which two shaft members each having an inclined portion are overlapped with each other with the inclined portions facing each other, and then pulling the shaft members in the longitudinal direction of the winding shaft to separate and remove the sheet.

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