JP2018002447A - Taking-up core for taking up sheet and manufacturing method of taking-up core, and taking-up body for taking up sheet and manufacturing method of taking-up body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a taking-up core capable of effectively suppressing occurrence of wrinkles formed when a sheet is taken up.SOLUTION: A taking-up core 10 for taking up a sheet comprises: a taking-up core body 1 including a circumferential surface 1a; and pressure-sensitive adhesive layers 2 arranged in a circumferential direction on the circumferential surface of the taking-up core. The multiple pressure-sensitive adhesive layers are arranged at intervals in a longitudinal direction of the taking-up core body. At least one of the multiple pressure-sensitive adhesive layers is formed spaced apart by a clearance 2a, in which no pressure-sensitive adhesive layer is formed, from adjacent ones in the circumferential direction of the taking-up core.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a winding core for winding a sheet, a method for manufacturing the winding core, a sheet winding body, and a method for manufacturing the winding body.

  Conventionally, a sheet having a metal layer is used in various fields. In general, such a sheet is manufactured as a long sheet having a length of several hundreds to thousands of meters in a manufacturing process, and is used after being cut into a desired size according to the application. Such a long sheet is usually wound on a circumferential surface of a winding core for winding the sheet, and is manufactured, stored, transported, and the like.

  For example, as a method for producing a laminated sheet in which a metal layer and a resin layer are laminated, a dry lamination method may be mentioned. In the dry laminating method, a metal foil (metal layer) and a resin film (resin layer) wound around a winding core are unwound and laminated via an adhesive. The obtained laminated sheet is wound up on a winding core and used for the next process or stored and transported as a product.

JP2013-193021A

  In a winding core for winding a sheet as described above, usually an adhesive layer or an adhesive layer (hereinafter referred to as “adhesive layer or adhesive layer”) is used as an “adhesive layer” for bringing the sheet into close contact with the winding core. Are provided at intervals. Such an adhesive layer is formed, for example, by attaching a plurality of double-sided adhesive tapes or the like in the circumferential direction of the winding core.

  When winding a sheet using a winding core, there is a problem that wrinkles are formed on the sheet from several m to several tens of m from the end in the length direction of the sheet adhesively bonded to the adhesive layer. Furthermore, in the sheet provided with the metal layer, since wrinkles are easily formed in the first place, there is a problem that wrinkles that extend in the length direction from such end portions are particularly easily formed. Since the portion of the sheet where the wrinkles are formed cannot be made into a product, the longer the portion where the wrinkles are formed, the lower the product yield.

  Under such circumstances, the present invention provides a winding core for winding a sheet, a method for manufacturing the winding core, and a winding wound around the winding core. The main object is to provide a body and a method for producing the wound body.

  Conventionally, in the above-described sheet winding core, a plurality of adhesive layers are provided at intervals around the entire circumference of the winding core in the circumferential direction. However, as a result of repeated studies by the present inventors, when a sheet is wound around such a winding core, air is collected in a small space formed by the adjacent adhesive layer and the sheet, and this air pool is It became clear that it was the cause of hemorrhoids.

  And when the inventors repeated further studies, a winding core body having a circumferential surface, and an adhesive layer provided along the circumferential direction on the circumferential surface of the winding core body; A plurality of adhesive layers are provided at intervals in the length direction of the winding core body, and at least one adhesive layer of the plurality of adhesive layers is wound. In the circumferential direction of the core body, a winding core formed with a gap where no adhesive layer is formed is used for winding the sheet, so that wrinkles occur when winding the sheet. It was found that it can be effectively suppressed. The present invention has been completed by further studies based on these findings.

That is, this invention provides the invention of the aspect hung up below.
Item 1. A winding core body having a circumferential surface;
On the circumferential surface of the winding core main body, an adhesive layer provided along the circumferential direction,
With
A plurality of the adhesive layers are provided at intervals in the length direction of the winding core body,
Among the plurality of adhesive layers, at least one of the adhesive layers is formed with a gap in which the adhesive layer is not formed in the circumferential direction of the winding core body,
Winding core for winding the sheet.
Item 2. Among the plurality of adhesive layers, at least two of the adhesive layers are each formed with a gap in which the adhesive layer is not formed in the circumferential direction of the winding core body. And
Item 2. The winding core according to item 1, wherein the gaps in the adhering adhesive layers adjacent to each other are provided at positions that do not overlap each other in the length direction of the winding core body.
Item 3. The winding according to Item 1 or 2, wherein all of the plurality of adhesive layers are formed with a gap in which the adhesive layer is not formed in a circumferential direction of the winding core body. core.
Item 4. Among the plurality of adhesive layers, at least one of the adhesive layers is formed with two or more gaps in which the adhesive layer is not formed in the circumferential direction of the winding core body. The winding core according to any one of Items 1 to 3.
Item 5. Item 5. The item according to any one of Items 1 to 4, wherein a length of the gap in a circumferential direction of the winding core body is 0.1% or more and 20% or less of a circumferential length of the winding core body. Winding core.
Item 6. Item 6. The winding core according to any one of Items 1 to 5, wherein the sheet includes a metal layer.
Item 7. Item 7. The winding core according to any one of Items 1 to 6, wherein the sheet has a thickness of 30 μm to 200 μm.
Item 8. Item 8. A sheet winding body obtained by winding a sheet on the winding core according to any one of Items 1 to 7.
Item 9. A step of laminating an adhesive layer along the circumferential direction on the circumferential surface of the winding core body having a circumferential surface;
In the step, a plurality of the adhesive layers are laminated at intervals in the length direction of the winding core body,
Among the plurality of adhesive layers, at least one of the adhesive layers is formed in the circumferential direction of the winding core body with a gap where the adhesive layer is not formed,
A method for manufacturing a winding core for winding a sheet.
Item 10. Item 8. A method for producing a wound body of a sheet, comprising a step of winding the sheet around the winding core according to any one of Items 1 to 7.

  ADVANTAGE OF THE INVENTION According to this invention, the winding core which suppresses generation | occurrence | production of the wrinkle at the time of winding of a sheet | seat effectively can be provided. Furthermore, according to this invention, the manufacturing method of the said winding core, the winding body which wound up the sheet | seat on the said winding core, and the manufacturing method of the said winding body can be provided.

It is a schematic diagram of the winding core of this invention. It is an example of the typical developed view developed so that the circumference surface of the winding core of the present invention may become a plane. It is an example of the typical developed view developed so that the circumference surface of the winding core of the present invention may become a plane. It is a schematic sectional drawing which shows an example of the laminated structure of the sheet | seat wound up by the winding core of this invention. It is a schematic sectional drawing which shows an example of the laminated structure of the sheet | seat wound up by the winding core of this invention. It is a schematic sectional drawing which shows an example of the laminated structure of the sheet | seat wound up by the winding core of this invention. It is the typical expanded view developed so that the circumference surface of the winding core manufactured in Examples 1-3 may become a plane. FIG. 6 is a schematic development view developed so that the circumferential surface of the winding core manufactured in Example 4 is a flat surface. FIG. 6 is a schematic development view developed so that the circumferential surface of the winding core manufactured in Example 5 becomes a flat surface. It is the typical expanded view developed so that the circumference surface of the winding core manufactured in Example 6 may become a plane. It is the typical expanded view developed so that the circumference surface of the winding core manufactured in Example 7 may become a plane. FIG. 10 is a schematic development view developed so that the circumferential surface of the winding core manufactured in Example 8 is a flat surface. FIG. 10 is a schematic development view developed so that the circumferential surface of the winding core manufactured in Example 9 is a flat surface. It is the typical expanded view developed so that the circumference surface of the winding core manufactured in Example 10 may become a plane. It is the typical expanded view developed so that the circumference surface of the winding core manufactured in Example 11 may become a plane. It is the typical expanded view developed so that the circumference surface of the winding core manufactured in Example 12 may become a plane. FIG. 4 is a schematic development view developed so that the circumferential surface of the winding core manufactured in Comparative Example 1 is a flat surface.

  The winding core of the present invention is for winding a sheet, and includes a winding core body and an adhesive layer. The winding core body has a circumferential surface. Moreover, the adhesive layer is provided along the circumferential direction on the circumferential surface of the winding core body. A plurality of adhesive layers are provided at intervals in the length direction of the winding core body. Furthermore, at least one adhesive layer among the plurality of adhesive layers is formed with a gap in which no adhesive layer is formed in the circumferential direction of the winding core body.

  Hereinafter, the winding core of the sheet of the present invention, the manufacturing method of the winding core, the winding body in which the sheet is wound around the winding core, and the manufacturing method of the winding body, with reference to FIGS. Will be described in detail.

  In the present specification, the indication of “to” indicating a numerical range indicates that the numerical value is greater than or equal to the numerical value attached to the left side and less than or equal to the numerical value attached to the right side. The notation "" means X or more and Y or less.

  In the present invention, the “adhesive layer” means “adhesive layer or adhesive layer”.

  As shown in FIG. 1, in the winding core 10 of the present invention, the winding core body 1 has a circumferential surface 1a. In the present invention, the shape of the winding core body 1 is not particularly limited as long as it has a circumferential surface 1a that can wind up the sheet 20 (see, for example, FIGS. 4 to 6) as the outer circumferential surface. For example, a cylindrical shape and a columnar shape as shown in FIG.

  The material constituting the winding core body 1 is not particularly limited, and examples thereof include paper, resin, metal, and the like.

  The length in the length direction y of the winding core body 1 can be set as appropriate according to the width of the sheet 20 to be wound. Examples of the length of the winding core body 1 include about 50 cm to 200 cm.

  Further, the length n (circumferential length) in the circumferential direction z of the winding core body 1 can be appropriately set according to the size of the sheet 20 to be wound. Examples of the length n (circumferential length) in the circumferential direction z of the winding core body 1 include about 10 cm to 75 cm.

  The winding core 10 of the present invention includes an adhesive layer 2 on the circumferential surface 1 a of the winding core body 1. The adhesive layer 2 is provided along the circumferential direction z of the circumferential surface 1 a of the winding core body 1. Although it does not restrict | limit especially as a shape of the adhesive layer 2, The adhesive layer 2 is formed so that it may extend in the circumferential direction z of the circumferential surface 1a of the winding core main body 1, for example, FIG. As shown in FIG. 3, it is generally rectangular in plan view.

  As shown in FIG. 1, a plurality of the adhesive layers 2 are provided at intervals in the length direction y of the winding core body 1. Further, among the plurality of adhesive layers 2, at least one adhesive layer 2 is formed in the circumferential direction z of the winding core body 1 with a gap 2a where the adhesive layer 2 is not formed. Has been.

  For example, FIG. 1 shows a schematic diagram in the case where three adhesive layers 2 are formed. The number of the adhesive layers 2 is not particularly limited as long as it is at least 2 or more, but effectively suppresses wrinkles during winding of the sheet 20 while securely sticking or bonding the sheet 20 to the winding core 10. From the viewpoint of doing, it is preferably about 2 to 10, more preferably about 5 to 8. In the present invention, the adhesive layer 2 present at a position overlapping in the circumferential direction z is counted as one. For example, in FIGS. 2 and 3, which are schematic development views in which the circumferential surface 1 a of the winding core 10 of the present invention is flat, the adhesive layer 2 of the winding core 10 of the present invention is provided. The numbers are all three.

  In the winding core 10 of the present invention, at least two adhesive layers 2 among the plurality of adhesive layers 2 are respectively formed in the circumferential direction z of the winding core body 1. The gaps 2a in the adjacent adhesive layer 2 are formed at positions where they do not overlap with each other in the length direction y of the winding core body 1. It is preferable. Thereby, at the time of winding of the sheet 20, air hardly accumulates in a space formed by the adjacent adhesive layer 2 and the sheet 20, and wrinkles at the time of winding the sheet 20 can be effectively suppressed. .

  Furthermore, in the winding core 10 of the present invention, all of the plurality of adhesive layers 2 leave a gap 2 a where the adhesive layer 2 is not formed in the circumferential direction z of the winding core body 1. Preferably it is formed. Thereby, at the time of winding of the sheet 20, air is less likely to accumulate in the space formed by the adjacent adhesive layer 2 and the sheet 20, and the wrinkles at the time of winding the sheet 20 are further effectively suppressed. be able to. From the same viewpoint, it is most preferable that the gaps 2a in all the adhesive layers 2 are provided at positions that do not overlap each other in the longitudinal direction y of the winding core body 1.

  For example, as shown in FIG. 3, in the winding core 10 of the present invention, at least one of the plurality of adhesive layers 2 is the circumferential direction z of the winding core body 1. In FIG. 2, two or more gaps 2a where the adhesive layer 2 is not formed may be formed. Thereby, the wrinkle formed at the time of winding the sheet 20 can be more effectively suppressed. As shown in FIG. 3, all the adhesive layers 2 are formed with two or more gaps 2 a in which the adhesive layer 2 is not formed in the circumferential direction z of the winding core body 1. May be.

  In one adhesive layer 2, the number of the gaps 2a is not particularly limited and may be 1 or more, but from the viewpoint of effectively suppressing wrinkles formed when the sheet 20 is wound up, Preferably about 1-5 is mentioned.

  In addition, the length m of the gap 2a in the circumferential direction z of the winding core body 1 is not particularly limited, but it suppresses air accumulation and more effectively suppresses wrinkles formed when the sheet 20 is wound. From the viewpoint of doing this, it is preferable that the length n (circumferential length) of the winding core body 1 in the circumferential direction z is about 0.1% to 20%.

  The width of the adhesive layer 2 (the length direction y of the take-up core body 1) can be appropriately set according to the size of the take-up core 10 and is not particularly limited. From the viewpoint of effectively suppressing wrinkles formed during winding of the sheet 20 while securely sticking or adhering to each other, it is preferably about 10 mm to 200 mm.

  Further, the interval between the adjacent adhesive layers 2 (the length direction y of the winding core body 1) can be appropriately set according to the size of the winding core 10, and is not particularly limited. From the viewpoint of effectively suppressing wrinkles formed during winding of the sheet 20 while securely adhering or adhering to the winding core, about 20 mm to 500 mm is preferable.

  What is necessary is just to set suitably as thickness of the adhesive layer 2 according to the magnitude | size of the winding core 10. FIG.

  The material constituting the adhesive layer 2 is not particularly limited as long as it can adhere to or adhere to the sheet 20. The adhesive layer 2 can be composed of, for example, a double-sided adhesive tape or a double-sided adhesive tape. Moreover, the adhesive layer 2 can also be comprised with the adhesive or the adhesive agent apply | coated to the circumferential surface 1a of the winding core main body 1. FIG. As the double-sided pressure-sensitive adhesive tape, double-sided adhesive tape, pressure-sensitive adhesive, and adhesive, commercially available products can be used.

  In the present invention, the sheet 20 wound around the winding core 10 is not particularly limited. As described above, in the sheet including the metal layer, since wrinkles are easily formed in the first place, at the time of winding, the length direction from the end in the length direction (winding direction) of the sheet adhesively bonded to the adhesive layer In particular, there is a problem that wrinkles are easily formed. On the other hand, according to the winding core 10 of the present invention, wrinkles formed when the sheet 20 is wound can be effectively suppressed even when the sheet 20 includes a metal layer. Hereinafter, the sheet 20 wound around the winding core 10 of the present invention will be described in detail.

  The sheet 20 wound around the winding core 10 of the present invention may include a metal layer. The sheet 20 having a metal layer is generally a laminated sheet having a resin layer and a metal layer. Specific examples of the sheet 20 include a laminate sheet having a metal layer 21 and a resin layer 22 as shown in FIG. 4 or 5, a metal layer 21, a resin layer 22, and a second layer as shown in FIG. 6. A laminated sheet having two resin layers 23 is exemplified.

  In the sheet 20, the metal layer 21 is usually a layer provided for functioning as a barrier layer for preventing water vapor, oxygen, light, and the like from entering inside, in addition to improving the strength of the sheet 20. The metal forming the metal layer 21 is not particularly limited, and examples thereof include aluminum, stainless steel, and titanium. Among these, aluminum is particularly prone to wrinkles, but the sheet 20 is provided with a metal layer 21 (for example, aluminum foil) formed of aluminum by using the winding core 10 of the present invention. It is possible to effectively suppress wrinkles formed at the time of winding.

  Although it does not restrict | limit especially as thickness of the metal layer 21, From a viewpoint of suppressing effectively the wrinkle formed at the time of winding of the sheet | seat 20, Preferably it is about 5 micrometers-80 micrometers, More preferably, about 5 micrometers-40 micrometers are mentioned.

  Further, when the sheet 20 is a laminated sheet, the resin constituting the resin layer 22 laminated with the metal layer 21 is not particularly limited, and polyolefin, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, Examples thereof include silicon resin, phenol resin, polyetherimide, polyimide, and a mixture or copolymer thereof.

  When the sheet 20 is a laminated sheet, the sheet 20 may have a laminated structure in which resin layers are laminated on both sides of the metal layer 21. The sheet 20 is, for example, a laminated sheet in which the same resin layer 22 is laminated on both sides of the metal layer 21 as shown in FIG. 5, or a resin layer 22 is laminated on one side of the metal layer 21 as shown in FIG. Alternatively, a laminated sheet in which a second resin layer 23 made of a resin different from the resin layer 22 is laminated on the other side may be used.

  As resin which comprises the 2nd resin layer 23, the same thing as resin illustrated by the above-mentioned resin layer 22 can be illustrated.

  Although it does not restrict | limit especially as thickness of the resin layer 22, From a viewpoint of suppressing the wrinkle formed at the time of winding of the sheet | seat 20 effectively, Preferably it is about 5 micrometers-100 micrometers, More preferably, about 5 micrometers-50 micrometers are mentioned. In addition, the thickness of the second resin layer 23 is not particularly limited, but from the same viewpoint, it is preferably about 5 μm to 100 μm, more preferably about 5 μm to 50 μm.

  In order to improve the adhesion between the metal layer 21 and the resin layer 22 or the resin layer 23, these layers may be bonded with an adhesive. The adhesive is not particularly limited, and examples thereof include a polyurethane two-component curable adhesive, polyamide, polyester, or a blend resin of these and a modified polyolefin.

  The thickness of the sheet 20 wound around the winding core 10 is not particularly limited, but generally, when the thickness is reduced, wrinkles at the time of winding are easily formed. In the present invention, from the viewpoint of effectively suppressing wrinkles formed when the sheet 20 is wound, the thickness of the sheet 20 is preferably about 30 μm to 200 μm, more preferably about 40 μm to 100 μm. Further, the length of the sheet 20 to be wound is not particularly limited, and examples thereof include about 1000 m to 6000 m. Although it does not restrict | limit especially as the width | variety of the sheet | seat 20 wound up, For example, about 50 cm-200 cm is mentioned.

  In addition, when the sheet has a small stiffness (easy to bend), when the sheet is wound up, air easily accumulates in the space formed by the adjacent adhesive layer 2 and the sheet, so that wrinkles are easily formed. However, in the winding core 10 of the present invention, wrinkle formation during winding is effectively suppressed even when the stiffness of the sheet is small. The stiffness of the sheet 20 can be evaluated by the loop stiffness value. The loop stiffness value of the sheet 20 (for example, measured by LOOP STIFFNESS TESTER manufactured by Toyo Seiki Co., Ltd. Measurement conditions: sample width 15 mm, loop circumference 100 mm, remaining crushing distance 15 mm) is preferably 4.5 to About 25.0 g, more preferably about 5.5 to 12.0 g.

  The sheet winding body of the present invention is formed by winding the sheet 20 as described above around the circumferential surface of the winding body 10 of the present invention. The winding speed when winding the sheet 20 is not particularly limited, but wrinkles are likely to occur as the winding speed increases. By using the winding core 10 of the present invention, for example, even when the winding speed is 50 m / min or more, wrinkle formation during winding is effectively suppressed. From the viewpoint of effectively suppressing wrinkles formed when the sheet 20 is wound, a preferable winding speed is about 50 m / min to 150 m / min.

  When winding the sheet on the winding core, the end of the sheet 20 in the longitudinal direction is adhered to the winding core while removing air accumulated in the adjacent adhesive layer and the sheet space by hand. If winding is started after bonding, formation of wrinkles during winding can be minimized. However, in general, in the sheet manufacturing process, since air is automatically wound by a so-called roll-to-roll using a winder rather than manually, air is particularly generated in the space between the adjacent adhesive layer and the sheet. There is a problem that it is easy to accumulate. On the other hand, by using the winding core 10 of the present invention, wrinkle formation during winding can be effectively suppressed even when the sheet 20 is automatically wound by roll-to-roll.

  The winding core 10 of the sheet of the present invention comprises a step of laminating an adhesive layer along the circumferential direction on the circumferential surface of the winding core body having a circumferential surface. A plurality of adhesive layers are laminated at intervals in the length direction of the winding core body, and at least one of the plurality of adhesive layers is disposed in the circumferential direction of the winding core body. It can be suitably manufactured by forming a gap where no adhesive layer is formed. The configurations of the take-up core body and the adhesive layer are as described above.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

<Examples 1 to 12 and Comparative Example 1>
A winding core body (cylindrical shape) made of plastic (FRP) having a circumference, a core diameter, and a length of 100 cm shown in Table 1 was prepared. A plurality of double-sided adhesive tapes were affixed at equal intervals on the circumferential surface of the winding core body in the length direction of the winding core body. Table 1 shows the number of adhesive tapes in the circumferential direction of the winding core body, the width of the adhesive tape, the distance between the adhesive tapes, the number of gaps existing in one adhesive tape, the length of each gap, and the gap ratio (gap length / circumference). As shown in Moreover, each clearance gap was formed in the position which does not overlap in the length direction of a winding core main body. The schematic development views developed so that the circumferential surfaces of the winding cores manufactured in Examples 1 to 12 and Comparative Example 1 are flat are shown in FIG. 7 (Examples 1 to 3) and FIG. 8 (Examples), respectively. 4), FIG. 9 (Example 5), FIG. 10 (Example 6), FIG. 11 (Example 7), FIG. 12 (Example 8), FIG. 13 (Example 9), FIG. 14 (Example 10) FIG. 15 (Example 11), FIG. 16 (Example 12), and FIG. 17 (Comparative Example 1).

<Sheet winding test>
Using each winding core obtained in Examples and Comparative Examples, a sheet winding test was performed, and the length of the ridge formed in the length direction from the end of the sheet was confirmed. The specific test contents are as follows. First, as a sheet used for winding, a nylon film as a resin layer and an aluminum alloy foil as a metal layer are bonded by an adhesive (thickness 2 μm) by a dry lamination method (thickness of nylon film and aluminum foil, And the total thickness was as shown in Table 1. Next, the said sheet | seat was wound up by the roll toe roll form on each winding core obtained by the Example and the comparative example. At this time, the winding speed was 100 m / min. The sheet wound around the winding core was unwound, and the state and workability of the wrinkles formed in the length direction from the end of the sheet were evaluated according to the following criteria.

(State of cocoon)
A: No wrinkle is formed B: A weak wrinkle is formed, but if the wrinkle is stretched, the wrinkle disappears C: A strong wrinkle is formed, and even if the wrinkle is stretched, the wrinkle does not disappear

(Workability)
A: The attachment of the sheet to the roll was very easy.
B: The attachment of the sheet to the roll was easy.

1 Winding Core Body 1a Circumferential Surface 2 Adhesive Layer 2a Gap 10 Winding Core 20 Sheet 21 Metal Layer 22 Resin Layer 23 Second Resin Layer x Winding Core Radial Direction y Winding Core Length Direction z Winding core circumferential direction m Clearance length n Winding core circumferential length (circumferential length)

Claims (10)

A winding core body having a circumferential surface;
On the circumferential surface of the winding core main body, an adhesive layer provided along the circumferential direction,
With
A plurality of the adhesive layers are provided at intervals in the length direction of the winding core body,
Among the plurality of adhesive layers, at least one of the adhesive layers is formed with a gap in which the adhesive layer is not formed in the circumferential direction of the winding core body,
Winding core for winding the sheet. Among the plurality of adhesive layers, at least two of the adhesive layers are each formed with a gap in which the adhesive layer is not formed in the circumferential direction of the winding core body. And
The winding core according to claim 1, wherein the gaps in the adjacent adhesive layers are provided at positions that do not overlap each other in the length direction of the winding core body.   The winding according to claim 1 or 2, wherein all of the plurality of adhesive layers are formed with a gap in which the adhesive layer is not formed in a circumferential direction of the winding core body. Core.   Among the plurality of adhesive layers, at least one of the adhesive layers is formed with two or more gaps in which the adhesive layer is not formed in the circumferential direction of the winding core body. The winding core according to any one of claims 1 to 3.   The length of the said clearance gap in the circumferential direction of the said winding core main body is 0.1% or more and 20% or less of the circumferential length of the said winding core main body. Winding core.   The winding core according to any one of claims 1 to 5, wherein the sheet includes a metal layer.   The winding core according to any one of claims 1 to 6, wherein the sheet has a thickness of 30 µm or more and 200 µm or less.   A sheet winding body in which the sheet is wound on the winding core according to claim 1. A step of laminating an adhesive layer along the circumferential direction on the circumferential surface of the winding core body having a circumferential surface;
In the step, a plurality of the adhesive layers are laminated at intervals in the length direction of the winding core body,
Among the plurality of adhesive layers, at least one of the adhesive layers is formed in the circumferential direction of the winding core body with a gap where the adhesive layer is not formed,
A method for manufacturing a winding core for winding a sheet.   The manufacturing method of the winding body of a sheet | seat provided with the process of winding a sheet | seat on the winding core in any one of Claims 1-7.