JP2018144920A - Winding method of web material, and winding core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a winding method of a web material capable of reducing a step trace caused at an end part of the web material, and of reducing buckling caused at both end parts of a cushion tape.SOLUTION: A winding method of a web material comprises the steps of attaching an end part of a web material 30 onto a belt-like cushion tape 20 extending in an axial direction of a winding core body, that is attached onto an outer circumferential surface of the winding core body 11; and winding the web material on the winding core body while additionally applying tension. The cushion tape is made of a material having anisotropy for which a tensile elastic modulus in a circumferential direction of the winding core body is smaller than a tensile elastic modulus in the axial direction. The cushion tape is deformed so as to fill a space formed between the web material and the outer circumferential surface of the winding core body on both end faces of the cushion tape by receiving stress due to winding of the web material.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a winding method for winding a web material around a winding core, and a winding core used for winding the web material.

  In order to wind up a web material such as a film or a sheet in a roll shape, a method is generally used in which the tip of the web material is fixed to the outer peripheral surface of a cylindrical core with an adhesive, and the core is rotated and wound. Yes.

  By the way, since the surface of the winding core is generally hard, a step is generated between the outer peripheral surface of the winding core and the winding end portion of the web material when a web material having plasticity is wound into a roll shape. Therefore, an irreversible deformation occurs in the web material wound on the step due to the step. The same deformation is transferred to the web material wound around the deformed web material. As a result, there has been a problem that irreversible step marks such as distortion are generated on the web material over several tens of laps from the start of winding. Generation | occurrence | production of such a level | step difference will reduce the flatness of a web material, and has become a cause of a product loss and cost increase.

  In order to reduce the occurrence of such step marks, Patent Document 1 discloses a technique of providing a cushioning material on the outer peripheral surface of the core. This technique is effective in reducing step marks because the winding end of the web material sinks into the cushioning material. However, if the cushioning material is too soft, the web material is tightened when winding the web material. The material may buckle and cause wrinkles. Moreover, since it is necessary to provide a buffer material in the whole outer peripheral surface of a core, the cost of a core is raised.

  Therefore, Patent Document 2 discloses a technique of providing a band-shaped cushioning material along the axial direction of the core on the outer peripheral surface of the core. In this technique, the tip of the web material is fixed on the cushioning material and wound around the outer peripheral surface of the core, and the step mark is reduced by sinking the tip of the web material into the cushioning material. In this technique, since the cushioning material is provided on a part of the outer peripheral surface of the winding core, the web material does not buckle due to winding when the web material is wound. Moreover, since it is only necessary to provide a buffer material on only a part of the outer peripheral surface of the core, it is possible to suppress an increase in the cost of the core.

JP 2013-199344 A International Publication No. 2014/178393

  However, when the cushioning material is provided on a part of the outer peripheral surface of the core, the following problems occur.

  6A to 6C are partial enlarged views showing a conventional method in which a cushioning material is provided on a part of the outer peripheral surface of the core and the web material is wound around the outer peripheral surface of the core.

  First, as shown in FIG. 6A, the leading end portion of the web material 130 is fixed on the cushioning material 120 provided on a part of the outer peripheral surface of the core 110. Here, a region where the tip portion of the web material 130 is in contact with the cushioning material 120 is 140A, and a region where the web material 130 is not in contact is 140B. An arrow C indicates the winding direction of the web material 130.

  Next, as shown in FIG. 6B, the web material 130 is wound around the outer peripheral surface of the core 110 while applying tension to the web material 130. In addition, in FIG.6 (b), the web material 130A, 130B of the 1st round and the 2nd round is shown in the wound state. At this time, the end portion 130a of the web material 130 sinks into the cushioning material 120 by the thickness of the web material 130A. Therefore, even if the web material 130B of the second round is wound on the web material 130A of the first round, no step is generated at the end portion 130a of the web material 130A. Thereby, it can suppress that a level | step difference mark generate | occur | produces resulting from the level | step difference which arises in the edge part 130a of 130 A of web materials.

  On the other hand, the cushioning material 120 in the region 140A is deformed by receiving pressure due to the winding of the web materials 130A and 130B, and a part 120A protrudes into the region 140C on the winding direction C side. Similarly, the cushioning material 120 in the region 140B is deformed by receiving pressure due to the winding of the web material 130B, and a part 120B of the cushioning material 120 protrudes into the region 140D opposite to the winding direction C. However, if the amount of protrusion is small, space portions 150 and 151 are formed between the web members 130A and 130B and the core 110 at the winding direction C of the cushioning material 120 and the opposite ends thereof, respectively. The

  In such a state, when the web material 120 is wound up over many turns, as shown in FIG. 6C, the web materials 130 </ b> A to 130 </ b> D corresponding to the positions where the space portions 150 and 151 are formed. In the parts 160 and 161, there is a problem that buckling occurs due to the space parts 150 and 151 generated at both ends of the cushioning material 120.

  The present invention has been made in view of the above problems, and its main purpose is to wind the web material by fixing the tip of the web material to a cushion tape (buffer material) provided on a part of the outer peripheral surface of the core. In the method of wrapping around the core, it is to reduce the level difference trace caused by the level difference generated at the end of the web material and to reduce the buckling due to the space generated at both ends of the cushion tape.

A web material winding method according to the present invention is a winding method for winding a web material around a winding core, and the winding core is a strip-like shape that extends in the axial direction of the core body on the outer peripheral surface of the core body. The cushion tape is affixed, and the step (a) of adhering the end of the web material on the cushion tape, and the step of winding the web material around the core body while applying tension to the web material ( the cushion tape is made of a material having anisotropy in which the tensile modulus in the circumferential direction of the core body is smaller than the tensile modulus in the axial direction of the core body, and in the step (b), The cushion tape is deformed so as to fill the space formed between the web material and the outer peripheral surface of the core body at both end surfaces in the circumferential direction of the cushion tape in response to the stress due to the winding of the web material. It is characterized by that.

  The winding core according to the present invention is a winding core used for winding a web material, and the winding core has a belt-like cushion tape that extends in the axial direction of the winding core body attached to the outer peripheral surface of the winding core body. The cushion tape is made of a material having anisotropy in which the tensile elastic modulus in the circumferential direction of the core body is smaller than the tensile elastic modulus in the axial direction of the core body.

  According to the present invention, in the method in which the tip of the web material is fixed to the cushion tape provided on a part of the outer peripheral surface of the winding core, and the web material is wound around the winding core, it is caused by the step generated at the end of the web material. It is possible to reduce the step marks and reduce buckling due to the space portions generated at both ends of the cushion tape.

It is a perspective view typically showing the composition of the core used for the winding method of the web material in one embodiment of the present invention. In one Embodiment of this invention, it is the elements on larger scale which showed typically the state which affixed the cushion tape on the outer peripheral surface of the core main body. (A)-(c) is the figure which showed typically the winding method which winds up the web material in one Embodiment of this invention to a winding core. It is sectional drawing which showed an example of the structure of the cushion tape in one Embodiment of this invention. (A), (b) is the figure which showed an example of the manufacturing method of the cushion tape in one Embodiment of this invention. (A)-(c) is the elements on larger scale which showed the conventional method which provides a shock absorbing material in a part of outer peripheral surface of a core, and winds a web material on the outer peripheral surface of a core.

  Before describing the embodiments of the present invention, the background to the idea of the present invention will be described.

  As shown in FIG. 6C, when the end of the web material 130 is fixed to the cushioning material 120 provided on the outer peripheral surface of the core 110 and wound around the core 110, the end of the web material 130 is In order to reduce the level difference caused by the step, the cushioning material 120 is made of a soft material having a hardness that allows the web material 130 to sink into the cushioning material 120 under the pressure of the web material 130 being wound. Preferably there is.

  However, if only the cushioning material 120 made of a soft material having such hardness is used, as shown in FIG. 6C, buckling due to the space portions 150 and 151 generated at both ends of the cushioning material 120 is caused. It is difficult to reduce. In order to reduce the buckling due to such space portions 150 and 151, the cushioning material 120 receives pressure due to the winding of the web material 130 and further deforms until the space portions 150 and 151 are filled. Must be soft material.

  However, when a soft material (typically a material having a 25% compressive load of JIS K 6354 of 10 kPa or less) that is deformed until the spaces 150 and 151 are filled is used for the buffer material 120, the buffer material 120 itself is It is difficult to become independent. Therefore, it becomes difficult to affix the strip-like elongated cushioning material 120 to the outer peripheral surface of the cushioning material 120. In addition, when the buffer material 120 itself is made of a non-adhesive material, it is necessary to form an adhesive or the like on the surface of the buffer material 120, but it is easy to form an adhesive on the surface of the buffer material 120 that does not stand by itself. Not. In addition, although a self-supporting property can be provided by providing a base material on the buffer material 120, this time, a new step mark is generated due to a step at the end of the base material.

  As described above, it is difficult to realize the cushioning material 120 that satisfies both the requirements of reducing buckling due to the spaces 150 and 151 and maintaining workability.

  The inventors of the present application have been studying a cushioning material that satisfies both of the above requirements, and have focused attention on a material having elastic anisotropy. In other words, if the cushioning material is made of a material having a high modulus of elasticity that can be self-supporting in a certain direction and a low modulus of elasticity that is very easily deformable in the other direction, both of the above requirements can be satisfied. The present inventors have come up with the present invention by thinking that a buffer material can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment. Moreover, it can change suitably in the range which does not deviate from the range which has the effect of this invention.

  FIG. 1 is a perspective view schematically showing a configuration of a winding core used in a web material winding method according to an embodiment of the present invention.

  As shown in FIG. 1, the cylindrical core 10 has a belt-like cushion tape 20 that extends in the axial direction X of the core body 11 attached to the outer peripheral surface of the core body 11.

  The web material winding method according to the present embodiment is performed by winding the web material in the circumferential direction Y of the core body 11 after fixing the end portion of the web material to the cushion tape 20 and fixing it.

  FIG. 2 is a partially enlarged view schematically showing a state in which the cushion tape 20 is attached to the outer peripheral surface of the core body 11 in the present embodiment. The cushion tape 20 in the present embodiment is made of a material having anisotropy in which the tensile elastic modulus in the circumferential direction Y of the core body 11 is smaller than the tensile elastic modulus in the axial direction of the core body 11. That is, the mechanical characteristics of the cushion tape 20 are hard in the axial direction X of the core body 11 and soft in the circumferential direction Y. Such a material can be formed, for example, by uniaxially stretching a resin (polymer) such as polydetrafluoroethylene. Here, the tensile elastic modulus was measured using a low-load physical property tester (model number EZ-S) manufactured by Shimadzu Corporation with a tensile tester for a sample having a width of 25 mm and a length of 50 mm at a load of 50 N, a speed of 50 mm / min. The value to be measured.

  Note that the cushion tape 20 formed by uniaxial stretching in this way has substantially the same characteristics in the thickness direction Z and in the circumferential direction Y. Therefore, such a cushion tape 20 has a soft characteristic also in the thickness direction Z.

  3A to 3C are diagrams schematically showing a winding method for winding the web material around the winding core in the present embodiment.

  First, as shown in FIG. 3A, the tip of the web material 30 is pasted on the cushion tape 20 provided on the outer peripheral surface of the core body 11. Here, an area where the tip portion of the web material 30 is in contact with the cushion tape 20 is 40A, and an area where the web material 30 is not in contact is 40B. An arrow C indicates the winding direction of the web material 30.

  Next, as shown in FIG. 3B, the web material 30 is wound around the outer peripheral surface of the core body 11 while applying tension to the web material 30. In addition, in FIG.3 (b), the web materials 30A and 30B of the 1st round and the 2nd round are shown in the wound state. At this time, the end 30a of the web material 30 sinks into the cushion tape 20 by the thickness of the web material 30A. Therefore, even if the web material 30B of the second round is wound on the web material 30A of the first round, no step is generated at the end 30a of the web material 30A. Thereby, generation | occurrence | production of the level | step difference trace resulting from the level | step difference which arises in the edge part 30a of 30 A of web materials can be suppressed.

  On the other hand, the cushion tape 20 in the region 40A is deformed by receiving pressure due to winding of the web materials 30A and 30B, and a part 20A of the cushion tape 20 protrudes into the region 40C on the winding direction C side. At this time, the cushion tape 20 is formed between the web material 30A and the outer peripheral surface of the core body 11 as shown in FIG. 6B because the tensile elastic modulus in the circumferential direction Y is small (soft). It is deformed so as to fill the space 150.

  Similarly, the cushion tape 20 in the region 40B is also deformed by the pressure due to the winding of the web material 30A, and a part 20B of the cushion tape 20 protrudes into the region 40D opposite to the winding direction C. At this time, the cushion tape 20 is formed between the web material 30A and the outer peripheral surface of the core body 11 as shown in FIG. 6B because the tensile elastic modulus in the circumferential direction Y is small (soft). It is deformed so as to fill the remaining space 151.

  Therefore, as shown in FIG. 3 (c), even if the web material 120 is wound around many times, the space 150 is generated at both ends of the cushion tape 20 as shown in FIG. 6 (c). , 151 can suppress the occurrence of buckling.

  In order to deform the cushion tape 20 so as to fill the spaces 150 and 151 formed between the web material 30 and the outer peripheral surface of the core body 11 under the pressure of the web material 30 being wound. The tensile elastic modulus in the circumferential direction Y of the core body 11 of the cushion tape 20 is preferably at least in the range of 0.25 MPa to 1.75 MPa. In addition, in order for the end 30a of the web material 30 to receive pressure from the winding of the web material 30 and sink into the cushion tape 20 by the thickness of the web material 30, the hardness in the thickness direction Z of the cushion tape 20 Is preferably at least 2.5 MPa or less. Here, the hardness indicates the hardness in the thickness direction Z of the cushion tape 20, and by using a dynamic ultra-micro hardness meter (model number DUH-21S) manufactured by Shimadzu Corporation, a triangular pyramid having a counter-ridge angle of 115 ° is used as an indenter, It is a value measured under conditions of 1 mN and a load speed of 0.015 mN / s. Furthermore, in order for the cushion tape 20 itself to be self-supporting without a base material, the tensile elastic modulus in the axial direction X of the core body 11 of the cushion tape 20 is preferably at least 6.0 MPa or more. .

  In the present embodiment, the material used for the cushion tape 20 is not particularly limited, and for example, a fluorine-based polymer can be used. The fluorine-based polymer is made of, for example, polytetrafluoroethylene. As such a fluorine-based polymer, for example, trade name “Chuko Flow” (registered trademark) manufactured by Chuko Kasei Kogyo Co., Ltd. can be used.

  As described above, the winding method of the web member 30 in the present invention is such that the cushion tape 20 to be attached to the outer peripheral surface of the core body 11 has a tensile elastic modulus in the circumferential direction Y of the core body 11 that is the core. Since it is made of a material having an anisotropy smaller than the tensile elastic modulus in the axial direction X of the main body 11, step marks caused by a step generated at the end of the web material 30 are reduced, and both ends of the cushion tape 20 are The buckling resulting from the space part which arises in a part can be reduced. In addition, since the cushion tape 20 itself is also self-supporting, the operation of attaching the cushion tape 20 to the outer peripheral surface of the core body 11 can be easily performed.

  In the present embodiment, the cushion tape 20 receives stress due to the winding of the web material 30, and between the web material 30 and the outer peripheral surface of the core body 11 at both end surfaces in the circumferential direction Y of the cushion tape 20. However, it does not necessarily mean that the space portion is completely filled.

  Moreover, in this embodiment, when the cushion tape 20 does not have adhesiveness, it is preferable to previously form adhesives 50 and 51 on both sides of the cushion tape 20 as shown in FIG. Here, the adhesive material 50 is an adhesive material formed on the surface to be attached to the outer peripheral surface of the core body 11, and the adhesive material 51 is formed on the surface on the side that fixes the end of the web material 30. Adhesive. For example, since the fluorine-based polymer does not have adhesiveness, when the cushion tape 20 is configured using the fluorine-based polymer, adhesives 50 and 51 as shown in FIG. It is preferable to keep it.

  Moreover, in this embodiment, if the thickness of the cushion tape 20 is thicker than the thickness of the web material 30, the thickness will not be specifically limited, For example, the range of 50 micrometers-200 micrometers is suitable.

  5A and 5B are views showing an example of a method for manufacturing the cushion tape 20 in the present embodiment.

  As shown in FIG. 5 (a), a long sheet 21 made of a fluoropolymer that is a material of the cushion tape 20 is prepared, and an adhesive 50 is applied to the surface along the longitudinal direction X of the long sheet 21. , Formed into a plurality of stripes. Further, the adhesive material 51 is also formed in a plurality of stripes on the back surface of the long sheet 21 in accordance with the position where the adhesive material 50 is formed. The adhesive materials 50 and 51 are, for example, pasted on both sides of the long sheet 21 by a roll-to-roll method, a sheet in which the adhesive material 50 is applied to the base material and a sheet in which the adhesive material 51 is applied to the base material. It can be formed by combining them.

Next, as shown in FIG. 5 (a), a long sheet 21 of adhesive material 50 and 51 on both sides are formed in accordance with the length in the axial direction X of the winding core _10, B 1 -B ₁ wire , And B ₂ -B ₂ line, and for each stripe, cut along A ₁ -A ₁ line, A ₂ -A ₂ line, and A ₃ -A ₃ line. Thereby, as shown in FIG.5 (b), the cushion tape 20 stuck on the outer peripheral surface of the core main body 11 is formed.

  Hereinafter, although the example and the example of the present invention are given and the composition and effect of the present invention are further explained, the present invention is not limited to these examples.

Example 1
A core body 11 made of ABS resin having an inner diameter of 3 inches (outside diameter of about 88 mm) is prepared, and a fluoropolymer (manufactured by Chuko Kasei Kogyo Co., Ltd .: trade name Chuko Flow (registered trademark)) on the outer peripheral surface of the core body 11 A cushion tape 20 made of The cushion tape 20 used in Example 1 was a base material-less tape, had a thickness of 100 μm, and the width in the circumferential direction Y of the core body 11 was 30 mm. The mechanical properties of the cushion tape 20 are 2.5 MPa in the thickness direction, 0.25 MPa in the circumferential direction Y of the core body 11, and 8.5 MPa in the axial direction X. It was. That is, the cushion tape 20 used in Example 1 is made of a material having anisotropy in which the tensile elastic modulus in the circumferential direction Y of the core body 11 is smaller than the tensile elastic modulus in the axial direction X.

(Comparative Example 1)
A cushion tape 20 made of the same material as in Example 1 was attached to the outer peripheral surface of the same core body 11 as in Example 1 with the anisotropic direction rotated 90 degrees from that in Example 1. That is, the cushion tape 20 used in Comparative Example 1 has an anisotropy in which the tensile elastic modulus (8.5 MPa) in the circumferential direction Y of the core body 11 is larger than the tensile elastic modulus (0.25 MPa) in the axial direction X. It consists of material which has.

(Example 2)
A cushion tape 20 made of a fluoropolymer was attached to the outer peripheral surface of the same core body 11 as in Example 1. The cushion tape 20 used in Example 2 was a base material-less tape, had a thickness of 70 μm, and the width in the circumferential direction Y of the core body 11 was 30 mm. The mechanical properties of the cushion tape 20 are as follows: hardness in the thickness direction is 0.20 MPa, tensile elastic modulus in the circumferential direction Y of the core body 11 is 1.75 MPa, and tensile elastic modulus in the axial direction X is 6.0 MPa. It was. That is, the cushion tape 20 used in Example 2 is made of a material having anisotropy in which the tensile elastic modulus in the circumferential direction Y of the core body 11 is smaller than the tensile elastic modulus in the axial direction X.

(Comparative Example 2)
A cushion tape 20 made of polyurethane foam was affixed to the outer peripheral surface of the same core body 11 as in Example 1. The cushion tape 20 used in Comparative Example 2 was a base material-less tape, had a thickness of 2 mm, and the width in the circumferential direction Y of the core body 11 was 30 mm. In addition, as the mechanical properties of the cushion tape 20, the hardness in the thickness direction was 5.0 MPa, the tensile elastic modulus in the circumferential direction Y of the core body 11 and the axial direction X was 8.0 MPa. That is, the cushion tape 20 used in Comparative Example 2 is made of a material in which the tensile elastic modulus of the core body 11 is isotropic.

(Comparative Example 3)
A cushion tape 20 made of polyurethane foam was affixed to the outer peripheral surface of the same core body 11 as in Example 1. The cushion tape 20 used in Comparative Example 3 was a tape with a base material made of polyethylene terephthalate having a thickness of 50 μm, a thickness of 500 μmm, and a width in the circumferential direction Y of the core body 11 was 30 mm. Further, as mechanical properties of the cushion tape 20, the hardness in the thickness direction was 1.0 MPa, the tensile elastic modulus in the circumferential direction Y of the core body 11 and the axial direction X was 3.0 MPa. That is, the cushion tape 20 used in Comparative Example 3 is made of a material whose tensile elastic modulus of the core body 11 is isotropic.

(Evaluation of step marks and buckling)
The winding core body 11 to which the cushion tapes 20 of Examples 1 and 2 and Comparative Examples 1 to 3 are respectively attached is attached to a winding device, and a PET film (with aluminum foil) having a thickness of 75 μm is wound on the winding tension. The film was wound up to 320 m at 66 N at a winding speed of 150 m / min. Then, after leaving the wound PET film at room temperature for 24 hours, the step marks at the winding end of the PET film when unrolled and the occurrence of buckling due to the space generated at both ends of the cushion tape 20 are observed. Each was confirmed visually.

  Table 1 shows the results.

  As shown in Table 1, in Example 1, the step mark at the winding end of the PET film could be confirmed up to the fourth turn, but was not confirmed in further turns. This is because the hardness in the thickness direction of the cushion tape 20 is as small as 2.5 MPa (very soft), so that the winding end of the PET film is subjected to stress due to winding, and the cushion tape is completely cushioned by the thickness. It is thought that it was sinking in 20. Further, the buckling due to the space portion generated at both ends of the cushion tape 20 could be confirmed up to the second round, but was not confirmed in the further rounds. This is because the tensile elastic modulus in the circumferential direction Y of the cushion tape 20 is as small as 0.25 MPa, so that the cushion tape 20 is subjected to stress due to winding, and is between the PET film and the outer peripheral surface of the core body 11. This is thought to be because the space was formed so as to fill the space.

  In addition, since the cushion tape 20 of Example 1 has a large tensile elastic modulus in the axial direction of 8.5 MPa, the cushion tape 20 itself is self-supporting even if it is a baseless tape. For this reason, the operation of attaching the cushion tape 20 to the outer peripheral surface of the core body 11 could be easily performed.

  On the other hand, in Comparative Example 1, although the cushion tape 20 made of the same material as that of Example 1 was used, the step mark at the winding end of the PET film was confirmed only up to the fourth round. However, buckling due to the space portions generated at both ends of the cushion tape 20 was confirmed up to the 30th turn. This is because the cushion tape 20 is affixed to the core body 11 with the direction of large tensile modulus in the circumferential direction Y, and the cushion tape 20 is formed between the PET film and the outer peripheral surface of the core body 11. This is probably because the space was not deformed so as to be sufficiently filled.

  In Example 2, the step mark at the winding end of the PET film could be confirmed up to the sixth round, but was not confirmed in the further rounds. Further, the buckling due to the space portion generated at both ends of the cushion tape 20 could be confirmed up to the third round, but was not confirmed in the further rounds. This is because, as in Example 1, the cushion tape 20 has a small hardness in the thickness direction of the cushion tape 20 of 0.20 MPa (very soft) and a tensile elastic modulus in the circumferential direction Y of 1.75 MPa. This is probably because it is very small. The cushion tape 20 of Example 2 is also made of a material having anisotropy in which the tensile elastic modulus in the circumferential direction Y of the core body 11 is smaller than the tensile elastic modulus in the axial direction X. Since the elastic modulus is as large as 6.0 MPa, the cushion tape 20 itself is self-supporting even if it is a base-less tape, and the cushion tape 20 can be easily attached to the outer peripheral surface of the core body 11. I was able to.

  On the other hand, in Comparative Example 2, step marks at the winding end of the PET film were confirmed up to the 100th turn. Moreover, the buckling resulting from the space part produced in the both ends of the cushion tape 20 was also confirmed to the 40th round. This is because the hardness in the thickness direction of the cushion tape 20 is as large as 5.0 MPa, and even if the winding end of the PET film is subjected to stress due to winding, it will sink sufficiently in the cushion tape 20 by the thickness. As a result, it is considered that step marks are generated. In addition, since the cushion tape 20 of Comparative Example 2 has isotropic mechanical characteristics, if the hardness in the thickness direction is large, of course, the circumferential direction Y and the axial direction X of the core body 11 are naturally. The tensile elastic modulus is also large as 8.0 MPa. Therefore, even if the cushion tape 20 receives stress due to winding, the space formed between the PET film and the outer peripheral surface of the core body 11 is not deformed so as to be sufficiently filled, and as a result, It is thought that buckling occurred. In addition, since the cushion tape 20 of Comparative Example 2 has a large hardness in the thickness direction and a large tensile elastic modulus in the circumferential direction Y and the axial direction X, the cushion tape 20 itself has self-supporting properties even if it is a baseless tape. .

  In Comparative Example 3, the step mark at the winding end of the PET film was confirmed only up to the sixth lap, but the buckling due to the space generated at both ends of the cushion tape 20 was confirmed up to the 30th lap. It was. This is considered due to the following reasons. That is, the cushion tape 20 of Comparative Example 3 has a small hardness in the thickness direction of 1.0 MPa (very soft), and the tensile elastic modulus in the circumferential direction Y of the core body 11 is also small as 3.0 MPa. Is isotropic, the tensile elastic modulus in the axial direction X of the core body 11 is also as small as 3.0 MPa. Therefore, in order to give the cushion tape 20 itself a self-supporting property, it is necessary to provide a base material on the cushion tape 20. As a result, since a new level difference is generated at the end of the base material, it is considered that the space formed between the PET film and the outer peripheral surface of the core body 11 remains and buckling occurs.

  As can be seen from the above results, in order to reduce the level difference caused by the level difference generated at the end of the PET film (web material) 30 and to reduce the buckling due to the space generated at both ends of the cushion tape 20. For the cushion tape 20, it is effective to use a material having anisotropy in which the tensile elastic modulus in the circumferential direction Y of the core body 11 is smaller than the tensile elastic modulus in the axial direction X of the core body 11. I understand that there is. As such a cushion tape 20, for example, a uniaxially stretched fluoropolymer is preferable and can be used as the base material-less tape 20. Further, the tensile elastic modulus in the circumferential direction Y of the core body 11 of the cushion tape 20 is preferably at least in the range of 0.25 MPa to 1.75 MPa. If it exists in this range, the buckling resulting from the space part produced in the both ends of the cushion tape 20 can be reduced effectively. Further, the hardness of the cushion tape 20 (a dynamic ultra-micro hardness meter (model number DUH-21S) manufactured by Shimadzu Corporation) is used. Is preferably at least 2.5 MPa or less. If it is this range, the level | step difference trace resulting from the level | step difference produced in the edge part of PET film (web material) 30 can be reduced effectively. Further, the tensile elastic modulus in the axial direction X of the core body 11 of the cushion tape 20 is preferably at least 6.0 MPa or more. If it is in this range, even if the cushion tape 20 is a base material-less tape, the cushion tape 20 itself can maintain its independence, and therefore the cushion tape 20 is attached to the outer peripheral surface of the core body 11. Can be easily performed.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible.

10 core
11 Core body
20 Cushion tape
21 Long sheet
30 Web material
50, 51 Adhesive

Claims (10)

A winding method for winding a web material around a core,
The core has a belt-like cushion tape that extends in the axial direction of the core body on the outer peripheral surface of the core body,
A step (a) of affixing an end of the web material on the cushion tape;
Winding the web material around the core body while applying tension to the web material (b),
The cushion tape is made of a material having anisotropy in which the tensile elastic modulus in the circumferential direction of the core body is smaller than the tensile elastic modulus in the axial direction of the core body,
In the step (b), the cushion tape receives stress due to the winding of the web material, and between the web material and the outer peripheral surface of the core body at both circumferential end surfaces of the cushion tape. A method of winding a web material, which is deformed so as to fill a formed space.   The web cushioning method according to claim 1, wherein the cushion tape is a baseless tape and is made of a uniaxially stretched fluoropolymer.   The web material winding method according to claim 1 or 2, wherein a tensile elastic modulus in a circumferential direction of the core body of the cushion tape is in a range of at least 0.25 MPa to 1.75 MPa.   The web material winding method according to any one of claims 1 to 3, wherein a tensile elastic modulus in an axial direction of the core body of the cushion tape is at least 6.0 MPa or more.   The web material winding method according to any one of claims 1 to 4, wherein the cushion tape has a hardness of at least 2.5 MPa. A core used for winding a web material,
The core has a belt-like cushion tape that extends in the axial direction of the core body on the outer peripheral surface of the core body,
The said cushion tape is a core which consists of a material which has the anisotropy whose tensile elastic modulus of the circumferential direction of the said core main body is smaller than the tensile elastic modulus of the axial direction of the said core main body.   The core according to claim 6, wherein the cushion tape is a baseless tape and is made of a uniaxially stretched fluoropolymer.   The core according to claim 6 or 7, wherein a tensile elastic modulus in a circumferential direction of the core body of the cushion tape is in a range of at least 0.25 MPa to 1.75 MPa.   The core according to any one of claims 6 to 8, wherein a tensile elastic modulus in an axial direction of the core body of the cushion tape is at least 6.0 MPa or more. The core according to any one of claims 6 to 9, wherein the hardness of the cushion tape is at least 2.5 MPa or less.

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