JP2009149420A - Winding core body for winding sheet-shaped article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a winding core body capable of forming the winding shape of a sheet-shaped article suppressing the generation of a waving phenomenon, slacking, and streaks, since the waving phenomenon is generated in a width direction end by winding-fastening caused by a change with time and a printing property is deteriorated, when a long sheet-shaped article, especially a synthetic resin film is wound around the winding core body after forming the film. <P>SOLUTION: At both ends of the winding core body 3, tapered portions 3a gradually decreased in a diameter toward end side are formed. The tapered portion 3a is formed from a position in a range of a length L=5-25 cm on a center side from an end surface 2a in the width direction of the sheet-shaped article 2 formed of the synthetic resin film wound around the winding core body 3 to a position exceeding at least an end surface 2a at an angle θ=0.1-2°. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a winding core used as a core for winding up a manufactured sheet-like material, and in particular, a synthetic resin film such as a decorative film for printing is wound up as a sheet-like material. It is related with the winding core suitable for.

  For example, a synthetic resin film such as a decorative film for printing in the form of a sheet is formed by cutting a long film continuously formed by T-die extrusion or the like into a predetermined width, a paper tube, a resin tube, a steel tube, etc. It is made to wind up to the core body of this, and is completed as winding. At this time, when the film is mainly a crystalline resin such as a polypropylene resin, a change with time occurs, and the winding is tightened at both ends in the width direction of the winding. Occurs, the flatness of the film is impaired, and printing may be lost during printing. Such winding tightening is caused by the difference in shrinkage due to the difference in cooling time while the both ends in the width direction of the film are rapidly cooled while the progress of cooling is slow in the center due to heat storage. . Since the printability is hindered by this undulation phenomenon, there is a possibility that the winding with the undulation phenomenon cannot be shipped as a defective product.

  As a measure for avoiding the above-described winding tightening phenomenon, for example, an aging treatment is performed in which a film formed on a steel core made of a steel tube is loosely wound and maintained in a constant temperature atmosphere for an appropriate time. There is a case in which the tightening is suppressed, and then a narrow winding, that is, a so-called small winding is formed while rewinding the paper tube.

  Further, Patent Document 1 discloses that a synthetic resin sheet is wound into a roll shape so that both ends of the roll do not swell and no wavy phenomenon appears at both ends in the sheet width direction when unrolled. In order to provide a resin sheet, a synthetic resin composition is formed into a continuous sheet having a constant width of 0.5 to 3.0 mm and wound into a roll. A sheet is disclosed in which both end surfaces in the sheet width direction form slopes that form a certain angle (except 90 °) with respect to the sheet surface.

JP-A-8-187790

  In the case of the above-described method of winding the formed film on a steel tube core, there is a risk that it may be disadvantageous in terms of manufacturing cost because it takes time and facilities for the aging process and the rewind process. There is.

  Moreover, in the long synthetic resin sheet disclosed in Patent Document 1, since it is thin due to the slopes formed at both ends in the width direction, the printability in the vicinity of the end portion is lowered, and the strength is easily lowered and easily damaged. There is a risk of becoming unsuitable for a decorative film for printing.

  Therefore, the present invention provides a winding core for sheet-like material that suppresses the occurrence of undulations at both ends in the width direction of the winding of the sheet-like material, and the occurrence of streak in the film in the film. The purpose is to provide a body.

  As technical means for achieving the above object, a winding core for winding a sheet according to the present invention is a sheet for winding a long sheet to form a cylindrical winding. In the winding core of the article, the outer peripheral surface of the winding core is 5 to 25 cm from each of the portions where both ends in the width direction of the wound sheet are positioned toward the center. A taper portion having an angle of 0.1 to 2 ° is formed up to a position passing through both end portions in the width direction in a state where each end edge side of the core body has a small diameter with a portion in the range as a base portion. It is a feature.

  That is, both end portions of the core body are formed in a tapered shape with a small diameter on the edge side. The tapered portion starts from a position of 5 to 25 cm from the end in the width direction of the sheet-like material wound around the core body, and continues to the edge of the core body. Therefore, in the case of winding that is formed in a state in which the edge of the winding core protrudes from the end in the width direction of the sheet-like material, the protruding portion is also formed in a taper shape. And the angle of a taper part is formed at 0.1-2 degrees. The angle of the tapered portion is an angle formed by the bus bar of the tapered portion and the axis of the winding core.

  A winding core for winding a sheet-like material according to the invention of claim 2 is characterized in that it is used for winding a film formed of a thermoplastic resin as the sheet-like material.

  In the case where the sheet-like material is a thermoplastic resin, there is a difference in the cooling rate between the end portion in the width direction and the center portion, so that winding of the end portion in the width direction tends to occur. For this reason, it will be used for the core of the sheet-like material by a thermoplastic resin film.

  A winding core for winding a sheet-like material according to the invention of claim 3 is characterized in that it is used for winding a film formed from a polypropylene resin as the sheet-like material.

  Widely used for building materials and packaging, it is a versatile product, high thermoplasticity, excellent moldability, changes with time and tends to cause tightness at both ends in the winding width direction. It is a core body.

  A winding core for winding a sheet according to the invention of claim 4 is characterized in that the sheet has a thickness of 40 to 400 μm.

  The synthetic resin film has a thickness of 40 to 400 μm.

  According to the winding core for winding a sheet-like material according to the present invention, it is possible to suppress as much as possible the tightening that may occur at both ends in the width direction and the wavy phenomenon resulting therefrom. Therefore, for example, when printing is performed over the entire width, it is possible to perform proper printing up to the end portion, thereby improving the yield of the product and reducing the manufacturing cost.

  Further, according to the winding core for sheet-like material according to the invention of claim 2, the core of the thermoplastic resin film tends to have a large difference in cooling rate between the end side and the center side. Therefore, it is possible to effectively suppress the occurrence of winding tightening and wavy phenomenon.

  In addition, according to the winding core for winding a sheet-like material according to the invention of claim 3, when applied to a polypropylene-based resin film that is rich in thermoplasticity and is likely to cause winding tightening, occurrence of winding tightening and wavy phenomena Can be made more effective.

  In addition, according to the winding core for sheet-like material according to the invention of claim 4, by applying to a thick sheet-like material that is liable to cause tightening and undulation, these effectively The phenomenon can be suppressed.

  Hereinafter, the winding core for winding a sheet-like material according to the present invention will be specifically described based on the illustrated preferred embodiment.

  FIG. 1 shows a winding 1 formed by winding a long sheet-like material 2 made of a synthetic resin film around a core body 3. The core body 3 is formed in a hollow cylindrical shape, and a paper tube, a synthetic resin tube, a steel tube, or a mixture thereof is used. In the case of a paper tube or the like, there is one in which a base 4 for protecting the end portion and rotatingly supporting the core body 3 is provided on the inner peripheral portion of the end portion as necessary. Further, both end portions of the core body 3 protrude from both end surfaces 2 a in the width direction of the sheet-like object 2. Note that winding may be performed in which the respective end portions of the core body 3 coincide with the both end surfaces 2a of the sheet-like material 2.

  The outer peripheral surface of each end portion of the core body 3, and a portion in the range of the length L from the end surface 2 a in the width direction of the wound sheet-like material 2 to the center side of the core body 3 is a base portion. As shown, the taper portion 3a is formed so as to gradually decrease in diameter toward the end edge side of the core body 3 at an angle θ. The tapered portion 3a extends to the end edge of the core body 3, and therefore, the tapered portion 3a is formed so as to cross the end surface 2a of the sheet-like object 2. The taper portion 3a is formed up to the end of the core body 3 in consideration of ease of processing, and the outer peripheral surface of the portion protruding outward from the end surface 2a of the sheet-like material 2 has the same diameter. You may form with the shape which becomes. Further, depending on the winding 1 to be formed, both end faces of the core body 3 and the both end faces 2a of the sheet-like material 2 may coincide with each other. It will be formed to the edge part.

  The winding core 3 configured as described above is wound around the sheet-like material 2 to form the winding 1, and in this case, the wavy phenomenon at both ends of the sheet-like material 2, the inside darumi, and the traces of the film performance Was evaluated. The evaluation was performed by changing the type of the core body 3, the length L of the range of the tapered portion 3 a, the taper angle θ, the material of the sheet-like material 2 to be wound up, and the like. In addition, this evaluation was performed for a range of about 300 m at the center of the sheet-like material 2 wound around the core body 3. The results are shown in Tables 1 to 4 in FIGS.

(1) Example 1
A paper tube having an inner diameter of 77 mm, an outer diameter of 110 mm, and a length of 1360 mm, and a paper tube in which the base 4 is fitted to the inner peripheral portion of the end (in the table, “paper tube (1) The sheet-like product 2 was wound up with a polypropylene resin film (PP (1) (product name: XP10081) manufactured by Riken Technos Co., Ltd.) having a thickness of 70 μm, a width of 1310 mm, and a total length of 3000 m. A T-die extruder manufactured by Mitsubishi Heavy Industries, Ltd. was used for film formation. As the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 1.8 mm. The results are shown as Example 1 in Table 1 of FIG. In the table, the evaluation result of the performance is excellent (all films from the core to 300 m from the core are good) with “◎”, good (film from the core to 100 m is bad) is “○”, acceptable (from the core) “△” indicates that the film up to 200 m is defective, and “×” indicates that it is not possible (all films from the core to 300 m are defective). In the following examples, performance evaluation is performed with the same symbols. That is, in the core body 3 in Example 1, “◎” was obtained in any of the wavy phenomenon, the middle dharmi, and the traces, and good results were obtained.
(2) Example 2
The winding core 3 of the paper tube (1) having a taper angle θ of 0.4 ° in Example 1 is used. The height h of the tapered portion 3a was 1.0 mm. Also in this case, the wavy phenomenon, middle dharmi, and trace were all “◎”.
(3) Example 3
The core 3 of the paper tube (1) having a taper angle θ of 1.0 ° in Example 1 is used. The height h of the tapered portion 3a was 2.6 mm. Also in this case, the wavy phenomenon, middle dharmi, and trace were all “◎”.
(4) Example 4
The core 3 of the paper tube (1) having a taper angle θ of 1.5 ° in Example 1 is used. The height h of the tapered portion 3a was 3.9 mm. In the core body 3 in Examples 1 to 3, the most favorable “」 ”results were obtained in any of the wavy phenomenon, middle dharmi, and trace, whereas in Example 4, the wavy phenomenon was Phenomenon and middle dharmi were “◯”, and the trace was “◎”.
(5) Example 5
The core 3 of the paper tube (1) having a taper angle θ of 0.3 ° in Example 1 is used. The height h of the tapered portion 3a was 0.8 mm. The result was “◎” for Nakadharmi, and “○” for wavy phenomena and traces.
(6) Example 6
The core 3 of the paper tube (1) having a taper angle θ of 1.8 ° in Example 1 is used. The height h of the tapered portion 3a was 4.7 mm. The wavy phenomenon was “◯”, the middle dharmi was “△”, and the trace was “◎”.
(7) Example 7
In this example, the core 3 of the paper tube (1) having a taper angle θ of 0.15 ° is used. The height h of the tapered portion 3a was 0.4 mm. The undulation phenomenon was “△”, the middle dharmi was “◎”, and the trace was “△”.
(8) Example 8
In the first embodiment, the core 3 of the paper tube (1) is used in which the length L of the tapered portion 3a is 10 cm and the taper angle θ is 0.7 °. The height h of the tapered portion 3a was 1.2 mm. The wavy phenomenon was “◯”, the inner dharmi was “◎”, and the trace was “◎”.
(9) Example 9
In the first embodiment, the winding core 3 of the paper tube (1) in which the length L of the tapered portion 3a is 10 cm and the taper angle θ is 1.0 ° is used. The height h of the tapered portion 3a was 1.7 mm. The wavy phenomenon was “◯”, the inner dharmi was “◎”, and the trace was “◎”.
(10) Example 10
In this embodiment, the core 3 of the paper tube (1) in which the length L of the tapered portion 3a in Example 1 is 20 cm and the taper angle θ is 0.7 ° is used. The height h of the tapered portion 3a was 2.4 mm. The wavy phenomenon was “◎”, the middle dharmi was “◯”, and the trace was “◎”.
(11) Example 11
In the first embodiment, the winding core 3 of the paper tube (1) in which the length L of the tapered portion 3a is 20 cm and the taper angle θ is 1.0 ° is used. The height h of the tapered portion 3a was 3.5 mm. The wavy phenomenon was “◎”, the middle dharmi was “◯”, and the trace was “◎”.
(12) Example 12
In this embodiment, the core 3 of the paper tube (1) in which the length L of the tapered portion 3a in Example 1 is 6 cm and the taper angle θ is 0.7 ° is used. The height h of the tapered portion 3a was 0.7 mm. The undulation phenomenon was “△”, the middle dharmi was “◎”, and the trace was “△”.
(13) Example 13
In the first embodiment, the winding core 3 of the paper tube (1) in which the length L of the tapered portion 3a is 6 cm and the taper angle θ is 1.0 ° is used. The height h of the tapered portion 3a was 1.0 mm. The undulation phenomenon was “△”, the middle dharmi was “◎”, and the trace was “△”.
(14) Example 14
In this embodiment, the core 3 of the paper tube (1) in which the length L of the tapered portion 3a in Example 1 is 24 cm and the taper angle θ is 0.7 ° is used. The height h of the tapered portion 3a was 2.9 mm. The wavy phenomenon was “◎”, the middle dharmi was “△”, and the trace was “◎”.
(15) Example 15
In the first embodiment, the winding core 3 of the paper tube (1) in which the length L of the tapered portion 3a is 24 cm and the taper angle θ is 1.0 ° is used. The height h of the tapered portion 3a was 4.2 mm. The wavy phenomenon was “◎”, the middle dharmi was “△”, and the trace was “◎”.
(16) Example 16
In Example 1, the length L of the taper portion 3a is 15 cm, the taper angle θ is 0.7 °, and the core 3 of the paper tube (1) is used. PP (1 ) Was wound up with a thickness of 90 μm. The height h of the tapered portion 3a was 1.8 mm. The wavy phenomenon was “◎”, the middle dharmi was “◎”, and the trace was “◎”.
(17) Example 17
In Example 1, the length L of the taper portion 3a is 15 cm, the taper angle θ is 0.7 °, and the core 3 of the paper tube (1) is used. PP (1 ) Was wound up with a thickness of 120 μm. The height h of the tapered portion 3a was 1.8 mm. The undulation phenomenon was “○”, the inside Dharmi was “○”, and the trace was “○”.
(18) Example 18
In Example 1, the length L of the taper portion 3a is 15 cm, the taper angle θ is 0.7 °, and the core 3 of the paper tube (1) is used. PP (1 ) Was wound up with a thickness of 200 μm. The height h of the tapered portion 3a was 1.8 mm. The undulation phenomenon was “○”, the inside Dharmi was “○”, and the trace was “○”.
(19) Example 19
In Example 1, the length L of the taper portion 3a is 15 cm, the taper angle θ is 0.7 °, and the core 3 of the paper tube (1) is used. PP (1 ) Was wound up with a thickness of 50 μm. The height h of the tapered portion 3a was 1.8 mm. The undulation phenomenon was “○”, the inside Dharmi was “○”, and the trace was “○”.
(20) Example 20
In Example 1, the length L of the taper portion 3a is 15 cm, the taper angle θ is 0.7 °, and the core 3 of the paper tube (1) is used. PP (1 ) Was wound up with a thickness of 30 μm. The height h of the tapered portion 3a was 1.8 mm. The wavy phenomenon was “△”, the middle dharmi was “△”, and the trace was “△”.
(21) Example 21
In Example 1, the length L of the taper portion 3a is 15 cm, the taper angle θ is 0.7 °, and the core 3 of the paper tube (1) is used. PP (1 ) Was wound up with a thickness of 420 μm. The height h of the tapered portion 3a was 1.8 mm. The wavy phenomenon was “△”, the middle dharmi was “△”, and the trace was “△”.
(22) Example 22
In this example, the core 3 of the paper tube (1) in which the length L of the tapered portion 3a in Example 1 is 15 cm and the taper angle θ is 0.7 ° is used. PP (2) of a grade different from that of -20 (made by Riken Technos Co., Ltd., product name: XP50071) was wound up with a thickness of 70 μm. The height h of the tapered portion 3a was 1.8 mm. The wavy phenomenon was “◎”, the middle dharmi was “◎”, and the trace was “◎”.
(23) Example 23
Using a paper tube (indicated as “paper tube (2)” in the table) having an inner diameter of 77 mm, an outer diameter of 110 mm, and a length of 1070 mm for the core 3, the sheet-like material 2 has a thickness of 70 μm and a width of 1030 mm. A PP (1) having a total length of 3000 m was wound up. As the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 1.8 mm. Both the wavy phenomenon and the inside Dharmi and the trace were “◎”.
(24) Example 24
A paper tube (1) was used as the core 3 and a PP (1) having a thickness of 70 μm, a width of 1310 mm, and a total length of 1500 m was wound up as a sheet-like material 2. As the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 1.8 mm. Both the wavy phenomenon and the inside Dharmi and the trace were “◎”.
(25) Example 25
Using a paper tube (1) for the core body 3 and forming a sheet-like material 2 into a polyvinyl chloride having a thickness of 70 μm, a width of 1310 mm, and a total length of 3000 m (PVC (1) (product name: H, FC1312) manufactured by Riken Technos Co., Ltd.) ). As the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 1.8 mm. Both the wavy phenomenon and the inside Dharmi and the trace were “◎”.
(26) Example 26
A paper tube (1) is used as the core 3 and a polyethylene sheet (PE (1) (product name: XP7023) manufactured by Riken Technos Co., Ltd.) having a thickness of 70 μm, a width of 1310 mm, and a total length of 3000 m is wound as the sheet-like material 2. Let As the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 1.8 mm. Both the wavy phenomenon and the inside Dharmi and the trace were “◎”.
(27) Example 27
Using a paper tube (1) for the core 3 and a sheet-like product 2, polyethylene terephthalate (PETG (1) (product name: Libester XT10073) manufactured by Riken Technos Co., Ltd.) having a thickness of 70 μm, a width of 1310 mm, and a total length of 3000 m is used. I wound it up. As the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 1.8 mm. Both the wavy phenomenon and the inside Dharmi and the trace were “◎”.
(28) Example 28
Using a resin tube (indicated as “resin tube (1)” in the table) with an inner diameter of 77 mm, an outer diameter of 110 mm, and a length of 1360 mm for the core 3, the sheet-like material 2 has a thickness of 70 μm and a width of 1310 mm. The PP (1) having a total length of 3000 m was wound up. As the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 1.8 mm. Both the wavy phenomenon and the inside Dharmi and the trace were “◎”.
(29) Example 29
Using a steel tube (indicated as “steel (1)” in the table) with an inner diameter of 77 mm, an outer diameter of 110 mm, and a length of 1360 mm for the core 3, the sheet-like material 2 has a thickness of 70 μm, a width of 1310 mm, PP (1) with a total length of 3000 m was taken up. As the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 1.8 mm. Both the wavy phenomenon and the inside Dharmi and the trace were “◎”.

  Next, performance evaluation of the winding 1 will be shown as a comparative example by changing the length L and the angle θ of the tapered portion 3a, the material of the sheet-like material 2, the material of the winding core 3, and the like. The core body 3 had dimensions of an inner diameter of 77 mm, an outer diameter of 110 mm, a length of 1360 mm, and a sheet-like material 2 having a thickness of 70 μm, a width of 1310 mm, and a total length of 3000 m was wound. The results are shown in Table 5 and Table 6 in FIGS.

(30) Comparative Example 1
The paper core (1) was used as the core 3 and the PP (1) was wound up as the sheet-like material 2. In addition, as the winding core 3, one having no taper portion 3a was used. The wavy phenomenon was “x”, the inner dharmi was “◎”, and the trace was “x”.
(31) Comparative Example 2
The paper core (1) was used as the core 3 and the PP (1) was wound up as the sheet-like material 2. Further, the core body 3 having a taper portion 3a having a length L of 15 cm and a taper angle θ of 0.05 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 0.13 mm. The wavy phenomenon was “x”, the inner dharmi was “◎”, and the trace was “x”.
(32) Comparative Example 3
The paper core (1) was used as the core 3 and the PP (1) was wound up as the sheet-like material 2. Further, as the winding core 3, a taper portion 3a having a length L of 15 cm and a taper angle θ of 2.3 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 6.0 mm. The undulation phenomenon was “△”, the middle dharmi was “×”, and the trace was “△”.
(33) Comparative Example 4
The paper core (1) was used as the core 3 and the PP (1) was wound up as the sheet-like material 2. Further, as the winding core 3, a taper portion 3a having a length L of 4 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 0.5 mm. The wavy phenomenon was “x”, the inner dharmi was “◎”, and the trace was “x”.
(34) Comparative Example 5
The paper core (1) was used as the core 3 and the PP (1) was wound up as the sheet-like material 2. Further, as the winding core 3, a taper portion 3a having a length L of 27 cm and a taper angle θ of 0.7 ° was used. In addition, the height h of the taper part 3a in the edge part of the sheet-like article 2 was 3.3 mm. The undulation phenomenon was “△”, the middle dharmi was “×”, and the trace was “△”.
(35) Comparative Example 6
The paper core (1) was used for the core 3 and the PVC (1) was wound up as the sheet 2. In addition, as the winding core 3, one having no taper portion 3a was used. The wavy phenomenon was “△”, the middle dharmi was “◎”, and the trace was “×”.
(36) Comparative Example 7
The paper core (1) was used for the core 3 and the PE (1) was wound up as the sheet-like material 2. In addition, as the winding core 3, one having no taper portion 3a was used. The wavy phenomenon was “△”, the middle dharmi was “◎”, and the trace was “×”.
(37) Comparative Example 8
The paper core (1) was used as the core 3 and the PETG (1) was wound up as the sheet-like material 2. In addition, as the winding core 3, one having no taper portion 3a was used. The wavy phenomenon was “△”, the middle dharmi was “◎”, and the trace was “×”.
(38) Comparative Example 9
PP (1) was wound up as the sheet-like material 2 using the resin tube (1) on the winding core 3. In addition, as the winding core 3, one having no taper portion 3a was used. The wavy phenomenon was “x”, the inner dharmi was “◎”, and the trace was “x”.
(39) Comparative Example 10
The steel core (1) was used for the core body 3, and PP (1) was wound up as the sheet-like object 2. In addition, as the winding core 3, one having no taper portion 3a was used. The wavy phenomenon was “x”, the inner dharmi was “◎”, and the trace was “x”.

  As described above, in Comparative Examples 1 to 10, in the evaluation of the performance, there is a case where any of the rippling phenomenon, the middle darumi, and the trace is “x” (impossible), and the use may be limited. There is. On the other hand, in the core body 3 shown in Examples 1 to 29, the undulation phenomenon, the middle darumi, and the traces all have a performance of “Δ” (possible) or more, and the range of applications is widened. In particular, with respect to the core bodies 3 of Examples 1 to 3, 16, and 22 to 29, the evaluation of “◎” (excellent) was obtained for all of the wavy phenomenon, the inside darumi, and the trace, and sufficient flatness was ensured. Therefore, it is adapted for use as a decorative film for printing on which printing is performed on the entire surface.

  According to the winding core of the sheet-like material according to the present invention, the occurrence of a rippling phenomenon that occurs in the wound sheet-like material, a phenomenon of defective products such as middle darumi, traces, etc. is reduced as much as possible, Since the application is not limited, it is particularly suitable for use in a winding core suitable for forming a wound synthetic resin film.

It is a front view explaining the shape of the winding core body concerning this invention, and the sheet-like thing wound up is shown with the imaginary line. It is Table 1 which shows the result of the evaluation of the performance regarding Examples 1-9 performed about the core body which concerns on this invention. It is Table 2 which shows the result of the evaluation of the performance regarding Examples 10-18 performed about the core body which concerns on this invention. It is Table 3 which shows the result of the evaluation of the performance regarding Examples 19-27 performed about the core body which concerns on this invention. 6 is a table 4 showing the results of performance evaluations on Examples 28 and 29 performed on the core according to the present invention. Table 5 showing the results of Comparative Examples 1 to 8 in which the performance of the core body according to the present invention was compared for the core body having a shape different from that of the conventional core body and the core body according to the present invention. is there. Table 5 shows the results of Comparative Examples 9 and 10 in which the performance of the core body according to the present invention was compared for the core body having a shape different from that of the conventional core body and the core body according to the present invention. is there.

Explanation of symbols

1 Winding 2 Sheet
2a End face 3 Winding core
3a Taper part 4 Base L Length of taper part θ Taper angle

Claims (4)

In a winding core for winding a sheet-like material for winding a long sheet-like material to form a cylindrical winding,
Using the outer peripheral surface of the winding core body as a base, a portion in the range of 5 to 25 cm from the portion where the widthwise both ends of the wound sheet-like material are located toward the center portion. For winding a sheet-like material, wherein a taper portion having an angle of 0.1 to 2 ° is formed up to a position passing through both end portions in the width direction in a state where each edge side of the core body has a small diameter. Winding core.   The core for winding a sheet-like material according to claim 1, wherein the sheet-like material is a film formed from a thermoplastic resin.   The core for winding a sheet-like material according to claim 1 or 2, wherein the sheet-like material is a film formed from a polypropylene resin.   The core for winding a sheet-like material according to any one of claims 1 to 3, wherein the sheet-like material has a thickness of 40 to 400 µm.

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