JP2023088086A - Winding core for web winding and web winding method - Google Patents

Abstract

To provide a winding core and a web winding method capable of suppressing deformation occurring in a wound web.SOLUTION: A cylindrical winding core for winding a web includes: a first cylindrical part; and a pair of second cylindrical parts connected to both longitudinal end parts of the first cylindrical part and having a constant outer diameter larger than that of the first cylindrical part. A step height from the outer peripheral surface of the first cylindrical part to the outer peripheral surface of the second cylindrical part is 70 μm or larger than the sum of the thickness of one layer of the web and the thickness of a tape for fixing the web to the winding core.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a winding core used for winding a web-shaped member and a web winding method.

Web-like products such as antireflection films and hard coat films or their intermediates are wound into rolls in the manufacturing process. A cylindrical core called a winding core is used to wind the web into a roll. At the time of winding, one end of the web is fixed and adhered to a cylindrical core using an adhesive tape, and there is a step corresponding to the sum of the thickness of the web and the thickness of the adhesive tape at the fixing point on the core. occurs.

If there is a step due to the edge of the web or the adhesive tape, the step is transferred to the web by the pressure applied to the web during winding, resulting in deformation of the web. In particular, when the thickness of the web is less than 50 μm, the deformation of the web due to the transfer of the steps becomes significant. Further, even if the thickness of the web is 50 μm or more, if the elastic modulus of the web is less than 3 GPa, deformation of the web occurs due to transfer of the step. The deformation of the web due to this step extends from several tens of meters to several hundreds of meters from the winding start portion, and if deformation occurs within the effective area of the web (the portion used after cutting), the product will be defective and the yield will be reduced. Therefore, various techniques have been proposed for suppressing deformation of the web due to the step at the start of winding.

For example, in Patent Document 1, a cushioning material is wrapped around the outer peripheral surface of a cylindrical core material body, and the ends of the web-like material are dropped into concave cuts or grooves provided in the cushioning material. It is described that unevenness and deformation caused by the step at the end are suppressed.

Patent Literature 2 describes a web winding core in which a cushion layer and a protective layer for protecting the cushion layer are provided on a cylindrical base material.

In Patent Document 3, a tape sticking groove extending in the circumferential direction or spirally is provided on the outer peripheral surface of a cylindrical film winding core, and the film is fixed by a double-sided adhesive tape fitted in the tape sticking groove. By doing so, it is described that traces of steps at the start of winding are reduced.

Patent Document 4 describes that winding steps are eliminated by providing a tape fixing groove in the winding core and fixing the winding material to the winding core with a step absorbing fixing tape attached to the tape fixing groove. there is

JP 2009-242059 A JP-A-6-206668 JP 2010-70269 A Japanese Unexamined Patent Application Publication No. 2008-7286

In Patent Document 4, pillow portions higher than the core are formed on both sides of the winding core or in the width direction of the winding core so that an air layer is formed between the winding material and the core when the winding material is wound. , the use of this air layer to alleviate stepped patterns and wrinkles, and the use of a single-sided adhesive material to raise both sides.

However, Patent Document 4 does not discuss in detail the thickness of the air layer to be formed between the winding material and the core, and there is room for improvement.

SUMMARY OF THE INVENTION An object of the present invention is to provide a winding core and a web winding method capable of suppressing deformation of a wound web.

The present invention relates to a cylindrical winding core for winding a web, comprising: a first cylindrical portion; and a pair of second tubular portions having a constant outer diameter larger than that of the web. It is characterized by being 70 µm or more larger than the sum of the thickness of the layer and the thickness of the tape for fixing the web to the winding core.

Further, in the web winding method according to the present invention, there is provided a first tubular portion, and a fixed outer diameter larger than that of the first tubular portion, which is connected to both ends in the length direction of the first tubular portion. and a pair of second tubular portions having a step of fixing one end of the web to a first tubular portion of the winding core using a tape which is 70 μm or more larger than the sum of the thickness of the tape for fixing to the winding core; and rotating the winding core. and winding the web.

ADVANTAGE OF THE INVENTION According to this invention, the winding-up method of the winding core and web which can suppress the deformation|transformation which arises in the wound web can be provided.

1 is a perspective view of a winding core according to a first embodiment; FIG. FIG. 2 is a perspective view showing a method of winding a web using the winding core according to the first embodiment; Sectional view along the III-III line shown in FIG. Enlarged view of the X portion shown in FIG. A perspective view of a winding core according to a modified example of the first embodiment. Front view of a winding core according to a modified example of the first embodiment A perspective view of a winding core according to a second embodiment. Front view of the winding core according to the second embodiment Graph showing the amount of deformation of the web when the web was wound using the winding cores according to Examples and Comparative Examples.

(First embodiment)
FIG. 1 is a perspective view of the winding core according to the first embodiment.

The winding core 11 is used for winding a long member (web) such as an optical film, and has a cylindrical shape as a whole. The winding core 11 is provided with a hollow portion coaxial with the central axis, and this hollow portion is fitted with a rotating shaft of the winding device or a jig or the like for connecting to the rotating shaft during use. Although the material of the winding core 11 is not particularly limited, for example, fiber reinforced plastic (FRP), metal, or the like can be used.

The winding core 11 includes a first tubular portion 1 and a pair of second tubular portions 2a and 2b.

The first tubular portion 1 has a cylindrical shape with a constant outer diameter. The lengthwise (axial) width W1 of the first tubular portion 1 (that is, the interval between the second tubular portions 2a and 2b) is set to be smaller than the width of the web to be wound.

The second tubular portions 2a and 2b are connected to both longitudinal ends of the first tubular portion 1, respectively. Each of the second tubular parts 2a and 2b is coaxial with the first tubular part 1 and has a constant outer diameter larger than that of the first tubular part 1. As shown in FIG. The relationship between the outer diameter of the first cylindrical portion 1 and the outer diameters of the second cylindrical portions 2a and 2b will be described later.

FIG. 2 is a perspective view showing a method of winding a web using the winding core according to the first embodiment, and FIG. 3 is a cross-sectional view along line III-III shown in FIG. 4 is an enlarged view of the X portion shown in FIG.

To wind the web 10 using the winding core 11, first, the winding core 11 is attached to a winding device (not shown). Although the thickness of the web to be wound is not particularly limited, it is, for example, 15 to 130 μm. Next, one end of the web 10 is fixed to the winding core 11 using the adhesive tape 9 . Specifically, a double-sided adhesive tape 9 is attached to the outer surface of the first tubular portion 1 . Next, a portion (one end of the web 10) including the edge 7 in the length direction of the web 10 overlaps the adhesive tape 9 attached to the first tubular portion 1, and the edges 8a and 8b in the width direction are overlapped with each other. The web 10 is positioned with respect to the winding core 11 so that the band-shaped regions including each overlap with each of the second tubular portions 2a and 2b, and one end (the portion including the edge 7) of the web 10 is adhered. It is fixed to the winding core 11 via the tape 9 (see FIG. 2). The thickness of the adhesive tape 9 used for fixing the web 10 is, for example, 10-30 μm. Next, by driving a winding device (not shown), the winding core 11 is rotated and the web 10 is wound around the winding core 11 . In addition, the adhesive tape 9 may be of a single-sided adhesive type. In this case, the web 10 is attached to the outer surface of the web 10 and the outer peripheral surface of the first tubular portion 1 by attaching the adhesive tape 9 to the outer surface of the first tubular portion 1 . You may fix to the cylindrical part 1 of 1.

Here, the details of the dimensions of each part of the winding core 11 will be described.

Since the outer diameters of the second tubular portions 2a and 2b are larger than the outer diameter of the first tubular portion 1, there is a gap between the first tubular portion 1 and the second tubular portions 2a and 2b. There is a step. As shown in FIG. 4, the step height h from the outer peripheral surface of the first tubular portion 1 to the outer peripheral surfaces of the second tubular portions 2a and 2b is determined by the thickness d1 of one layer of the web 10 and the thickness of the adhesive tape 9. The difference Δh between the step height h and the total thickness (d1+d2) of the web 10 and the adhesive tape 9, which is larger than the sum of the thickness d2, is set to 70 μm or more. When the difference Δh between the step height h and the total thickness (d1+d2) of the web 10 and the adhesive tape 9 is 70 μm or more, the step formed by the thickness of the edge 7 portion of the web 10 and the thickness of the adhesive tape 9 is transferred. Deformation of the web due to bending can be reduced. Specifically, the length of the deformed portion at the winding start portion of the web 10 can be shortened, and the length of the web 10 that can be used as a product can be increased, thereby improving the product yield.

If the step height h from the outer peripheral surface of the first tubular portion 1 to the outer peripheral surfaces of the second tubular portions 2a and 2b is at least equal to the total thickness (d1+d2) of the web 10 and the adhesive tape 9, that is, , .DELTA.h of 0, the web 10 has no step at the winding start portion, so that deformation of the web 10 caused by the end portion of the web 10 and the adhesive tape 9 is eliminated. However, when the inventors of the present application have studied, when the step height h is equal to the total thickness (d1+d2) of the web 10 and the adhesive tape 9, compared to the case of using a winding core with a constant diameter without a step, , the deformation of the web is reduced, but the degree of reduction is not sufficient. Further, if the step height h is 70 μm or more larger than the total thickness (d1+d2) of the web 10 and the adhesive tape 9, the length of the portion where the deformation caused by the one end of the web 10 and the adhesive tape 9 can be significantly reduced. Do you get it. The difference Δh between the step height h and the total thickness (d1+d2) of the web 10 and the adhesive tape 9 is more preferably 100 μm or more. Sections can be made shorter.

Even if the difference Δh between the step height h and the total thickness (d1+d2) of the web 10 and the adhesive tape 9 is increased to about several hundred μm, the deformation caused by one end of the web 10 and the adhesive tape 9 can be reduced. is possible. However, since the web 10 is wound under a predetermined tension, if Δh becomes too large, the part to be wound on the first tubular portion 1 will be tightly wound (that is, the first cylindrical portion 1 with a relatively small outer diameter will be wound). The winding diameter of the portion wound up by the cylindrical portion 1 of 1 is likely to become smaller). When the portion wound up by the first tubular portion 1 is tightened, wrinkles are generated in the web 10, and deformation (tight winding traces) due to the wrinkles is generated. Therefore, if Δh is too large, the length of the portion where the seam is formed becomes long, leading to a decrease in product yield. Therefore, the difference Δh between the step height h and the total thickness (d1+d2) of the web 10 and the adhesive tape 9 is more preferably 200 μm or less. In this case, it is possible to suppress tight winding of the portion wound by the first cylindrical portion 1 and reduce occurrence of tight winding traces.

From the above, the difference Δh between the step height h and the total thickness (d1 + d2) of the web 10 and the adhesive tape 9 is most preferably 100 μm or more and 200 μm or less. Therefore, it is possible to reduce the deformation of the web 10 caused by the winding core 11 and to reduce the winding marks caused by the tension difference generated in the web 10 due to the step of the winding core 11 .

As described above, the axial width W1 of the first tubular portion 1 (that is, the distance between the second tubular portions 2a and 2b) is set shorter than the width of the web 10 to be wound. The width W1 of the first cylindrical portion 1 is preferably shorter than the width of the web 10 by 10 mm or more. When the width W1 of the first tubular portion 1 is shorter than the width of the web 10 by 10 mm or more, the overlapping width of each region including the edges 8a and 8b in the width direction of the web 10 and the second tubular portions 2a and 2b can be ensured, and the winding of the web 10 can be stably performed. It is more preferable that the overlapping width between the regions including the edges 8a and 8b in the width direction of the web 10 and the second tubular portions 2a and 2b is 5 mm or more. Since the width of each of the portions wound by the second tubular portions 2a and 2b is 5 mm or more, tight winding of the portion wound by the first tubular portion 1 can be reduced. It is preferable that the overlapping width between the regions including the widthwise edges 8a and 8b of the web 10 and the second tubular portions 2a and 2b is 15 mm or less. Even if the width of overlap between the region including the edges 8a and 8b of the web 10 and the second tubular portions 2a and 2b exceeds 15 mm, there is no problem with the winding itself, but if the width of overlap is 15 mm or less , it is preferable because the width of the effective area used as a product can be widened.

As described above, the winding core 11 according to the present embodiment includes the first tubular portion 1 and the second tubular portions 2a and 2b having relatively large outer diameters provided at both ends thereof. and the step height h from the outer peripheral surface of the first tubular portion 1 to the outer peripheral surfaces of the second tubular portions 2a and 2b is 70 μm or more larger than the total thickness (d1+d2) of the web 10 and the adhesive tape 9 is set. When one end of the web 10 is attached to the outer peripheral surface of the first tubular portion 1 using the adhesive tape 9, the step height between the first tubular portion 1 and the second tubular portions 2a and 2b, Due to the difference in the total thickness (d1+d2) of the web 10 and the adhesive tape 9, the transfer of the step caused by the thickness of the edge of the web 10 and the adhesive tape 9 can be reduced. Therefore, according to the present embodiment, it is possible to realize the winding core 11 that can suppress deformation of the web caused by the step caused by the adhesive tape 9 and the end of the web 10 used when fixing the web 10 to the winding core 11 . . If the web 10 is wound using this winding core 11, the length of the deformed portion at the start of winding can be shortened, so defects in the portion used as a product can be reduced and the yield can be improved.

(Modification)
5 is a perspective view of a winding core according to a modification of the first embodiment, and FIG. 6 is a front view of a winding core according to a modification of the first embodiment.

The winding core 12 has a first tubular portion 1 and a pair of second tubular portions 2a and 2b similar to those described above, and a pair of third tubular portions 3a and 3b. Prepare. The third tubular portions 3a and 3b are connected to the second tubular portions 2a and 2b, respectively. Each of the third tubular portions 3a and 3b is coaxial with the first tubular portion 1 and the second tubular portions 2a and 2b and has a smaller outer diameter than the second tubular portions 2a and 2b. .

The method of winding the web using the winding core 12 according to the modified example is the same as that of the above-described first embodiment. are overlapped with the second tubular portions 2a and 2b, respectively, and one end of the web is fixed to the first tubular portion 1 using an adhesive tape. After that, by driving a winding device (not shown), the winding core 12 is rotated and the web is wound.

Also in the winding core 12 according to the modified example, the step height from the outer peripheral surface of the first tubular portion 1 to the outer peripheral surfaces of the second tubular portions 2a and 2b is 70 μm greater than the total thickness of the web and the adhesive tape. It is set to be larger than Therefore, due to the difference between the step height and the total thickness of the web and the adhesive tape, deformation of the web due to the thickness of the end portion of the web 10 and the thickness of the adhesive tape 9 can be reduced when the web is wound.

(Second embodiment)
FIG. 7 is a perspective view of the winding core according to the second embodiment, and FIG. 8 is a front view of the winding core according to the second embodiment.

The winding core 13 includes a first tubular portion 1, a pair of tapered portions 5a and 5b, and a pair of second tubular portions connected to the first tubular portion 1 via the pair of tapered portions 5a and 5b. It comprises tubular portions 2a and 2b.

The first tubular portion 1 has a cylindrical shape with a constant outer diameter. A pair of tapered portions 5 a and 5 b are connected to both ends of the first cylindrical portion 1 . The second tubular parts 2a and 2b are coaxial with the first tubular part 1 and have a constant outer diameter larger than that of the first tubular part 1. As shown in FIG. The tapered portions 5a and 5b are configured such that their outer diameters decrease from the connecting portions with the second tubular portions 2a and 2b toward the central portion in the longitudinal direction of the first tubular portion 1. As shown in FIG. The taper angle of the tapered portions 5a and 5b is preferably 0.2 to 2.0° (the slope of the side surfaces of the tapered portions 5a and 5b is 0.1 to 1.0°). The interval between the second cylindrical portions 2a and 2b (the interval in the length direction (axial direction) of the winding core 13) is set to be smaller than the width of the web to be wound, as in the first embodiment. ing.

The web winding method using the winding core 13 according to the present embodiment is the same as that of the above-described first embodiment. One end of the web is fixed to the first tubular part 1 using adhesive tape, with the edges overlapping the second tubular parts 2a and 2b respectively. After that, by driving a winding device (not shown), the winding core 13 is rotated and the web is wound.

Also in this embodiment, the first cylindrical portion 1 and the second cylindrical portions 2a and 2b are configured to satisfy the same dimensional relationship as in the first embodiment. That is, the height of the step from the outer surface of the first tubular portion 1 to the outer peripheral surfaces of the second tubular portions 2a and 2b is 70 µm from the total thickness of one layer of the web to be wound and the adhesive tape for fixing the web. It is set to be larger than When the difference between the height of the step and the total thickness of the web and the adhesive tape is 70 μm or more, the transfer of the step caused by one end of the web and the adhesive tape is reduced, and deformation occurring at the winding start portion of the web can be reduced. . Moreover, the difference between the step height from the outer surface of the first tubular portion 1 to the outer peripheral surfaces of the second tubular portions 2a and 2b and the total thickness of the web and the adhesive tape is preferably 200 μm or less. As described in the first embodiment, if the difference between the step height and the total thickness of the web and the adhesive tape is 200 μm or less, tight winding of the portion wound around the first cylindrical portion 1 is suppressed. , the tight winding mark (deformation caused by wrinkles caused by tight winding) generated in the portion wound by the first tubular portion 1 can be reduced.

Further, in the winding core 13 according to the present embodiment, the center of the first tubular portion 1 is provided between both ends of the first tubular portion 1 and each of the second tubular portions 2a and 2b. Tapered portions 5a and 5b are provided in which the outer diameter gradually decreases toward the end. This makes it possible to reduce the tightening of the wound portion of the web wound by the tapered portions 5a and 5b (particularly, the portions near the second cylindrical portions 2a and 2b). Therefore, when the web is wound using the winding core 13 according to the present embodiment, it is possible to further reduce traces of winding due to tight winding of the web. Further, if the taper angle of the taper portions 5a and 5b is within the range of 0.2 to 2.0°, the taper angle is from the second cylindrical portions 2a and 2b toward the central portion of the first cylindrical portion. Since the outer diameter gradually decreases, tight winding can be suppressed more effectively.

In each of the above-described embodiments, an example in which the outer diameter of the first tubular portion 1 is constant has been described. As long as the difference in outer diameter between 2a and 2b satisfies the above condition, the outer diameter of the first tubular portion 1 may not be constant.

EXAMPLES Examples in which the present invention is specifically carried out will be described below.

As Examples 1 to 5, fiber-reinforced plastic was used, the outer diameter of the first cylindrical portion was constant at 167.00 mm, and the outer diameter of the second cylindrical portion was 167.28 mm (Example 1). , 167.40 mm (Example 2), 167.50 mm (Example 3), 167.56 mm (Example 4), 167.84 mm (Example 5). bottom. In the winding core according to the example, the width of the first cylindrical portion is 1320 mm, the width of each of the second cylindrical portions is 90 mm, and the step from the first cylindrical portion to the second cylindrical portion is The height h was set to 140 μm (Example 1), 200 μm (Example 2), 250 μm (Example 3), 280 μm (Example 4) and 420 μm (Example 5). Further, as a comparative example, a winding core having a constant outer diameter of 167.00 mm was produced using fiber-reinforced plastic.

The winding cores according to Examples and Comparative Examples were set in a winding device, and one end of a web having a width of 1340 mm, a thickness of 45 μm, and an elastic modulus of 3 GPa was fixed to the first cylindrical portion via an adhesive tape having a thickness of 25 μm. bottom. As the web, a hard coat film was used in which a hard coat layer mainly composed of acrylic resin was laminated on one surface of a base material of triacetyl cellulose (TAC). After that, the winding core was rotated by a winding device, and the web was wound up by 3000 m. Winding was performed with an initial tension of 250 N per full width of the web and a tension taper rate (reduction rate of winding tension) of 9.6% when winding 3000 m.

After 24 hours from the completion of winding, the wound web is unwound, and the presence or absence of web deformation is visually checked. ) was measured. In addition, for each of the examples and the comparative examples, as the deformation of the web, the core tape mark where the step at one end of the web (due to the thickness of the web and the thickness of the adhesive tape) was transferred, and the first cylindrical portion Each confirmation was made with the winding marks due to the winding tightening of the wound web.

FIG. 9 is a graph showing the amount of web deformation when the web is wound using the winding cores according to the examples and the comparative examples. The sum of the thickness of one layer of the web (d1 in FIG. 4) and the thickness of the adhesive tape (d2 in FIG. 4) is 70 μm. The difference Δh (FIG. 4) from the sum of the thicknesses of the adhesive tapes was 70 μm (Example 1), 130 μm (Example 2), 180 μm (Example 3), 210 μm (Example 4) and 350 μm (Example 5). is.

As shown in FIG. 9, when the web is wound by the winding core according to the comparative example, the winding core tape mark where the step is transferred due to the thickness of the end portion of the web fixed to the winding core and the thickness of the adhesive tape. occurred, and the amount of occurrence was 56 m from one end of the web. Since the winding core according to the comparative example had a constant outer diameter and no steps on the outer peripheral surface, there was no trace of tightening winding.

On the other hand, when the web was wound with the winding cores according to Examples 1 to 5, the step height from the outer peripheral surface of the first tubular portion to the outer peripheral surface of the second tubular portion was the same as that of the web. and the total thickness of the adhesive tape by 70 μm or more, the difference in level due to the thickness of the web edge and the thickness of the adhesive tape is reduced, and the length of the portion where the winding core tape mark is generated is significantly shorter than in the comparative example. rice field. In particular, as is clear from Examples 2 and 3, when the step height h of the first tubular portion and the second tubular portion is 100 μm or more larger than the total thickness of the web and the adhesive tape, the traces of the winding core tape The length of the part where the was generated was remarkably shortened.

Further, when the cores according to Examples 4 and 5 were used, the length of the portion where the core tape marks were generated was shorter than when the cores according to Examples 1 to 3 were used. However, compared to Examples 1 to 3, the difference Δh (FIG. 4) between the step height h and the total thickness of the web and the adhesive tape is large, so the web wound up by the first tubular portion There was a trace of winding due to the tightening of the winding that occurred in the Therefore, the difference Δh (FIG. 4) between the step height h and the total thickness of the web and the adhesive tape is 100 μm or more and 200 μm or less. It has been confirmed that this is the most preferable in terms of reducing web deformation. However, the amount of deformation of the web (the length from the end of the fixed web) in Examples 4 and 5 was 31 m and 34 m, respectively. The length is shortened, and it was confirmed that deformation of the web can be reduced if the step height is 70 μm or more than the total thickness of the web and adhesive tape.

INDUSTRIAL APPLICABILITY The present invention can be used as a winding core for winding a web-shaped member such as an optical film or a barrier film, and a method for winding the web.

1 First tubular portions 2a, 2b Second tubular portions 5a, 5b Tapered portion 7 Edges 8a, 8b Edges 9 Adhesive tape 10 Webs 11, 12, 13 Winding core

Claims (6)

A cylindrical winding core for winding a web,
a first cylindrical portion;
a pair of second tubular portions connected to both ends in the length direction of the first tubular portion and having a constant outer diameter larger than that of the first tubular portion;
The step height from the outer peripheral surface of the first tubular portion to the outer peripheral surface of the second tubular portion is the thickness of one layer of the web and the thickness of the tape for fixing the web to the winding core. A core having a thickness greater than the sum of the thickness and the thickness by 70 μm or more. 2. The winding core according to claim 1, wherein the difference between the step height and the sum of the thickness of one layer of the web and the thickness of the tape is 100 [mu]m or more and 200 [mu]m or less. 3. The winding core according to claim 1, wherein the interval between said second cylindrical portions is shorter than the width of said web by 10 mm or more. A pair of tapers between both ends of the first tubular portion and each of the second tubular portions, the outer diameter of which gradually decreases toward the central portion in the longitudinal direction of the first tubular portion. The winding core according to any one of claims 1 to 3, which has a portion. A web reeling method comprising:
a first tubular portion; and a pair of second tubular portions connected to both longitudinal ends of the first tubular portion and having a constant outer diameter larger than that of the first tubular portion; and the step height from the outer peripheral surface of the first tubular portion to the outer peripheral surface of the second tubular portion is the thickness of one layer of the web and the web is fixed to the winding core a step of fixing one end of the web using the tape to the first cylindrical portion of the winding core that is 70 μm or more larger than the sum of the thickness of the tape for
and winding the web by rotating the winding core. In the step of fixing one end of the web, the one end of the web is attached to the winding core so that a portion having a width of 5 mm or more including both edges in the width direction of the web overlaps each of the second tubular portions. 6. A method of winding a web according to claim 5, characterized in that it is fixed to a core.

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