Method of manufacturing film roll

Abstract

To provide a method of manufacturing a film roll in which the film roll having a defect of deformation of a rolled film suppressed can be manufactured.SOLUTION: A method of manufacturing a film roll according to an embodiment of the present invention is a method of taking up a long-sized film around a core to manufacture the film roll, and comprises, successively in order: a first take-up process of taking up the film around the core through a near winding type take-up operation until a lamination thickness of the film reaches 3-15 mm after fixing the film to the core; and a second take-up process of taking up the film around the core through a touch winding type take-up operation to obtain the film roll.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for producing a film roll. [Background technology]

[0002] A film roll is manufactured by winding a long length of film around a core. When winding the film around the core, if air gets mixed in between adjacent pieces of film in the radial direction, defects such as wrinkles will occur in the film that constitutes the film roll. Therefore, when manufacturing a film roll, in order to prevent the above-mentioned air from getting mixed in, a touch roll (for example, see Patent Document 1) is usually pressed against the surface of the film wound around the winding shaft, so that the film is wound while applying a certain pressure to the film. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-106057 Summary of the Invention [Problem to be solved by the invention]

[0004] When winding a film around a core, it is necessary to fix the film to the core with a mounting member such as double-sided tape. In this case, a step occurs near the end of the film fixed to the core due to the thickness of the film end and the double-sided tape. If a film with such a step is wound up while pressing a touch roll against the surface of the film wound around the winding shaft, deformation defects (wrinkles, unevenness, etc.) are likely to occur in the film.

[0005] Therefore, an object of the present invention is to provide a method for manufacturing a film roll that is capable of manufacturing a film roll in which deformation defects in the wound film are suppressed. [Means for solving the problem]

[0006] A method for producing a film roll according to one aspect of the present invention is a method for producing a film roll by winding a long film around a core. In this method for producing a film roll, a first winding step is performed in which the film is fixed to the core, and then the film is wound around the core by a near-winding winding operation until the film has a layer thickness of 3 mm to 15 mm, and a second winding step is performed in which the film is wound around the core by a touch-winding winding operation to obtain the film roll.

[0007] In the method for producing the film roll, a first winding step is performed in which the film is wound up by a near-winding winding operation. After the near-winding winding operation is performed until the film has a layer thickness of 3 mm to 15 mm, the winding operation is continuously switched to a touch-winding winding operation, and the film is wound up by the touch-winding winding operation.

[0008] In the near winding operation, the film is less likely to be pressed against the core compared to the touch winding operation, so air is more likely to be entrained in the first winding step. Furthermore, the near winding operation is performed until the film layer thickness reaches 3 mm to 15 mm. Therefore, the influence of deformation factors (e.g., steps) associated with the film being fixed to the core at the beginning of winding can be absorbed. After the first winding step is performed as described above, the second winding step is performed. In the second winding step, the film is wound using the touch winding operation, so air entrainment is suppressed. Therefore, deformation of the film associated with air entrainment is also reduced. Therefore, the above-mentioned film roll manufacturing method can manufacture a film roll in which deformation defects of the wound film are suppressed.

[0009] The near-winding type winding operation is an operation in which the film is wound while a touch roll is brought into contact with the film immediately before it is wound around the winding core, and the touch-winding type winding operation may be an operation in which the film is wound while the touch roll is pressed against the surface of the film wound around the winding core.

[0010] In the near-winding winding operation, the distance between the surface of the film wound around the core and the touch roll may be 0.1 mm to 10 mm. The distance is the distance along a line connecting the center of the core and the center of the touch roll when viewed from the axial direction of the core. In this case, the near-winding winding operation can be reliably performed even if winding misalignment, axial vibration, etc. occur.

[0011] In the touch winding operation, the touch roll may press the surface of the film wound around the core with a linear pressure of 100 N / m to 1000 N / m, which can further prevent air from being mixed in during the touch winding operation.

[0012] The winding operation of the near winding type and the winding operation of the touch winding type are performed while applying tension to the film, and the tension may be higher during the winding operation of the near winding type than during the winding operation of the touch winding type. Air is easily entrained in the near winding type, but by setting the tension of the near winding type higher, the amount of entrained air can be reduced, and wrinkles due to excessive entrainment of air can be prevented. As a result, it is easy to manufacture a film roll capable of manufacturing a film roll in which deformation defects in the wound film are suppressed while suppressing the occurrence of defects such as wrinkles due to the entrainment of air during winding.

[0013] In the first winding step, the film may be fixed to the core by an attachment member.

[0014] The attachment member is, for example, a double-sided tape. Effect of the Invention

[0015] According to the present invention, a method for manufacturing a film roll can be provided that is capable of manufacturing a film roll in which deformation defects in the wound film are suppressed. [Brief description of the drawings]

[0016] [Figure 1]FIG. 1 is a schematic diagram for explaining a method for producing a film roll according to one embodiment. [Diagram 2] FIG. 2 is a diagram illustrating an example of a method for fixing a film to a core. [Diagram 3] FIG. 3 is a diagram illustrating a near-winding type winding operation. [Figure 4] FIG. 4 is a diagram illustrating the winding operation of the touch winding method. [Diagram 5] FIG. 5 is a diagram for explaining another example of the contact state of the film with the roll used in the near winding type and the touch winding type. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and duplicated explanations will be omitted. The dimensional ratios of the drawings do not necessarily correspond to those in the description.

[0018] Fig. 1 is a schematic diagram for explaining a method for producing a film roll according to one embodiment. The film roll 2 is produced by transporting a long film 4 along a transport line 6 and winding the film 4 around a core 10 set in a winder 8. Fig. 1 shows a state in which a first winding step, which will be described later, is being carried out. In the following explanation, the roll formed in the process of winding the film 4 around the core 10 as shown in Fig. 1 will also be referred to as the film roll 2.

[0019] An example of the film 4 is a resin film. The resin film can be formed by, for example, a solution casting film forming method or extrusion molding. Examples of materials for the resin film include TAC (triacetyl cellulose), PMMA (polymethyl methacrylate (acrylic)), PET (polyethylene terephthalate), and COP (cyclic olefin resin).

[0020] The tensile modulus of elasticity in the MD direction (machine direction or transport direction) of the film 4 is, for example, 10,000 MPa or less, preferably 8,000 MPa or less, and more preferably 6,000 MPa or less. The lower limit of the MD direction of the film 4 is, for example, 2,000 MPa, 2,500 MPa, or 3,000 MPa. Therefore, the tensile modulus of elasticity in the MD direction of the film 4 is, for example, 2,000 MPa to 10,000 MPa, preferably 2,500 MPa to 8,000 MPa or less, and more preferably 3,000 MPa to 6,000 MPa or less. As the tensile modulus of elasticity, for example, a value measured by a method defined in JIS K 7127 (Testing method for tensile properties of plastic films and sheets with a thickness of 1 mm or less) can be used.

[0021] The film 4 may be the following optical film. The optical film may be a single layer, or an optical laminate in which two or more layers are laminated. An example of a single layer optical film is a thermoplastic resin film described below. Examples of layers constituting the optical laminate include a polarizer, a thermoplastic resin film, an optical functional layer, an adhesive layer, a pressure-sensitive adhesive layer, a separate film, a protective film, a touch sensor panel, and the like. The film 4 may be a surface-treated film (for example, a film coated with a hard coat).

[0022] The length of the film 4 in the longitudinal direction is not particularly limited, but is, for example, in the range of 1000 m or more and 10000 m or less, preferably 1000 m or more and 6000 m or less. The length of the film 4 in the width direction is not particularly limited, but may be, for example, 2.5 m or less. The thickness of the film 4 is, for example, 250 μm or less, preferably 150 μm or less, more preferably 100 μm or less. The lower limit of the thickness of the film 4 may be any thickness that can be formed into the film 4, but is, for example, 30 μm or 40 μm.

[0023] The transport line 6 is a transport path for transporting the film 4 to the winder 8, and is formed by a plurality of transport rolls 12. The transport rolls 12 also function as guide rolls for the film 4. The transport speed of the film 4 along the transport line 6 is, for example, 10 m / min to 250 m / min, preferably 20 m / min to 200 m / min, more preferably 30 m / min to 150 m / min, and even more preferably 30 m / min to 90 m / min.

[0024] The winding machine 8 is a two-shaft turret-type rewinder capable of winding the film 4 alternately around two winding cores 10. For ease of explanation, when the two winding cores 10 are to be distinguished from one another in the following description, they will be referred to as winding core 10A and winding core 10B.

[0025] The winding machine 8 has a shaft portion 14A on which the winding core 10A is attached, a first support portion 16A that rotatably supports the shaft portion 14A, a shaft portion 14B on which the winding core 10B is attached, a second support portion 16B that rotatably supports the shaft portion 14B, a first guide roll 18A, a third support portion 16C that rotatably supports the first guide roll 18A, a second guide roll 18B, a fourth support portion 16D that rotatably supports the second guide roll 18B, and a rotating shaft 20.

[0026] The first support portion 16A, the second support portion 16B, the third support portion 16C, and the fourth support portion 16D are fixed to the rotating shaft 20. The first support portion 16A and the second support portion 16B are fixed to the rotating shaft 20 so as to be located on opposite sides of the rotating shaft 20. The third support portion 16C and the fourth support portion 16D are fixed to the rotating shaft 20 so as to be located on opposite sides of the rotating shaft 20. Furthermore, the third support portion 16C and the fourth support portion 16D are arranged so that an imaginary plane including the axes of the first guide roll 18A and the second guide roll 18B is perpendicular to an imaginary plane including the axes of the shaft portion 14A and the shaft portion 14B.

[0027] An example of a case where a film roll 2 is manufactured using the winding machine 8 will be described. First, as shown in FIG. 1, a desired length of film 4 is wound around the core 10A to manufacture the film roll 2 as a final product. Then, the winding machine 8 is rotated around the rotation shaft 20. As a result, the film 4 comes into contact with the core 10B while being guided by the first guide roll 18A as the winding machine 8 rotates. At this stage, the film 4 is cut to separate the film roll 2 provided on the core 10A side from the film 4. Furthermore, an end of the film 4 is fixed to the core 10B, and the next film roll 2 is manufactured using the core 10B. The winding machine 8 may include a mechanism for rotating and driving the shafts 14A and 14B, a mechanism for cutting the film 4 described above (for example, an automatic cutter), and the like.

[0028] The winding cores 10A and 10B are not particularly limited as long as they are used for winding a film. Examples of the material of the winding cores 10A and 10B include rubber, plastic, metal (e.g., aluminum), and composite materials thereof. The surfaces of the winding cores 10A and 10B may be covered with a sheet made of a soft material such as sponge. The size of the winding cores 10A and 10B is not particularly limited and can be appropriately set according to the size of the film 4 to be wound. The outer diameter of the winding cores 10A and 10B (the distance from the center of the winding core to the outer surface of the winding core) may be, for example, 2 inches to 15 inches (50.8 mm to 381 mm) or 2 inches to 12 inches (50.8 mm to 305 mm). The shape of the winding core may be cylindrical or columnar. When the shape of the winding core is columnar, the core thickness can be appropriately selected depending on the material and the like.

[0029] When switching between winding cores 10A and 10B, the flow of film 4 to winder 8 may be stopped. For example, in the method for producing film roll 2, accumulator 22 may be used as shown in FIG.

[0030] The accumulator 22 is provided on the conveying line 6. The accumulator 22 absorbs the flow of the film 4 and temporarily stops the flow of the film 4 downstream of the accumulator 22. The accumulator 22 has a plurality of first conveying rolls 12A and a plurality of second conveying rolls 12B. The first conveying rolls 12A and the second conveying rolls 12B are arranged alternately along the conveying line 6. For example, as shown in FIG. 1, the second conveying roll 12B is located above the first conveying roll 12A. The film 4 is stretched alternately across the first conveying roll 12A and the second conveying roll 12B. The first conveying roll 12A and the second conveying roll 12B are arranged so as to be movable up and down relative to each other.

[0031] In the accumulator 22, the first transport roll 12A and the second transport roll 12B are raised and lowered relative to one another in the vertical direction, thereby allowing the film 4 to accumulate in the accumulator 22. As a result, for example, it is possible to stop the flow of the film 4 downstream of the accumulator 22 without stopping the transport of the film 4 upstream of the accumulator 22.

[0032] When the film 4 is wound by the winder 8, a touch roll 24 is used. The size of the touch roll 24, such as the width and outer diameter, can be appropriately selected depending on the width of the film. The outer diameter of the touch roll 24 can be, for example, 50 mm to 300 mm in order to apply a certain pressure to the film 4. The outer diameter of the touch roll 24 is generally uniform in the width direction, but it may have a shape in which the outer diameter is not uniform in the width direction, such as a crown roll. The material of the touch roll 24 is not particularly limited as long as it is applicable to film winding, and may be, for example, a rubber roll or a roll in which rubber is wound around the outside of a carbon roller. The touch roll 24 is disposed in contact with the film 4 near the core 10 (core 10A in FIG. 1) around which the film 4 is wound. The touch roll 24 is rotatably supported by a first position adjustment unit 26 so that a constant pressure can be applied to the film 4 even if the diameter of the film roll 2 increases as a result of the film 4 being wound around the core 10. The first position adjustment unit 26 is, for example, a cylinder (e.g., an air cylinder). The first position adjustment unit 26 finely adjusts the position of the touch roll 24. The touch roll 24 may also be called, for example, a winding nip roll, a contact roll, a rider roll, or a lay-on roll. The touch roll 24 may be part of the winding machine 8. A brake mechanism may be used to slow down or stop the rotation of the touch roll 24. The brake mechanism may be part of the winding machine 8. The brake mechanism may be provided, for example, on a shaft that rotatably supports the touch roll 24.

[0033] The first position adjustment unit 26 is attached to a second position adjustment unit 28 for adjusting the relative position of the touch roll 24 with respect to the core 10. The moving distance of the touch roll 24 using the second position adjustment unit 28 is greater than the moving distance of the touch roll 24 using the first position adjustment unit 26. In this embodiment, the second position adjustment unit 28 is a slide-type position adjustment mechanism. The second position adjustment unit 28 may have, for example, a support plate 28A and a guide unit 28B that is provided on the support plate 28A and guides the movement of the first position adjustment unit 26. In this case, the position of the touch roll 24 can be adjusted by moving the first position adjustment unit 26 along the guide unit 28B. The second position adjustment unit 28 may be a swing-type position adjustment mechanism.

[0034] Next, a specific example of a method for manufacturing the film roll 2 will be described. The manufacturing method of the film roll 2 (or the winding method of the film 4) for each of the winding cores 10A and 10B in the winding machine 8 is the same. Therefore, a case where the film roll 2 is manufactured using the winding core 10A as shown in FIG. 1 will be described.

[0035] The method for manufacturing the film roll 2 includes a first winding step in which the film 4 is wound around the core 10A by a near-winding type winding operation, and a second winding step in which the film 4 is wound around the core 10A by a touch-winding type winding operation to obtain the film roll 2. The process will be described in detail below.

[0036] [First winding process] In the first winding step, the film 4 is attached to the winding core 10A. For example, as shown in FIG. 2, the film 4 is fixed to the winding core 10A by an attachment member 30. An example of the attachment member 30 is a double-sided tape. The thickness of the double-sided tape is, for example, 5 μm to 20 μm. For example, the film 4 may be fixed to the winding core 10A by an adhesive. Thereafter, as shown in FIG. 1, the film 4 is transported along the transport line 6 while the shaft portion 14A to which the winding core 10A is attached is rotated, thereby winding the film 4 around the winding core 10A. In the first winding step, the film 4 is wound by a near-winding winding operation.

[0037] The near-winding winding operation will be described with reference to Fig. 3. As shown in Fig. 3, the near-winding winding operation is an operation in which the film 4 is wound while the touch roll is in contact with the film 4 immediately before it is wound around the winding core 10A. In the near-winding winding operation, the touch roll 24 functions as a near roll. In order to make the touch roll 24 function as a near roll, the position of the touch roll 24 with respect to the winding core 10A can be adjusted by the second position adjustment unit 28.

[0038] In a near-winding winding operation, the distance d between the surface of the film 4 wound around the winding core 10A and the touch roll 24 is, for example, 0.1 mm to 10 mm, and preferably 1 mm to 5 mm. The "surface of the film 4 wound around the winding core 10A" is the surface of the film roll 2 formed by winding the film 4 around the winding core 10A. As shown in FIG. 3, the distance d is the distance along the imaginary line L1 connecting the center of the touch roll 24 and the center of the winding core 10A when viewed from the axial direction of the winding core 10, and is the distance between the imaginary line L2 (or imaginary plane) and the imaginary line L3 (or imaginary plane). The distance d can be the distance between the center of the winding core 10A and the center of the touch roll 24 minus the radius of the touch roll 24, the radius of the winding core 10A, and the thickness (lamination thickness) of the film 4 wound around and laminated on the winding core 10A. The imaginary line L2 is a line that includes the intersection point between the imaginary line L1 and the surface of the film 4 (the surface of the film roll 2) and is perpendicular to the imaginary line L1. The imaginary line L3 is a line that includes the intersection point between the imaginary line L1 and the surface of the touch roll 24 and is perpendicular to the imaginary line L1.

[0039] When the distance d is equal to or less than the upper limit of the above range, the film 4 is less likely to become misaligned during the first winding process and when switching from the first winding process to the second winding process, so that the end faces of the film roll 2 are less likely to become uneven and deformation defects such as wrinkles are less likely to occur in the film roll 2.

[0040] On the other hand, if the distance d is 0.0 mm, that is, if the film 4 at the time of being wound comes into contact with the film 4 on the winding core 10A, the film 4 will be deformed by the pressure of the touch roll 24. Therefore, it is essential that the film 4 at the time of being wound does not come into contact with the film 4 on the winding core 10A. By setting the distance d to 0.1 mm, it is possible to prevent such contact.

[0041] In the near-winding winding operation, the wrap angle θ between the film roll 2 and the touch roll 24 formed on the winding core 10A is, for example, greater than 0°. As shown in FIG. 3, the wrap angle θ in this embodiment is the angle formed by the film 4 (specifically, the film 4 downstream of the touch roll 24 on the conveyor line 6) wound on the winding core 10A with respect to a virtual line (for example, the above-mentioned virtual line L2) perpendicular to the virtual line L1 connecting the center of the touch roll 24 and the center of the winding core 10A. The wrap angle θ is preferably 0.1° or more, and more preferably 0.3° or more. The upper limit of the wrap angle θ is, for example, 90°, and may be 45° or 30°. Therefore, the wrap angle θ is, for example, 0.1° to 90° or 0.1° to 45°.

[0042] As the film 4 is wound, the lamination thickness t of the film 4 increases. Therefore, in the first winding step, for example, the touch roll 24 is retreated (or retracted) by the first position adjustment unit 26 in accordance with the lamination thickness t so as to maintain a constant pressure on the film 4. The lamination thickness t of the film 4 corresponds to the thickness of the film roll 2 being formed on the winding core 10A.

[0043] The first winding step is performed until the lamination thickness t of the film 4 wound around the core 10A reaches a predetermined thickness. The predetermined thickness is 3 mm to 15 mm, and preferably 4 mm to 10 mm. In this embodiment, since the lamination thickness t in the first winding step is equal to or greater than the lower limit of the above range, deformation defects of the film 4 due to steps caused by the attachment member 30 (e.g., double-sided tape) or the film end are unlikely to occur. Meanwhile, since the lamination thickness t is equal to or less than the upper limit of the above range, winding misalignment and deformation wrinkles due to air entrapment during winding are unlikely to occur.

[0044] [Second winding process] The touch winding operation will be described with reference to FIG. 4. As shown in FIG. 4, the touch winding operation is an operation in which the film 4 is wound while pressing the touch roll 24 against the surface of the film 4 wound around the winding core 10A (the surface of the film roll 2 formed on the winding core 10A). In the first winding step, after the lamination thickness t of the film 4 reaches a predetermined thickness, as shown by the outline arrow in FIG. 4, the touch roll 24 is moved so as to come into contact with the surface of the film 4 wound around the winding core 10A, thereby switching from the near winding winding operation to the touch winding operation. The movement of the touch roll 24 can be performed, for example, by sliding the first position adjustment unit 26 using the second position adjustment unit 28. Note that the means for moving the touch roll 24 is not limited to the above method, and known means can be adopted.

[0045] In a touch winding type winding operation, the touch roll 24 presses the surface of the film 4 wound around the winding core 10A with a linear pressure (touch pressure) of, for example, 100 N / m to 1000 N / m, preferably 150 N / m to 750 N / m, and more preferably 200 N / m to 500 N / m. As the film 4 is wound, the lamination thickness t of the film 4 increases. Therefore, for example, the touch roll 24 is retreated by the first position adjustment unit 26 in accordance with the lamination thickness t so as to maintain a constant pressure on the film 4.

[0046] In the second winding step, the film 4 that is to form the film roll 2 is wound up from the portion wound up in the first winding step onwards, thereby producing the film roll 2 as a final product (for example, a finished product).

[0047] In the first winding step and the second winding step, it is preferable to apply tension to the film 4. For example, this is because sagging of the film 4 can be prevented when the film 4 is wound. It is preferable to wind the film 4 while applying a higher tension to the film 4 during a near-winding winding operation than during a touch-winding winding operation. Such tension can be adjusted, for example, by the tension adjusting device 32 shown in FIG. 1.

[0048] The tension adjusting device 32 is provided on the conveyor line 6 so as to be able to adjust the tension of the film 4 when it is taken up by the winder 8. When the accumulator 22 is used, the tension adjusting device 32 is disposed between the accumulator 22 and the winder 8. The tension adjusting device 32 has a pair of nip rolls 34, 34. The nip roll 34 used for tension adjustment can be replaced with a suction roll.

[0049] The pair of nip rolls 34, 34 are disposed so as to sandwich the film 4. The pair of nip rolls 34, 34 rotate in opposite directions to each other and feed the film 4 in the transport direction of the film 4. The tension of the film 4 between the tension adjuster 32 and the winder 8 can be adjusted by adjusting the rotation speed of the pair of nip rolls 34, 34 relative to the winding speed of the film 4 on the winding core 10A. The method of tension control is not limited to the above-mentioned method as long as the tension can be controlled. For example, dancer control using a dancer roll may be used.

[0050] In the first winding step, the tension at the start of winding (initial tension) is, for example, 150 N / m to 350 N / m, preferably 180 N / m to 320 N / m, and more preferably 200 N / m to 300 N / m. For example, the tension can be gradually lowered at the start of winding and switched from the near winding type to the touch winding type, so that the tension when the touch roll 24 comes into contact is, for example, 60% to 80% of the initial tension. After switching to the touch winding type, it is preferable to gradually lower the tension to, for example, 40% to 50% of the initial tension until the lamination thickness t increases by 10 mm.

[0051] In the near winding type, air is easily entrained when winding the film 4, as described below. When winding the film 4 in the near winding type, a higher tension is applied than in the touch winding type, thereby making it possible to prevent defects such as wrinkles that are caused by entrained air. By gradually decreasing the tension from the initial tension as described above, it is easier to prevent defects such as wrinkles compared to a sudden change in tension when switching from the near winding type to the touch winding type, for example.

[0052] When the tension is reduced from the initial tension as described above, the gradient of change in tension (amount of change in tension over a certain distance or time) may not be constant. For example, at the stage of switching from the near winding mode to the touch winding mode, the gradient of change in tension may be small. In one embodiment, the tension may be temporarily stopped from being reduced (i.e., the gradient of change is substantially set to zero) before switching from the near winding mode to the touch winding mode, and then the tension may be reduced again after switching from the near winding mode to the touch winding mode in that state (i.e., in a state where the tension is not changed). This makes it easier to prevent winding misalignment caused by the impact when switching from the near winding mode to the touch winding mode.

[0053] Next, the effects of the above-mentioned manufacturing method will be described. In the following description, the winding cores 10A and 10B will be referred to as the winding cores 10 unless they are to be distinguished from each other.

[0054] In the manufacturing method of the film roll 2, first, a first winding step is performed in which the film 4 is wound by a near-winding winding operation. After the near-winding winding operation is performed until the lamination thickness t of the film 4 reaches a predetermined thickness, the winding operation is continuously switched to a touch-winding winding operation, and the film 4 is wound by the touch-winding winding operation.

[0055] In a near-winding winding operation, the film is less likely to be pressed against the winding core than in a touch-winding winding operation, so air is more likely to be entrained in the first winding step. Furthermore, the near-winding winding operation is continued until the lamination thickness t of the film 4 reaches a predetermined thickness. Therefore, even if the film 4 is fixed to the winding core 10 using an attachment member 30 such as double-sided tape at the beginning of winding, the marks (e.g. steps) of the attachment member 30 can be absorbed.

[0056] A more specific description will be given based on the form described in this embodiment. In the case of the near winding type, the amount of air entrained is large as described above. However, by not pressing the touch roll 24, it is difficult to transfer step deformation (for example, deformation caused by a step occurring in a portion of the film 2 fixed to the winding core 10A) of the lower layer (the layer on the winding core 10A side in the laminated state of the film 2 wound around the winding core 10A). Therefore, the step is difficult to propagate to the upper layer of the film 2 that is laminated. Furthermore, by entraining air with the near winding type, it is easy to absorb the deformation factors caused by the film 2 being fixed to the winding core 10A.

[0057] If the near-winding winding operation is maintained to wind up the entire film 4, the film 4 will continue to be wound while entraining air, resulting in large deformation due to winding misalignment, air entrapment, etc., and as a result, deformation defects are likely to occur.

[0058] In contrast, in the manufacturing method of the film roll 2, a first winding step using a near-winding type winding operation is performed, followed by a second winding step. In the second winding step, the film 4 is wound using a touch-winding type winding operation. This suppresses air entrapment. Furthermore, since the film 4 is wound while being pressed against the core 10 more than in the near-winding type, no winding misalignment occurs. As a result, air entrapment and deformation of the film 4 due to winding misalignment are also reduced.

[0059] As described above, the manufacturing method of the film roll 2 can prevent deformation caused by marks (e.g., steps) made by the mounting member 30 at the beginning of winding. Furthermore, because the method switches from near winding to touch winding midway, deformation caused by misalignment of the film 4, air intrusion, and the like can also be prevented when forming the outer portions of the film roll 2. Therefore, the film roll 2 can be manufactured while suppressing deformation defects (e.g., wrinkles, unevenness, etc.) of the film 4. Because the above-mentioned deformation defects are suppressed, the above-mentioned manufacturing method can manufacture a film roll 2 with a good appearance.

[0060] A near-winding winding operation is performed before a touch-winding winding operation. The near-winding winding operation is performed from the beginning of winding the film 4, so the touch roll 24 and the film 4 are in contact with each other when the transport speed of the film 4 is, for example, 10 m / min or less. Therefore, even if the transport speed of the film 4 increases in the near-winding winding operation, the rotation speed of the touch roll 24 also increases accordingly. Therefore, when the touch roll 24 is pressed against the surface of the film 4 wound around the winding core 10 for the touch-winding winding operation, the touch roll 24 rotates at a constant speed. Therefore, even if the touch roll 24 is pressed against the surface of the film 4, the occurrence of scratches and the like can be prevented.

[0061] In the near-winding operation, when the distance d is 0.1 mm to 10 mm, the near-winding operation can be reliably performed even if winding deviation, axial vibration, or the like occurs.

[0062] When the portion to which film 4 is fixed is soft, such as when core 10 is made of rubber or when core 10 is covered with a sheet made of a soft material such as sponge, it is easy to reduce the step caused by fixing the end of film 4 to core 10.

[0063] When the winding machine 8 is a two-shaft turret-type rewinder as shown in Fig. 1, for example, a first winding process and a second winding process are performed on the winding core 10A to produce the film roll 2. Then, as described above, the winding machine 8 is rotated around the rotation shaft 20 to set the winding core 10B at the position of the winding core 10A shown in Fig. 1. Then, the film roll 2 is produced in the same manner as when the film roll 2 is formed on the winding core 10A. This makes it possible to produce the film roll 2 efficiently.

[0064] When the winding machine 8 is a two-shaft turret-type rewinder, by using the accumulator 22, it is possible to stop the flow of the film 4 downstream of the accumulator 22 without stopping the transport of the film 4 upstream of the accumulator 22. This makes it easy to switch between the winding cores 10A and 10B. When the film 4 is being produced upstream of the accumulator 22 (for example, when the film 4 is being produced by extrusion molding), it is possible to switch between the winding cores 10A and 10B while continuing the production of the film 4. This allows the film roll 2 to be produced efficiently.

[0065] In the winding machine 8, which is a two-shaft turret rewinder, when the winding core 10 around which the film 4 is wound is switched between winding core 10A and winding core 10B, it is preferable that the touch roll 24 is directly or indirectly attached to the second position adjustment unit 28. This is because the touch roll 24 can be retracted by the second position adjustment unit 28 when the winding machine 8 is rotated around the rotation shaft 20.

[0066] For example, when a film roll 2 is manufactured using the core 10A and then the next film roll 2 is manufactured using the core 10B, the touch roll 24 is withdrawn and separated from the core 10A after the first film roll 2 is manufactured. At this time, the touch roll 24 continues to rotate by inertia due to the rotational force during winding, so it is preferable to temporarily slow down or stop the rotation of the touch roll 24. This makes it possible to reduce the difference between the transport speed of the film 4 and the rotational speed of the touch roll 24 (or to make it substantially zero) even if the touch roll 24 is brought into contact with the film 4 for a near-winding winding operation when the next film roll 2 is manufactured. Therefore, it is possible to prevent scratches on the film 4 caused by the touch roll 24 coming into contact with the film 4. The rotation of the touch roll 24 can be slowed down or stopped, for example, by controlling the brake mechanism described above.

[0067] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and is intended to include the scope indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0068] The winding machine 8 is not limited to a two-shaft turret type rewinder. For example, the winding machine may have one shaft portion to which the winding core 10 is attached, or may have three or more shafts.

[0069] As shown in FIG. 5, the film 4 may be wound around (or hung over) a touch roll 24 .

[0070] The roll used in the near winding type and the touch winding type has been described as a touch roll. However, the roll used in the near winding type and the touch winding type is not limited as long as it is a roll for performing the winding operation of the near winding type and the touch winding type in this technical field. A common roll does not need to be used in the winding operation of the near winding type and the touch winding type.

[0071] The above-described embodiments and various modified examples may be combined as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0072] 2...film roll, 4...film, 10, 10A, 10B...winding core, 24...touch roll, 30...mounting member, θ...holding angle, t...lamination thickness.

Claims

1. A method for producing a film roll by winding a long film around a core, comprising: a first winding step of fixing the film to the winding core and then winding the film onto the winding core by a near-winding winding operation until the film has a laminate thickness of 3 mm to 15 mm; a second winding step of winding the film around the core by a touch-winding type winding operation to obtain the film roll; Do the following in this order: In the first winding step, the film is fixed to the winding core by an attachment member, the attachment member is a double-sided tape, The thickness of the double-sided tape is 5 μm to 20 μm. A method for manufacturing a film roll.

2. The near-winding winding operation is an operation in which the film is wound while a touch roll is brought into contact with the film immediately before being wound onto the winding core, The touch winding type winding operation is an operation in which the film is wound while pressing the touch roll against the surface of the film wound around the winding core. The method for producing the film roll according to claim 1 .

3. In the near-winding type winding operation, the distance between the surface of the film wound around the winding core and the touch roll is 0.1 mm to 10 mm; The distance is the distance along a line connecting the center of the winding core and the center of the touch roll when viewed from the axial direction of the winding core. The method for producing a film roll according to claim 2 .

4. In the touch winding type winding operation, the touch roll presses the surface of the film wound around the core with a linear pressure of 100 N / m to 1000 N / m. The method for producing a film roll according to claim 2 or 3.

5. The near-winding type winding operation and the touch-winding type winding operation are performed while applying tension to the film, The tension is higher during the near winding operation than during the touch winding operation. The method for producing the film roll according to any one of claims 1 to 4.

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