JP7363038B2 - Core tube for film roll - Google Patents

Description

The present invention relates to a core tube for a film roll used when constructing a film roll, and preferably a film used when constructing a film roll from a polyvinyl alcohol film, particularly preferably a polyvinyl alcohol film for producing a polarizing film. Regarding core tubes for rolls. Here, the film roll is constructed by winding a strip-shaped film around the outer peripheral surface of a cylindrical film roll core tube a plurality of times.

For example, a polyvinyl alcohol film (PVA film) is used as a polarizing film for a liquid crystal display. The manufactured PVA-based film is shipped as a film roll that is wound multiple times around the outer peripheral surface of a cylindrical film roll core tube (sometimes simply referred to as a "core tube"). More specifically, holding members included in the winding device are inserted into both ends of the core tube to hold the core tube, and a strip-shaped PVA film is wound around the outer peripheral surface of the core tube multiple times while rotating the core tube. A film roll is formed.

Furthermore, when manufacturing a polarizing film, a PVA-based film is unwound from a film roll and subjected to dyeing, stretching, and orientation treatments. More specifically, the holding members provided in the unwinding device are inserted into both ends of the core tube of the film roll to hold the film roll, and while the film roll is rotated, the belt-shaped PVA film is unwound for dyeing, stretching, and orientation. Processing is performed.

Generally, a cylindrical member made of metal, for example aluminum, is used as a core tube for a film roll. The inner diameter of the core tube is set to a size that allows the holding member to be inserted and held. That is, since the inner diameter of the cylindrical member (core tube) that can be held by the holding member is predetermined, the inner diameter of the core tube is set to a predetermined value for the holding member to be used.

In recent years, as liquid crystal displays have become larger in size, PVA films used as polarizing films have become wider and longer. As the PVA film becomes wider and longer, the weight of the PVA film wrapped around the film roll core tube also increases, and therefore it is necessary to take measures to strengthen the film roll core tube.

As a measure to improve the strength of the core tube, it is possible to change the material of the core tube to a material with higher strength. However, materials with higher strength are often expensive and make the film roll expensive, which is not desirable as a strength measure.

Another possible strength measure is to increase the thickness of the core tube. However, increasing the thickness increases the weight of the core tube, which may cause the core tube to bend due to its own weight, which is not desirable as a strength measure.

As another strength measure, it is conceivable to increase the outer diameter of the core tube without changing the thickness of the core tube. However, since increasing the outer diameter of the core tube also increases the inner diameter, the existing holding member cannot hold the core tube, and as a result, the holding member must be changed, which is not desirable as a strength measure. do not have.

Further, a technique related to a film roll core is described in Patent Document 1. Patent Document 1 discloses that both ends have sufficient strength so that they can be held at both ends, making them easy to handle, as well as reducing weight and cost. A core for a film roll is described in which even if dew condensation occurs on the circumferential surface, it does not flow easily to the outside (see paragraph numbers 0011, 0015, and 0016). That is, the film roll core of Patent Document 1 is intended to improve the strength of both ends, and is not intended to improve the overall strength.

Patent No. 6170921

The problem to be solved by the present invention is to provide a core tube for a film roll which can have improved strength and which can be held by inserting an existing holding member.

The present invention relates to a core tube for a film roll, which is formed into a cylindrical shape, is held by holding members inserted into both ends of the core tube, and is used when forming a film roll by winding a band-shaped film around the outer peripheral surface of the core tube. and a core tube body formed in a cylindrical shape, which is formed in a cylindrical shape and is fitted into and fixed to both ends of the core tube body, and whose inner diameter is large enough to allow the holding member to be inserted and held. This is a core tube for a film roll, characterized in that it is provided with a connecting member that is set at the center of the core tube.

Moreover, it is preferable that the core tube main body is formed of carbon fiber.

Further, it is preferable that the connecting member is made of metal.

Further, the connecting member includes an outer portion formed in a cylindrical shape and an inner portion formed in a cylindrical shape and fitted inside the outer portion, and the outer portion and the inner portion are connected to each other. are preferably made of different metals.

Further, it is preferable that the connecting member has a taper on the inner circumferential surface on the side of the core tube body, the inner diameter of which increases toward the center of the core tube body.

Moreover, it is preferable that a protective layer is formed on the outer circumferential surface of the core tube body to protect a film to be wound thereon.

According to the present invention, since the connecting member that can be held by inserting an existing holding member into both ends of the core tube main body is fixed, even if the outer diameter and inner diameter of the core tube main body are increased, the existing holding member The film roll core tube can be held and used by the holding member without changing. As a result, if the core tube for a film roll of the present invention is used, a film roll can be formed using an existing winding device, and if the core tube for a film roll of the present invention is used, a film roll can be formed using an existing winding device. Existing unwind equipment can be used to unwind the film.

In addition, in the conventional technology, the holding members are inserted directly into both ends of the cylindrical core tube to hold it, so it is necessary to set the inner diameter of the core tube to a predetermined value with respect to the holding member. It is difficult to increase the outer diameter. On the other hand, in the present invention, since the holding member is inserted into the connecting member and held, the inner diameter and outer diameter of the cylindrical core tube body can be set independently of the holding member. Thereby, it is possible to easily realize a film roll core tube having a larger outer diameter than a conventional core tube.

By increasing the outer diameter of the film roll core tube (more precisely, the core tube body), the strength can be improved. That is, the strength of the core tube body can be improved when a film roll is formed by wrapping a strip-shaped film around the outer peripheral surface of the core tube body multiple times. This is because when comparing a core tube body with a larger outer diameter and a core tube body with a smaller outer diameter, the core tube body with a larger outer diameter has a larger outer peripheral surface area, and the wound film acts on the core tube body. This is because the applied force is dispersed and the pressure is reduced, making it possible to withstand larger forces. This makes it possible to form a film roll in which a wider and longer film is wound.

In addition, when a film roll is formed using a film roll core tube with a large outer diameter, it is possible to reduce the occurrence of wrinkles in the film compared to a film roll using a film roll core tube with a small outer diameter. Habits can be alleviated. This makes it possible to suppress deterioration in the quality of the film and to facilitate handling of the film unwound from the film roll.

Further, by fitting and fixing the connecting members to both ends of the core tube main body, it is possible to suppress water due to dew condensation inside the core tube main body from flowing out to the outside. This prevents water due to condensation from reaching the film wound around the film roll core tube, thereby suppressing deterioration in film quality.

Further, according to the present invention, by forming the core tube body from carbon fiber, the strength can be improved and the weight can be reduced compared to the case where the core tube body is formed from metal. This makes it possible to realize a core tube for a film roll that is lightweight and hard to bend.

Further, according to the present invention, since the connecting member is made of metal, it is possible to ensure sufficient adhesion with the holding member, and it is also possible to suppress wear, damage, deformation, etc. of the portion in contact with the holding member. .

Further, according to the present invention, the connecting member is formed by combining the outer part and the inner part formed of different metals, so that the outer part is formed of a metal that has good adhesion to the core tube body, and the inner part can be made of metal that has good adhesion to the holding member. This makes the connection between the film roll core tube and the holding member strong, and allows smooth winding and feeding of the film.

Further, according to the present invention, a taper is formed on the inner circumferential surface of the connecting member on the core tube body side, so that the inner diameter increases toward the center of the core tube body. Cleaning work becomes easier. In other words, if there is no taper, there will be a step between the inner circumferential surface of the connecting member and the inner circumferential surface of the core tube body, which corresponds to the inner diameter difference, so water and foreign matter accumulated inside the core tube body will be removed. When cleaning, this difference in level becomes an obstacle and makes cleaning work difficult. On the other hand, when a taper is formed as in the present invention, it is possible to reduce the level difference between the inner circumferential surface of the connecting member and the inner circumferential surface of the core tube body. Water and foreign matter can be easily removed, making cleaning work easier.

In addition, if the maximum diameter of the taper is set to be the same as the inner diameter of the core tube body, there will be no step between the inner circumferential surface of the connecting member and the inner circumferential surface of the core tube body, and the inner circumferential surfaces will be smoothly connected to each other. It turns out. With this configuration, the interior of the core tube main body can be cleaned smoothly without being aware of the presence of the step.

Furthermore, according to the present invention, by forming a protective layer on the outer circumferential surface of the core tube body, deterioration in film quality is suppressed compared to the case where a film roll is formed by directly wrapping the film around the outer circumferential surface of the core tube body. can do.

FIG. 1 is a sectional view showing one end of a core tube 1 for a film roll according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a simplified structure of the holding member 2 used to hold the film roll core tube 1. FIG. 3 is a cross-sectional view showing the structure of a film roll core tube 11 according to an embodiment of the present invention.

The explanation of the constituent elements described below is an example (representative example) of the embodiment of the present invention, and the present invention is not limited to these contents.
FIG. 1 is a sectional view showing one end of a film roll core tube 1 according to an embodiment of the present invention, and FIG. 2 is a configuration of a holding member 2 used to hold the film roll core tube 1. FIG. 2 is a simplified cross-sectional view.

The film roll core tube 1 is formed into a cylindrical shape, and is held by predetermined holding members 2 inserted into both ends of the core tube 1, and is used when forming a film roll by winding a band-shaped film around the outer peripheral surface of the core tube 1. . The film roll core tube 1 includes a core tube main body 3 formed in a cylindrical shape, a boss ring 4 that is a connecting member formed in a cylindrical shape and fitted into and fixed to both ends of the core tube main body 3, respectively. It is configured to include a clad pipe 5 which is a protective layer provided on the outer circumferential surface of the core tube main body 3.

Note that the boss rings 4 that are fitted into and fixed to both ends of the core tube body 3 are the same, and the structures of both ends of the core tube body 3 are the same, so in FIG. The other end is omitted.

The core tube main body 3 is a cylindrical member, and is made of carbon fiber, for example. The inner diameter R1 of the core tube main body 3 is set larger than the outer diameter R2 of the holding member 2. Therefore, even if the holding member 2 is inserted into both ends of the core tube main body 3, it cannot be held, so the boss ring 4 is fitted into each end and fixed, and the holding member 2 is inserted into the boss ring 4. It is configured to be retained.

The boss ring 4 is a cylindrical member, and is made of metal, for example. The metals used are stainless steel, iron, aluminum, etc. The inner diameter R3 of the boss ring 4 is set to a size that allows the holding member 2 to be inserted and held. That is, since the inner diameter of the cylindrical member that can be held by the holding member 2 is predetermined, the inner diameter R3 of the boss ring 4 is set to a predetermined value for the holding member 2. Therefore, the holding member 2 can be inserted into and held by the boss ring 4, and thereby the core tube main body 3 is also held by the holding member 2 together with the boss ring 4.

The boss ring 4 includes a fitting portion 4a that is fitted into the core tube body 3, and a protrusion portion 4b that abuts the end of the core tube body 3. The outer diameter R4 of the protruding portion 4b is set to be the same as the outer diameter R5 of the core tube body 3, and the outer diameter R6 of the fitting portion 4a is smaller than the outer diameter R4 of the protruding portion 4b and the inner diameter of the core tube body 3. To be more precise, it is set to be the same as the inner diameter R7 of the portion of the core tube main body 3 into which the fitting portion 4a is fitted. As a result, the fitting part 4a of the boss ring 4 can be fitted into the end of the core tube main body 3, and further, until the end surface of the core tube main body 3 comes into contact with the stepped part between the fitting part 4a and the protruding part 4b. Can be inserted.

In the configuration shown in FIG. 1, with respect to the end of the core tube body 3, the inner diameter R7 of the portion where the fitting portion 4a of the boss ring 4 is fitted is larger than the inner diameter R1 of the center side of the core tube body 3, and the fitting portion A thin portion 3a is formed having the same outer diameter R6 of 4a. Note that by forming the thin wall portion 3a, the center side of the core tube main body 3 becomes a thick wall portion 3b. In this configuration, the boss ring 4 is fitted and fixed until the tip of the fitting portion 4a abuts the step between the thin wall portion 3a of the core tube body 3 and the thick wall portion 3b on the central side.

The structure of the holding member 2 is not particularly limited, and may be any structure that can be inserted into the boss ring 4 and can hold the boss ring 4 and the core tube body 3 by coming into contact with the inner peripheral surface of the boss ring 4. Bye. For example, the holding member 2 shown in FIG. 2 is provided on a predetermined base B, is a member formed in a substantially cylindrical shape, and is configured to be rotatable about the center line G1 of the cylinder as a rotation axis. Further, the holding member 2 is provided with a pressing portion 2a made of urethane or the like on its outer periphery, and the pressing portion 2a can expand or contract in diameter in the radial direction of the rotating shaft by, for example, supplying or cutting off air pressure. It is composed of The boss ring 4 and the core tube main body 3 (the film roll core tube 1) are held by the pressing portion 2a coming into contact with the inner circumferential surface of the boss ring 4. Further, as the holding member 2 rotates, the film roll core tube 1 also rotates.

Further, the boss ring 4 has a taper 4c formed on the inner circumferential surface on the core tube body 3 side, the inner diameter of which increases toward the center of the core tube body 3.

Further, a clad pipe 5 serving as a protective layer is provided on the outer circumferential surface of the core tube main body 3. The clad pipe 5 is made of metal, such as stainless steel. The inner diameter R9 of the clad pipe 5 is set to be the same as the outer diameter R5 of the core tube body 3. Note that the outer peripheral surface of the clad pipe 5 made of metal may be subjected to plating treatment, for example, plating treatment with chrome.

A film roll is formed by wrapping a strip-shaped film, for example, a PVA film, multiple times around the outer peripheral surface of the film roll core tube 1 having such a configuration.

As described above, according to this embodiment, since the boss ring 4 that can be inserted into and held by the existing holding member 2 is fixed to both ends of the core tube body 3, the outer diameter R5 and the inner diameter of the core tube body 3 are fixed. Even if R1 is increased, the film roll core tube 1 can be held and used by the holding member 2 without changing the existing holding member 2. As a result, if the film roll core tube 1 is used, a film roll can be formed using an existing winding device, and if a film roll using the film roll core tube 1 is used, an existing winding device can be used to form the film roll. The device can be used to unwind the film.

Furthermore, in the conventional technology, since the holding member 2 is inserted directly into both ends of the cylindrical core tube to hold it, it is necessary to set the inner diameter of the core tube to a predetermined value with respect to the holding member 2. It is difficult to increase the outside diameter of the tube. On the other hand, in this embodiment, since the holding member 2 is inserted into the boss ring 4 and held, the inner diameter R1 and outer diameter R5 of the cylindrical core tube main body 3 can be set independently of the holding member 2. can. Thereby, it is possible to easily realize a film roll core tube 1 having a larger outer diameter than a conventional core tube.

Increasing the outer diameter of the film roll core tube 1 can improve the strength. That is, the strength can be improved when a film roll is formed by winding a strip-shaped film around the outer peripheral surface of the film roll core tube 1 a plurality of times. This is because when comparing the film roll core tube 1 with a large outer diameter and the film roll core tube with a small outer diameter, the film roll core tube 1 with a larger outer diameter has a larger outer circumferential surface area, which makes it easier to wrap. This is because the force acting on the film roll core tube 1 from the film is dispersed and the pressure is reduced, making it possible to withstand larger forces. This makes it possible to form a film roll in which a wider and longer film is wound.

Furthermore, when a film roll is formed using a film roll core tube 1 having a large outer diameter, the occurrence of wrinkles in the film can be reduced compared to a film roll using a film roll core tube having a small outer diameter. Curling tendency can be alleviated. This makes it possible to suppress deterioration in the quality of the film and to facilitate handling of the film unwound from the film roll.

Further, by fitting and fixing the boss rings 4 to both ends of the core tube main body 3, it is possible to suppress water due to dew condensation inside the core tube main body 3 from flowing out to the outside. This prevents water due to condensation from reaching the film wound around the film roll core tube 1, thereby suppressing deterioration in film quality.

Furthermore, by forming the core tube main body 3 from carbon fiber, the strength can be improved and the weight can be reduced compared to the case where the core tube main body 3 is formed from metal. This makes it possible to realize a film roll core tube 1 that is lightweight and hard to bend.

Moreover, by forming the boss ring 4 from metal, sufficient adhesion with the holding member 2 can be ensured, and wear, damage, deformation, etc. of the portion with which the holding member 2 comes into contact can be suppressed.

In the configuration shown in FIG. 1, the boss ring 4 is constructed as one component made of one type of material (metal), but it may also be constructed by combining two components made of different metals. good. That is, the boss ring 4 is composed of an outer portion formed in a substantially cylindrical shape, and an inner portion formed in a substantially cylindrical shape and fitted inside the outer portion, and the outer portion and the inner portion are formed in a substantially cylindrical shape. The parts may be made of different metals.

In this way, if the connecting member is formed by combining the outer part and the inner part formed of different metals, the outer part can be formed of a metal that has good adhesion to the core tube body, and the inner part can be made of a metal that has good adhesion to the core tube body. It can be made of metal with good adhesion. This makes the connection between the film roll core tube and the holding member strong, and allows smooth winding and feeding of the film.

Further, by forming the taper 4c, cleaning work inside the core tube main body 3 becomes easier. In other words, if there is no taper 4c, a step corresponding to the inner diameter difference will be created between the inner peripheral surface of the boss ring 4 and the inner peripheral surface of the core tube body 3, so that water accumulated inside the core tube body 3 will be removed. This level difference becomes an obstacle when removing dirt and foreign matter, making cleaning work difficult. On the other hand, when the taper 4c is formed, the difference in level between the inner circumferential surface of the boss ring 4 and the inner circumferential surface of the core tube body 3 can be reduced, so that the water accumulated inside the core tube body 3 can be reduced. and foreign matter can be easily removed, making cleaning work easier.

Note that if the maximum diameter R8 of the taper 4c is set to be the same as the inner diameter R1 of the core tube body 3 as shown in FIG. As a result, the inner peripheral surfaces are smoothly connected to each other. With this configuration, the interior of the core tube main body 3 can be smoothly cleaned without being aware of the presence of the step.

Further, by providing the clad pipe 5 on the outer peripheral surface of the core tube body 3, the film is wound around the outer peripheral surface of the clad pipe 5. By providing the clad pipe 5, the surface condition of the outer peripheral surface around which the film is wound can be adjusted to an appropriate condition, compared to the case where the film is directly wound around the outer peripheral surface of the core tube body to form a film roll. , it is possible to suppress deterioration of film quality.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.
FIG. 3 is a cross-sectional view showing the structure of a film roll core tube 11 according to an embodiment of the present invention. Regarding the film roll core tube 11, the same components as the film roll core tube 1 shown in FIG. 1 are given the same reference numerals, and detailed description thereof will be omitted. Further, the outer diameter of the holding member 2 used is 202 mm, and the inner diameter of the cylindrical member that can be stably held by this holding member 2 is 203.2 mm.

The outer diameter R0 of the film roll core tube 11 is 300 mm, and the length L1 is 6200 mm. The core tube body 3 is made of carbon fiber, and has a length L2 of 6100 mm, an outer diameter R5 of 299 mm, an inner diameter R1 of 279.4 mm, and a thickness t1 of 9.3 mm.

The boss ring 14 includes an outer portion 14d formed in a cylindrical shape and an inner portion 14e formed in a cylindrical shape and fitted inside the outer portion 14d. The outer portion 14d is made of stainless steel, and the inner portion 14e is made of aluminum. Note that the boss ring 14 is the same as the boss ring 4 shown in FIG. 1 in that it is composed of a fitting part 14a and a protruding part 14b, and that a taper 14c is formed on the inner peripheral surface on the core tube main body 3 side. .

By using the boss ring 14 that combines the outer portion 14d and the inner portion 14e formed of different metals, it is possible to ensure sufficient adhesion with the holding member 2, and also ensure sufficient adhesion with the core tube body 3. You can also ensure sex. This makes it possible to firmly hold the film roll core tube 11 by the holding member 2, making it possible to smoothly wind up and feed out the film.

The boss ring 14 is fitted into and fixed to both ends of the core tube main body 3, but unlike the configuration shown in FIG. Fixed. Therefore, in the boss ring 14, the fitting portion 14a has an outer diameter R6 of 280 mm, and the protruding portion 14b has an outer diameter R4 of 298 mm. Note that the inner diameter of the outer portion 14d and the outer diameter R10 of the inner portion 14e are set to 260 mm, and the inner diameter R3 of the boss ring 14 is set to 203.2 mm in relation to the holding member 2. Further, the length L3 of the fitting portion 14a is set to 170 mm, and the length L4 of the protruding portion 14b is set to 70 mm.

Further, the maximum diameter R8 of the taper in the boss ring 14 is set to 270 mm. Since the maximum diameter of the taper is set smaller than the inner diameter R1 of the core tube body 3, a step of 4.7 mm is created between the taper 14c of the boss ring 14 and the inner peripheral surface of the core tube body 3. Therefore, when cleaning the inside of the core tube main body 3, it is necessary to be aware of this level difference when cleaning, but since the level difference is relatively small, about 4.7 mm, cleaning work will not be difficult. do not have.

The clad pipe 5 is made of stainless steel. The length L5 is 6200 mm, the outer diameter R11 is 300 mm (same as the outer diameter R0 of the film roll core tube 11), the inner diameter R9 is 298 mm (same as the outer diameter R5 of the core tube body 3), and the thickness t2 is It is 1.0 mm. This clad pipe 5 covers the entire outer circumferential surface of the core tube main body 3 and the protruding portion 14b of the boss ring 14.

1, 11 Core tube for film roll 2 Holding member 3 Core tube body 4, 14 Boss ring 5 Clad pipe L1 Length of core tube 11 for film roll L2 Length of core tube body 3 L3 Fitting portion 14a of boss ring 14 Length L4 Length of the protruding portion 14b of the boss ring 14 L5 Length of the clad pipe 5 R1 Inner diameter of the core tube body 3 R2 Outer diameter of the holding member 2 R3 Inner diameter of the boss rings 4, 14 R4 Protrusion of the boss rings 4, 14 Outer diameter of portions 4b, 14b R5 Outer diameter of core tube body 3 R6 Outer diameter of fitting portions 4a, 14a of boss rings 4, 14 R7 Inner diameter of thin wall portion 3a formed at the end of core tube body 3 R8 Taper 4c , 14c R9 Inner diameter of clad pipe 5 R10 Inner diameter of outer portion 14d and outer diameter of inner portion 14e of boss ring 14 R11 Outer diameter of clad pipe 5

Claims (2)

A film roll core tube formed into a cylindrical shape, held by holding members inserted at both ends thereof, and used when forming a film roll by winding a band-shaped film around the outer peripheral surface of the core tube,
A core tube body formed in a cylindrical shape,
a connecting member that is formed in a cylindrical shape and includes a fitting portion that is fitted into and fixed to both ends of the core tube body, and whose inner diameter is set to a size that allows the holding member to be inserted and held; Equipped with
The part of the core tube body into which the fitting part is fitted forms a thin part whose inner diameter is larger than the inner diameter of the center side of the core tube body and is set to be the same as the outer diameter of the fitting part. A core tube for film rolls. The connecting member includes a protruding portion that comes into contact with the end of the core tube body, the outer diameter of the protruding portion is set to be the same as the outer diameter of the core tube body, and the outer diameter of the fitting portion is set to be the same as the outer diameter of the core tube body. The film roll core tube according to claim 1 , wherein the core tube is set smaller than the outer diameter of the portion.

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