JP2007050955A - Web turn device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a web turn device which is free from any crimp or tramp even when a web is thin, and smoothly inverts face and back sides of the web. <P>SOLUTION: The web turn device 20 for inverting face and back sides of a traveling web 1 comprises: an inlet roll 6 having a rotor shaft for conveying in the web; a first turn bar 4 which is mounted in an inclined manner at the angle of substantially 45° with respect to the traveling direction of the web; a second turn bar 5 substantially orthogonal to the first turn bar; and an outlet roll 8 having a rotor shaft for conveying out the web. The inlet roll and the outlet roll have a projecting crown shape. The first and second turn bars have a mesh part consisting of very small holes. A plurality of air ports are formed in a turn bar inner cylinder at portions corresponding to or communicated with the mesh part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a web turn device that reverses the front and back of a traveling web.

  2. Description of the Related Art Conventionally, a web turn device that reverses the front and back of a running web in order to treat the front and back surfaces of the web has been already known (for example, Patent Document 1). The apparatus includes a first turn bar mounted at an angle of approximately 45 ° with respect to the traveling direction of the web, a turn roll disposed on a side of the first turn bar and having a rotation axis along the traveling direction of the web. The second turn bar is provided so as to be substantially orthogonal to the first turn bar. Then, the web that has traveled is folded back by the first turn bar and guided to the turn roll, is folded back by the turn roll and guided to the second turn bar, and is folded back by the second turn bar, so that the front and back of the web are reversed.

  An example of a product manufactured by processing the front and back surfaces of a web is a magnetic tape. In manufacturing a magnetic tape, a product is manufactured by providing at least a magnetic layer on the surface of a support (plastic film) and a back layer on the back surface.

The recording capacity of magnetic tape is increasing year by year, and the thickness of the tape is becoming thinner in order to increase the capacity per tape roll. For such thin webs, there have been cases where the above-described web turn device cannot sufficiently cope.

Japanese Patent No. 3340327

  In the above-described conventionally known web turn device, an air blowing hole is provided in the turn bar so that the web runs smoothly on the turn bar, and the web floats on the turn bar and travels through the air layer. However, in the conventional apparatus, the floating amount tends to be large at the center of the web and small at the end, causing wrinkles, and the end of the web is likely to flutter. There was a tendency to be easily scratched. This phenomenon becomes prominent on thin webs, and has been a major problem in the production of high recording density magnetic tapes, for example, in recent years.

  An object of the present invention is to provide a web turn device that can smoothly reverse the front and back of a web without causing wrinkles or fluttering even with a thin web.

  As a result of intensive studies on the above problems, the inventors of the present invention can achieve the above object by forming the web turn device with the following configuration, thereby achieving the present invention.

That is, a web turn device that reverses the front and back of a traveling web, and an inlet roll having a rotor shaft for carrying the web;
A first turn bar mounted at an angle of approximately 45 ° with respect to the running direction of the web;
A turn roll disposed on a side of the first turn bar and having a rotor shaft along a running direction of the web;
A second turn bar arranged substantially perpendicular to the first turn bar and above or below the first turn bar;
An exit roll having a rotor shaft for carrying out the web, wherein the first turn bar and the second turn bar are composed of a turn bar inner cylinder and a net sleeve covering the turn bar, and the net sleeve includes the web sleeve A mesh portion made of fine holes is provided on the substantially abutting surface, and the turn bar inner cylinder is provided with a plurality of air blowing holes in a portion corresponding to and communicating with the mesh portion. .
The entrance roll, the turn roll, and the exit roll have a convex crown shape.

  The diameters of the plurality of air blowing holes provided in the substantially contact surfaces of the first turn bar and the second turn bar with the web are set to be small at the center portion in the width direction of the abutting web and large at the end portions. It is characterized by that.

  The number distribution of the plurality of air blowing holes provided on the substantially contact surface with the web of the first turn bar and the second turn bar is set so as to be small at the center portion in the width direction of the abutting web and large at the end portion. It is characterized by.

  Since a plurality of air blowing holes are provided on the substantially abutting surface of the turn bar with the web, and a mesh is provided to cover the plurality of air blowing holes, wrinkles are generated and the edges are fluttered even with a thin web. Can be prevented. Further, this effect can be further increased by making the inlet roll, the turn roll, and the outlet roll into a convex crown shape or appropriately controlling the diameter and the number of holes of the air blowing holes in the width direction of the web.

  Hereinafter, an example of the web turn device according to the present invention will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, a web turn device 20 of this example includes a planar rectangular device frame 2 for connecting the components, a rotatable inlet roll 6 for carrying the web 1 into the device, and running of the web. The first turn bar 4 that bends the direction of 90 °, the turn roll 7 that is rotatably provided to bend the running direction of the web 180 °, the second turn bar 5 that bends the running direction of the web 90 °, and the web are carried out to the next process. It is comprised from the exit roll 8 provided rotatably.

  The inlet roll 6, the turn roll 7, and the outlet roll 8 have their cylindrical surfaces processed into a convex crown shape. The optimum crown amount is determined by the width, thickness, material, and the like of the web to be run, but it is usually preferably 500 μm to 2000 μm. The crown amount here refers to the difference in roll diameter between the roll center and the roll end. By processing the cylindrical surface of each of these rolls into a convex crown shape, the tension at the center of the web on the turn bar can be increased compared to the end, preventing the occurrence of wrinkles, and at the center. The flying height of the web can be controlled.

  As shown in FIGS. 2-1 to 2-3, the first turn bar 4 and the second turn bar 5 are composed of a turn bar inner cylinder 50 and a net sleeve 51 covering the turn bar inner cylinder 50. A mesh portion 51a composed of fine holes is provided on the substantially abutting surface with the web 1 to be formed, and the turn bar inner cylinder 50 is provided with a plurality of air blowing holes 50b, a plurality of portions corresponding to and communicating with the mesh portion 51a. A plurality of grooves 50a including the air blowing holes 50b are provided in a direction parallel to the axis of the turn bar. The mesh portion 51a is preferably provided in a surface portion where the web 1 traveling with the turn bar substantially contacts, and the air blowing hole 50b is provided so as to correspond to and communicate with the lower portion thereof. The reason for providing the air blowing hole and the mesh part on the surface portion that substantially contacts is that if the air blowing hole 50b and the mesh part 51a are provided on the entire surface of the turn bar, the number of parts processing increases, and the amount of air to be supplied increases. This is because it is economical and the air blowing portion in the width direction of the turn bar is limited to the substantially abutting surface, so that the running of the web is stabilized and the vibration in the width direction is reduced. According to the detailed study by the present inventors, when the width of the air blowing portion in the web width direction is set to 105 to 130% of the width of the web, the web width fluctuation during running and the web It has been found that there is less flapping at the edges. The contact surface of the turn bar with the web in the circumferential direction is usually 180 °, but if the angle of the air blowing portion (θ in FIG. 2-3) is set in the range of 185 to 230 °, the thin web It has been found that running is smoother and preferable.

  The air blowing holes and mesh conditions (hole diameter, number of holes, mesh diameter, mesh opening ratio) provided in the turn bar are optimized according to the web width, thickness, material, etc. and air supply conditions. It is preferable to set appropriately. The hole diameter of the air blowing hole is set to be small at the center part in the width direction of the abutting web and large at the end part, or the hole number distribution of the air blowing hole is small at the center part in the width direction of the abutting web. If it is set so as to increase at the end, the flying height of the web on the turn bar can be made more uniform in the width direction, and flapping at the end of the web can be further reduced, which is preferable.

  The mesh part 51a provided on the substantially contact surface of the first turn bar 4 and the second turn bar 5 with the web 1 only needs to be able to evenly rectify the air flow from the air blowing holes 50b. Conventionally known materials such as processed materials, sintered metal materials, and porous ceramic materials can be used.

The operation state of the web turn device 20 having the above configuration will be described. Note that the web 1 travels along the left-right direction of the main body in FIG. 1, and when it is carried into the main body, the back surface of the web 1 is assumed to be upward.
(1) The traveling web 1 is guided to the first turn bar 4 through the inlet roll 6. Since the cylindrical surface of the inlet roll 6 is processed into a convex crown shape, the tension at the central portion of the web is increased, and the floating amount of the central portion of the web on the turn bar can be controlled, so that the web 1 is formed on the first turn bar 4. It has the effect of preventing wrinkles.
(2) The web 1 turned 90 ° by the first turn bar 4 is guided to the turn roll 7. When the first turn bar 4 is turned 90 °, the air rectified uniformly from the plurality of air blowing holes 50b of the first turn bar 4 through the mesh portion 51a is blown from the substantially abutting surface through which the web 1 passes. Therefore, when the web 1 is folded, there is no wobbling or flapping in the width direction, and no wrinkles or the like are generated. In this state, the surface of the web 1 is upward.
(3) The web 1 guided to the turn roll 7 is turned back by at least two turn rolls and guided to the second turn bar. In this case, the back surface of the web 1 is upward. Since the cylindrical surface of the turn roll 7 is processed into a convex crown shape, the tension at the center of the web is increased, and the floating amount of the center of the web on the turn bar can be controlled, so that the second turn bar on the first turn bar 4 5 is effective in preventing wrinkles from occurring on the web. In the case of this example, the two turn rolls are composed of two. However, based on the idea of the present invention, for example, one turn roll may be formed depending on the structure of the turn bar and the way of passing the web as exemplified in Japanese Patent No. 3340327. It is also possible to configure.
(4) The web 1 guided to the second turn bar 5 is turned 90 ° by the second turn bar 5 and reaches the exit roll with the surface of the web 1 facing upward. That is, the front and back of the web 1 are reversed by the web turn device 20 and carried out to the next process through the exit roll 8. Since the exit roll 8 has a cylindrical surface processed into a convex crown shape, the tension at the center of the web is increased, and the floating amount of the center of the web on the turn bar can be controlled, so that the web is wrinkled on the second turn bar 5. This has the effect of preventing the occurrence of In the second turn bar 5 as well, similarly to the first turn bar 4, air rectified uniformly from the plurality of air blowing holes 50b through the mesh portion 51a is blown from the substantially abutting surface through which the web 1 passes. The web 1 does not wobble or flutter in the width direction, and wrinkles and the like do not occur.

In the air blowing holes 50b provided in the first turn bar 4 and the second turn bar 5, the diameter of the air blowing holes 50b is set to be small at the center portion in the width direction of the web 1 to be contacted and large at the end portions. However, if the distribution of the number of the air blowing holes 50b is set to be small at the center portion in the width direction of the web 1 to be contacted and large at the end portion, the flying height of the web on the turn bar is further uniform in the width direction. It is possible to reduce the occurrence of wrinkles and the flapping of the web end.

It is a top view of the web turn apparatus of an example of the present invention. It is a perspective view of the 1st and 2nd turn bar. It is a perspective view of the inner cylinder of a 1st, 2nd turn bar. It is sectional drawing of the 1st, 2nd turn bar.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Web 2 Apparatus frame 3 Air supply port 4 1st turn bar 5 2nd turn bar 6 Inlet roll 7 Turn roll
8 Exit roll
20 Web turn device
50 Turnbar inner cylinder
51 Net sleeve
51a Net sleeve mesh
50a groove
50b Air outlet

Claims (4)

A web turn device for reversing the front and back of a traveling web, an inlet roll having a rotor shaft for carrying the web;
A first turn bar mounted at an angle of approximately 45 ° with respect to the running direction of the web;
A turn roll disposed on a side of the first turn bar and having a rotor shaft along a running direction of the web;
A second turn bar arranged substantially orthogonal to the first turn bar and above or below the first turn bar, and an outlet roll having a rotor shaft for carrying out the web;
Each of the first turn bar and the second turn bar includes a turn bar inner cylinder and a net sleeve covering the turn bar, and the net sleeve has a mesh portion formed of fine holes on a substantially abutting surface with the web. The turn bar inner cylinder is provided with a plurality of air blowing holes in a portion corresponding to and communicating with the mesh portion. The web turn device according to claim 1, wherein the entrance roll, the turn roll, and the exit roll have a convex crown shape. The diameters of the plurality of air blowing holes provided in the substantially contact surfaces of the first turn bar and the second turn bar with the web are set so as to be small at the center in the width direction of the web to be contacted and large at the end. The web turn device according to claim 1. The number distribution of the plurality of air blowing holes provided on the substantially contact surface with the web of the first turn bar and the second turn bar is set so as to be small at the center portion in the width direction of the abutting web and large at the end portion. web turn device of claim 1 or 3, characterized in that is.

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