JP4508777B2 - Sheet cooling device - Google Patents

Description

The present invention is a plastic film, plastic sheet, paper relates to equipment for cooling the sheet material, such as laminated material.

  In a manufacturing process, a processing process, and the like of a sheet-like material, it is widely performed to cool the heated sheet-like material. Conventionally, a sheet-like material is cooled by passing it in a form wound around a roll kept at a low temperature (called a cooling roll) while continuously running the sheet-like material, and using heat conduction from the sheet-like material to the cooling roll. I was going. In addition, although it is not cooling with respect to a sheet-like thing, the method (refer patent document 1) which sprays liquefied gas, such as liquid nitrogen, and cools rapidly using the evaporation latent heat as a cooling method in a heating furnace (refer patent document 1). ing.

However, in the method of cooling a sheet-like material using a cooling roll, if the traveling speed of the sheet-like material is increased in order to increase the processing capacity, the heat conduction time between the cooling roll and the sheet-like material is shortened, resulting in insufficient cooling, A product defect (for example, in the case of a laminating process such as a laminator, a product defect in which a failure occurs in crystallization of the adhesive layer and the peel strength decreases) has occurred. As measures against this problem, measures such as lowering the set temperature of the cooling roll or increasing the diameter of the cooling roll have been taken, but due to restrictions on installation space and the like, sufficient cooling capacity could not be secured. In addition, it is conceivable to apply the method using the liquefied gas described in Patent Document 1 to the cooling of the sheet-like material and spray the liquefied gas on the traveling sheet-like material to cool it. In this case, although the cooling capacity can be secured, it is dangerous to change the oxygen concentration in the atmosphere in a manned environment, so that a separate facility such as sealing the apparatus is necessary, resulting in a problem that the equipment cost becomes extremely high.
Japanese Patent No. 2696351

The present invention has been made in view of such a problem, and while using a device having a simple structure, the sheet-like material during traveling can be efficiently cooled, thereby increasing the traveling speed of the sheet-like material. and to provide a cold 却装 location that makes it possible to sufficiently cool the object.

  As a result of studies to improve the cooling efficiency of the sheet-like material, the present inventors have found the following matters. That is, in the conventional method using a cooling roll, a minute air layer is formed between the cooling roll and the sheet-like material, and this impedes heat transfer, so that the heat transfer coefficient does not increase so much. Therefore, it is conceivable to cool by directly bringing a cooling medium such as water into contact with the sheet material. In that case, although the heat transfer coefficient at the interface between the sheet material and the cooling medium increases, Since a boundary layer is formed on the cooling medium side and heat transfer in the boundary layer is poor, the heat transfer coefficient as a whole does not increase so much. On the other hand, when the cooling medium is sprayed onto the sheet-like material at a high speed as innumerable droplets, the heat transfer coefficient between the droplet colliding with the sheet-like material and the sheet-like material is large. The droplets cool the sheet-like material efficiently, and the temperature of the droplet itself rises and partially evaporates to cool the sheet-like material by latent heat, and many of the collided droplets bounce off the sheet-like material. Since the sheet is separated from the sheet material, innumerable new droplets collide with the sheet material one after another and cool. As a result, the sheet-like material can be cooled very efficiently.

The present invention has been made on the basis of such knowledge, and the invention according to claim 1 includes a support that supports a sheet-like object that travels continuously through a predetermined path, and is supported by the support. A nozzle that blows a water droplet airflow on a traveling sheet material, and a water removal device that is provided downstream of a water droplet airflow spray position by the nozzle and removes water adhering to the sheet material. And a water removing device configured with an air knife that blows air onto the surface of the sheet-like material, and a chamber that accommodates a region in which the water droplets are blown onto the sheet-like material with the nozzle and a region in which air is blown with the air knife. A sheet-like material cooling apparatus having a cover provided in this manner and suction means for sucking the inside of the cover .

  The invention according to claim 2 is characterized in that, in the invention according to claim 1 described above, the average particle diameter of the water droplets contained in the water-containing droplet airflow is 50 to 100 μm.

The cold 却装 location of the present invention described above, the water droplet stream that was configured to blow, sheet innumerable water droplets to a sheet-like material is continuously collide against the sheet material traveling As the water is cooled, a part of it evaporates and the sheet-like material is cooled even by the latent heat. Even if the heat absorption capacity of each water droplet is very small, a very large number of water droplets (for example, tens of thousands to millions per second) In particular, the sheet material can be cooled very efficiently by colliding with the sheet material and cooling. For this reason, the traveling speed of the sheet-like material can be increased without causing poor cooling, and the production capacity or processing capacity of the sheet-like material can be greatly improved. In addition, it is possible to blow and dry water droplets attached to the sheet-like material by blowing air with an air knife downstream of the water-droplet air current blowing position, Since the inside of the cover covering the position and the air blowing position is sucked, the water droplet airflow or air after spraying on the sheet-like material can be sucked and removed from the chamber to prevent airflow leakage to the surroundings. Furthermore, the apparatus used for the cooling apparatus of the present invention may have a relatively simple structure such as a water removing apparatus such as a nozzle for blowing a water-containing droplet stream, an air knife, etc. Therefore, the equipment cost does not increase too much. . Moreover, since the medium used for cooling is water, the environment is not deteriorated as in the case of using a liquefied gas such as liquid nitrogen.

  Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a sheet-like material cooling device according to an embodiment of the present invention, wherein 1 is a sheet-like material such as a resin film to be cooled, and 2 is cooling for cooling the sheet-like material 1. Device. The cooling device 2 travels while being supported by a support roll 5 that constitutes a support body that supports the sheet-like object 1 that travels continuously through a predetermined path, and an outer peripheral surface of the support roll 5. A nozzle 6 that blows the water-containing airflow 7 against the sheet-like material 1, and a water removal device 8 that is provided downstream of the water-droplet airflow blowing position by the nozzle 6 and removes water adhering to the sheet-like material 1. Etc.

  The support roll 5 has a configuration in which a cooling medium such as cooling water is passed inside so as not to raise the temperature to a high temperature even when receiving heat from the entering high-temperature sheet-like material 1. It also acts as a cooling roll. In addition, the support body which supports the sheet-like object 1 so as to pass a predetermined path is not limited to the illustrated support roll 5, but has another structure, for example, a structure in which the sheet-like object 1 is supported by a belt, You may use the thing of the structure which supports the sheet-like object 1 with many small diameter rolls.

  The nozzle 6 for spraying the water-containing air stream is capable of injecting an air stream containing countless minute water droplets onto the sheet-like object 1 at a high speed. In this embodiment, the nozzle 6 is connected to the air pipe 11 and the water pipe 12. An aerosol nozzle having a function of changing the supplied water into very fine water droplets and spraying it on an air stream at high speed is used. Here, in order to increase the cooling efficiency when cooling the sheet-like material 1 by spraying the water-containing stream of water droplets, it is desirable to spray a large amount of fine water droplets at a high speed at a high speed. The average particle diameter of the water droplets in the inside is preferably about 50 to 100 μm. Moreover, it is preferable to set it as 20 m / sec or more as a spraying speed of the water-containing droplet air current to the sheet-like article 1. In addition, the measurement of the average particle diameter of the water droplets may be performed using a known measurement method, for example, directly photographed water droplet particles provided by the name of “VisiSize System” by Nippon Laser Co., Ltd. By using an image analysis type particle size distribution measuring system that measures the particle size from the image, the average particle size of the water droplets can be measured.

Water removal device 8 state, and are not capable of removing the water adhering to the sheet-like material 1 is used an air knife to blow dry air 9 so as to and dried blowing off water on the surface of the sheet 1. Further, in a region where the nozzle 6 and the air knife 8 are arranged, a cover 15 is provided so as to surround the nozzle 6, the air knife 8 and the sheet-like material 1 facing the nozzle 6, and the water droplet 7 is sprayed on the sheet-like material 1. A chamber 16 for accommodating the region and a region where air is blown by the air knife 8 is formed, and a suction means (not shown) for sucking the inside of the cover 16 is connected to the cover 15 via a duct 17. . In order to prevent the cover 15 from coming into contact with the sheet-like object 1 and causing trouble, the tip of the cover 15 is slightly separated from the sheet-like object 1 so that a small gap is formed between them.

  Next, the cooling operation by the cooling device 2 having the above configuration will be described. The sheet 1 heated to a high temperature (for example, about 140 ° C.) travels from the upstream side of the support roll 5 and travels while being supported by the outer peripheral surface of the support roll 5. While the sheet-like material 1 travels while being supported by the outer peripheral surface of the support roll 5, the back surface of the sheet-like material 1 is cooled by the support roll 5 kept at a low temperature. The water droplet airflow 7 is sprayed at a high speed and is cooled by the water droplet airflow.

  Here, as shown in FIG. 2A, the water-containing airflow 7 is accompanied by countless fine waterdrops 20, and these waterdrops 20 collide with the surface of the sheet-like object 1 one after another. When each water droplet 20 collides with the surface of the sheet-like material 1, the heat of the sheet-like material 1 is transmitted to the water droplet 20, but since the heat transfer efficiency at that time is large, each water droplet 20 quickly heats the sheet-like material 1. The sheet-like material 1 is efficiently cooled. Moreover, a part of the heated water droplet 20 evaporates, and the sheet-like material 1 is cooled by latent heat. Many water droplets 20 that have collided with the sheet-like object 1 and cooled the sheet-like object 1 instantaneously bounce off the sheet-like object 1 and leave the sheet-like object. Thus, innumerable new water droplets 20 collide with the sheet-like material 1 one after another and cool. Each water droplet 20 has a very small diameter and a small heat absorption capacity, but tens of thousands to several millions of water droplets 20 per second continuously collide with the sheet material 1 to cool the sheet material 1. As a result, the sheet-like object 1 is cooled very efficiently. In addition, as shown in FIG.2 (b), when the flowing water 23 is made to contact the surface of the sheet-like material 1 and it cools, the boundary layer 23a which does not flow in the contact interface with the sheet-like material 1 of the flowing water 23 is shown. In this boundary layer 23a, heat transfer is performed by heat conduction, so the heat transfer efficiency is poor, most of the running water 23 does not contribute to cooling, and the cooling rate does not increase even though a large amount of running water is used. . In contrast, in the present invention, by using the water-containing droplet airflow, most of the water droplets in the airflow can be effectively used for cooling, and the sheet-like material 1 can be efficiently cooled.

  Thereafter, dry air is blown from the air knife 8 to the sheet-like material 1 cooled by the water-containing droplet air flow 7 from the nozzle 6, and the dry air blows off water droplets adhering to the surface of the sheet-like material 1 and the sheet. The surface of the product 1 is dried. While spraying the water-containing air stream 7 by the nozzle 6 and dry air from the air knife 8, the chamber 16 surrounded by the cover 15 is negatively pressurized by the suction means via the duct 17. Being sucked. As a result, the water-containing airflow after sprayed onto the sheet-like material 1 with the nozzle 6 and the dry air after sprayed onto the sheet-like material 1 with the air knife 8 are sucked and removed from the chamber 16 to prevent airflow leakage to the surroundings. Has been.

  As described above, the sheet-like object 1 that is running while being supported by the support roll 5 is efficiently cooled, and after adhering moisture is removed, it is sent downstream. As a result of confirmation by the present inventors, it has been found that the cooling efficiency is greatly improved when the water droplet airflow blowing by the nozzle 6 is used in combination as compared with the case of cooling only by the support roll 5 kept at a low temperature. That is, when the sheet-like material 1 is a resin film having a thickness of 120 to 170 μm and the temperature of the sheet-like material 1 before entering the support roll 5 is about 140 to 160 ° C., cooling is performed only by the support roll 5. In this case, the temperature of the sheet 1 after cooling decreased only to about 70 to 80 ° C. at a traveling speed of 40 to 50 m / min. Even at 80-100 m / min, the temperature of the sheet 1 after cooling dropped to about 40-50 ° C. Thus, by using the cooling device 2 shown in the embodiment, the traveling speed of the sheet-like material 1 can be significantly increased without causing poor cooling, and the productivity can be greatly improved.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and it is needless to say that the present invention can be appropriately changed within the scope of the claims. .

Schematic sectional view of a cooling device according to an embodiment of the present invention (A) is schematic sectional drawing explaining the state which sprays a water-containing droplet stream on a sheet-like material, and cools, (b) is schematic sectional drawing explaining the state which cools a sheet-like material with flowing water

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet-like material 2 Cooling device 5 Support roll 6 Nozzle (aerosol nozzle)
7 Water-containing droplet air flow 8 Water removal device (air knife)
9 Dry Air 11 Air Piping 12 Water Piping 15 Cover 16 Chamber 17 Duct 20 Water Drop 23 Running Water

Claims (2)

A support that supports the sheet-like material that continuously travels so as to pass through a predetermined path, a nozzle that blows a water-drop stream on the sheet-like material that is supported by the support, and water-containing droplets produced by the nozzle A water removal device that is provided downstream from the airflow blowing position and removes water adhering to the sheet-like material, the water removal device comprising an air knife that blows air onto the surface of the sheet-like material; A sheet-like object having a cover provided so as to form a chamber for accommodating a region in which a water droplet is blown by the nozzle and a region in which air is blown by the air knife on the sheet-like material, and a suction means for sucking the inside of the cover Cooling system . The cooling device for a sheet-like material according to claim 1, wherein an average particle diameter of water droplets contained in the water-containing droplet airflow is 50 to 100 µm.

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