CA2798032A1 - Apparatus for change of direction of long sheet, and article floating apparatus - Google Patents
Apparatus for change of direction of long sheet, and article floating apparatus Download PDFInfo
- Publication number
- CA2798032A1 CA2798032A1 CA2798032A CA2798032A CA2798032A1 CA 2798032 A1 CA2798032 A1 CA 2798032A1 CA 2798032 A CA2798032 A CA 2798032A CA 2798032 A CA2798032 A CA 2798032A CA 2798032 A1 CA2798032 A1 CA 2798032A1
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- Canada
- Prior art keywords
- porous resin
- direction changing
- resin layer
- changing device
- perforated container
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H23/00—Registering, tensioning, smoothing or guiding webs
- B65H23/04—Registering, tensioning, smoothing or guiding webs longitudinally
- B65H23/24—Registering, tensioning, smoothing or guiding webs longitudinally by fluid action, e.g. to retard the running web
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H23/00—Registering, tensioning, smoothing or guiding webs
- B65H23/04—Registering, tensioning, smoothing or guiding webs longitudinally
- B65H23/32—Arrangements for turning or reversing webs
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2401/00—Materials used for the handling apparatus or parts thereof; Properties thereof
- B65H2401/10—Materials
- B65H2401/11—Polymer compositions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2401/00—Materials used for the handling apparatus or parts thereof; Properties thereof
- B65H2401/20—Physical properties, e.g. lubricity
- B65H2401/242—Porosity
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2406/00—Means using fluid
- B65H2406/10—Means using fluid made only for exhausting gaseous medium
- B65H2406/11—Means using fluid made only for exhausting gaseous medium producing fluidised bed
- B65H2406/113—Details of the part distributing the air cushion
- B65H2406/1131—Porous material
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
- Laminated Bodies (AREA)
- Registering, Tensioning, Guiding Webs, And Rollers Therefor (AREA)
Abstract
A direction-changing apparatus (4) comprises a columnar container (1) which has pores (2) and a porous resin layer (3) which covers the pores (2). A compressed air is supplied into the container (1). The air which is diffused from the surface of the resin layer (3) floats a long sheet (6) which is caught by the apparatus (4). The apparatus (4) can generate a stable floating force with a small quantity of the compressed air. The resin layer (3) comprises a laminated structure composed of polytetrafluoroethylene films. The surface of the resin layer (3) is treated with an antistatic agent or a water-repellent/oil-repellent agent. Each of the PTFE films is reinforced with a PTFE woven fabric. The resin layer (3) has a thickness of 0.1 to 20 mm and a ventilation coefficient of 100 to 15000 mL/(cm2·min·MPa). The container (1) is a stainless pipe.
Description
Specification [Title of Invention] APPARATUS FOR CHANGE OF DIRECTION
OF LONG SHEET, AND ARTICLE FLOATING APPARATUS
[Technical Field]
[0001]
The present invention relates to devices for changing (switching) the running direction of a long sheet, and more particularly, relates to direction changing devices for changing the running direction of a long sheet so as to float the running long sheet using a pillared perforated container that emits air from its surface.
OF LONG SHEET, AND ARTICLE FLOATING APPARATUS
[Technical Field]
[0001]
The present invention relates to devices for changing (switching) the running direction of a long sheet, and more particularly, relates to direction changing devices for changing the running direction of a long sheet so as to float the running long sheet using a pillared perforated container that emits air from its surface.
[0002]
A hollow pillared perforated container termed a "turn bar" has hitherto been known, which changes the running direction of a running long sheet. The turn bar uses air supplied into a perforated container and emitted from the holes of the perforated container toward a long sheet, to cause the long sheet to run while maintaining the state where the long sheet is floating from the perforated container, and thereby changes the running direction of the long sheet such that the perforated container serves as the changing point.
A hollow pillared perforated container termed a "turn bar" has hitherto been known, which changes the running direction of a running long sheet. The turn bar uses air supplied into a perforated container and emitted from the holes of the perforated container toward a long sheet, to cause the long sheet to run while maintaining the state where the long sheet is floating from the perforated container, and thereby changes the running direction of the long sheet such that the perforated container serves as the changing point.
[0003]
Patent Document 1 discloses a direction changing device (turn roll) for changing the running direction of a running long sheet (long base material), the turn roll including: air supply openings for supplying air to a hollow space within the turn roll; and air flow holes provided in the circumferential surface of the turn roll.
Patent Document I discloses that, to adjust in the width direction of the turn roll the amount of emission from the air flow holes, partitions are provided so as to divide the hollow space within the turn roll in the width direction of the turn roll, and for each of the hollow spaces within the turn roll divided by the partitions, independent air supply openings are provided that can adjust the amount of air supply.
Patent Document 1 discloses a direction changing device (turn roll) for changing the running direction of a running long sheet (long base material), the turn roll including: air supply openings for supplying air to a hollow space within the turn roll; and air flow holes provided in the circumferential surface of the turn roll.
Patent Document I discloses that, to adjust in the width direction of the turn roll the amount of emission from the air flow holes, partitions are provided so as to divide the hollow space within the turn roll in the width direction of the turn roll, and for each of the hollow spaces within the turn roll divided by the partitions, independent air supply openings are provided that can adjust the amount of air supply.
[0004]
Patent Document 2 discloses a direction changing device (object floatation device) for conveying a long sheet (film-like object) while floating the long sheet with a fluid, the direction changing device including: a multilayer surface formed with a plurality of thin plates so as to have a fluid hole serving as a passage for an externally supplied fluid; a fluid-conveying surface formed near the multilayer surface; and fluid flow paths formed between the thin plates, the fluid flow paths allowing the fluid to flow from the fluid hole to the fluid-conveying surface.
Patent Document 2 discloses a direction changing device (object floatation device) for conveying a long sheet (film-like object) while floating the long sheet with a fluid, the direction changing device including: a multilayer surface formed with a plurality of thin plates so as to have a fluid hole serving as a passage for an externally supplied fluid; a fluid-conveying surface formed near the multilayer surface; and fluid flow paths formed between the thin plates, the fluid flow paths allowing the fluid to flow from the fluid hole to the fluid-conveying surface.
[0005]
Patent Document 3 discloses a direction changing device (film floatation direction changing device) for changing the running direction of a running long sheet (film), the direction changing device including: a plurality of gas flow holes formed in a film-conveying surface; and a horizontally long hollow body. Further, both axial ends of the hollow body are fixed to the device body, and a supply tube for supplying a compressed fluid is connected within at least one axial end of the hollow body, such that the film is conveyed in a non-contact state by emitting air from the gas flow holes in the film-conveying surface. In particular, a cross-sectional shape of a corner portion of a direction changing member placed at a direction changing portion of a conveyance guide used to convey the film by floatation is semielliptical, elliptical arc, semicircular, or circular arc, and surfaces on the entrance side and the detachment side for the conveyed film form linear surfaces parallel to the conveying direction of the film. Further, Patent Document 3 also discloses that a string-like object is wound at constant intervals around the film-conveying surface having a plurality of gas flow holes in the direction changing portion, the film-conveying surface being the surface of a thin plate, whereby spiral gaps are formed on the surface so as to have a constant pitch.
[Prior Art Documents]
[Patent Documents]
Patent Document 3 discloses a direction changing device (film floatation direction changing device) for changing the running direction of a running long sheet (film), the direction changing device including: a plurality of gas flow holes formed in a film-conveying surface; and a horizontally long hollow body. Further, both axial ends of the hollow body are fixed to the device body, and a supply tube for supplying a compressed fluid is connected within at least one axial end of the hollow body, such that the film is conveyed in a non-contact state by emitting air from the gas flow holes in the film-conveying surface. In particular, a cross-sectional shape of a corner portion of a direction changing member placed at a direction changing portion of a conveyance guide used to convey the film by floatation is semielliptical, elliptical arc, semicircular, or circular arc, and surfaces on the entrance side and the detachment side for the conveyed film form linear surfaces parallel to the conveying direction of the film. Further, Patent Document 3 also discloses that a string-like object is wound at constant intervals around the film-conveying surface having a plurality of gas flow holes in the direction changing portion, the film-conveying surface being the surface of a thin plate, whereby spiral gaps are formed on the surface so as to have a constant pitch.
[Prior Art Documents]
[Patent Documents]
[0006]
[Patent Document 1] Japanese Patent Laid-open Publication No. 2002-193508 [Patent Document 2] Japanese Patent Laid-open Publication No. 2000-016648 [Patent Document 3] Japanese Patent Laid-open Publication No. 8-245028 [Summary of the Invention]
[Problems to be Solved by the Invention]
[Patent Document 1] Japanese Patent Laid-open Publication No. 2002-193508 [Patent Document 2] Japanese Patent Laid-open Publication No. 2000-016648 [Patent Document 3] Japanese Patent Laid-open Publication No. 8-245028 [Summary of the Invention]
[Problems to be Solved by the Invention]
[0007]
Each of the conventional direction changing devices floats a long sheet by applying air emitted from the surface of a perforated container, to the long sheet at a high rate. Accordingly, Patent Documents 1 to 3 basically discloses a technical content in which the opening areas of air flow holes are reduced in order to increase the flow rate of emitted air.
Each of the conventional direction changing devices floats a long sheet by applying air emitted from the surface of a perforated container, to the long sheet at a high rate. Accordingly, Patent Documents 1 to 3 basically discloses a technical content in which the opening areas of air flow holes are reduced in order to increase the flow rate of emitted air.
[0008]
However, for the purpose of increasing the flow rate of air, it is necessary to use a large high pressure generator for increasing the internal pressure in the perforated container. In addition, there has been a problem that air contains minute particles (dust) and therefore the use of the direction changing device at a high flow rate decreases the air cleanliness in the room. Further, there also has been a problem that the emission of a large amount of air into the room raises and scatters dust already accumulated in the room and therefore expands dust contamination.
Thus, the conventional direction changing devices are not suitable for use in the field where high air cleanliness is required, such as a clean room.
However, for the purpose of increasing the flow rate of air, it is necessary to use a large high pressure generator for increasing the internal pressure in the perforated container. In addition, there has been a problem that air contains minute particles (dust) and therefore the use of the direction changing device at a high flow rate decreases the air cleanliness in the room. Further, there also has been a problem that the emission of a large amount of air into the room raises and scatters dust already accumulated in the room and therefore expands dust contamination.
Thus, the conventional direction changing devices are not suitable for use in the field where high air cleanliness is required, such as a clean room.
[0009]
In view of the above circumstances, it is an object of the present invention to provide a direction changing device that can be used even when the internal pressure in a perforated container is low, and can reduce the amount of minute particles in a room by reducing the amount of air diffusing from the perforated container.
[Means of Solving the Problems]
In view of the above circumstances, it is an object of the present invention to provide a direction changing device that can be used even when the internal pressure in a perforated container is low, and can reduce the amount of minute particles in a room by reducing the amount of air diffusing from the perforated container.
[Means of Solving the Problems]
[0010]
The present inventors have intensively studied to aim the realization of a direction changing device that can solve the following opposite problems at the same time: one is to securely float a long sheet from the surface of a perforated container and the other is to decrease the amount of air diffusing from the perforated container.
In the course of the study, they have examined the use of a porous ceramic sintered product as the direction changing device. However, there is fear that the porous ceramic sintered product needs a large volume of compressed air to securely float the long sheet, resulting in an increase in the installation cost and running cost of compressed air supplying equipment. There is also fear that the fine particles of the sintered product are stirred up in the air to cause a decrease in the air cleanness. As a result of the further study, they have obtained the knowledge that the formation of a porous resin layer so as to cover the holes of a perforated container makes it possible to securely float a long sheet from the surface of a direction changing device even if the internal pressure in the perforated container is set to be relatively low.
The present inventors have intensively studied to aim the realization of a direction changing device that can solve the following opposite problems at the same time: one is to securely float a long sheet from the surface of a perforated container and the other is to decrease the amount of air diffusing from the perforated container.
In the course of the study, they have examined the use of a porous ceramic sintered product as the direction changing device. However, there is fear that the porous ceramic sintered product needs a large volume of compressed air to securely float the long sheet, resulting in an increase in the installation cost and running cost of compressed air supplying equipment. There is also fear that the fine particles of the sintered product are stirred up in the air to cause a decrease in the air cleanness. As a result of the further study, they have obtained the knowledge that the formation of a porous resin layer so as to cover the holes of a perforated container makes it possible to securely float a long sheet from the surface of a direction changing device even if the internal pressure in the perforated container is set to be relatively low.
[0011]
A direction changing device for long sheets of the present invention, which can solve the above problems, comprises a pillared perforated container and a porous resin layer covering holes of the perforated container.
A direction changing device for long sheets of the present invention, which can solve the above problems, comprises a pillared perforated container and a porous resin layer covering holes of the perforated container.
[0012]
In the above direction changing device, it is recommended to take the mode that the porous resin layer comprises a layered structure of a porous resin membrane.
In the above direction changing device, it is recommended to take the mode that the porous resin layer comprises a layered structure of a porous resin membrane.
[0013]
In the above direction changing device, it is recommended to take the mode that the porous resin layer comprises a wound structure of a porous resin membrane.
In the above direction changing device, it is recommended to take the mode that the porous resin layer comprises a wound structure of a porous resin membrane.
[0014]
In the above direction changing device, it may be preferred that the porous resin layer has a thickness of 0.1 to 20 mm.
In the above direction changing device, it may be preferred that the porous resin layer has a thickness of 0.1 to 20 mm.
[0015]
In the above direction changing device, it is recommended to take the mode that the external surface of the porous resin layer at least partly has a cylindrical curved surface.
In the above direction changing device, it is recommended to take the mode that the external surface of the porous resin layer at least partly has a cylindrical curved surface.
[0016]
In the above direction changing device, it may be preferred that the porous resin layer has an air flow coefficient of 100 to 15,000 mL/(cm2.min.MPa).
In the above direction changing device, it may be preferred that the porous resin layer has an air flow coefficient of 100 to 15,000 mL/(cm2.min.MPa).
[0017]
In the above direction changing device, it may be preferred that the porous resin layer has a variation coefficient of air flow coefficient of not higher than 30%.
In the above direction changing device, it may be preferred that the porous resin layer has a variation coefficient of air flow coefficient of not higher than 30%.
[0018]
In the above direction changing device, it is recommended to take the mode that the porous resin membrane is a porous polytetrafluoroethylene membrane.
In the above direction changing device, it is recommended to take the mode that the porous resin membrane is a porous polytetrafluoroethylene membrane.
[0019]
In the above direction changing device, it is recommended to take the mode that a reinforcing membrane is formed between the perforated container and the porous resin layer or formed within the porous resin layer.
In the above direction changing device, it is recommended to take the mode that a reinforcing membrane is formed between the perforated container and the porous resin layer or formed within the porous resin layer.
[0020]
In the above direction changing device, it is recommended to take the mode that a part of the reinforcing membrane is fixed to the porous resin layer.
In the above direction changing device, it is recommended to take the mode that a part of the reinforcing membrane is fixed to the porous resin layer.
[0021]
In the above direction changing device, it is recommended to take the mode that a liquid repellent agent is added to a surface of the porous resin layer.
In the above direction changing device, it is recommended to take the mode that a liquid repellent agent is added to a surface of the porous resin layer.
[0022]
In the above direction changing device, it may be preferred that one or more holes each having an internal diameter of not smaller than 1 mm are formed per cm2 of surface area of the perforated container.
In the above direction changing device, it may be preferred that one or more holes each having an internal diameter of not smaller than 1 mm are formed per cm2 of surface area of the perforated container.
[0023]
In the above direction changing device, it is recommended to take the mode that a compressed gas supplying apparatus is connected to the perforated container.
In the above direction changing device, it is recommended to take the mode that a compressed gas supplying apparatus is connected to the perforated container.
[0024]
In the above direction changing device, it can be put into practice in the mode that a water vapor generating apparatus is connected to the perforated container and the direction changing device is used for food conveyance.
In the above direction changing device, it can be put into practice in the mode that a water vapor generating apparatus is connected to the perforated container and the direction changing device is used for food conveyance.
[0025]
Another direction changing device for long sheets of the present invention, which can solve the above problems, comprises a plurality of object floatation members arranged in parallel, which members each comprises a pillared perforated container and a porous resin layer covering holes of the perforated container.
Another direction changing device for long sheets of the present invention, which can solve the above problems, comprises a plurality of object floatation members arranged in parallel, which members each comprises a pillared perforated container and a porous resin layer covering holes of the perforated container.
[0026]
In the above direction changing device, it may be preferred that a porous resin membrane is further provided detachably on the porous resin layer.
In the above direction changing device, it may be preferred that a porous resin membrane is further provided detachably on the porous resin layer.
[0027]
An object floatation device of the present invention comprises a plurality of object floatation members arranged in parallel, which members each comprises a pillared perforated container and a porous resin layer covering holes of the perforated container.
[Effects of the Invention]
An object floatation device of the present invention comprises a plurality of object floatation members arranged in parallel, which members each comprises a pillared perforated container and a porous resin layer covering holes of the perforated container.
[Effects of the Invention]
[0028]
According to the direction changing devices of the present invention, the formation of a porous resin layer so as to cover the holes of a perforated container makes it possible to securely float a long sheet from the porous resin layer even with a relatively low pressure in the perforated container. In addition, the amount of air diffusing from the direction changing device is small, and therefore, air cleanliness is improved in a room where the direction changing device is operated.
[Brief Description of the Drawings]
According to the direction changing devices of the present invention, the formation of a porous resin layer so as to cover the holes of a perforated container makes it possible to securely float a long sheet from the porous resin layer even with a relatively low pressure in the perforated container. In addition, the amount of air diffusing from the direction changing device is small, and therefore, air cleanliness is improved in a room where the direction changing device is operated.
[Brief Description of the Drawings]
[0029]
[FIG. 1] It is a view showing the production process of a direction changing device in the mode for carrying out the present invention.
[FIG. 2] It is a view showing the production process of the direction changing device in the mode for carrying out the present invention.
[FIG. 3] It is a perspective view showing the production process of the direction changing device in the mode for carrying out the present invention.
[FIG. 4] It is a view showing the usage example of the direction changing device in the mode for carrying out the present invention.
[FIG. 5] It is a view showing the usage example of another direction changing device in the mode for carrying out the present invention.
[FIG. 6] It is a view showing an object conveyance device in the mode for carrying out the present invention.
[FIG. 7] It is a view showing a test apparatus for the direction changing devices in Examples of the present invention.
[Mode for Carrying Out the Invention]
[FIG. 1] It is a view showing the production process of a direction changing device in the mode for carrying out the present invention.
[FIG. 2] It is a view showing the production process of the direction changing device in the mode for carrying out the present invention.
[FIG. 3] It is a perspective view showing the production process of the direction changing device in the mode for carrying out the present invention.
[FIG. 4] It is a view showing the usage example of the direction changing device in the mode for carrying out the present invention.
[FIG. 5] It is a view showing the usage example of another direction changing device in the mode for carrying out the present invention.
[FIG. 6] It is a view showing an object conveyance device in the mode for carrying out the present invention.
[FIG. 7] It is a view showing a test apparatus for the direction changing devices in Examples of the present invention.
[Mode for Carrying Out the Invention]
[0030]
Direction changing devices of the present invention will be described below by reference to the drawings. FIGS. I and 2 are views showing the production process of a direction changing device in the mode for carrying out the present invention. FIG. 3 is a perspective view of the completed direction changing device.
First, as shown in FIG. 1, a hollow pillared perforated container I is prepared, which has holes 2 formed in its side surface. Then, as shown in FIG. 2, a porous resin layer 3 is formed so as to cover the holes 2 of the perforated container 1. This produces, as shown in FIG. 3, the direction changing device having the pillared perforated container I and the porous resin layer 3 covering the holes 2 of the perforated container 1. The porous resin layer 3 may be formed with a monolayer porous resin membrane. However, if the porous resin layer 3 has a layered structure (including a wound structure) of porous resin membranes, it is possible to secure a preferred thickness described later.
Direction changing devices of the present invention will be described below by reference to the drawings. FIGS. I and 2 are views showing the production process of a direction changing device in the mode for carrying out the present invention. FIG. 3 is a perspective view of the completed direction changing device.
First, as shown in FIG. 1, a hollow pillared perforated container I is prepared, which has holes 2 formed in its side surface. Then, as shown in FIG. 2, a porous resin layer 3 is formed so as to cover the holes 2 of the perforated container 1. This produces, as shown in FIG. 3, the direction changing device having the pillared perforated container I and the porous resin layer 3 covering the holes 2 of the perforated container 1. The porous resin layer 3 may be formed with a monolayer porous resin membrane. However, if the porous resin layer 3 has a layered structure (including a wound structure) of porous resin membranes, it is possible to secure a preferred thickness described later.
[0031]
When a pressurized gas is fed into the perforated container I of the direction changing device in the mode for carrying out the present invention, the pressurized gas passes through the holes 2, further passes through the porous resin layer 3, and diffuses to the outside of the direction changing device. Although the state of the air flow and the internal pressure distribution on the surface of the porous resin layer 3 at this time have not been fully elucidated, it is considered that a very minute air flow is generated not only in the vertical direction of the porous resin layer 3 but also isotropically in various directions. Unlike the conventional direction changing devices, a large amount of high-rate air flow is not observed, however, a very smooth floatation for an object acts near the surface of the porous resin layer 3.
When a pressurized gas is fed into the perforated container I of the direction changing device in the mode for carrying out the present invention, the pressurized gas passes through the holes 2, further passes through the porous resin layer 3, and diffuses to the outside of the direction changing device. Although the state of the air flow and the internal pressure distribution on the surface of the porous resin layer 3 at this time have not been fully elucidated, it is considered that a very minute air flow is generated not only in the vertical direction of the porous resin layer 3 but also isotropically in various directions. Unlike the conventional direction changing devices, a large amount of high-rate air flow is not observed, however, a very smooth floatation for an object acts near the surface of the porous resin layer 3.
[0032]
The characteristics of such a porous resin material cannot be found in porous ceramic sintered products and others, which have been simultaneously studied by the present inventors.
The characteristics of such a porous resin material cannot be found in porous ceramic sintered products and others, which have been simultaneously studied by the present inventors.
[0033]
FIG. 4 is a view showing the example of use of the direction changing device in the mode for carrying out the present invention. In FIG. 4, a long sheet (e.g., one used as a conveyor belt for articles) is hooked around half the direction changing device, and a pressurized gas is fed into the perforated container I in this state, whereby air diffuses from the surface of the porous resin layer 3. This causes the long sheet to float, and therefore, the long sheet runs smoothly.
FIG. 4 is a view showing the example of use of the direction changing device in the mode for carrying out the present invention. In FIG. 4, a long sheet (e.g., one used as a conveyor belt for articles) is hooked around half the direction changing device, and a pressurized gas is fed into the perforated container I in this state, whereby air diffuses from the surface of the porous resin layer 3. This causes the long sheet to float, and therefore, the long sheet runs smoothly.
[0034]
As the material forming the porous resin layer 3, there can be used various porous films made of resins which may include polyolefins such as polyethylene and polypropylene; polyvinyl chloride; polyamide; polycarbonate; polyphenylene ether;
polyethylene terephthalate; polybutylene terephthalate; polyurethane; their mixtures;
and their layered products. In particular, ultrahigh molecular weight polyolefins and polytetrafluoroethylene (PTFE) may be preferred because they have high melting viscosities, and therefore, even if some heat is applied to the porous resin layer 3 after its production, the forms of pores are not significantly changed.
As the material forming the porous resin layer 3, there can be used various porous films made of resins which may include polyolefins such as polyethylene and polypropylene; polyvinyl chloride; polyamide; polycarbonate; polyphenylene ether;
polyethylene terephthalate; polybutylene terephthalate; polyurethane; their mixtures;
and their layered products. In particular, ultrahigh molecular weight polyolefins and polytetrafluoroethylene (PTFE) may be preferred because they have high melting viscosities, and therefore, even if some heat is applied to the porous resin layer 3 after its production, the forms of pores are not significantly changed.
[0035]
In the above resins, polytetrafluoroethylene has high melting viscosity, high heat resistance, and small amounts of gas and dust generation, and therefore, it may be more preferred when the direction changing device is used for applications such as clean rooms. Further, polytetrafluoroethylene has excellent surface release properties, and therefore, even if the supply of the pressurized gas into the perforated container I is stopped due, for example, to an electric power failure during the running of the long sheet, the porous resin layer 3 and the long sheet relatively smoothly slide even while being in contact with each other. This makes it possible to minimize the damage of the long sheet caused by the sudden stoppage of the entire device system. Thus, the use of polytetrafluoroethylene as the material forming the porous resin layer 3 produces a very advantageous effect, even in the state where the pressurized gas is supplied.
In the above resins, polytetrafluoroethylene has high melting viscosity, high heat resistance, and small amounts of gas and dust generation, and therefore, it may be more preferred when the direction changing device is used for applications such as clean rooms. Further, polytetrafluoroethylene has excellent surface release properties, and therefore, even if the supply of the pressurized gas into the perforated container I is stopped due, for example, to an electric power failure during the running of the long sheet, the porous resin layer 3 and the long sheet relatively smoothly slide even while being in contact with each other. This makes it possible to minimize the damage of the long sheet caused by the sudden stoppage of the entire device system. Thus, the use of polytetrafluoroethylene as the material forming the porous resin layer 3 produces a very advantageous effect, even in the state where the pressurized gas is supplied.
[0036]
In addition, the use of PTFE as the material of the porous resin layer 3 makes it possible to use the direction changing device in the temperature range of from very low temperatures, e.g., minus 100 C, to high temperatures, e.g., 260 C. If the direction changing device is connected to a vapor generator for supplying heated water vapor having a high heat capacity into the perforated container 1, it is also possible to convey food while cooking it.
In addition, the use of PTFE as the material of the porous resin layer 3 makes it possible to use the direction changing device in the temperature range of from very low temperatures, e.g., minus 100 C, to high temperatures, e.g., 260 C. If the direction changing device is connected to a vapor generator for supplying heated water vapor having a high heat capacity into the perforated container 1, it is also possible to convey food while cooking it.
[0037]
As the porous resin membrane forming the porous resin layer 3, there can be used a membrane having a porous structure obtained by the phase separation method;
a membrane having a porous structure obtained with a pore-forming agent; and a membrane having a porous structure obtained by expansion processing. When a pore-forming agent is used, a large content of filler as the pore-forming agent makes the pore size distribution wider, and the filler is likely to be removed.
Thus, it is desirable that the content percentage of the filler may be not greater than 50% by mass.
As the porous resin membrane forming the porous resin layer 3, there can be used a membrane having a porous structure obtained by the phase separation method;
a membrane having a porous structure obtained with a pore-forming agent; and a membrane having a porous structure obtained by expansion processing. When a pore-forming agent is used, a large content of filler as the pore-forming agent makes the pore size distribution wider, and the filler is likely to be removed.
Thus, it is desirable that the content percentage of the filler may be not greater than 50% by mass.
[0038]
When the porous resin membrane is formed by expansion processing, using a polytetrafluoroethylene material, the porous resin membrane can be obtained by extruding a mixture of a PTFE fine powder and a lubricant to produce a formed product (paste-formed product); removing the lubricant from the formed product;
and then expanding the formed product thus treated. The paste-formed product to be expanded can be any of unbaked, semi-baked, and baked products. The unbaked products may be more preferred because of their excellent self-welding properties.
The expansion method may be any of uniaxial, simultaneous biaxial, and sequential biaxial expansion methods, each carried out at or below the melting point of PTFE.
Specifically, for example, the methods disclosed in the following publications can serve as useful references: Japanese Patent Publication Nos. 56-45773, 56-17216;
53-55378, and 55-55379; Japanese Patent Laid-Open Publication Nos. 59-109534 and 61-207446.
When the porous resin membrane is formed by expansion processing, using a polytetrafluoroethylene material, the porous resin membrane can be obtained by extruding a mixture of a PTFE fine powder and a lubricant to produce a formed product (paste-formed product); removing the lubricant from the formed product;
and then expanding the formed product thus treated. The paste-formed product to be expanded can be any of unbaked, semi-baked, and baked products. The unbaked products may be more preferred because of their excellent self-welding properties.
The expansion method may be any of uniaxial, simultaneous biaxial, and sequential biaxial expansion methods, each carried out at or below the melting point of PTFE.
Specifically, for example, the methods disclosed in the following publications can serve as useful references: Japanese Patent Publication Nos. 56-45773, 56-17216;
53-55378, and 55-55379; Japanese Patent Laid-Open Publication Nos. 59-109534 and 61-207446.
[0039]
It is recommended that the porosity of the porous resin membrane may be, for example, not lower than 40% (preferably not lower than 60% and more preferably not lower than 70%) and not higher than 95% (preferably not higher than 93%
and more preferably not higher than 90%). The porosity of the porous resin membrane can appropriately be adjusted by the expansion ratio. The reason why the porosities as described above are recommended is as follows: when the porosity is too low, the air flow resistance of the porous resin layer 3 becomes increased, and therefore, a pressurized gas having a high pressure is required in order to float the long sheet.
On the other hand, the upper limit of the porosity is not particularly limited, but the above range is recommended, because when the porosity is too great, the porous resin layer 3 cannot completely make uniform the air flow from each of the holes 2 of the perforated container 1.
It is recommended that the porosity of the porous resin membrane may be, for example, not lower than 40% (preferably not lower than 60% and more preferably not lower than 70%) and not higher than 95% (preferably not higher than 93%
and more preferably not higher than 90%). The porosity of the porous resin membrane can appropriately be adjusted by the expansion ratio. The reason why the porosities as described above are recommended is as follows: when the porosity is too low, the air flow resistance of the porous resin layer 3 becomes increased, and therefore, a pressurized gas having a high pressure is required in order to float the long sheet.
On the other hand, the upper limit of the porosity is not particularly limited, but the above range is recommended, because when the porosity is too great, the porous resin layer 3 cannot completely make uniform the air flow from each of the holes 2 of the perforated container 1.
[0040]
The porosity of the porous fluororesin membrane can be calculated based on formula (1) described below, using an apparent density D2 obtained by measuring the mass W and apparent volume V including holes, of the porous fluororesin membrane (D2 = W/V in units of g/cm3), and a true density when no holes are formed (2.2 g/cm3 in the case of PTFE). In this connection, the thickness used to calculate the volume V can be set to be the average thickness measured with a dial thickness gauge (the measurements of the average thickness were made using "SM-1201 ", available from Teclock Corporation, in the state where no load was applied other than the spring load of the gauge body).
Porosity [(2.2 - D2) / 2.2)] x 100 (1) [0041]
The thickness of a single porous resin membrane is not particularly limited.
The total thickness of the porous resin layer 3 (the thickness of a single porous resin membrane in the case where the porous resin membrane is a monolayer; and the total thickness of the porous resin membranes in the case where a plurality of porous resin membranes are layered) may be, for example, not smaller than 0.1 mm, preferably not smaller than 0.4 mm, and more preferably not smaller than 1 mm. This is because if the total thickness of the porous resin layer 3 is too small, there occurs phenomenon that the porous resin layer 3 may be removed to bulge outward away from the perforated container I due to the pressure of the pressurized gas.
Further, it is not possible to completely make uniform the air flow from the holes 2 of the perforated container 1. In this connection, the pore diameter of the porous resin membrane may be about 0.2 to 10 gm, preferably about 0.2 to 5 gm.
The porosity of the porous fluororesin membrane can be calculated based on formula (1) described below, using an apparent density D2 obtained by measuring the mass W and apparent volume V including holes, of the porous fluororesin membrane (D2 = W/V in units of g/cm3), and a true density when no holes are formed (2.2 g/cm3 in the case of PTFE). In this connection, the thickness used to calculate the volume V can be set to be the average thickness measured with a dial thickness gauge (the measurements of the average thickness were made using "SM-1201 ", available from Teclock Corporation, in the state where no load was applied other than the spring load of the gauge body).
Porosity [(2.2 - D2) / 2.2)] x 100 (1) [0041]
The thickness of a single porous resin membrane is not particularly limited.
The total thickness of the porous resin layer 3 (the thickness of a single porous resin membrane in the case where the porous resin membrane is a monolayer; and the total thickness of the porous resin membranes in the case where a plurality of porous resin membranes are layered) may be, for example, not smaller than 0.1 mm, preferably not smaller than 0.4 mm, and more preferably not smaller than 1 mm. This is because if the total thickness of the porous resin layer 3 is too small, there occurs phenomenon that the porous resin layer 3 may be removed to bulge outward away from the perforated container I due to the pressure of the pressurized gas.
Further, it is not possible to completely make uniform the air flow from the holes 2 of the perforated container 1. In this connection, the pore diameter of the porous resin membrane may be about 0.2 to 10 gm, preferably about 0.2 to 5 gm.
[0042]
On the other hand, if the total thickness of the porous resin layer 3 is too great, it becomes difficult to prevent the pressurized gas from leaking in the directions of the sides of the porous resin layer 3. Further, an increase in the air flow resistance of the porous resin layer 3 requires a pressurized gas having a very high pressure in order to float the long sheet. Thus, the total thickness of the porous resin layer 3 may be, for example, not greater than 20 mm, preferably not greater than 15 mm, and more preferably not greater than 10 mm.
On the other hand, if the total thickness of the porous resin layer 3 is too great, it becomes difficult to prevent the pressurized gas from leaking in the directions of the sides of the porous resin layer 3. Further, an increase in the air flow resistance of the porous resin layer 3 requires a pressurized gas having a very high pressure in order to float the long sheet. Thus, the total thickness of the porous resin layer 3 may be, for example, not greater than 20 mm, preferably not greater than 15 mm, and more preferably not greater than 10 mm.
[0043]
As the layered form of the porous resin membrane, for example, it is possible to wind a plurality of porous resin membranes concentrically around the perforated container 1. In particular, one closer to the perforated container I may preferably have higher porosity in the layered form of a plurality of porous resin membranes. A
porous resin membrane having low porosity is, on the one hand, effective in allowing air to uniformly diffuse, but is, on the other hand, likely to cause clogging from dust in the air, and therefore, may lack stable driving performance over a long period of time. Accordingly, it is effective to use a porous resin membrane having high porosity, which is unlikely to cause clogging, on the perforated container 1 side of the direction changing device, and use a porous resin membrane having low porosity, which is effective in allowing air to uniformly diffuse, on the outer side of the direction changing device. For example, the porosity of the porous resin membrane closest to the perforated container I is set to be equal to or greater than 1.5 times, more preferably equal to or greater than 2 times, and still more preferably equal to or greater than 3 times, the porosity of the porous resin membrane on the outermost surface side of the direction changing device.
As the layered form of the porous resin membrane, for example, it is possible to wind a plurality of porous resin membranes concentrically around the perforated container 1. In particular, one closer to the perforated container I may preferably have higher porosity in the layered form of a plurality of porous resin membranes. A
porous resin membrane having low porosity is, on the one hand, effective in allowing air to uniformly diffuse, but is, on the other hand, likely to cause clogging from dust in the air, and therefore, may lack stable driving performance over a long period of time. Accordingly, it is effective to use a porous resin membrane having high porosity, which is unlikely to cause clogging, on the perforated container 1 side of the direction changing device, and use a porous resin membrane having low porosity, which is effective in allowing air to uniformly diffuse, on the outer side of the direction changing device. For example, the porosity of the porous resin membrane closest to the perforated container I is set to be equal to or greater than 1.5 times, more preferably equal to or greater than 2 times, and still more preferably equal to or greater than 3 times, the porosity of the porous resin membrane on the outermost surface side of the direction changing device.
[0044]
As another layered form of the porous resin membrane, it is possible to wind a single porous resin membrane around the perforated container 1. Such winding is preferred because after being wound around the perforated container 1, the porous resin membrane may be caused to contract by heating, and thereby is fixed to the perforated container 1. To float a long sheet 6, the vicinity of the surface of the porous resin layer 3 serves as an important part, and therefore, this part needs to be secured as a space where nothing is placed. Accordingly, it is not desirable that the porous resin layer 3 may be fixed using some instrument at the outer side of the porous resin layer 3. Thus, the layering by winding as described above is effective as fixing means using the heating contraction of the porous resin membrane, and therefore, it may be extremely preferred as the form of the direction changing device of the present invention. A preferred number of windings may be, for example, not less than two, more preferably not less than five, and still more preferably not less than seven, around the perforated container 1. There is no particular upper limit to the number of windings. From the viewpoint of the production efficiency of the direction changing device, the number of windings may be, for example, not more than 100, preferably not more than 50.
As another layered form of the porous resin membrane, it is possible to wind a single porous resin membrane around the perforated container 1. Such winding is preferred because after being wound around the perforated container 1, the porous resin membrane may be caused to contract by heating, and thereby is fixed to the perforated container 1. To float a long sheet 6, the vicinity of the surface of the porous resin layer 3 serves as an important part, and therefore, this part needs to be secured as a space where nothing is placed. Accordingly, it is not desirable that the porous resin layer 3 may be fixed using some instrument at the outer side of the porous resin layer 3. Thus, the layering by winding as described above is effective as fixing means using the heating contraction of the porous resin membrane, and therefore, it may be extremely preferred as the form of the direction changing device of the present invention. A preferred number of windings may be, for example, not less than two, more preferably not less than five, and still more preferably not less than seven, around the perforated container 1. There is no particular upper limit to the number of windings. From the viewpoint of the production efficiency of the direction changing device, the number of windings may be, for example, not more than 100, preferably not more than 50.
[0045]
In the layering of the porous resin membrane, it is effective to carry out vacuum treatment on the direction changing device before heat treatment, in order to remove the air present between the layers. If necessary, it is also possible to use an adhesive of, for example, a thermoplastic resin fine powder or a heat-curable resin such as an epoxy resin, to adhere the layers of porous resin membranes together. It is possible to use not only a technique of simply applying an adhesive to the surface of a porous resin membrane, but also, for example, a technique of impregnating the pore portions of a porous resin membrane with an adhesive of a heat-curable resin;
drying the resulting product to thereby become semi-cured (B-staged); layering the resulting product; and carrying out heat treatment.
In the layering of the porous resin membrane, it is effective to carry out vacuum treatment on the direction changing device before heat treatment, in order to remove the air present between the layers. If necessary, it is also possible to use an adhesive of, for example, a thermoplastic resin fine powder or a heat-curable resin such as an epoxy resin, to adhere the layers of porous resin membranes together. It is possible to use not only a technique of simply applying an adhesive to the surface of a porous resin membrane, but also, for example, a technique of impregnating the pore portions of a porous resin membrane with an adhesive of a heat-curable resin;
drying the resulting product to thereby become semi-cured (B-staged); layering the resulting product; and carrying out heat treatment.
[0046]
It is desirable that the air permeation coefficient (K: an index of air flow resistance in units of mL/(cm2.min.MPa); hereinafter, the units may occasionally be omitted) of the porous resin layer 3 may be set to be 100 to 15000. This is because when the air permeation coefficient (K) is set to be not smaller than 100, it is possible to float the long sheet more securely. Further, when the air permeation coefficient (K) is smaller than 100, it may be necessary to very increase the surface smoothness of the porous resin layer 3, which is not economical.
It is desirable that the air permeation coefficient (K: an index of air flow resistance in units of mL/(cm2.min.MPa); hereinafter, the units may occasionally be omitted) of the porous resin layer 3 may be set to be 100 to 15000. This is because when the air permeation coefficient (K) is set to be not smaller than 100, it is possible to float the long sheet more securely. Further, when the air permeation coefficient (K) is smaller than 100, it may be necessary to very increase the surface smoothness of the porous resin layer 3, which is not economical.
[0047]
On the other hand, when the air permeation coefficient (K) is greater than 15000, there is fear that a large volume of compressed air is required, resulting in an increase in the installation cost and running cost of compressed air supplying equipment. Further, when the long tape 6 to float is placed on an action surface as the surface of the porous resin layer 3, the diffusion of compressed air from the holes under the long tape 6 is greatly prevented, and therefore, it is not possible to obtain stability. Accordingly, it is desirable that the air permeation coefficient (K) may be set to be not greater than 15000. The air permeation coefficient (K) may more preferably be set to be 300 to 10000, still more preferably 500 to 7000.
On the other hand, when the air permeation coefficient (K) is greater than 15000, there is fear that a large volume of compressed air is required, resulting in an increase in the installation cost and running cost of compressed air supplying equipment. Further, when the long tape 6 to float is placed on an action surface as the surface of the porous resin layer 3, the diffusion of compressed air from the holes under the long tape 6 is greatly prevented, and therefore, it is not possible to obtain stability. Accordingly, it is desirable that the air permeation coefficient (K) may be set to be not greater than 15000. The air permeation coefficient (K) may more preferably be set to be 300 to 10000, still more preferably 500 to 7000.
[0048]
The air permeation coefficient (K) can be measured in such a manner as described above. First, compressed air having a constant pressure (MPa) is supplied to the perforated container 1, and the amount of air (mL/min) diffusing on the floatation action surface as the surface of the porous resin layer 3 is measured (using a high precision film flow meter SF-1 U, available from HORIBA STEC, Co., Ltd.).
Then, the measured value of the amount of diffusing air is divided by a measurement area (cm2) to obtain the amount of emission V per unit area (mL/cm2.min).
Further, similar measurements are carried out by making various changes in the pressure P
(MPa) of compressed air to be supplied to the perforated container 1. Then, the measured values are plotted on a graph where the horizontal axis represents the supply pressure (P) and the vertical axis represents the amount of emission (V), and the inclination of the obtained straight line is defined as the air permeation coefficient (K). That is, the following formulas (2) and (3) are obtained, and therefore, the air permeation coefficient (K) can be specified.
V (mL/cm2.min) = KP (2) K (mL/(cm2.min.MPa)) = V/P (3) [0049]
It is desirable that the values of the air permeation coefficient (K) should not vary significantly between different regions of the porous resin layer 3. This is in order to float the long sheet 6 in a balanced and stable manner. Accordingly, the variation coefficient of the air permeation coefficient may preferably be not higher than 30%, more preferably not higher than 15%. When the variation coefficient (C) is higher than 30%, there is fear that the stability of floatation may be deteriorated.
In particular, when the long tape 6 has a narrow width, there is possibility that the long tape 6 may lack the stability of floatation.
The air permeation coefficient (K) can be measured in such a manner as described above. First, compressed air having a constant pressure (MPa) is supplied to the perforated container 1, and the amount of air (mL/min) diffusing on the floatation action surface as the surface of the porous resin layer 3 is measured (using a high precision film flow meter SF-1 U, available from HORIBA STEC, Co., Ltd.).
Then, the measured value of the amount of diffusing air is divided by a measurement area (cm2) to obtain the amount of emission V per unit area (mL/cm2.min).
Further, similar measurements are carried out by making various changes in the pressure P
(MPa) of compressed air to be supplied to the perforated container 1. Then, the measured values are plotted on a graph where the horizontal axis represents the supply pressure (P) and the vertical axis represents the amount of emission (V), and the inclination of the obtained straight line is defined as the air permeation coefficient (K). That is, the following formulas (2) and (3) are obtained, and therefore, the air permeation coefficient (K) can be specified.
V (mL/cm2.min) = KP (2) K (mL/(cm2.min.MPa)) = V/P (3) [0049]
It is desirable that the values of the air permeation coefficient (K) should not vary significantly between different regions of the porous resin layer 3. This is in order to float the long sheet 6 in a balanced and stable manner. Accordingly, the variation coefficient of the air permeation coefficient may preferably be not higher than 30%, more preferably not higher than 15%. When the variation coefficient (C) is higher than 30%, there is fear that the stability of floatation may be deteriorated.
In particular, when the long tape 6 has a narrow width, there is possibility that the long tape 6 may lack the stability of floatation.
[0050]
The variation coefficient (C) can be measured in such a manner as described below. First, the floatation action surface as the surface of the porous resin layer 3 is divided into five equal sections. The air permeation coefficient (K) is measured at a measuring point representing each section, and the variation coefficient (C) of the air permeation coefficient (K) can be calculated according to formula (4) described below, using the average value (Km) and the value of the standard deviation ((Y) of five measured values of the respective five sections.
C (%) = (a/Km) x 100 (4) [0051]
A reinforcing membrane may preferably be formed between the perforated container I and the porous resin layer 3, or within the porous resin layer 3.
This is in order to prevent the porous resin layer 3 from being removed to bulging outward away from the perforated container I due to the pressure of the pressurized gas. For example, the reinforcing membrane can be inserted between porous resin membranes to be layered. As the material of the reinforcing membrane, there can be used materials having strength and rigidity without impairing air permeability, such as glass fiber woven fabrics; carbon fiber woven fabrics; nonwoven fabrics; woven fabrics made of super engineering plastic fibers, e.g., aramid and Teflon (registered trademark); and stainless meshes. The position where the reinforcing membrane is placed may be any of a position close to the perforated container 1, a position far from the perforated container 1, and a position between the close and far positions.
When the reinforcing membrane is placed at a position close to the perforated container 1, it is possible to expect the function of distributing the pressurized gas throughout the porous resin layer 3, and the buffer function of reducing pressure.
When the reinforcing membrane is placed at a position far from the perforated container 1, the thickness of the porous resin membrane forming the outermost layer may be not smaller than 100 gm, preferably not smaller than 150 gm, and more preferably not smaller than 200 gm, in order to prevent the irregularities of the reinforcing membrane from affecting the surface of the porous resin layer 3 (i.e., in order not to disrupt the laminar flow properties of the pressurized gas diffusing from the surface of the porous resin layer 3).
The variation coefficient (C) can be measured in such a manner as described below. First, the floatation action surface as the surface of the porous resin layer 3 is divided into five equal sections. The air permeation coefficient (K) is measured at a measuring point representing each section, and the variation coefficient (C) of the air permeation coefficient (K) can be calculated according to formula (4) described below, using the average value (Km) and the value of the standard deviation ((Y) of five measured values of the respective five sections.
C (%) = (a/Km) x 100 (4) [0051]
A reinforcing membrane may preferably be formed between the perforated container I and the porous resin layer 3, or within the porous resin layer 3.
This is in order to prevent the porous resin layer 3 from being removed to bulging outward away from the perforated container I due to the pressure of the pressurized gas. For example, the reinforcing membrane can be inserted between porous resin membranes to be layered. As the material of the reinforcing membrane, there can be used materials having strength and rigidity without impairing air permeability, such as glass fiber woven fabrics; carbon fiber woven fabrics; nonwoven fabrics; woven fabrics made of super engineering plastic fibers, e.g., aramid and Teflon (registered trademark); and stainless meshes. The position where the reinforcing membrane is placed may be any of a position close to the perforated container 1, a position far from the perforated container 1, and a position between the close and far positions.
When the reinforcing membrane is placed at a position close to the perforated container 1, it is possible to expect the function of distributing the pressurized gas throughout the porous resin layer 3, and the buffer function of reducing pressure.
When the reinforcing membrane is placed at a position far from the perforated container 1, the thickness of the porous resin membrane forming the outermost layer may be not smaller than 100 gm, preferably not smaller than 150 gm, and more preferably not smaller than 200 gm, in order to prevent the irregularities of the reinforcing membrane from affecting the surface of the porous resin layer 3 (i.e., in order not to disrupt the laminar flow properties of the pressurized gas diffusing from the surface of the porous resin layer 3).
[0052]
When porous resin membranes are adhered together, or a porous resin layer (membrane) and the reinforcing membrane are adhered together, it is desirable that the adhesion may be carried out only in a part of the porous resin layer (membrane).
This is in order not to inhibit a gas from passing through the porous resin layer.
When fusion bonding is carried out using a reinforcing membrane having air permeability and fusion bonding properties, the fusion bonding may be carried out all over the porous resin layer.
When porous resin membranes are adhered together, or a porous resin layer (membrane) and the reinforcing membrane are adhered together, it is desirable that the adhesion may be carried out only in a part of the porous resin layer (membrane).
This is in order not to inhibit a gas from passing through the porous resin layer.
When fusion bonding is carried out using a reinforcing membrane having air permeability and fusion bonding properties, the fusion bonding may be carried out all over the porous resin layer.
[0053]
In this connection, heat-curable resins such as phenol and polyimide can also be used as the material of the reinforcing membrane. These materials, however, cannot be self-welded, and therefore, require an adhesive. There is fear that clogging of pores may occur from the adhesive. Thus, when such a resin material is used, it is desirable that the resin material may be layered with the porous resin membrane in the state where the resin material is semi-cured (B-staged), before being completely cured.
In this connection, heat-curable resins such as phenol and polyimide can also be used as the material of the reinforcing membrane. These materials, however, cannot be self-welded, and therefore, require an adhesive. There is fear that clogging of pores may occur from the adhesive. Thus, when such a resin material is used, it is desirable that the resin material may be layered with the porous resin membrane in the state where the resin material is semi-cured (B-staged), before being completely cured.
[0054]
The surface of the porous resin layer 3 may preferably be subjected to antistatic treatment, or a liquid-repellent agent (e.g., a liquid-repellent polymer) may preferably be added to the surface of the porous resin layer 3 for waterproofing and antifouling. As the method of antistatic treatment, there can be used, for example, treatment with an antistatic agent containing a quaternary ammonium surfactant, or with an antistatic agent containing conductive fine powder such as silicate, carbon nanotube, or carbon nanofiber. As the method of waterproof/antifouling treatment, there can be used, for example, coating the surface of the porous resin layer 3 with a water/oil-repellent polymer. This treatment makes it possible to prevent various contaminants such as machine oils and water droplets from penetrating into, or being held in, the pores of the porous resin layer 3. The contaminants reduce the air permeability of the porous resin layer 3. In this connection, the "liquid-repellent agent" as used in the claims and the specification refers to a substance having the property or function of repelling a liquid, and examples of the "liquid-repellent agent" may include "water-repellent agents", "oil-repellent agents", and "water/oil-repellent agents".
The surface of the porous resin layer 3 may preferably be subjected to antistatic treatment, or a liquid-repellent agent (e.g., a liquid-repellent polymer) may preferably be added to the surface of the porous resin layer 3 for waterproofing and antifouling. As the method of antistatic treatment, there can be used, for example, treatment with an antistatic agent containing a quaternary ammonium surfactant, or with an antistatic agent containing conductive fine powder such as silicate, carbon nanotube, or carbon nanofiber. As the method of waterproof/antifouling treatment, there can be used, for example, coating the surface of the porous resin layer 3 with a water/oil-repellent polymer. This treatment makes it possible to prevent various contaminants such as machine oils and water droplets from penetrating into, or being held in, the pores of the porous resin layer 3. The contaminants reduce the air permeability of the porous resin layer 3. In this connection, the "liquid-repellent agent" as used in the claims and the specification refers to a substance having the property or function of repelling a liquid, and examples of the "liquid-repellent agent" may include "water-repellent agents", "oil-repellent agents", and "water/oil-repellent agents".
[0055]
The material of the perforated container I is not particularly limited, but there can be used a stainless material or a resin material. It is desirable that in the surface of the perforated container 1, one or more holes each having an inner diameter of not smaller than 1 mm may be formed per 20 cm2 of surface area of the perforated container.
The material of the perforated container I is not particularly limited, but there can be used a stainless material or a resin material. It is desirable that in the surface of the perforated container 1, one or more holes each having an inner diameter of not smaller than 1 mm may be formed per 20 cm2 of surface area of the perforated container.
[0056]
As described above, the present inventors also have simultaneously studied a porous ceramic sintered product in contrast with a porous resin material.
Thus, findings obtained from these studies will be described for confirmation. The pore structure of a porous ceramic sintered product is determined by the particle diameter, the shape, and the sintering method of fine powder, which is a raw material.
It is, however, extremely difficult and costly to make the sizes of the pores uniform and align the directions of the pores. In the present invention, a porous resin material is used, of which pore structure is easy to control. This greatly makes uniform the distribution of the pores of the porous resin membrane in the thickness direction and aligns the directions of the pores, and therefore, aligns the vectors of a pressurized gas diffusing on the surface of the porous resin membrane. This makes it possible to float an object to float by uniformly supporting it. That is, pores having a pore diameter in units of micron or submicron are uniformly and densely distributed in the aligned direction. This makes it possible to obtain a gas laminar flow having excellent static pressure characteristics from a pressurized gas having a low pressure.
In contrast, the pore structure of the porous ceramic sintered product is isotropic in a three-dimensional manner. Accordingly, a pressurized gas diffuses also from surfaces (end surfaces) other than the surface opposing an object to float.
For example, the end surfaces are sealed by applying a heat-curable resin or the like to the end surfaces and curing the heat-curable resin, which, however, is a very time-consuming work. In the present invention, the porous resin has a soft structure, and therefore, it is possible to easily seal the end surfaces only by mechanically compressing or heat-compressing the end surfaces. Further, the porous ceramic sintered product is generally formed as a large bulk object, and is cut into a required shape, or is worked into a required shape by sintering and forming with a mold.
Thus, the porous ceramic sintered product has the demerit that cutting step and mold-forming step complicate the production process. In this respect, it is also one of the merits of the direction changing device of the present invention that it is easy to produce.
As described above, the present inventors also have simultaneously studied a porous ceramic sintered product in contrast with a porous resin material.
Thus, findings obtained from these studies will be described for confirmation. The pore structure of a porous ceramic sintered product is determined by the particle diameter, the shape, and the sintering method of fine powder, which is a raw material.
It is, however, extremely difficult and costly to make the sizes of the pores uniform and align the directions of the pores. In the present invention, a porous resin material is used, of which pore structure is easy to control. This greatly makes uniform the distribution of the pores of the porous resin membrane in the thickness direction and aligns the directions of the pores, and therefore, aligns the vectors of a pressurized gas diffusing on the surface of the porous resin membrane. This makes it possible to float an object to float by uniformly supporting it. That is, pores having a pore diameter in units of micron or submicron are uniformly and densely distributed in the aligned direction. This makes it possible to obtain a gas laminar flow having excellent static pressure characteristics from a pressurized gas having a low pressure.
In contrast, the pore structure of the porous ceramic sintered product is isotropic in a three-dimensional manner. Accordingly, a pressurized gas diffuses also from surfaces (end surfaces) other than the surface opposing an object to float.
For example, the end surfaces are sealed by applying a heat-curable resin or the like to the end surfaces and curing the heat-curable resin, which, however, is a very time-consuming work. In the present invention, the porous resin has a soft structure, and therefore, it is possible to easily seal the end surfaces only by mechanically compressing or heat-compressing the end surfaces. Further, the porous ceramic sintered product is generally formed as a large bulk object, and is cut into a required shape, or is worked into a required shape by sintering and forming with a mold.
Thus, the porous ceramic sintered product has the demerit that cutting step and mold-forming step complicate the production process. In this respect, it is also one of the merits of the direction changing device of the present invention that it is easy to produce.
[0057]
FIG. 5 is a view showing the usage example of another direction changing device in the mode for carrying out the present invention. In FIG. 5, a direction changing device comprises a plurality of object floatation members 13 arranged in parallel, which members each comprises a pillared perforated container I and a porous resin layer 3 covering holes 2 of the perforated container 1. A long sheet 6 is hooked around about half the direction changing device, and a pressurized gas is fed into each of the perforated containers I in this state, whereby air diffuses from the surfaces of the porous resin layers 3. This causes the long sheet 6 to float, and therefore, the long sheet 6 runs smoothly.
FIG. 5 is a view showing the usage example of another direction changing device in the mode for carrying out the present invention. In FIG. 5, a direction changing device comprises a plurality of object floatation members 13 arranged in parallel, which members each comprises a pillared perforated container I and a porous resin layer 3 covering holes 2 of the perforated container 1. A long sheet 6 is hooked around about half the direction changing device, and a pressurized gas is fed into each of the perforated containers I in this state, whereby air diffuses from the surfaces of the porous resin layers 3. This causes the long sheet 6 to float, and therefore, the long sheet 6 runs smoothly.
[0058]
In the example of FIG. 5, the object floatation members 13 are arranged in a circular shape. A plurality of object floatation members 13, however, only need to be arranged in parallel (i.e., such that the object floatation members are directed in the same direction), and may be arranged in, for example, an ellipsoidal shape.
In the example of FIG. 5, the object floatation members 13 are arranged in a circular shape. A plurality of object floatation members 13, however, only need to be arranged in parallel (i.e., such that the object floatation members are directed in the same direction), and may be arranged in, for example, an ellipsoidal shape.
[0059]
In the above-described direction changing device in the mode for carrying out the present invention, a porous resin membrane (not shown) may preferably be further provided detachably on each of the porous resin layers 3. This is because even when a liquid, a sticky object, or the like has become attached to the porous resin membrane during the operation of the direction changing device, the porous resin membrane may be replaced with another porous resin membrane. This greatly facilitates the maintenance of the direction changing device. The material of the porous resin membrane may be similar to that of the porous resin membrane included in the porous resin layer 3, and may most preferably be a porous PTFE
material.
In the above-described direction changing device in the mode for carrying out the present invention, a porous resin membrane (not shown) may preferably be further provided detachably on each of the porous resin layers 3. This is because even when a liquid, a sticky object, or the like has become attached to the porous resin membrane during the operation of the direction changing device, the porous resin membrane may be replaced with another porous resin membrane. This greatly facilitates the maintenance of the direction changing device. The material of the porous resin membrane may be similar to that of the porous resin membrane included in the porous resin layer 3, and may most preferably be a porous PTFE
material.
[0060]
FIG. 6 shows an object floatation device derived from the direction changing device of the present invention. As shown in FIG. 6, object floatation members 13, each having a porous resin layer 3 on the surface of a perforated container 1, are arranged in parallel, whereby a conveyed object 12 can be conveyed by floating it.
When the conveyed object 12 is heavy, the perforated container I may have a prismatic shape. This increases the area of the surface of the porous resin layer 3 opposing the conveyed object 12, and therefore, increases floatation.
Alternatively, it is also possible to increase floatation by laying numerous perforated containers 1 each having a reduced diameter. Although the object floatation device of the present invention is different in an object to float from the direction changing device of the present invention for changing the running direction of a long sheet; however, these devices are the same in the variations of the perforated container I and the porous resin layer 3 that can be used, and the same in the effects that can be enjoyed. Thus, the variations and the effects are not described in detail.
FIG. 6 shows an object floatation device derived from the direction changing device of the present invention. As shown in FIG. 6, object floatation members 13, each having a porous resin layer 3 on the surface of a perforated container 1, are arranged in parallel, whereby a conveyed object 12 can be conveyed by floating it.
When the conveyed object 12 is heavy, the perforated container I may have a prismatic shape. This increases the area of the surface of the porous resin layer 3 opposing the conveyed object 12, and therefore, increases floatation.
Alternatively, it is also possible to increase floatation by laying numerous perforated containers 1 each having a reduced diameter. Although the object floatation device of the present invention is different in an object to float from the direction changing device of the present invention for changing the running direction of a long sheet; however, these devices are the same in the variations of the perforated container I and the porous resin layer 3 that can be used, and the same in the effects that can be enjoyed. Thus, the variations and the effects are not described in detail.
[0061]
In the example of FIG. 6, the object floatation members 13 are arranged on the same plane. A plurality of object floatation members 13, however, only need to be arranged in parallel, and the object floatation members 13 may be arranged on a curved surface.
[Examples]
In the example of FIG. 6, the object floatation members 13 are arranged on the same plane. A plurality of object floatation members 13, however, only need to be arranged in parallel, and the object floatation members 13 may be arranged on a curved surface.
[Examples]
[0062]
The direction changing devices in Example of the present invention will be described below by reference to Examples and Reference Examples. As a matter of course, the present invention is not limited to these Examples.
The direction changing devices in Example of the present invention will be described below by reference to Examples and Reference Examples. As a matter of course, the present invention is not limited to these Examples.
[0063]
1. Evaluation Apparatus FIG. 7 is a view showing a test apparatus for the direction changing devices in Example of the present invention. In FIG. 7, a direction changing device 4 and guide rails 9 are fixed on a test bench 5. On the direction changing device 4 having a perforated container I and a porous resin layer 3, a long sheet 6 was hooked such that one end of the long sheet 6 was attached to a fixing bar 8 and the other end of the long sheet 6 was attached to a weight 7. An adhesive tape was used as the long sheet 6, and the pressure-sensitive adhesive side of the adhesive tape was opposed to the long sheet 6. A compressed gas supply apparatus (e.g., a compressor) 11 was connected to the direction changing device 4 by a gas supply hose 10. A
pressurized gas supplied from the compressed gas supply device 11 was introduced to the direction changing device 4, and thereby floated the long sheet 6. The fixing bar 8 was shifted along the guide rails 9 in the horizontal direction in this state, whereby the direction of the adhesive tape as the long sheet 6 was changed by 90 degrees on the direction changing device 4.
1. Evaluation Apparatus FIG. 7 is a view showing a test apparatus for the direction changing devices in Example of the present invention. In FIG. 7, a direction changing device 4 and guide rails 9 are fixed on a test bench 5. On the direction changing device 4 having a perforated container I and a porous resin layer 3, a long sheet 6 was hooked such that one end of the long sheet 6 was attached to a fixing bar 8 and the other end of the long sheet 6 was attached to a weight 7. An adhesive tape was used as the long sheet 6, and the pressure-sensitive adhesive side of the adhesive tape was opposed to the long sheet 6. A compressed gas supply apparatus (e.g., a compressor) 11 was connected to the direction changing device 4 by a gas supply hose 10. A
pressurized gas supplied from the compressed gas supply device 11 was introduced to the direction changing device 4, and thereby floated the long sheet 6. The fixing bar 8 was shifted along the guide rails 9 in the horizontal direction in this state, whereby the direction of the adhesive tape as the long sheet 6 was changed by 90 degrees on the direction changing device 4.
[0064]
(Example 1) As the perforated container 1, there was used a stainless pipe having four holes each having a diameter of 5 mm in its central portion at equal intervals in the circumferential direction. The stainless pipe had an outer diameter of 34 mm, an inner diameter of 28 mm, and a length of 150 mm; both ends of the stainless pipe were welded and sealed with stainless plates each having a thickness of 2 mm;
and a hole was formed at one end so that a connector of the gas supply hose 10 was attached to the one end.
(Example 1) As the perforated container 1, there was used a stainless pipe having four holes each having a diameter of 5 mm in its central portion at equal intervals in the circumferential direction. The stainless pipe had an outer diameter of 34 mm, an inner diameter of 28 mm, and a length of 150 mm; both ends of the stainless pipe were welded and sealed with stainless plates each having a thickness of 2 mm;
and a hole was formed at one end so that a connector of the gas supply hose 10 was attached to the one end.
[0065]
As the porous resin membrane, there was used a bi-directionally expanded porous PTFE film (available from W.L. Gore & Associates Co., Ltd.; film thickness:
125 pm; and apparent density: 0.436). The bi-directionally expanded porous PTFE
film was produced from PTFE fine powder available from Daikin Industries, Ltd.
(product name: Polyflon F 104) through the respective steps of paste extrusion, rolling, lubricant drying, expansion, and baking. The bi-directionally expanded porous PTFE film was cut into a size having a width of 250 mm and a length of 3 m when used.
As the porous resin membrane, there was used a bi-directionally expanded porous PTFE film (available from W.L. Gore & Associates Co., Ltd.; film thickness:
125 pm; and apparent density: 0.436). The bi-directionally expanded porous PTFE
film was produced from PTFE fine powder available from Daikin Industries, Ltd.
(product name: Polyflon F 104) through the respective steps of paste extrusion, rolling, lubricant drying, expansion, and baking. The bi-directionally expanded porous PTFE film was cut into a size having a width of 250 mm and a length of 3 m when used.
[0066]
As the reinforcing membrane, there was used a woven fabric made of expanded PTFE (available from W.L. Gore & Associates Co., Ltd.; single fiber fineness: 380 deniers; and basis weight: 183 g/m2), and the woven fabric was cut into a size having a width of 250 mm and a length of I m.
As the reinforcing membrane, there was used a woven fabric made of expanded PTFE (available from W.L. Gore & Associates Co., Ltd.; single fiber fineness: 380 deniers; and basis weight: 183 g/m2), and the woven fabric was cut into a size having a width of 250 mm and a length of I m.
[0067]
On a glass plate, the bi-directionally expanded porous PTFE film and the expanded PTFE woven fabric prepared as described above were spread in overlap with each other so as to have the same width, while being extended so as not to make wrinkles. In this connection, at the front end portion, an overlap was made such that the front end of the bi-directionally expanded porous PTFE film was placed 10 cm ahead of the front end of the expanded PTFE woven fabric.
On a glass plate, the bi-directionally expanded porous PTFE film and the expanded PTFE woven fabric prepared as described above were spread in overlap with each other so as to have the same width, while being extended so as not to make wrinkles. In this connection, at the front end portion, an overlap was made such that the front end of the bi-directionally expanded porous PTFE film was placed 10 cm ahead of the front end of the expanded PTFE woven fabric.
[0068]
The stainless pipe described above was placed on the bi-directionally expanded porous PTFE film at the front end portion of the spread bidirectionally expanded porous PTFE film and expanded PTFE woven fabric. Then, the bi-directionally expanded porous PTFE film and the expanded PTFE woven fabric were wound concentrically around the stainless pipe, while tension was applied thereto so as not to make sag and wrinkles, such that the bi-directionally expanded porous PTFE film at the front end portion was placed on the stainless pipe side (the innermost layer side).
The stainless pipe described above was placed on the bi-directionally expanded porous PTFE film at the front end portion of the spread bidirectionally expanded porous PTFE film and expanded PTFE woven fabric. Then, the bi-directionally expanded porous PTFE film and the expanded PTFE woven fabric were wound concentrically around the stainless pipe, while tension was applied thereto so as not to make sag and wrinkles, such that the bi-directionally expanded porous PTFE film at the front end portion was placed on the stainless pipe side (the innermost layer side).
[0069]
The stainless pipe, around which the bi-directionally expanded porous PTFE
film and the expanded PTFE woven fabric had been wound, was placed in an oven while being mounted on a jig that supported the stainless pipe at both ends, and was subjected to heat treatment at 340 C. The product thus treated was removed from the oven about 10 hours later, while remaining mounted on the jig, and was cooled to room temperature by natural cooling.
The stainless pipe, around which the bi-directionally expanded porous PTFE
film and the expanded PTFE woven fabric had been wound, was placed in an oven while being mounted on a jig that supported the stainless pipe at both ends, and was subjected to heat treatment at 340 C. The product thus treated was removed from the oven about 10 hours later, while remaining mounted on the jig, and was cooled to room temperature by natural cooling.
[0070]
Then, the portions of the bi-dierctionally expanded porous PTFE film and the expanded PTFE woven fabric, which portions protruded from both ends of the stainless pipe, were cut off with a cutter knife, such that the film and the woven fabric have a width of 150 mm (the same as the length of the stainless pipe).
Further, both ends of the stainless pipe were fastened by stainless hose bands (available from TOYOX Co., Ltd.; product name: Escargot). By the above method, a direction changing device (1) was obtained, around which the bi-directionally expanded porous PTFE film and the expanded PTFE woven fabric were wound. In this connection, the outermost diameter of the direction changing device (1) was 42 mm.
Then, the portions of the bi-dierctionally expanded porous PTFE film and the expanded PTFE woven fabric, which portions protruded from both ends of the stainless pipe, were cut off with a cutter knife, such that the film and the woven fabric have a width of 150 mm (the same as the length of the stainless pipe).
Further, both ends of the stainless pipe were fastened by stainless hose bands (available from TOYOX Co., Ltd.; product name: Escargot). By the above method, a direction changing device (1) was obtained, around which the bi-directionally expanded porous PTFE film and the expanded PTFE woven fabric were wound. In this connection, the outermost diameter of the direction changing device (1) was 42 mm.
[0071]
(Example 2) As the porous resin membrane, there was used a uniaxially expanded porous PTFE film (available from W.L. Gore & Associates Co., Ltd.; film thickness:
m; and apparent density: 0.564). The uniaxially expanded porous PTFE film was produced from PTFE fine powder available from Daikin Industries, Ltd. (product name: Polyflon F104) through the respective steps of paste extrusion, rolling, lubricant drying, expansion, and baking. The uniaxially expanded porous PTFE
film was cut into a size having a width of 250 mm and a length of 4 m.
(Example 2) As the porous resin membrane, there was used a uniaxially expanded porous PTFE film (available from W.L. Gore & Associates Co., Ltd.; film thickness:
m; and apparent density: 0.564). The uniaxially expanded porous PTFE film was produced from PTFE fine powder available from Daikin Industries, Ltd. (product name: Polyflon F104) through the respective steps of paste extrusion, rolling, lubricant drying, expansion, and baking. The uniaxially expanded porous PTFE
film was cut into a size having a width of 250 mm and a length of 4 m.
[0072]
As the reinforcing membrane, there was used a woven fabric made of expanded PTFE (available from W.L. Gore & Associates Co., Ltd.; fineness: 380 deniers; and basis weight: 183 g/m2), and the woven fabric was cut into a size having a width of 250 mm and a length of 50 cm when used.
As the reinforcing membrane, there was used a woven fabric made of expanded PTFE (available from W.L. Gore & Associates Co., Ltd.; fineness: 380 deniers; and basis weight: 183 g/m2), and the woven fabric was cut into a size having a width of 250 mm and a length of 50 cm when used.
[0073]
A direction changing device (2) was obtained under other conditions similar to those of Example 1. The outer diameter of the direction changing device (2) was 39 mm.
A direction changing device (2) was obtained under other conditions similar to those of Example 1. The outer diameter of the direction changing device (2) was 39 mm.
[0074]
(Example 3) As the porous resin membrane, a polypropylene porous membrane (product name: NG100, available from Tokuyama Corporation; thickness: 110 m) was cut into a size having a width of 250 mm and a length of 2 m.
(Example 3) As the porous resin membrane, a polypropylene porous membrane (product name: NG100, available from Tokuyama Corporation; thickness: 110 m) was cut into a size having a width of 250 mm and a length of 2 m.
[0075]
As the reinforcing membrane, a 300 mesh stainless screen (available from Mesh Corporation; wire diameter: 30 m) was cut into a size having a width of mm and a length of 2 m.
As the reinforcing membrane, a 300 mesh stainless screen (available from Mesh Corporation; wire diameter: 30 m) was cut into a size having a width of mm and a length of 2 m.
[0076]
Around a stainless pipe, which was the same as in Example 1, the stainless screen was first wound concentrically, and the polypropylene porous membrane was then wound concentrically without making wrinkles. Around the resulting product, a uniaxially expanded porous PTFE film, which was the same as in Example 2, was further wound five times. The uniaxially expanded porous PTFE film was used because it contracts when subjected to heat treatment and has the effect of fastening.
Around a stainless pipe, which was the same as in Example 1, the stainless screen was first wound concentrically, and the polypropylene porous membrane was then wound concentrically without making wrinkles. Around the resulting product, a uniaxially expanded porous PTFE film, which was the same as in Example 2, was further wound five times. The uniaxially expanded porous PTFE film was used because it contracts when subjected to heat treatment and has the effect of fastening.
[0077]
The stainless pipe was placed in an oven while being mounted on a jig, which was the same as in Example 1, and subjected to heat treatment at 155 C. The product thus treated was removed from the oven about 5 hours later, while remaining mounted on the jig, and was cooled to room temperature by natural cooling.
The stainless pipe was placed in an oven while being mounted on a jig, which was the same as in Example 1, and subjected to heat treatment at 155 C. The product thus treated was removed from the oven about 5 hours later, while remaining mounted on the jig, and was cooled to room temperature by natural cooling.
[0078]
A direction changing device (3) was obtained by subsequently carrying out the same treatment as in Example 1. The outer diameter of the direction changing device (3) was 37 mm.
[00791 The air permeation coefficient (K) of the porous resin membrane and the coefficient of variation (C) of the air permeation coefficient (K) in each of the above direction changing devices (1) to (3) are shown in Table I below.
>C >C >C
O cC
O O O >C >C >C
v N
pip O
O
U O
a CO
>C 4 >C >C >C
CO
O O O a . a L cd ~y:y Q-I
O >C >C >C N
N
O
nC
ti c S]. 0..
o_ O O O >C >C >C
L
a a O O a X >C >C
^ c o a~
. . U O 00 O .--i F W N M
O O
U O O Cl M N
Q O
p N O C .N O C.M. 0 0 O 0 O C p 00 -0 p. U by v =v . U U 'Cp v U ' U M v U W (U
Q chi =n (~ C d [j C) b Q d Q v .b = b [00811 (Reference Example 1) A commercially available porous pipe made of ultrahigh molecular weight polyethylene (available from Kabushiki Gaisha Someya Seisakusho; inner diameter:
30 mm; outer diameter: 40 mm; thickness: 5 mm; length: 150 mm; and average air hole diameter: 5 gm) was used without modification as a direction changing device (4).
[0082]
(Reference Example 2) A commercially available porous pipe made of ultrahigh molecular weight polyethylene (available from Kabushiki Gaisha Someya Seisakusho; inner diameter:
30 mm; outer diameter: 40 mm; thickness: 5 mm; length: 150 mm; and average air hole diameter: 15 gm) was used without modification as a direction changing device (5).
[0083]
(Reference Example 3) A commercially available diffuser tube made of porous ceramics (product name: Air Stone NR-5304, available from IWAKI Co., Ltd.) was used without modification as a direction changing device (6).
[0084]
The air permeation coefficient (K) of the porous pipe or the diffuser tube and the coefficient of variation (C) of the air permeation coefficient (K) of each of the direction changing devices (4) to (6) are shown in Table I above.
[0085]
2. Evaluation Method The direction changing devices (1) to (6) were each attached to the test apparatus as shown in FIG. 7, and were tested for change in the running direction of an adhesive tape. A load of 100 g/cm was applied to an adhesive tape (product name: No. 3705 Super, available from Nitto Denko Corporation; width: 5 cm) by dangling the weight 7 of 500 g by the adhesive tape. The pressure-sensitive adhesive surface was opposed to the direction changing device, and the adhesive tape was caused to reciprocate in the longitudinal direction on the direction changing device in the state where the running direction was changed by 90 degrees (FIG. 7).
Thus, it was determined whether or not the adhesive tape was able to be shifted without being affected by the pressure-sensitive adhesive (the first test).
[0086]
In addition, after being left in this state for an hour, the adhesive tape was shifted again in the longitudinal direction. Thus, it was determined whether or not the adhesive tape was able to be shifted without being affected by the pressure-sensitive adhesive (the second test).
[0087]
Table I shows the results of the tests carried out by changing the pressure of the pressurized gas to 0.05 MPa, 0.1 MPa, 0.2 MPa, and 0.3 MPa. The direction changing devices used were six types, i.e., (1) to (6). Table I shows the results of the tests carried out in the initial state of the operation of each direction changing device (the first test), and the results of the tests carried out an hour later (the second test).
[0088]
The evaluation criteria of Table I are as follows:
0: the adhesive tape is able to be shifted without being affected by the pressure-sensitive adhesive.
0: the adhesive tape is affected by the pressure-sensitive adhesive such that jams occur in places.
X: the adhesive tape is not able to be shifted because the pressure-sensitive adhesive is adhered to the direction changing device.
[0089]
As can be seen from the test results shown in Table 1, in the direction changing devices (4) to (6) using a porous pipe made of ultrahigh molecular weight polyethylene or a porous pipe made of porous ceramics, a slight improvement was found when the pressure of the pressurized gas was increased to 0.3 MPa.
However, at lower pressures, the adhesive tape was not able to be shifted because the pressure-sensitive adhesive became adhered to the direction changing device. In contrast, in the direction changing device (1) to (3) as Example of the present invention using a porous resin membrane, the state of the floatation of the adhesive tape was excellent.
Thus, the adhesive tape was able to be shifted very smoothly without being affected by the pressure-sensitive adhesive.
[Explanation of Numerals]
[0090]
1 Perforated container 2 Hole 3 Porous resin membrane 4 Direction changing device 5 Test bench 6 Long sheet 7 Weight 8 Fixation bar 9 Guide rails Gas supplying hose 11 Compressed gas supplying apparatus 12 Conveyed object 5 13 Object floatation member
A direction changing device (3) was obtained by subsequently carrying out the same treatment as in Example 1. The outer diameter of the direction changing device (3) was 37 mm.
[00791 The air permeation coefficient (K) of the porous resin membrane and the coefficient of variation (C) of the air permeation coefficient (K) in each of the above direction changing devices (1) to (3) are shown in Table I below.
>C >C >C
O cC
O O O >C >C >C
v N
pip O
O
U O
a CO
>C 4 >C >C >C
CO
O O O a . a L cd ~y:y Q-I
O >C >C >C N
N
O
nC
ti c S]. 0..
o_ O O O >C >C >C
L
a a O O a X >C >C
^ c o a~
. . U O 00 O .--i F W N M
O O
U O O Cl M N
Q O
p N O C .N O C.M. 0 0 O 0 O C p 00 -0 p. U by v =v . U U 'Cp v U ' U M v U W (U
Q chi =n (~ C d [j C) b Q d Q v .b = b [00811 (Reference Example 1) A commercially available porous pipe made of ultrahigh molecular weight polyethylene (available from Kabushiki Gaisha Someya Seisakusho; inner diameter:
30 mm; outer diameter: 40 mm; thickness: 5 mm; length: 150 mm; and average air hole diameter: 5 gm) was used without modification as a direction changing device (4).
[0082]
(Reference Example 2) A commercially available porous pipe made of ultrahigh molecular weight polyethylene (available from Kabushiki Gaisha Someya Seisakusho; inner diameter:
30 mm; outer diameter: 40 mm; thickness: 5 mm; length: 150 mm; and average air hole diameter: 15 gm) was used without modification as a direction changing device (5).
[0083]
(Reference Example 3) A commercially available diffuser tube made of porous ceramics (product name: Air Stone NR-5304, available from IWAKI Co., Ltd.) was used without modification as a direction changing device (6).
[0084]
The air permeation coefficient (K) of the porous pipe or the diffuser tube and the coefficient of variation (C) of the air permeation coefficient (K) of each of the direction changing devices (4) to (6) are shown in Table I above.
[0085]
2. Evaluation Method The direction changing devices (1) to (6) were each attached to the test apparatus as shown in FIG. 7, and were tested for change in the running direction of an adhesive tape. A load of 100 g/cm was applied to an adhesive tape (product name: No. 3705 Super, available from Nitto Denko Corporation; width: 5 cm) by dangling the weight 7 of 500 g by the adhesive tape. The pressure-sensitive adhesive surface was opposed to the direction changing device, and the adhesive tape was caused to reciprocate in the longitudinal direction on the direction changing device in the state where the running direction was changed by 90 degrees (FIG. 7).
Thus, it was determined whether or not the adhesive tape was able to be shifted without being affected by the pressure-sensitive adhesive (the first test).
[0086]
In addition, after being left in this state for an hour, the adhesive tape was shifted again in the longitudinal direction. Thus, it was determined whether or not the adhesive tape was able to be shifted without being affected by the pressure-sensitive adhesive (the second test).
[0087]
Table I shows the results of the tests carried out by changing the pressure of the pressurized gas to 0.05 MPa, 0.1 MPa, 0.2 MPa, and 0.3 MPa. The direction changing devices used were six types, i.e., (1) to (6). Table I shows the results of the tests carried out in the initial state of the operation of each direction changing device (the first test), and the results of the tests carried out an hour later (the second test).
[0088]
The evaluation criteria of Table I are as follows:
0: the adhesive tape is able to be shifted without being affected by the pressure-sensitive adhesive.
0: the adhesive tape is affected by the pressure-sensitive adhesive such that jams occur in places.
X: the adhesive tape is not able to be shifted because the pressure-sensitive adhesive is adhered to the direction changing device.
[0089]
As can be seen from the test results shown in Table 1, in the direction changing devices (4) to (6) using a porous pipe made of ultrahigh molecular weight polyethylene or a porous pipe made of porous ceramics, a slight improvement was found when the pressure of the pressurized gas was increased to 0.3 MPa.
However, at lower pressures, the adhesive tape was not able to be shifted because the pressure-sensitive adhesive became adhered to the direction changing device. In contrast, in the direction changing device (1) to (3) as Example of the present invention using a porous resin membrane, the state of the floatation of the adhesive tape was excellent.
Thus, the adhesive tape was able to be shifted very smoothly without being affected by the pressure-sensitive adhesive.
[Explanation of Numerals]
[0090]
1 Perforated container 2 Hole 3 Porous resin membrane 4 Direction changing device 5 Test bench 6 Long sheet 7 Weight 8 Fixation bar 9 Guide rails Gas supplying hose 11 Compressed gas supplying apparatus 12 Conveyed object 5 13 Object floatation member
Claims (17)
- [Claim 1]
A direction changing device for long sheets, comprising a pillared perforated container and a porous resin layer covering holes of the perforated container. - [Claim 2]
The direction changing device according to claim 1, wherein the porous resin layer comprises a layered structure of a porous resin membrane. - [Claim 3]
The direction changing device according to claim 1 or 2, wherein the porous resin layer comprises a wound structure of a porous resin membrane. - [Claim 4]
The direction changing device according to any of claims 1 to 3, wherein the porous resin layer has a thickness of 0.1 to 20 mm. - [Claim 5]
The direction changing device according to any of claims 1 to 4, wherein the external surface of the porous resin layer at least partly has a cylindrical curved surface. - [Claim 6]
The direction changing device according to any of claims 1 to 5, wherein the porous resin layer has a air flow coefficient of 100 to 15,000 mL/(cm2.min.MPa). - [Claim 7]
The direction changing device according to claim 6, wherein the porous resin layer has a variation coefficient of air flow coefficient of not higher than 30%. - [Claim 8]
The direction changing device according to any of claims 2 to 7, wherein the porous resin membrane is a porous polytetrafluoroethylene membrane. - [Claim 9]
The direction changing device according to any of claims 1 to 8, wherein a reinforcing membrane is formed between the perforated container and the porous resin layer or formed within the porous resin layer. - [Claim 10]
The direction changing device according to claim 9, wherein a part of the reinforcing membrane is fixed to the porous resin layer. - [Claim 11]
The direction changing device according to any of claims 1 to 10, wherein a liquid repellent agent is added to a surface of the porous resin layer. - [Claim 12]
The direction changing device according to any of claims 1 to 11, wherein one or more holes each having an internal diameter of not smaller than 1 mm are formed per 20 cm2 of surface area of the perforated container. - [Claim 13]
The direction changing device according to any of claims 1 to 12, wherein a compressed gas supplying apparatus is connected to the perforated container. - [Claim 14]
The direction changing device according to any of claims 1 to 13, wherein a water vapor generating apparatus is connected to the perforated container and the direction changing device is used for food conveyance. - [Claim 15]
A direction changing device for long sheets, comprising a plurality of object floatation members arranged in parallel, which members each comprises a pillared perforated container and a porous resin layer covering holes of the perforated container. - [Claim 16]
The direction changing device according to any of claims 1 to 15, wherein a porous resin membrane is further provided detachably on the porous resin layer. - [Claim 17]
An object floatation device comprising a plurality of object floatation members arranged in parallel, which members each comprises a pillared perforated container and a porous resin layer covering holes of the perforated container.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010126137A JP2011251803A (en) | 2010-06-01 | 2010-06-01 | Apparatus for changing direction of long sheet |
| JP2010-126137 | 2010-06-01 | ||
| PCT/JP2011/062547 WO2011152430A1 (en) | 2010-06-01 | 2011-05-31 | Apparatus for change of direction of long sheet, and article floating apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2798032A1 true CA2798032A1 (en) | 2011-12-08 |
Family
ID=45066790
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2798032A Abandoned CA2798032A1 (en) | 2010-06-01 | 2011-05-31 | Apparatus for change of direction of long sheet, and article floating apparatus |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP2011251803A (en) |
| KR (1) | KR20130086940A (en) |
| CN (1) | CN102947207A (en) |
| CA (1) | CA2798032A1 (en) |
| WO (1) | WO2011152430A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10294057B2 (en) | 2014-09-05 | 2019-05-21 | New Way Machine Components, Inc. | Gas bearing, porous media vacuum roller and porous media air turn |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101746253B1 (en) * | 2013-02-01 | 2017-06-12 | 주식회사 엘지화학 | Roll printing apparatus and roll printing method using the same |
| JP6040829B2 (en) * | 2013-03-27 | 2016-12-07 | 日本ゼオン株式会社 | Manufacturing method of secondary battery separator, secondary battery separator and battery |
| JP6024556B2 (en) * | 2013-03-27 | 2016-11-16 | 日本ゼオン株式会社 | Method for producing film-like substrate with coating layer |
| KR101506141B1 (en) * | 2013-11-04 | 2015-03-26 | 코닝정밀소재 주식회사 | Device for regulating a tension and method of continuously processing a web |
| JP6695107B2 (en) * | 2015-08-03 | 2020-05-20 | 株式会社テクノスマート | Floating device and method of manufacturing a levitating device |
| JP6527981B1 (en) * | 2018-03-27 | 2019-06-12 | 株式会社タンケンシールセーコウ | Turn bar |
| JP7451882B2 (en) * | 2019-05-30 | 2024-03-19 | 日本ゼオン株式会社 | conveyor roller |
| CN110217627B (en) * | 2019-07-01 | 2020-07-28 | 重庆瑞霆塑胶有限公司 | Air roller for film traction |
| JPWO2023021818A1 (en) | 2021-08-16 | 2023-02-23 |
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| JPS5355378A (en) | 1976-10-30 | 1978-05-19 | Nitto Electric Ind Co | Method of producing porous polytetrafluoroethylene film |
| DE2834508C2 (en) | 1978-08-07 | 1986-04-03 | Olympia Werke Ag, 2940 Wilhelmshaven | Electrophotographic copier with a photoconductive layer on a drum or on a belt |
| JPS5617216A (en) | 1979-07-24 | 1981-02-19 | Central Jidosha Kk | Plastic press die and production thereof |
| US4239505A (en) | 1979-09-07 | 1980-12-16 | Union Carbide Corporation | Purge gas conditioning of high intensity ionization system for particle removal |
| JPS59109534A (en) | 1982-12-14 | 1984-06-25 | Nitto Electric Ind Co Ltd | Porous polytetrafluoroethylene object |
| JPS61207446A (en) | 1985-03-11 | 1986-09-13 | Nitto Electric Ind Co Ltd | Porous polytetrafluoroethylene sheet and production thereof |
| AU7877491A (en) * | 1990-05-11 | 1991-12-10 | Rudolph J. Liedtke | Air bearing for web material |
| DE4127602A1 (en) * | 1991-08-21 | 1993-02-25 | Hoechst Ag | METHOD AND DEVICE FOR THE CONTACT-FREE LEADING OF A COATED MATERIAL TAPE |
| JP2788207B2 (en) | 1995-03-16 | 1998-08-20 | 株式会社ベルマティック | Film floating direction change device |
| JP3892974B2 (en) | 1998-06-26 | 2007-03-14 | Ｂｅｌｌｍａｔｉｃ株式会社 | Laminated object levitation device |
| JP2002193508A (en) | 2000-12-26 | 2002-07-10 | Hirano Tecseed Co Ltd | Air turn roll |
| DE102004032647A1 (en) * | 2004-07-06 | 2006-02-16 | Voith Paper Patent Gmbh | Deflection device for non-contact deflection of a fibrous web |
-
2010
- 2010-06-01 JP JP2010126137A patent/JP2011251803A/en not_active Withdrawn
-
2011
- 2011-05-31 KR KR1020127030211A patent/KR20130086940A/en not_active Application Discontinuation
- 2011-05-31 WO PCT/JP2011/062547 patent/WO2011152430A1/en active Application Filing
- 2011-05-31 CN CN2011800270734A patent/CN102947207A/en active Pending
- 2011-05-31 CA CA2798032A patent/CA2798032A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10294057B2 (en) | 2014-09-05 | 2019-05-21 | New Way Machine Components, Inc. | Gas bearing, porous media vacuum roller and porous media air turn |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2011251803A (en) | 2011-12-15 |
| KR20130086940A (en) | 2013-08-05 |
| CN102947207A (en) | 2013-02-27 |
| WO2011152430A1 (en) | 2011-12-08 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Discontinued |
Effective date: 20140602 |