Elastic roll, nip roll, and conveyance device
11365078 · 2022-06-21
Assignee
Inventors
Cpc classification
B65H27/00
PERFORMING OPERATIONS; TRANSPORTING
B65H2601/52
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
An elastic roll includes: a roll core; an inner-layer laminate covering an outer-peripheral surface of the roll core parallel to a roll longitudinal direction; a surface-layer elastomer including a tubular portion covering an outer-peripheral surface of the inner-layer laminate, and edge portions connected to the tubular portion, covering both end surfaces of the inner-layer laminate orthogonal to the roll longitudinal direction, and arranged in a manner being in contact with the roll core; and end-portion sealing structural bodies configured to press the edge portions of the surface-layer elastomer against the roll core.
Claims
1. An elastic roll comprising: a roll core; an inner-layer laminate covering an outer-peripheral surface of the roll core parallel to a roll longitudinal direction; a surface-layer elastomer including a tubular portion covering an outer-peripheral surface of the inner-layer laminate, and edge portions connected to the tubular portion, covering both end surfaces of the inner-layer laminate orthogonal to the roll longitudinal direction, and arranged in a manner being in contact with the roll core; and end-portion sealing structural bodies configured to press the edge portions of the surface-layer elastomer against the roll core.
2. The elastic roll according to claim 1, wherein the end-portion sealing structural bodies include sealing members and pressing mechanisms, each pressing mechanism is configured to press each sealing member against the roll core, and the sealing members are configured to press the edge portions covering both the end surfaces of the inner-layer laminate against the roll core.
3. The elastic roll according to claim 2, wherein the roll core includes, in areas that are not covered by the inner-layer laminate at both end portions of the roll core in the roll longitudinal direction, steps to cause a diameter of the roll core to decrease toward an end portion of the roll core in the roll longitudinal direction, each edge portion of the surface-layer elastomer is in contact with a stepped surface of each step of the roll core, and the sealing member is configured to press the edge portion of the surface-layer elastomer against the stepped surface in the roll longitudinal direction.
4. The elastic roll according to claim 3, wherein a thickness of the edge portion in the roll longitudinal direction is greater than a height of the step when the sealing member does not press the edge portion of the surface-layer elastomer against the stepped surface in the roll longitudinal direction.
5. The elastic roll according to claim 3, wherein the sealing member includes an annular projection protruding toward the surface-layer elastomer, and the pressing mechanism is configured to press the sealing member in the roll longitudinal direction to dent a portion of the edge portion being in contact with the annular projection.
6. The elastic roll according to claim 5, wherein a thickness of the edge portion in the roll longitudinal direction is smaller than a height of the step, an exposed area that is not covered by the surface-layer elastomer is present on a surface of the step parallel to the roll longitudinal direction, and an innermost diameter of the annular projection of the sealing member is a same as an outside diameter of the step, and an inner-peripheral portion of the annular projection and the exposed area of the step are fitted together.
7. The elastic roll according to claim 2, wherein a profile of the sealing member projected in the roll longitudinal direction has a size contained inside an outermost periphery of a cross-section of the surface-layer elastomer in a plane orthogonal to the roll longitudinal direction.
8. The elastic roll according to claim 1, wherein the end-portion sealing structural bodies are configured to press the edge portions against the roll core in a roll radial direction.
9. A nip roll comprising the elastic roll according to claim 1, the elastic roll being used, in a process in which a chemical solution comes into contact with a web substrate, to drain the chemical solution carried by conveyance of the web substrate, wherein the inner-layer laminate is formed of an elastomer, and has hardness lower than that of an elastomer forming the surface-layer elastomer, and the elastomer forming the surface-layer elastomer has high resistance to the chemical solution.
10. A conveyance device configured to bring a chemical solution into contact with a web substrate, the conveyance device comprising a nipping mechanism, wherein a nip roll used for the nipping mechanism is the nip roll according to claim 9.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1)
(2)
(3)
(4)
(5)
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(8)
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
(9) Cases in which examples of embodiments of the present invention are applied to a nip roll will now be described with reference to the drawings.
(10)
(11) Around the outer-peripheral surface of the roll core 21 except both end portions thereof in the roll longitudinal direction, the inner-layer laminate 22 is wound. The surface-layer elastomer 23 is wound so as to cover the outer-peripheral surface of the inner-layer laminate 22 and both end surfaces thereof in the roll longitudinal direction. The edge portions 23b of the surface-layer elastomer 23 are in contact with the roll core 21. The edge portions 23b of the surface-layer elastomer 23 that are in contact with the roll core 21 are pressed against the roll core 21 by the end-portion sealing structural bodies 24.
(12) The roll core 21 generally has a cylindrical shape on both ends of which shafts configured to serve as bearing fitted portions are formed, but may have various shapes depending on functions required to the roll and intended use, for example. Similarly, as an internal structure thereof, various structures may be used. As a material thereof, various materials such as plastic and metal may be used. However, from a viewpoint of durability, metallic materials such as iron and stainless steel are often used in general. Stainless steel excellent in corrosion resistance is preferably used particularly when it is used in a process using a chemical solution.
(13) The inner-layer laminate 22 wound around the outer-peripheral surface of the roll core 21 is often bonded onto the roll core 21 with adhesive in general, and thus a material having adhesiveness to the material of the roll core 21 is preferably used therefor. As the material, a plastic or an elastomer in various types may be appropriately selected to be used according to required functions. For example, when hardness of the roll is wanted to be reduced, ethylene propylene rubber, silicone rubber, urethane rubber, or laminated rubber thereof or the like that enables the inner-layer laminate 22 to have lower hardness can be used. Alternatively, using polyvinyl chloride or ABS resin, for example, for the inner-layer laminate 22 enables a roll having higher hardness to be provided while reducing the volume of the inner-layer laminate 22.
(14) The surface-layer elastomer 23 covering the outer-peripheral surface and both end surfaces of the inner-layer laminate 22 is preferably bonded onto the inner-layer laminate 22, and is more preferably bonded also onto the roll core 21. A material thereof is selected appropriately according to functions required of a surface of the nip roll 20. Consequently, when the adhesiveness of the surface-layer elastomer 23 to the inner-layer laminate 22 is poor, it is preferable to change the material of the inner-layer laminate 22. Adhesiveness is determined generally depending on compatibility with each other among the surface-layer elastomer 23, the inner-layer laminate 22, and an adhesive. However, because the surface-layer elastomer 23 herein is brought into direct contact with a web substrate and a chemical solution as described later, the material should be selected such that the functions required of the nip roll 20 are implemented to the greatest extent possible at the highest priority. A material having excellent adhesiveness to the material of the surface-layer elastomer 23 thus selected only needs to be selected as the material of inner-layer laminate 22. Pressure uniformity in the roll width direction that is one of properties of the nip roll 20 tends to be more excellent when the hardness of the whole laminate wound around the outer periphery of the roll core is lower. However, because the surface-layer elastomer 23 that is brought into direct contact with the web substrate and the chemical solution is required to have high resistance to the chemical solution, options for the material are limited. Thus, it is preferable that the hardness of the whole laminate can be adjusted over a wide range by setting the hardness of the elastomer forming the inner-layer laminate 22 to be lower than that of the elastomer forming the surface-layer elastomer 23.
(15) When being used under environments in which a chemical solution such as water, oil, or an organic solvent adheres to the nip roll 20, a material that is not easily eroded by the chemical solution to be used is preferably used for the surface-layer elastomer 23. For example, ethylene propylene rubber is not suitable under environments in which mineral oil adheres thereto, and nitrile rubber is not suitable under environments in which phosphoric ester-based hydraulic oil adheres thereto. Under environments in which an organic solvent such as butyl acrylate, acetic acid, or dichlorobenzene that tends to erode many materials adheres thereto, room for choice for materials is significantly limited, and thus the choice has to be made considering, at high priority, that the material has resistance to the chemical solution to be used. Thus, a case may arise in which a material having poor adhesiveness to the roll core 21 has to be selected. Even if bonding can be made, there may be a case in which an adhesive layer formed between the surface-layer elastomer 23 and the roll core 21 is eroded by the chemical solution. In such cases, the chemical solution will enter from a gap between the roll core 21 and the surface-layer elastomer 23 to erode the inner-layer laminate 22.
(16) In view of this, in an embodiment of the present invention, in order to prevent the chemical solution from entering from the gap between the roll core 21 and the surface-layer elastomer 23, a structure is used in which the edge portions 23b of the surface-layer elastomer 23 are strongly pressed against the roll core 21 by the end-portion sealing structural bodies 24. The roll core 21 is a member having high stiffness, and thus a problem in which pressing force disperses and the sealing performance accordingly decreases can be avoided. As the configuration of the end-portion sealing structural body 24, any structure may be used if the function of pressing the edge portions 23b against the roll core 21 is implemented. For example, a ring-shaped member having an inside diameter smaller than the outside diameter of the edge portions 23b may be attached, or a structure of inserting a cylindrical member the inside diameter of which is tapered may be used.
(17) A structure may be used in which the end-portion sealing structural body 24 includes a sealing member and a pressing mechanism, the pressing mechanism is configured to press the sealing member against the roll core 21, and the sealing member is configured to press the edge portions 23b against the roll core 21. Examples of this structure include a structure commonly called “hose band” for clamping with a band-shaped structural body the inside diameter of which decreases when a screw is tightened. The band-shaped structural body corresponds to the sealing member, and the screw corresponds to the pressing mechanism.
(18) The material used for the end-portion sealing structural bodies 24 is preferably a material having resistance to the chemical solution to be used.
(19) In the embodiment in
(20)
(21) As illustrated in
(22) In the nip roll 20A illustrated in
(23) In the structure of Patent Literature 2 illustrated in
(24) When the thickness h3 of the edge portion 23b is greater than the height h4 of the step 211, the protruding length d of the edge portion 23b can provide sufficient adhesion between the surface-layer elastomer 23 and the roll core 21. The protruding length d is preferably 0.3 mm or more. The upper limit of the protruding length d is not limited to a particular value. However, the protruding length d may be set within a range that enables the sealing member 241 to come into tight contact with the contact surface 212 of the roll core 21A while being pressed in the roll longitudinal direction, and can be appropriately determined according to the material of the surface-layer elastomer 23A and the compressing force in the roll longitudinal direction.
(25) Furthermore, in the nip roll 20A, it is preferable that the maximum outside diameter R1 of the sealing member 241 be set smaller than the outside diameter R2 of the surface-layer elastomer 23A (i.e., the size of the sealing member 241 be set such that its profile projected in the roll longitudinal direction is contained inside the outermost periphery of the surface-layer elastomer 23A in a plane orthogonal to the roll longitudinal direction) because this setting enables the nip roll 20A to be used also for a nip system to be nipped having a roll surface length that is greater than the nip roll surface length h5. There are occasions when outside diameters of the edge portions 23b of the surface-layer elastomer 23A bulge due to compressing force applied by the end-portion sealing structural bodies 24A, and accordingly contact pressure against a roll to be nipped rises locally. For applications in which such contact pressure distribution is not preferable, it is preferable to taper the edge portions 23b of the surface-layer elastomer 23A to reduce the outside diameter thereof.
(26)
(27)
(28) The above-described nip rolls 20, 20A, 20B, 20D, and 20E in which the elastic roll of the present invention is used can prevent the inner-layer laminate 22 from being eroded by the chemical solution and the like to be used. Thus, by using these nip rolls as drain rolls in a web conveyance device for the purpose of chemical solution treatment, the functions thereof can be implemented stably for a long period of time.
(29) In the elastic roll of the present invention, because the surface-layer elastomers 23 to 23E exert resistance to the chemical solution and the like, the need of requiring resistance to the chemical solution and the like of the inner-layer laminate 22 is eliminated. Thus, an optimum material for the inner-layer laminate 22 can be selected in consideration of properties such as roll hardness, and the range of choice for materials of the inner-layer laminate 22 is extended. The edge portions 23b of the surface-layer elastomers 23 to 23E are pressed by the end-portion sealing structural bodies 24 to 24E against the roll cores 21 to 21E, respectively, which eliminates the need of considering adhesiveness between each of the surface-layer elastomers 23 to 23E and the corresponding one of the roll cores 21 to 21E. Thus, an optimum material for the surface-layer elastomers 23 to 23E can be selected in consideration of properties such as chemical-solution resistance, and also the range of choice for materials of surface-layer elastomers 23 to 23E is extended. Consequently, the elastic roll of the present invention can achieve high-level compatibility of required functions such as roll hardness and durability to chemical solutions that generally conflict with each other.
(30) In the description of the embodiments above, cases in which the elastic roll of the present invention is used as a nip roll have been described. However, the present invention is not limited to these cases, and the elastic roll may be used as a coating roll, a laminate press roll, a conveyance roll, a sizing roll, a mangle roll, a scouring roll, a touch roll, and an ink roll, for example.
EXAMPLES
(31) Roll durability to a chemical solution was evaluated in Examples and Comparative Examples described below.
Example 1
(32) With the nip roll 20D illustrated in
(33) (1) Roll Structure
(34) Surface-layer elastomer: Fluorine-containing rubber (having resistance to the chemical solution to be used)
(35) Inner-layer laminate: Synthetic rubber (without resistance to the chemical solution to be used)
(36) Roll core: SUS316
(37) Protruding length of projections: 0.5 mm
(38) (2) Immersion Conditions
(39) Chemical solution: Dichlorobenzene
(40) Immersion period: Two weeks
(41) As a result of the test, the volume change of the nip roll 20D between before and after the test was smaller than 1%. The volume change was calculated by the following formula after determining the volumes of an elastomer portion before and after the test.
Volume change (%)={(Volume of elastomer portion after test)−(Volume of elastomer portion before test)}/(Volume of elastomer portion before test)×100
As for each volume of the elastomer portion, the cross-sectional area of the elastomer portion was determined based on the average outside diameter of the surface-layer elastomer and the outside diameter of the roll-core, and a product of the cross-sectional area of the elastomer portion and the length of the surface-layer elastomer in the roll longitudinal direction was obtained as the volume of the elastomer portion (the surface-layer elastomer and the inner-layer laminate). The average outside diameter of the surface-layer elastomer was obtained by measuring outside diameters thereof at pitches into which the length thereof in the roll longitudinal direction was evenly divided by 100 while changing positions in the roll longitudinal direction, and then averaging the measured outside diameters.
Example 2
(42) With the nip roll 20A illustrated in
(43) (1) Roll Structure
(44) Surface-layer elastomer: Fluorine-containing rubber (having resistance to the chemical solution to be used)
(45) Inner-layer laminate: Synthetic rubber (without resistance to the chemical solution to be used)
(46) Roll core: SUS316
(47) Protruding length of surface-layer elastomer (reference sign “d” in
(48) As a result of the test, the volume change between before and after the test was smaller than 1%.
Example 3
(49) With the nip roll 20 illustrated in
(50) (1) Roll Structure
(51) Surface-layer elastomer: Fluorine-containing rubber (having resistance to the chemical solution to be used) Inner-layer laminate: Synthetic rubber (without resistance to the chemical solution to be used)
(52) Roll core: SUS316
(53) It was known that the surface-layer elastomer had sufficient resistance to the chemical solution to be used. By applying sufficient pressure with the end-portion sealing structural bodies to press the surface-layer elastomer against the roll core, the used chemical solution did not enter the inner-layer laminate, and consequently the volume change was reduced to be smaller than 1%.
Comparative Example 1
(54) The same test as in Example 1 except that the end-portion sealing structural bodies were removed was conducted, and consequently the volume change exceeded 5%.
Comparative Example 2
(55) With the roll illustrated in
(56) (1) Roll Structure
(57) Mold-release layer (surface-layer elastomer): Fluorine-containing rubber (having resistance to the chemical solution to be used)
(58) Elastic body layer (inner-layer laminate): Synthetic rubber (without resistance to the chemical solution to be used)
(59) Sealing plates: Fluorine-containing rubber (having resistance to the chemical solution to be used)
(60) Roll core: SUS316
(61) As a result of the test, the volume change exceeded 5%.
Comparative Example 3
(62) With the roll illustrated in
(63) (1) Roll Structure
(64) Mold-release layer (surface-layer elastomer): Fluorine-containing rubber (having resistance to the chemical solution to be used)
(65) Elastic body layer (inner-layer laminate): Synthetic rubber (without resistance to the chemical solution to be used) Sealing plates: Fluorine-containing resin coating (having resistance to the chemical solution to be used) Roll core: SUS316
(66) As a result of the test, the volume change exceeded 5%. In observation after the test, cracks were found in the fluorine-containing resin.
Comparative Example 4
(67) With the roll illustrated in
(68) (1) Roll Structure
(69) Mold-release layer (surface-layer-elastomer): Fluorine-containing rubber (having resistance to the chemical solution to be used)
(70) Elastic body layer (inner-layer laminate): Synthetic rubber (without resistance to the chemical solution to be used) Sealing plates: Fluorine-containing resin coating (having resistance to the chemical solution to be used) Roll core: SUS316
(71) The present invention is highly preferable as an elastic nip roll used in a conveyance device configured to subject a web substrate to chemical solution treatment. However, the application range thereof is not limited to these.
REFERENCE SIGNS LIST
(72) 1 web substrate 2 drain roll 3 drier 4 wet conveying process 5 guide roll d protruding length 20, 20A, 20B, 20D, 20E nip roll 21, 21A, 21B, 21D, 21E roll core 22 inner-layer laminate 23, 23A, 23B, 23D, 23E surface-layer elastomer 24, 24A, 24B, 24D, 24E end-portion sealing structural body 211 step 212 contact surface 241 sealing member 242 pressing mechanism 243, 243E projection 244 inner wall 301 shaft 302 rubber elastic body 303 synthetic resin layer 304 coating member 311 roll core (base) 312 elastic body layer 313 mold-release layer 314 sealing plate 315 fixing plate 316 fixing bolt