Roller surface hardening

Abstract

The present disclosure relates to rollers, such as coated nip rollers and calender rollers, and methods of applying the coatings. More specifically, the present disclosure relates to nip rollers or calender rollers having a hardening layer applied to their surfaces to prevent damage from contaminants.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 277,477, filed November 9, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to rollers, such as coated nip rollers and calender rollers, and methods of applying the coatings. More specifically, the present disclosure relates to nip rollers or calender rollers having a hardening layer applied to their surfaces to prevent damage from contaminants. [Background technology]

[0003] The accurate formation of thin films, alternatively referred to in the art as sheets, webs, or substrates, is an industrial challenge. Accurate formation of thin films is particularly difficult when significant levels of pressure must be applied in a practical manufacturing environment. The rollers that apply the pressure must themselves be precisely shaped to form a thin film having dimensions and surface properties within the required design parameters.

[0004] Additionally, there is the issue of dirt, particles, and other impurities that are naturally present in the production environment. Even with care and cleaning, it is inevitable that one or more contaminant particles will eventually remain on the rollers' surfaces. When particles accumulate on the surfaces of rollers that contact each other during machine operation, the particles become compressed between the rollers during machine operation. When such particles are compressed between the rollers, they add large force concentrations to the rollers' surfaces. This is known as contact fatigue and is evidenced by the development of fatigue pits on both sides of the rollers that contact each other.

[0005] Due to surface imperfections on the rollers, contact fatigue has a detrimental effect on the quality of the formed product. In a real production environment, it is necessary to prevent the formation of pits, surface deformations, and other undesirable microstructural features that accumulate on the roller surface.

[0006] Given the need for precise and uniform surfaces in thin films, even minor damage caused by contaminants can adversely affect the function of the thin films when they are assembled into final products and used. Therefore, the hardness of the rollers needs to be increased to prevent damage caused by the concentrated pressure exerted by the contaminants. One method of increasing hardness to prevent damage to the rollers includes applying a hardening layer. Traditional methods of applying hardness coatings to rollers include jet spraying of tungsten carbide and electroplating of chromium. However, the jet sprayed tungsten carbide and electroplated chromium thin films themselves can have micrometer-scale defects such as pinholes. In addition to avoiding these shortcomings, it would be beneficial to construct a coating that provides the rollers with exceptional hardness and therefore performance. Summary of the Invention

[0007] To reduce damage from dirt, particles, and other impurities, a calender roller apparatus is provided that includes a hardened layer formed by one of chemical vapor deposition (CVD) or plasma-assisted chemical vapor deposition (PACVD) of diamond-like coating (DLC), and physical vapor deposition (PVD) of tungsten carbide.

[0008] In one embodiment, the technology described herein relates to a method of forming a dry electrode thin film, the method including contacting a hardened surface roller with a dry electrode or dry electrode precursor powder and applying at least one force to the dry electrode or dry electrode precursor powder with the hardened surface roller to form a dry electrode thin film.

[0009] In some embodiments, the technology described herein relates to methods in which the hardened surface roller includes at least a diamond-like coating or a hardened layer of tungsten carbide.

[0010] In some embodiments, the technology described herein relates to methods where the thickness of the cured layer is between 1 μm and about 300 μm.

[0011] In some embodiments, the technology described herein relates to methods where the hardened surface roller comprises at least one underlayer.

[0012] In some embodiments, the technology described herein relates to methods where the underlayer comprises one of tungsten carbide, a diamond-like coating, copper, or chromium.

[0013] In some embodiments, the technology described herein relates to methods where the underlayer has a thickness of about 1 μm to about 300 μm.

[0014] In some embodiments, the technology described herein relates to methods where the hardened surface roller is at least one of a nip roller or a calender roller.

[0015] In one embodiment, the technology described herein relates to a system that includes a roller that includes a stiffening layer disposed on a surface of the roller.

[0016] In some embodiments, the technology described herein relates to a system in which the hardening layer comprises one of tungsten carbide, chromium, or a diamond-like coating.

[0017] In some embodiments, the technology described herein relates to systems in which the stiffening layer has a thickness of from about 1 μm to about 300 μm.

[0018] In some embodiments, the technology described herein relates to a system further including an underlayer disposed between the surface of the roller and the hardened layer, the underlayer including one of tungsten carbide, diamond-like coating, copper, or chromium.

[0019] In some embodiments, the technology described herein relates to a system in which the underlayer has a thickness of about 1 μm to about 300 μm.

[0020] Aspects, features, benefits, and advantages of the embodiments described herein will become apparent with reference to the following description, the appended claims, and the accompanying drawings. [Brief description of the drawings]

[0021] [Figure 1] 1 shows a diagram of a calender roller used to create a thin film, according to an embodiment.

[0022] [Diagram 2] 1 shows a diagram of a cross-sectional view of a calender roller with a stiffening layer applied, according to an embodiment.

[0023] [Diagram 3] 1 illustrates a method of applying a diamond-like coating by chemical vapor deposition, according to an embodiment.

[0024] [Figure 4] 1 illustrates a method of applying tungsten carbide by physical vapor deposition, according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The disclosure is not limited to the particular systems, devices, and methods described, which may vary, and the terminology used herein is for the purpose of describing particular variations or embodiments only, and is not intended to limit the scope.

[0026] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Nothing in this disclosure should be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used in this document, the term "including" means "including, but not limited to."

[0027] This disclosure describes a calender roller apparatus including a hardening layer to protect against damage from contaminants and impurities, and a method for applying the hardening layer. The calender rollers can be coated with chemical vapor deposition of diamond-like coatings and physical vapor deposition of tungsten carbide to increase the hardness of the rollers and prevent damage caused by high pressures exerted on the rollers by contaminants and impurities.

[0028] As used herein, "uncoated roller" means a roller that does not have a hardening layer applied to it. For example, one embodiment of an uncoated roller includes a roller that does not include a tungsten carbide layer or a diamond-like coating.

[0029] As used herein, "diamond-like coating" or "DLC" refers to a thin film composed of crystallized carbon. For example, one embodiment of a diamond-like coating includes a hardened layer synthetically produced by chemical vapor deposition of carbon.

[0030] As used herein, "contaminants" means small impurities that are present on the roller during production of the thin film and that can damage either the thin film or the roller when pressure is applied. Contaminants are not limited and often depend on the production environment in which the roller is located, and examples of contaminants include one or more of dirt particles, metal particles, metal shavings, electrode particles, inorganic particles, conductive particles, insulating particles, uncured polymer particles, or cured polymer particles.

[0031] As used herein, "low pressure environment" means an environment having a pressure low enough to effect deposition by a selected process. For example, one embodiment of a low pressure environment includes an environment at a pressure below atmospheric pressure.

[0032] 1 shows a diagram 100 of a powder mill 100 that includes calender rollers 101 used to create a thin film, according to an embodiment. Powder enters from a hopper 102 above the calender rollers, where it is compressed into a thin film.

[0033] 2 shows a diagram 200 of a cross-sectional view of a calender roller 201 to which a hardening layer 202 has been applied, according to an embodiment. The hardening layer 202 used can include any material known to one skilled in the art that is effective for calendering thin films. In some embodiments, the hardening layer 202 is selected from one of chromium, tungsten carbide, and diamond-like coatings. In some embodiments, the hardening layer 202 is disposed on the surface of the calender roller 201.

[0034] In some embodiments, the thickness of the stiffening layer 202 is about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 6 μm, about 7 μm, about 8 μm, about 9 μm, about 10 μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm, or about 50 μm, about 100 μm, about 150 μm, about 200 μm, about 250 μm, about 300 μm, or any range between any two or more of the foregoing values, such as about 1 μm to about 300 μm, about 10 μm to about 300 μm, about 100 μm to about 300 μm, 1 μm to about 200 μm, about 10 μm to about 200 μm, or about 100 μm to about 200 μm.

[0035] FIG. 3 illustrates a method 300 for depositing a diamond-like coating by chemical vapor deposition, according to an embodiment. In this method, an uncoated roller is placed inside a low-pressure environment in block 301. Inside the low-pressure environment, the uncoated roller is exposed to volatile precursors, including but not limited to one or more of methane (CH4) and carbon monoxide (CO), in block 302. These precursors react on the surface of the uncoated roller to form a diamond-like coating. Although the deposition of the diamond-like coating is described above by chemical vapor deposition, it is understood that variations of CVD, such as plasma-assisted chemical vapor deposition (PACVD), can also be used. Once deposition is complete, the roller can be removed from the low-pressure environment in block 303.

[0036] The thickness of the deposited diamond-like coating is about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 6 μm, about 7 μm, about 8 μm, about 9 μm, about 10 μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm, or about 50 μm, about 100 μm, about 150 μm, about 200 μm, about 250 μm, about 300 μm, or any range between any two or more of the foregoing values, such as about 1 μm to about 300 μm, about 10 μm to about 300 μm, about 100 μm to about 300 μm, 1 μm to about 200 μm, about 10 μm to about 200 μm, or about 100 μm to about 200 μm.

[0037] FIG. 4 illustrates a method 400 for depositing a hardened layer, for example of tungsten carbide, according to an embodiment. In this method, an uncoated roller is placed inside a low pressure environment in block 401. In the low pressure environment, the uncoated roller is exposed to a volatile precursor in block 402. The volatile precursor includes, but is not limited to, one or more of tungsten hexachloride (WCl6) with hydrogen (H2) and methane (CH4), or WCL6 with H2 and methanol (C3OH). This results in the deposition of a tungsten carbide coating. Although the deposition of tungsten carbide is described above by chemical vapor deposition, it is understood that variations of CVD, such as plasma-assisted chemical vapor deposition (PACVD), can also be used. Once deposition is complete, the roller can be removed from the low pressure environment in block 403.

[0038] The thickness of the deposited cured layer is about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 6 μm, about 7 μm, about 8 μm, about 9 μm, about 10 μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm, or about 50 μm, about 100 μm, about 150 μm, about 200 μm, about 250 μm, about 300 μm, or any range between any two or more of the foregoing values, such as about 1 μm to about 300 μm, about 10 μm to about 300 μm, about 100 μm to about 300 μm, 1 μm to about 200 μm, about 10 μm to about 200 μm, or about 100 μm to about 200 μm.

[0039] In certain embodiments, an underlayer provides additional protection or surface adhesion and can include, but is not limited to, one or more of chromium, diamond-like coating (DLC), tungsten carbide (WC), or copper (Cu).

[0040] In some embodiments, the curable layer has a thickness of about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 6 μm, about 7 μm, about 8 μm, about 9 μm, about 10 μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm, or about 50 μm, about 100 μm, about 150 μm, about 200 μm, about 250 μm, about 300 μm, or any range between any two or more of the foregoing values, such as about 1 μm to about 300 μm, about 10 μm to about 300 μm, about 100 μm to about 300 μm, 1 μm to about 200 μm, about 10 μm to about 200 μm, or about 100 μm to about 200 μm.

[0041] The composition and microstructure of diamond-like coating can be adjusted according to the requirements of surface hardness, chemical resistance, toughness, and other desired properties.Examples of such diamond-like coating include one or more of ta-C type (tetrahedrally bonded amorphous carbon without hydrogen), aC:H type (amorphous carbon with hydrogen), aC:H:Me type (Me=W, Ti, metal-doped amorphous carbon with hydrogen), aC:H:Si type (Si-doped amorphous carbon with hydrogen), aC:H:X type (non-metal-doped amorphous carbon with hydrogen), aC:Me type (Me=Ti, metal-doped amorphous carbon without hydrogen), ta-C:H type (tetrahedrally bonded amorphous carbon with hydrogen).

[0042] The roller applications of the present disclosure include, but are not limited to, nip rollers or calendar rollers. In one embodiment, rollers including nip rollers or calendar rollers are surface hardened with at least one of diamond-like coating or tungsten carbide and used to process electrode materials. In some embodiments, the electrode material being processed is one or more of an anode or cathode, each of which may be individually a dry anode or cathode formed substantially without the use of solvents. These various electrodes are collectively referred to as dry electrodes, even though they may have a variety of compositions, microstructures, and functionality.

[0043] In one embodiment, there is a method of forming a dry electrode thin film. In some embodiments, the method includes contacting a roller with a dry electrode or dry electrode precursor material and applying at least one force to the dry electrode or dry electrode precursor powder with the hardened surface roller to form a dry electrode thin film.

[0044] A dry electrode or dry electrode precursor can generally be any material useful as an electrode known to one of ordinary skill in the art. In some embodiments, the dry electrode or dry electrode precursor is one of an anode or a cathode. In some embodiments, the anode or cathode can be a dry anode or dry cathode, respectively, formed substantially without solvent.

[0045] Electrodes, such as dry electrodes, can be implemented within electrical energy storage cells, which are widely used to power electronic, electromechanical, electrochemical, and other useful devices. Such cells include batteries, such as primary chemical cells and secondary (rechargeable) cells.

[0046] In some embodiments, the hardened surface roller provides additional durability when the roller is used to impart force to the electrode, for example, when the roller is configured to rotate faster or slower than the electrode or other sheet or web moves over the roller.

[0047] In the above detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, like symbols typically identify like components unless otherwise indicated by context. The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings, can be arranged, substituted, combined, separated, and designed in a wide variety of configurations, as expressly contemplated herein.

[0048] The present disclosure is not limited to the specific embodiments described in this application, but are intended as examples of various aspects. As will be apparent to those skilled in the art, many modifications and variations can be made without departing from the spirit and scope thereof. Functionally equivalent methods and apparatuses that are within the scope of the present disclosure, as well as those recited herein, will be apparent to those skilled in the art from the above description. Such modifications and alterations are intended to be included within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, and the full scope of equivalents to which such claims are entitled. It is to be understood that the present disclosure is not limited to specific methods, reagents, compounds, compositions, or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0049] With respect to the use of substantially any plural and / or singular term herein, those skilled in the art can convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. For clarity, various singular / plural permutations may be explicitly set forth herein.

[0050] Those skilled in the art will understand that the terms used in the specification, in general, and in the claims, in particular (e.g., the body of the claims), are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including but not limited to," etc.). While various components, methods, and devices are described in terms of "comprising" (interpreted as meaning "including but not limited to") various components or steps, compositions, methods, and devices may also "essentially comprise" or "consist of" various components and steps, and such terms should be interpreted as defining an essentially closed collection of elements. Those skilled in the art will further understand that if a specific number of claim recitations are intended to be introduced, such intent will be explicitly recited in the claim, and the absence of such recitation is not an indication that such intent is not presented.

[0051] For example, as an aid to understanding, the following appended claims may include the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed as implying that introducing a claim recitation with the indefinite article "a" or "an" limits any particular statement that includes such an introduced claim recitation to embodiments that include only one such statement, even when that same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"); the same applies to the use of definite articles used to introduce claim recitations.

[0052] In addition, when a specific number of claim recitations is explicitly recited, one of ordinary skill in the art will understand that such recitation should be interpreted to mean at least the recited number (e.g., a minimum recitation of "two recitations" without other modifiers means at least two recitations, or two or more recitations). Furthermore, when a rule similar to "at least one of A, B, and C, etc." is used, such an interpretation is generally intended in the sense that one of ordinary skill in the art would understand the rule (e.g., "a system including at least one of A, B, and C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In cases where a rule similar to "at least one of A, B, or C, etc." is used, such an interpretation is generally intended in the sense that one of skill in the art would understand the rule (e.g., "a system including at least one of A, B, C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Furthermore, one of skill in the art will appreciate that virtually any disjunction and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" is understood to include the possibilities of "A" or "B" or "A and B."

[0053] Additionally, when features or aspects of the disclosure are described in a Markush group, one of skill in the art will understand that the disclosure is also thereby described in terms of any individual component or subgroup of components of that Markush group.

[0054] It will be appreciated by those of skill in the art that for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges of that range. Any range listed can be readily recognized as fully descriptive and capable of dividing the same range into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range described herein can be easily broken down into a lower third, middle third, upper third, etc. Also, as will be appreciated by those of skill in the art, all terms such as "up to," "at least," etc., can refer to ranges that include the recited numbers and can then be subdivided into subranges as described above. Finally, it will be appreciated by those of skill in the art that a range includes each of the individual elements. Thus, for example, a population having 1-3 cells refers to a population having 1, 2, or 3 cells. Similarly, a population having 1-5 cells refers to a population having 1, 2, 3, 4, or 5 cells, etc.

[0055] Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements thereof, each of which are intended to be encompassed by the disclosed embodiments, may subsequently be made by those skilled in the art.

Claims

1. 1. A method for forming a dry electrode film, comprising: contacting a hardened surface roller with a dry electrode or dry electrode precursor powder; applying at least one force to the dry electrode or the dry electrode precursor powder with the hardened surface roller to form the dry electrode thin film.

2. The method of claim 1 , wherein the hardened surface roller comprises at least a hardened layer of a diamond-like coating or tungsten carbide.

3. The method of claim 2, wherein the thickness of the cured layer is from about 1 μm to about 300 μm.

4. The method of claim 1 , wherein the hardened surface roller comprises at least one underlayer.

5. The method of claim 4 , wherein the underlayer is comprised of one of tungsten carbide, a diamond-like coating, copper, or chromium.

6. The method of claim 4, wherein the underlayer has a thickness of about 1 μm to about 50 μm.

7. The method of claim 1 , wherein the hardened surface roller is at least one of a nip roller or a calender roller.

8. 1. A system comprising: A roller, The system includes a roller, the roller including a stiffening layer disposed on a surface of the roller.

9. The system of claim 8 , wherein the hardened layer is comprised of one of tungsten carbide, chromium, or a diamond-like coating.

10. The method of claim 8, wherein the thickness of the cured layer is from about 1 μm to about 300 μm.

11. a sublayer disposed between the surface of the roller and the stiffening layer; The system of claim 8 , wherein the underlayer is comprised of one of tungsten carbide, a diamond-like coating, copper, or chromium.

12. The system of claim 11 , wherein the underlayer has a thickness of about 1 μm to about 300 μm.

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