CA3007648A1

CA3007648A1 - Textured work roll for a metal substrate

Info

Publication number: CA3007648A1
Application number: CA3007648A
Authority: CA
Inventors: Renato Rufino Xavier; Francisco Carvalho; Adriano Manuel Povoa FERREIRA
Original assignee: Ferreira Adriano Manuel Povoa; Novelis Inc Canada
Current assignee: Novelis Inc Canada
Priority date: 2015-12-10
Filing date: 2016-11-15
Publication date: 2017-06-15
Anticipated expiration: 2036-11-15
Also published as: JP2019507014A; AU2016369269A1; JP6695428B2; KR20180094011A; RU2705831C1; US20170165728A1; AU2016369269B2; EP3386657A1; BR112018011559A2; CA3007648C; CN108290188A; MX2018006958A; WO2017099957A1

Abstract

A textured work roll can impart a desired texture on a metal substrate, such as an aluminum or aluminum alloy sheet. The textured work roll can be used for applying a gloss finish on the metal substrate. The textured work roll can be textured by grinding the work roll to form a ground work roll; electro-discharge texturing the work roll to form an electro-discharge textured work roll; and polishing the work roil to form a polished work roil. The polished work can have an Ra value between 0.30 µm and 0.70 µm. The polished work roll can be used to apply the gloss finish on the metal substrate.

Description

TEXTURED WORK ROLL FOR A METAL SUBSTRATE
Cross-Reference to Related Application [0001] This application claims the benefit of U.S. Provisional Application No.
62/265,692 filed December 10, 2015, which is incorporated herein by reference in its entirety.
Field of the Invention

[0002] The present disclosure relates generally to work rolls for metal rolling. More specifically, but not by way of limitation, this disclosure relates to a textured work roll for applying a gloss finish on a metal substrate during rolling and methods for texturing a work roll for applying a gloss finish on a metal substrate.
Background

[0003] Metal rolling can be used for forming metal strips from stock, such as ingots or thicker metal strips. Metal rolling can involve a metal strip or substrate (e.g., aluminum or other metal material) passing between a pair of work rolls of a mill stand and the pair of work rolls can apply pressure to reduce the thickness of the metal strip.

[0004] A texture of a work roll used to roll a metal substrate may be an important factor in the performance of a metal rolling operation and the final material properties of the rolled metal substrate. For example, a finely polished or smooth work roll may not be able to provide sufficient friction to grip the metal strip during rolling operations.
Conversely, a work roll with a relatively rough texture may be limited to small reductions in thickness of the metal strip to avoid transferring an undesirable surface finish to the metal strip and generating unacceptable levels of debris due to the tendency for projections of the rough surface texture on the work roll to break off during processing. Various techniques may be used to modify the surface finish and/or surface texture of a work roll. Many work roll texturing processes may increase the surface roughness of the work roll to a degree that can impact the quality and efficiency of the rolling process. It may be desirable to texture a work roll for imparting a desirable texture on a metal strip.
Summary 100051 The term embodiment and the like terms are intended to refer broadly to all the subject matter of this disclosure and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the claims below. Embodiments of the present disclosure covered herein are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the disclosure and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this disclosure, any or all drawings, and each claim.
[00061 Certain aspects and features of the present disclosure relate to texturing a work roll for applying an isotropic gloss finish on a metal substrate (e.g., a metal sheet or plate) during a rolling process and a textured work roll for applying the isotropic gloss finish on a metal substrate. In some examples, the metal substrate can be an aluminum sheet or an aluminum alloy sheet. A gloss finish can refer to a relatively uniform glossiness with a slightly matted appearance on a surface of the metal substrate. A metal substrate with a gloss finish can have uniform glossiness and an isotropic surface (e.g., a surface that is substantially identical in all directions) with minimal directionality. Various techniques can be used to texture a work roll (e.g., a cold mill work roll) for applying the gloss finish on the metal substrate. For example, the work roll can be textured by grinding or polishing the work roll and/or by electro-discharge texturing ("EDT') techniques. In some examples, a combination of techniques can be used to texture the work roll for applying a gloss finish on a surface of a metal substrate.
100071 According to one non-limiting example, a work roll can be textured by grinding a surface of the work roll to reduce a roughness of the surface and form a ground work roll surface. The ground work roll surface can have a surface roughness (Ra) value from approximately 0.2 pm to approximately 0.5 gm. In another example, the ground work roll can have an Ra value from approximately 0.3 pm to approximately 0.5 gm. In some examples, the ground work roll surface can have a skewness (Rsk) value from approximately -1.5 to approximately 0.5. Subsequently, various EDT techniques can be used to texture the ground work roll surface to form an EDT work roll surface. The EDT work roll surface can have an Ra value from approximately 0.5 gm to approximately 1.0 gm. In another example, the EDT work roll surface can have an Ra value from approximately 0.5 gm to approximately 0.8 gm. The EDT work roll surface can have an Rsk value from approximately -1.0 to approximately 1Ø The EDT work roll surface may also have a peak count (Pc) from approximately 80/cm to approximately 140/cm. In some examples, the EDT work roll surface can be an isotropic surface with minimal directionality. The EDT work roll surface can be polished to reduce a roughness of the EDT work roll surface and form a polished work roll surface. The polished work roll surface can have an Ra value from approximately 0.3 gm to approximately 0.7 gm. The polished work roll surface can also have an Rsk value from approximately -3.0 to approximately 0Ø The polished work roll surface may also have a Pc from approximately 100/cm to approximately 1 80/cm.

[0008] In some examples, the polished work roll surface having an Ra value between approximately 0.3 gm and approximately 0.7 gm can be used to apply a gloss finish on a metal substrate. In one exemplary application, a work roll having a polished work roll surface with an Ra value between approximately 0.3 gm and approximately 0.7 gm can be used in a cold mill for cold rolling the metal substrate to apply a gloss finish on the metal substrate. Cold rolling the metal substrate using a polished work roll with an Ra value between approximately 0.30 gm and approximately 0.70 pm can cause the metal substrate to have enhanced characteristics, including, for example, increased resistance to high pressure, reduced friction, or increased lubricant retention.
Brief Description of the Drawings [00091 Illustrative examples of the present disclosure are described in detail below with reference to the following drawing figures:
[0010] FIG. lA is a schematic perspective view of a ground work roll surface according to one example.
10011] FIG. 1B is a graph depicting the roughness of the ground work roll surface of FIG. 1A.
[0012] FIG. 1C is a schematic perspective view of the ground work roll surface of FIG. lA
after electro-discharge texturing.
[0013] FIG. ID is a graph depicting the roughness of the work roll surface after electro-discharge texturing.
[0014] FIG. 1E is a schematic perspective view of the surface texture of the work roll surface of FIG. 1C undergoing polishing.
[0015] FIG. IF is a schematic perspective view of the work roll surface of FIG. 1E after polishing.

[0016] FIG. 1G is a graph depicting the roughness of the work roll surface of FIG. IF.
[0017] FIG. 2 is a micrograph of an engineered surface finish on a metal work roll for rolling metal sheet, according to one example of the present disclosure.
[0018] FIG. 3 is a flow chart depicting an example of a process for texturing a work roll that can be used to apply a gloss finish on a metal substrate, according to one example of the present disclosure.
[0019] FIG. 4 is a flow chart depicting an example of a process for applying a gloss finish on a metal substrate using a polished work roll, according to one example of the present disclosure.
Detailed Description [0020] The subject matter of embodiments of the present invention is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.
[0021] Certain aspects and features of the present disclosure are directed to texturing a work roll by applying an engineered texture or particular texture on the work roll for imparting a gloss finish on a metal substrate such as, but not limited to, an aluminum sheet for manufacturing cans or for use in other products or applications. The gloss finish may refer to a finish on a surface of the metal substrate such that the surface has a relatively uniform glossiness with a slightly matted appearance. A surface of the work roll having a gloss finish may have an appearance intermediate to an appearance of a bright sheet finish (e.g., a foil-like finish) and a standard can stock finish. In another example, the gloss finish may refer to a "satin-gloss" appearance on a surface of the metal substrate. In still another example, a surface of a metal substrate with a gloss finish can be isotropic and have minimum directionality as compared with a traditional rolled grit finish.
[0022] In some examples, a work roll (e.g., a cold mill work roll) may be textured for applying a gloss finish on a metal substrate. For example, the work roll may be textured by grinding a surface of the work roll using electro-discharge texturing ("EDT") techniques to texture the surface of the work roll and then polishing the surface of the work roll to provide a final work roll engineered surface texture (e.g., a work roll having a particular or desired surface texture).
Polishing the surface of the work roll after texturing the work roll using EDT
can smooth upper peaks of the EDT surface. In some examples, a work roll textured as described above for imparting a gloss finish on a metal substrate can be polished after using EDT
techniques until the work roll has a surface roughness (Ra) value from about 0.3 gm to about 0.7 gm.
[0023] An exemplary method of preparing a work roll for applying a gloss finish on a metal substrate may include the steps of grinding an unfinished work roll (e.g., a smooth work roll that does not contain scratch marks or other defects) until a surface of the work roll has an Ra value from about 0.20 gm to about 0.50 gm. In another example, the method can include grinding the unfinished work roll until a surface of the work roll has an Ra value from about 0.30 gm to about 0.50 gm. Grinding the unfinished work roll may also include grinding the unfinished work roll until the surface of the work roll has an Rsk value from about -1.5 to about 0.5. The work roll can then be further processed with electro-discharge texturing to produce an isotropic surface texture with minimiun directionality and an Ra value from about 0.50 gm to about 1.0 gm. In another example, the work roll can be processed with electro-discharge texturing to produce an isotropic texture with minimum directionality and an Ra value from about 0.50 gm to about 0.8 gm. The isotropic surface texture may also have an Rsk value from about -1.0 to about 1.0 or a Pc from approximately 80/cm to approximately 140/cm. The work roll, now with an isotropic surface texture, may be polished to form a work roll surface having an Ra value from about 0.30 pm to about 0.70 gm. The texture of the work roll surface may also have an Rsk value from approximately -3.0 to approximately 0.0 or a Pc from about 100/cm to about 180/cm.
[0024] Another exemplary method of applying an isotropic gloss finish on a metal substrate includes: grinding an unfinished work roll to form a ground work roll having a surface texture with an Ra value from about 0.20 gm to about 0.50 gm (e.g., a ground work roll having a surface texture with an Ra value from about 0.30 gm to about 0.50 gm); electro-discharge texturing the ground work roll to create an isotropic work roll surface texture having an Ra value from about 0.30 Lim to about 1.0 gm (e.g., an Ra value from about 0.50 gm to about 0.8 gm); polishing the isotropic work roll surface texture to produce a finished work roll with an engineered or particular surface texture having an Ra value from about 0.30 um to about 0.70 gm; inserting the finished work roll into a cold mill; and cold rolling the metal substrate with the finished work roll to apply the isotropic gloss finish on the metal substrate.
[0025] Cold rolling a metal substrate using a work roll with a surface texture having an Ra value from about 0.30 gm to about 0.70 gm may impart enhanced characteristics on the metal substrate. For example, cold rolling a metal substrate using a surface textured work roll with an Ra value from about 0.30 gm to about 0.70 gm may allow an isotropic gloss finish to be applied on the metal substrate. Cold rolling the metal substrate using the surface textured work roll may also improve the resistance of the metal substrate to high pressure, tolerating higher deformation without premature failure. In another example, cold rolling a metal substrate using the surface textured work roll may reduce the friction coefficient of the metal substrate.
In still another example, cold rolling a metal substrate using the surface textured work roll may improve lubricant retention of the metal substrate, which may reduce an amount of lubricant subsequently needed for further processing the metal substrate into a beverage can or other highly formed metal product. In yet another example, cold rolling a metal substrate using the surface textured work roll may cause the metal substrate to have more consistent friction characteristics, improving the metal performance during drawing, deep drawing, and other high-forming metal forming processes. In some examples, cold rolling a metal substrate using the engineered surface texture work roll may cause the metal substrate to have improved formability, which may allow the metal substrate to be less prone to issues during subsequent manufacturing or processing, such as product cracking.
[0026] These advantages, among others, can allow a metal substrate, which can be in the form of a metal sheet or plate, that is cold rolled using a surface textured work roll as described above to be further processed into beverage cans, beverage can components (e.g., a can body, can end, or can tab), beverage bottles, other food containers, and/or any other highly-formed metal product with improved ease and efficiency. For example, one or more improved tribological characteristics of a metal substrate with an isotropic gloss surface imparted by a surface textured work roll as described herein may allow for faster processing and more stable operating conditions because the friction characteristics of the metal sheet or plate may be more consistent between different batches of material and/or along the same strip of metal sheet or plate. Furthermore, the improved ability of the surface of the metal substrate to retain lubrication may further reduce friction during processing and reduce the need to apply extra lubrication to the metal substrate. In some examples, improving the quality and consistency of friction for a metal sheet or plate can lead to faster processing with reduced galling, earing, and wrinkling of the metal through subsequent forming operations.
[0027] These illustrative examples are given to introduce the reader to the general subject matter discussed herein and are not intended to limit the scope of the disclosed concepts. The following sections describe various additional features and examples with reference to the drawings in which like numerals indicate like elements, and directional descriptions are used to describe the illustrative examples but, like the illustrative examples, should not be used to limit the present disclosure.
[0028] FIGs. IA and 1B are a schematic perspective view of a ground work roll surface and a graph depicting the roughness of the ground work roll surface, respectively.
The work roll, which may initially begin with a standard surface finish devoid of marks, scratches, and/or other imperfections that could interfere with the application of an engineered texture surface, may be ground (e.g., using a grit wheel) to achieve a surface finish having an Ra value from about 0.2 gm to about 0.5 gm (e.g., an Ra value from about 0.3 gm to about 0.5 gm).
After grinding the work roll, the surface of the work roll may be composed of peaks and valleys and anisotropic.
[0029] FIGs. 1C and ID are a schematic perspective view of the work roll surface of FIGs.
1A-B after electro-discharge texturing (EDT) and a graph depicting the surface roughness of the EDT work roll surface, respectively. As shown in FIG. 1C, a texture of the work roll after EDT
processing is a relatively uniform, isotropic series of conical peaks with no directional bias. In some examples, using an EDT process to texture the work roll can cause build up on the ground texture of FIG. IA and produce a texture on the work roll with an Ra value from about 0.5 gm to about 1.0 IIM with an isotropic distribution that has no directional bias. In another example, using the EDT process to texture the work roll can produce a texture on the work roll with an Ra value from about 0.5 gm to about 0.8 gm. In some examples, the texture on the work roll produced with the EDT process may not be uniform in spacing, direction, or texture shape.
Rather, the texture produced by EDT processing may be randomized to the extent that on a macroscopic level, the EDT texture is isotropic with no directional bias. At this stage, the work roll texture may be characterized as having relatively sharp, jagged peaks that may not be suitable for rolling metal sheet or plate with relatively large thickness reductions. The sharp peaks of this texture can be relatively weak and may break off and lead to a buildup of debris on the metal sheet or plate at thickness reductions of greater than about 5%.
[0030] FIG. 1E is a schematic perspective view of the work roll surface undergoing a final polishing step to remove the peaks of the texture produced by EDT processing as described above. In the example depicted in FIG. 1E, relatively narrow, weak peaks of the EDT texture of the work roll shown in FIG. 1D may break and be discarded during polishing.
[0031] FTGs. 1F and IG are a schematic perspective view of a work roll surface after polishing to form an engineered surface texture and a graph depicting the surface roughness of the polished work roll surface, respectively. In the example depicted in FIG. 1F, polishing the work roll surface can remove sharp peaks of the EDT texture, which results in a surface texture of the work roll having flatter tops and a lower Ra value from about 0.3 gm to about 0.7 gm.
Furthermore, the surface texture depicted in FIGs. IF and 1G may tend toward a more negative skewness, indicating that the surface texture may be characterized by relatively deeper depressions and flatter peaks. In some examples, this surface texture may be better adapted to rolling metal sheet or plate with reductions in thickness of greater than 5%.
The flattened peaks of the engineered surface texture are more durable and allow for greater pressure and rolling efficiency without breakage and buildup of debris.

[0032] FIG. 2 is a micrograph of an engineered surface finish on a metal work roll for rolling metal sheet In some examples, the engineered surface finish on the metal work roll can refer to a metal work roll having a surface texture with an Ra value from about 0.3 gm to about 0.7 pm (e.g., a polished work roll with having a surface texture as described above with respect to FIGs.
1F and 1G).
[0033] In some examples, a work roll may be textured for imparting an isotropic gloss finish on a metal substrate. FIG. 3 is a flow chart depicting an example of a process for producing an engineered surface texture on a work roll that can be used to impart a gloss finish on a metal substrate.
[0034] At block 302, an unfinished work roll may be ground to produce a ground work roll with a ground finish or a surface texture having an Ra value from about 0.2 pm to about 0.5 pm.
In another example, the unfinished work roll may be ground to produce a ground work roll with a ground finish or a surface texture having an Ra value from about 0.3 um to about 0.5 gm (e.g., an Ra value of about 0.35 gm or any other suitable Ra value). An unfinished work roll may be a smooth work roll with a standard surface finish and no scratch marks, blemishes, indentations, or other surface imperfections that could prevent application of the engineered surface texture. In some cases, the unfinished work roll may be obtained from any suitable commercial source. The unfinished work roll may be made from any suitable material, such as, for example steel, ceramics, or any other material suitable for producing a work roll with an engineered surface texture.
[0035] The unfinished work roll may be ground using a grit wheel. Examples of the grit wheel include, but are not limited to, 360 and below grit wheels. The grit wheel may be used to grind the unfinished work roll until a particular or desired roughness or Ra value of a surface of the work roll is achieved. For example, the grit wheel can be used to grind the surface of the unfinished work roll to an Ra value from about 0.20 pm to about 0.50 pm (e.g., from about 0.30 to about 0.50 pm) to produce a ground work roll that can be further processed.
In another example, the grit wheel can be used to grind the surface of the unfinished work roll to an Rsk value from approximately -1.5 to approximately 0.5.
100361 At block 304, the ground work roll may be electro-discharge texturized to form an EDT
work roll. The electro-discharge texturing process can build up the ground texture produced at block 302 to a textured finish or an isotropic texture with a larger Ra value from about 0.5 pm to about 1.0 pm. In another example, the electro-discharge texturing process can build up the ground texture produced at block 302 to a textured finish or an isotropic texture with an Ra value from about 0.5 pm to about 0.8 pm (e.g., an Ra value of about 0.6 pm, 0.75 pm, or any other suitable Ra value). In some cases, electro-discharge texturizing the work roll may involve using an electrical discharge or a spark to repeatedly melt and solidify the surface of the ground work roll. The resulting EDT texture can be a roughened surface with craters, peaks, and valleys and no directionality.
[0037] In some cases, the ground work roll may be electro-discharge texturized until a particular or desired roughness or Ra value is achieved. For example, the ground work roll can be electro-discharge texturized to form an EDT work roll with an Ra value from about 0.50 gm to about 1.0 pm (e.g., an Ra value from about 0.5 gm to about 0.8 pm). In another example, the EDT work roll can have an Rsk value from approximately -1.0 to approximately 1Ø In still another example, the EDT work roll can have a Pc value from about 80/cm to about 140/cm. In some cases, a polarity of an electrode used while electro-discharge texturizing the ground work roll can be alternated while electro-discharge texturizing the ground work roll, which may affect the Ra value of the EDT work roll.
[0038] In block 306, the EDT work roll is polished to form a polished work roll. In some examples, a sand belt, sandpaper, superfinisher, etc. may be used to polish the EDT work roll to achieve a polished finish. Examples of a type of sandpaper that can be used to polish the EDT
work roll include, but are not limited to, a 2x15 gm sandpaper or a 1x9 gm sandpaper.
100391 In some examples, electro-discharge texturizing the ground work roll in block 304 can cause sharp peaks to form on a surface of the EDT work roll. The sharp peaks may break off and form debris on a metal substrate if the EDT work roll is used to cold roll a metal substrate. In some examples, polishing the EDT work roll in block 306 may break the sharp peaks and smooth the EDT work roll, which may prevent debris from forming on a metal substrate during cold rolling.
[0040] Polishing the EDT work roll in block 306 can also form a polished work roll that can have a lower Ra value than the EDT work roll of block 304. For example, the polished work roll can have an Ra value from about 0.30 gm to about 0.70 gm (e.g., an Ra value of 0.6 gm, 0.65 gm, between approximately 0.6 gm and 0.65 gm, or any other suitable Ra value).
In some examples, the polished work roll can have an Rsk value from approximately -3.0 to approximately 0Ø In still another example, the polished work roll can have a Pc value from approximately 100/cm to approximately 180/cm.
[0041] In some examples, a polished work roll with an Ra value from about 0.30 gm to about 0.70 gm can be used to apply a gloss finish on a metal substrate. For example, FIG. 4 is a flow chart depicting an example of a process for applying a gloss finish on a metal substrate using a polished work roll, according to one example.

[0042] In block 402, a polished work roll is inserted into a cold mill. The polished work roll can be a work roll that has an Ra value from about 0.30 gm to about 0.70 gm (e.g., a polished work roll formed in block 306 of FIG. 3).
[0043] In block 404, a metal substrate can be rolled using the polished work roll. The metal substrate can be an aluminum sheet or an aluminum alloy sheet or any suitable substrate. In some cases, the metal substrate is cold rolled using the polished work roll to apply a gloss finish on the metal substrate, which, as described above, can refer to a uniform glossiness of the metal substrate and/or can refer to a metal substrate having a surface that is isotropic with minimal directionality.
[0044] In some examples, applying the gloss finish to the metal substrate may allow the metal substrate to be suitable for any product that would benefit from a gloss finish lacking strong directionality and having limited surface peaks (e.g., but not limited to, litho applications, can applications, and lacquer applications). For example, the gloss finish described herein can be suitable for can ends (e.g., an end of a beverage can), a can body (e.g., a body of a beverage can), a can tab (e.g., a tab of a beverage can), reflectors, painted and laminated products, signage, transportation, anodizing quality, and decorative finishes. Applying the gloss finish to a can end or other product may be advantageous as a potential for reducing coating weights since the roughness peak volumes are reduced for a similar average transverse roughness.
100451 In addition, cold rolling the metal substrate using a polished work roll with an Ra value from about 0.30 gm to about 0.70 gm can cause the metal substrate to have enhanced characteristics. For example, cold rol I ing a metal substrate using the polished work roll can cause the metal substrate to have increased resistance to high pressure, tolerating higher deformation without premature failure. In another example, cold rolling the metal substrate using the polished work roll can reduce the friction coefficient of the metal substrate. In still another example, cold rolling the metal substrate using the polished work roll can increase the lubricant retention of the metal substrate, which may reduce an amount of lubricant subsequently needed for the metal substrate. For example, cold rolling the metal substrate using the polished work roll can cause the metal substrate to have a negative skew (e.g., have a valley extending into a surface of the metal substrate), which can increase a volume of lubricant stored in the metal substrate.
[0046] In some examples, cold rolling the metal substrate using the polished work roll can cause the metal substrate to have more consistent friction characteristics throughout the metal substrate. In some cases, cold rolling the metal substrate using the polished work roll can cause the metal substrate to have improved formability, which may allow the metal substrate to be less prone to issues resulting from low formability, such as product cracking.
[0047] Different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible.
Similarly, some features and subcombinations are useful and may be employed without reference to other features and subcombinations. Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent.
Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications can be made without departing from the scope of the claims below.

Claims

Claims That which is claimed is:

1. A method of texturing a work roll comprising:
grinding an unfinished work roll surface to form a ground work roll surface;
electro-discharge texturing the ground work roll surface to form an electro-discharge textured work roll surface; and polishing the electro-discharge textured work roll surface to form a polished work roll surface for applying a gloss finish on a metal substrate.

2. The method of claim 1, wherein grinding the unfinished work roll surface comprises grinding the unfinished work roll surface to form the ground work roll surface with an Ra value from about 0.30 µm to about 0.50 µm.

3. The method of any one of claims 1-2, wherein electro-discharge texturing the ground work roll surface comprises electro-discharge texturing the ground work roll surface to form the electro-discharge textured work roll surface with an Ra value from about 0.50 µm to about 0.8 µm.

4. The method of any one of claims 1-3, wherein the electro-discharge textured work roll surface has an isotropic surface with minimal directionality.

5. The method of any one of claims 1-4, wherein polishing the electro-discharge textured work roll surface comprises polishing the electro-discharge textured work roll surface to form the polished work roll surface that has an Ra value from about 0.30 µm to about 0.70 µm.

6. A work roll prepared according to the method of any one of claims 1-4.

7. The work roll of claim 6 comprising:
a surface having an Ra value between about 0.30 µm and about 0.70 µm after the work roll has been electro-discharge textured and polished.

8. The work roll of any one of claims 6-7, wherein the work roll is a cold mill work roll.

9. The method of claim 1, further comprising:
inserting the polished work roll into a cold mill; and cold rolling the metal substrate with the polished work roll for applying the gloss finish on the metal substrate.

10. The method of claim 9, wherein the metal substrate is aluminum or an aluminum alloy sheet.

11. The method of any one of claims 9-10 wherein grinding the work roll comprises grinding the work roll until the ground work roll has an Ra value between about 0.30 µm and about 0.50 µm.

12. The method of any one of claims 9-11, wherein electro-discharge texturing the ground work roll comprises electro-discharge texturing the ground work roll until the electro-discharge textured work roll has an Ra value between about 0.50 µm and about 0.8 µm.

13. The method of any one of claims 9-12, wherein polishing the electro-discharge textured work roll comprises polishing the electro-discharge textured work until the polished work roll has an Ra value between about 0.30 µm and about 0.70 µm.

14. A product formed from a work roll textured according to the method of any one of claims 1-5 or 9-13, wherein the product is aluminum for canning.

15. The product of claim 14, wherein the product is a can body, a can end, or a can tab.

16. The method of any one of claims 1-4, further comprising:
cold rolling the metal substrate with the polished work roll surface, wherein the polished work roll surface has an Ra value between about 0.30 µm and about 0.70 µm after the polished work roll has been electro-discharge textured and polished.

17. A metal strip rolled according to the method of claim 16, wherein the metal strip is an aluminum or aluminum alloy sheet.