EP1166905B1 - Method for producing an aluminium sheet and aluminium sheet - Google Patents

Method for producing an aluminium sheet and aluminium sheet Download PDF

Info

Publication number
EP1166905B1
EP1166905B1 EP01202510A EP01202510A EP1166905B1 EP 1166905 B1 EP1166905 B1 EP 1166905B1 EP 01202510 A EP01202510 A EP 01202510A EP 01202510 A EP01202510 A EP 01202510A EP 1166905 B1 EP1166905 B1 EP 1166905B1
Authority
EP
European Patent Office
Prior art keywords
aluminium sheet
microns
process step
range
surface roughness
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.)
Revoked
Application number
EP01202510A
Other languages
German (de)
French (fr)
Other versions
EP1166905A8 (en
EP1166905A3 (en
EP1166905A2 (en
Inventor
Josephus Maria Théophiel Dens
Els Verboom
Jean Pierre Jules Baekelandt
Ansgar Maria Geibel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alvance Aluminium Duffel BV
Original Assignee
Corus Aluminium NV
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=26643193&utm_source=***_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP1166905(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Corus Aluminium NV filed Critical Corus Aluminium NV
Publication of EP1166905A2 publication Critical patent/EP1166905A2/en
Publication of EP1166905A8 publication Critical patent/EP1166905A8/en
Publication of EP1166905A3 publication Critical patent/EP1166905A3/en
Application granted granted Critical
Publication of EP1166905B1 publication Critical patent/EP1166905B1/en
Anticipated expiration legal-status Critical
Revoked legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B1/227—Surface roughening or texturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
    • B21B2003/001—Aluminium or its alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
    • B21B27/005—Rolls with a roughened or textured surface; Methods for making same

Definitions

  • the invention relates to a method for producing an aluminium sheet with a decorative surface structure and to a curved aluminium sheet (see e.g. JP-A 404 1003).
  • Sheet material such as for example of aluminium, aluminium alloys and stainless steel, with a decorative surface structure is used, inter alia, for domestic appliances, such as for example the outside of refrigerators and freezers, and for the front panels of audiovisual equipment.
  • Sheet material of this type has a shiny metallic or if desired a matt metallic appearance and, if desired, can be provided with an organic covering layer for further decoration or protection.
  • a typical shiny metallic surface structure is generally obtained by blasting the sheet material with, for example, glass beads or stainless steel shot.
  • One drawback of a surface structure obtained by blasting with beads is that the sheet material is handled in batches and sometimes even by hand, and consequently is rather expensive.
  • an end product such as for example a refrigerator door
  • this product is manually or semi-automatically provided with the desired shiny or matt peened surface structure.
  • the existing thicknesses for outer sides of domestic materials do not allow, for example, manual blasting with glass beads, on account of the risk of deformation caused by the blasting pressure, and furthermore there is a risk of non-uniformity caused by the manual blasting.
  • a desired aluminium sheet material of this type must be less expensive than the cost of sheet material with a surface structure obtained by treatment by means of blasting, in particular with glass beads.
  • the result is a method which can be operated continuously and on an industrial scale to produce aluminium sheet with the desired decorative surface structure described above on at least one side of the aluminium sheet, which decorative surface structure closely to very closely approximates to that of the known finish obtained using glass beads, while the cost price of the finished product is considerably lower than that of aluminium sheet material which is blasted in batches or by hand.
  • a cold-rolled aluminium sheet which is provided typically has a surface roughness Ra in a range from 0.2 to 0.6 microns, measured in accordance with DIN 4768.
  • Mill finish is a term which is known to the person skilled in the art and refers to microscopically visible thin lines oriented substantially in the rolling direction.
  • the method obtained results in a relatively inexpensive semi-finished product on a coil with a desired decorative surface structure, which semi-finished product can then be used to produce end products, such as for example doors for domestic appliances, which then require no further manual treatment.
  • the decorative surface structure of the known finish obtained using glass beads is closely approximated to with a surface roughness of up to Ra 3.0 microns
  • the roughness Ra which is applied in process step (b) is preferably at most 2.5 microns. Below this value, the decorative surface structure very closely approximates to that of the known finish obtained using glass beads.
  • the surface roughness is applied to the aluminium sheet by means of rollers with a non-deterministic structure, more preferably by means of electro-discharge texturing rollers, or EDT rollers for short.
  • a desired surface structure to be applied, for example, to a coil of aluminium sheet material continuously and on an industrial scale.
  • the application of the desired surface roughness by means of EDT rollers is achieved, inter alia, through the fact that the original mill finish on the cold-rolled aluminium sheet of the desired final thickness has completely or almost completely disappeared.
  • the desired result is obtained in one or more light cold-rolling passes. This changes the thickness of the final aluminium sheet by less than 15%, and typically about up to 6%, with respect to the cold-rolled aluminium starting material.
  • the surface roughness is applied to the aluminium sheet by means of rollers with a non-deterministic structure which are produced with the aid of the precision texturing process.
  • a small quantity of chromium is applied to the roller in the form of circular or spherical spots.
  • the roller with the non-deterministic structure has a surface roughness Ra in a range between 2 and 6 microns, preferably between 3 and 6 microns, measured in accordance with DIN 4768.
  • a desired decorative surface structure within the desired Ra range is achieved on the aluminium sheet.
  • the roughened aluminium sheet in a process step (c) is provided with a coating layer, for example by means of painting, in which case the coating layer is a layer of paint, or by means of nano-coating, in which case the coating layer is a nano-coating, or by means of anodization, in which case the coating layer is an anodized layer.
  • the nano-coating may comprise a sol-gel process.
  • the choice of thickness and the type of layer is determined by the end use of the aluminium sheet.
  • the decorative surface structure can be attained or even adapted to the desired appearance of the peened surface structure.
  • the surface can in this way be provided with a desired colour.
  • the surface of the roughened aluminium sheet is provided with better protection against scratches and other external influences by the coating layer.
  • the roughened aluminium sheet is anodized in a process step (c) or is provided with an anodized layer with a thickness in a range of up to 15 microns, more preferably in a range from 3 to 15 microns, by means of anodization.
  • the anodization may be carried out in the customary continuous way on an industrial scale by passing strip material continuously through an anodization bath. Colour anodization is also possible. It has been found that the continuously produced and anodized strip material can also undergo further operations, such as for example punching, bending and light deep-drawing without excessive cracking of the anodized layer which has been applied.
  • anodization over, for example, painting offers very good protection against external chemical influences, such as against spilt cooking ingredients such as tomato sauce and mustard.
  • the aluminium sheet after the application of the desired surface roughness and before the anodization, is pickled in a process step (b1).
  • the aluminium sheet may be chemically or electrochemically pickled in an alkaline or acidic medium. More preferably, the aluminium sheet is pickled in an alkaline medium.
  • the intermediate pickling prior to anodization leads to the final sheet material acquiring a surface structure which is somewhat more matt in terms of appearance. For a number of applications of the aluminium sheet obtained using the method according to the invention, this is a highly desirable property of the sheet material.
  • a further advantage is that a pickling treatment is relatively simple to incorporate in a continuous industrial production line which is suitable for the method according to the invention.
  • the cold-rolled aluminium sheet is brought into a strengthened state, also known as an H temper by the person skilled in the art.
  • H temper also known as an H temper by the person skilled in the art.
  • This designation applies to products which have been cold-formed after annealing or after hot-forming or to a combination of strengthening and annealing or stabilizing for hardness, in order to obtain the specific mechanical properties.
  • Typical examples which, however, do not limit the invention are an H14 and an H22 temper. It has been found that in particular wrought aluminium alloys with an H temper are very suitable for the application, efficiently and reproducibly on an industrial scale, of the desired surface roughness by cold-rolling, and in particular by EDT rolling.
  • the invention is also embodied by a curved aluminium sheet part, such as for example the door of a refrigerator or a freezer or the housing of a remote control for audiovisual equipment, produced from an aluminium sheet obtained using the method according to the invention.
  • Aluminium sheet made from the AA5754 alloy in an H temper with a thickness of 0.7 mm on an industrial scale is provided with a surface roughness Ra of 1.35 microns, measured in accordance with DIN 4768, using an industrial EDT roller.
  • the EDT roller used in this example has a surface roughness Ra of approximately 2.5 microns.
  • the roughened aluminium sheet is then pickled lightly in an alkaline solution based on sodium hydroxide, and is then provided, in a sulphuric acid solution, with an anodized layer with a thickness of 5 microns.
  • the final surface roughness Ra of the aluminium sheet obtained was 1.31 microns.
  • the aluminium sheet obtained is then provided with a protective plastic film and was then bent to form a door panel for a refrigerator.
  • the final surface of the door panel provided a very good approximation to the appearance of a finish obtained using glass beads.
  • Gloss measurements were also carried out at an angle of 60°, in accordance with ASTM D-523, on the cold-rolled aluminium sheet after the roughening with the aid of the EDT roller and after the anodization. The results were 175.4 and 25.6 gloss units, respectively.
  • Aluminium sheet produced from the AA5005 alloy in an H temper with a thickness of 0.5 mm on an industrial scale was provided with a surface roughness Ra of 1.53 microns, measured in accordance with DIN 4768, using an industrial EDT roller.
  • the roughened aluminium sheet was then pickled very lightly in an alkaline solution based on sodium hydroxide and was then provided, in a sulphuric acid solution, with an anodized layer with a thickness of 5 microns.
  • the final surface roughness Ra of the aluminium sheet obtained was 1.52 microns.
  • the aluminium sheet obtained was then provided with a protective plastic film and was then bent to form a panel for a remote control.
  • the final surface of the remote control provided a very close approximation to the appearance of a finish obtained using glass beads.
  • Gloss measurements at an angle of 60° were once again carried out, in accordance with ASTM D-523, on the cold-rolled aluminium sheet after the roughening with the aid of the EDT roller and after the anodization. The results were 182.2 and 23.1 gloss units, respectively.
  • Aluminium sheet which was produced from the AA5754 alloy in an H temper with a thickness of 0.7 mm on an industrial scale was provided with a surface roughness Ra of 2.1 microns, measured in accordance with DIN 4768, using an industrial EDT roller.
  • the EDT roller used in this example has a surface roughness Ra of approximately 3.8 microns.
  • the roughened aluminium sheet was pickled lightly in an alkaline solution based on sodium hydroxide and was then provided, in a sulphuric acid solution, with an anodized layer with a thickness of 5 microns.
  • the ultimate surface roughness Ra of the aluminium sheet obtained was 2.0 microns.
  • the aluminium sheet obtained was then provided with a protective plastic film and was then bent to form a door panel of a refrigerator.
  • the ultimate surface of the door panel provided a very close approximation to the appearance of a finish obtained using glass beads.
  • Gloss measurements at an angle of 60° were also carried out, in accordance with ASTM D-523, on the cold-rolled aluminium sheet after the roughening with the aid of the EDT roller and after the anodization. The results were 128.3 and 22.7 gloss units, respectively.
  • aluminium sheets were provided with a surface roughness of Ra 0.9 micron and Ra 1.0 micron with the aid of EDT rollers. Visual inspection revealed that these sheets do not have a surface structure which approximates the desired surface structure which would be obtained by blasting with glass beads.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Metal Rolling (AREA)
  • Laminated Bodies (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)

Abstract

Method for producing an aluminium sheet with a decorative surface structure on at least one side, comprising the successive process steps of: (a) providing a cold-rolled aluminium sheet of a desired thickness; (b) using cold-rolling to apply a surface roughness Ra to at least one side of the aluminium sheet, in a range from 1.2 to 3.0 microns measured in accordance with DIN 4768.

Description

  • The invention relates to a method for producing an aluminium sheet with a decorative surface structure and to a curved aluminium sheet (see e.g. JP-A 404 1003).
  • The values which are given in this patent application for surface roughness Ra are all measured in accordance with DIN 4768.
  • Sheet material, such as for example of aluminium, aluminium alloys and stainless steel, with a decorative surface structure is used, inter alia, for domestic appliances, such as for example the outside of refrigerators and freezers, and for the front panels of audiovisual equipment. Sheet material of this type has a shiny metallic or if desired a matt metallic appearance and, if desired, can be provided with an organic covering layer for further decoration or protection. A typical shiny metallic surface structure is generally obtained by blasting the sheet material with, for example, glass beads or stainless steel shot. One drawback of a surface structure obtained by blasting with beads is that the sheet material is handled in batches and sometimes even by hand, and consequently is rather expensive. Furthermore, it is often the case that an end product, such as for example a refrigerator door, is produced, and then this product is manually or semi-automatically provided with the desired shiny or matt peened surface structure. Moreover, the existing thicknesses for outer sides of domestic materials do not allow, for example, manual blasting with glass beads, on account of the risk of deformation caused by the blasting pressure, and furthermore there is a risk of non-uniformity caused by the manual blasting.
  • There is a market demand for aluminium sheet material with a surface structure which approximates the surface structure of a glass bead finish as closely as possible. A desired aluminium sheet material of this type must be less expensive than the cost of sheet material with a surface structure obtained by treatment by means of blasting, in particular with glass beads.
  • It is an object of the invention to provide a method for producing an aluminium sheet with a desired decorative surface structure as described above applied to at least one side of the aluminium sheet.
  • This problem is solved by the features of claim 1.
  • The result is a method which can be operated continuously and on an industrial scale to produce aluminium sheet with the desired decorative surface structure described above on at least one side of the aluminium sheet, which decorative surface structure closely to very closely approximates to that of the known finish obtained using glass beads, while the cost price of the finished product is considerably lower than that of aluminium sheet material which is blasted in batches or by hand. A cold-rolled aluminium sheet which is provided typically has a surface roughness Ra in a range from 0.2 to 0.6 microns, measured in accordance with DIN 4768. Furthermore, the method according to the invention ensures that the original mill finish has completely or almost completely disappeared. Mill finish is a term which is known to the person skilled in the art and refers to microscopically visible thin lines oriented substantially in the rolling direction. Furthermore, the method obtained results in a relatively inexpensive semi-finished product on a coil with a desired decorative surface structure, which semi-finished product can then be used to produce end products, such as for example doors for domestic appliances, which then require no further manual treatment.
  • Although the decorative surface structure of the known finish obtained using glass beads is closely approximated to with a surface roughness of up to Ra 3.0 microns, the roughness Ra which is applied in process step (b) is preferably at most 2.5 microns. Below this value, the decorative surface structure very closely approximates to that of the known finish obtained using glass beads.
  • It has been found that the appearance of the finish obtained using glass beads is still very closely approximated to in particular with surface roughness values of over Ra 1.8 microns.
  • In one embodiment of the method according to the invention, the surface roughness is applied to the aluminium sheet by means of rollers with a non-deterministic structure, more preferably by means of electro-discharge texturing rollers, or EDT rollers for short. This allows a desired surface structure to be applied, for example, to a coil of aluminium sheet material continuously and on an industrial scale. Furthermore, the application of the desired surface roughness by means of EDT rollers is achieved, inter alia, through the fact that the original mill finish on the cold-rolled aluminium sheet of the desired final thickness has completely or almost completely disappeared. During the application of the surface structure by means of EDT rollers, the desired result is obtained in one or more light cold-rolling passes. This changes the thickness of the final aluminium sheet by less than 15%, and typically about up to 6%, with respect to the cold-rolled aluminium starting material.
  • In another embodiment of the method according to the invention, the surface roughness is applied to the aluminium sheet by means of rollers with a non-deterministic structure which are produced with the aid of the precision texturing process. In this process, a small quantity of chromium is applied to the roller in the form of circular or spherical spots.
  • In an embodiment according to the method, the roller with the non-deterministic structure has a surface roughness Ra in a range between 2 and 6 microns, preferably between 3 and 6 microns, measured in accordance with DIN 4768. Depending on the reduction in the thickness of the aluminium sheet which is employed during the roughening in one or more cold-rolling passes, in this way a desired decorative surface structure within the desired Ra range is achieved on the aluminium sheet.
  • In one embodiment of the method according to the invention, in a process step (c) the roughened aluminium sheet is provided with a coating layer, for example by means of painting, in which case the coating layer is a layer of paint, or by means of nano-coating, in which case the coating layer is a nano-coating, or by means of anodization, in which case the coating layer is an anodized layer. The nano-coating may comprise a sol-gel process.
  • The choice of thickness and the type of layer is determined by the end use of the aluminium sheet. Depending on the thickness and the type of layer, the decorative surface structure can be attained or even adapted to the desired appearance of the peened surface structure. Alternatively, the surface can in this way be provided with a desired colour. Moreover, the surface of the roughened aluminium sheet is provided with better protection against scratches and other external influences by the coating layer.
  • In an embodiment of the method according to the invention, the roughened aluminium sheet is anodized in a process step (c) or is provided with an anodized layer with a thickness in a range of up to 15 microns, more preferably in a range from 3 to 15 microns, by means of anodization. The anodization may be carried out in the customary continuous way on an industrial scale by passing strip material continuously through an anodization bath. Colour anodization is also possible. It has been found that the continuously produced and anodized strip material can also undergo further operations, such as for example punching, bending and light deep-drawing without excessive cracking of the anodized layer which has been applied. Despite the application of a thin anodized layer, the surface roughness applied remains within the given range, and therefore the desired decorative surface structure is also retained. Since it is no longer necessary for a product to be anodized in batches after deformation, there is a considerable reduction in cost of the end product.
  • Another advantage of anodization over, for example, painting is that the anodized layer obtained by anodization offers very good protection against external chemical influences, such as against spilt cooking ingredients such as tomato sauce and mustard.
  • In one embodiment of the method according to the invention, the aluminium sheet, after the application of the desired surface roughness and before the anodization, is pickled in a process step (b1). The aluminium sheet may be chemically or electrochemically pickled in an alkaline or acidic medium. More preferably, the aluminium sheet is pickled in an alkaline medium. The intermediate pickling prior to anodization leads to the final sheet material acquiring a surface structure which is somewhat more matt in terms of appearance. For a number of applications of the aluminium sheet obtained using the method according to the invention, this is a highly desirable property of the sheet material. A further advantage is that a pickling treatment is relatively simple to incorporate in a continuous industrial production line which is suitable for the method according to the invention.
  • In principle, all wrought aluminium alloys which can be treated successfully by means of anodization can be processed in the method according to the invention. However, it has been found that the aluminium alloys which cannot be heat-treated can be processed more successfully than the aluminium alloys which can be heat-treated.
  • Very good results are obtained with the method according to the invention if an aluminium alloy selected from the Aluminium Association (AA)1xxx series, (AA)3xxx series, (AA)5xxx series and (AA)6xxx series is used for the cold-rolled aluminium sheet. It is preferable to select a wrought aluminium alloy which cannot be heat-treated from the AA5xxx series. These are the aluminium alloys in which magnesium is the most important alloying element. Typical examples which, however, do not limit the invention are the alloys AA5005 and AA5754.
  • More preferably, the cold-rolled aluminium sheet is brought into a strengthened state, also known as an H temper by the person skilled in the art. This designation applies to products which have been cold-formed after annealing or after hot-forming or to a combination of strengthening and annealing or stabilizing for hardness, in order to obtain the specific mechanical properties. Typical examples which, however, do not limit the invention are an H14 and an H22 temper. It has been found that in particular wrought aluminium alloys with an H temper are very suitable for the application, efficiently and reproducibly on an industrial scale, of the desired surface roughness by cold-rolling, and in particular by EDT rolling.
  • The invention is also embodied by a curved aluminium sheet part, such as for example the door of a refrigerator or a freezer or the housing of a remote control for audiovisual equipment, produced from an aluminium sheet obtained using the method according to the invention.
  • The invention will now be explained with reference to a number of examples, which do not restrict the invention.
    • Example 1
  • Aluminium sheet made from the AA5754 alloy in an H temper with a thickness of 0.7 mm on an industrial scale is provided with a surface roughness Ra of 1.35 microns, measured in accordance with DIN 4768, using an industrial EDT roller. The EDT roller used in this example has a surface roughness Ra of approximately 2.5 microns. The roughened aluminium sheet is then pickled lightly in an alkaline solution based on sodium hydroxide, and is then provided, in a sulphuric acid solution, with an anodized layer with a thickness of 5 microns. The final surface roughness Ra of the aluminium sheet obtained was 1.31 microns. The aluminium sheet obtained is then provided with a protective plastic film and was then bent to form a door panel for a refrigerator. The final surface of the door panel provided a very good approximation to the appearance of a finish obtained using glass beads. Gloss measurements were also carried out at an angle of 60°, in accordance with ASTM D-523, on the cold-rolled aluminium sheet after the roughening with the aid of the EDT roller and after the anodization. The results were 175.4 and 25.6 gloss units, respectively.
    • Example 2
  • Aluminium sheet produced from the AA5005 alloy in an H temper with a thickness of 0.5 mm on an industrial scale was provided with a surface roughness Ra of 1.53 microns, measured in accordance with DIN 4768, using an industrial EDT roller. The roughened aluminium sheet was then pickled very lightly in an alkaline solution based on sodium hydroxide and was then provided, in a sulphuric acid solution, with an anodized layer with a thickness of 5 microns. The final surface roughness Ra of the aluminium sheet obtained was 1.52 microns. The aluminium sheet obtained was then provided with a protective plastic film and was then bent to form a panel for a remote control. The final surface of the remote control provided a very close approximation to the appearance of a finish obtained using glass beads. Gloss measurements at an angle of 60° were once again carried out, in accordance with ASTM D-523, on the cold-rolled aluminium sheet after the roughening with the aid of the EDT roller and after the anodization. The results were 182.2 and 23.1 gloss units, respectively.
    • Example 3
  • Aluminium sheet which was produced from the AA5754 alloy in an H temper with a thickness of 0.7 mm on an industrial scale was provided with a surface roughness Ra of 2.1 microns, measured in accordance with DIN 4768, using an industrial EDT roller. The EDT roller used in this example has a surface roughness Ra of approximately 3.8 microns. Then, the roughened aluminium sheet was pickled lightly in an alkaline solution based on sodium hydroxide and was then provided, in a sulphuric acid solution, with an anodized layer with a thickness of 5 microns. The ultimate surface roughness Ra of the aluminium sheet obtained was 2.0 microns. The aluminium sheet obtained was then provided with a protective plastic film and was then bent to form a door panel of a refrigerator. The ultimate surface of the door panel provided a very close approximation to the appearance of a finish obtained using glass beads. Gloss measurements at an angle of 60° were also carried out, in accordance with ASTM D-523, on the cold-rolled aluminium sheet after the roughening with the aid of the EDT roller and after the anodization. The results were 128.3 and 22.7 gloss units, respectively.
  • For comparison purposes, aluminium sheets were provided with a surface roughness of Ra 0.9 micron and Ra 1.0 micron with the aid of EDT rollers. Visual inspection revealed that these sheets do not have a surface structure which approximates the desired surface structure which would be obtained by blasting with glass beads.
  • It should be noted that it may be advantageous, in particular for a relatively thick anodized layer and/or substantial deformation operations carried out on the decorative aluminium sheet provided with the decorative surface structure to be curved or bent before the curved aluminium sheet is anodized, despite the higher costs associated with batchwise anodization. This has the advantage that the anodized layer cannot be damaged during the deformation.

Claims (12)

  1. Method for producing an aluminium sheet with a decorative surface structure on at least one side, comprising the successive process steps of:
    (a) providing a cold-rolled aluminium sheet of a desired thickness;
    (b) using cold-rolling to apply a surface roughness Ra to at least one side of the aluminium sheet, in a range from 1.2 to 3.0 microns measured in accordance with DIN 4768,
    characterized in that after process step (b) the roughened aluminium sheet surface is provided, in a process step (c), with an anodized layer with a thickness in a range of up to 20 microns by means of anodization.
  2. Method according to Claim 1, characterized in that said anodized layer has a thickness in a range up to 15µm.
  3. Method according to Claim 2, characterized in that said anodized layer has a thickness in the range of 3 to 15µm.
  4. Method according to Claim 1 to 3, characterized in that during process step (b) the surface roughness is applied by means of rollers with a non-deterministic texture.
  5. Method according to Claim 4, characterized in that during process step (b) the surface roughness is applied by means of electro-discharge texturing (EDT) rollers.
  6. Method according to Claims 1 to 5, characterized in that after process step (b) and before process step (c) the aluminium sheet is pickled in a process step (b1).
  7. Method according to Claim 6, characterized in that during the process step (b1) the aluminium sheet is chemically or electrochemically pickled in an alkaline or acidic medium.
  8. Method according to one of Claims 1 to 7, characterized in that during process step (b) a surface roughness in a range of Ra 1.3 to 3.0 microns is applied, preferably in a range of Ra 1.5 to 3.0 microns, measured in accordance with DIN 4768.
  9. Method according to one of Claims 1 to 8, characterized in that the roughness Ra which is applied in process step (b) is at most 2.5 microns, measured in accordance with DIN 4768.
  10. Method according to claim 1, 2 or 3 characterized in that the surface roughness Ra applied in step (b) is over 1.8µm, measured in accordance with DIN 4768.
  11. Method according to one of the preceding Claims 1 to 10, characterized in that an aluminium alloy from the AA1xxx series, the AA3xxx series, the AA5xxx series or the AA6xxx series is selected for the composition of the aluminium sheet provided.
  12. Curved aluminium sheet obtained by the method according to one of Claims 1 to 11, having on at least one side a roughened surface of the aluminum sheet having a surface roughness Ra in the range 1.2 to 3.0 microns measured in accordance with DIN 4768 the curved aluminium sheet further characterized in having, on said roughened surface an anodization layer with a thickness in a range of up to 20 microns.
EP01202510A 2000-06-29 2001-06-29 Method for producing an aluminium sheet and aluminium sheet Revoked EP1166905B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
NL1015568 2000-06-29
NL1015568 2000-06-29
NL1015921 2000-08-11
NL1015921 2000-08-11

Publications (4)

Publication Number Publication Date
EP1166905A2 EP1166905A2 (en) 2002-01-02
EP1166905A8 EP1166905A8 (en) 2002-05-08
EP1166905A3 EP1166905A3 (en) 2003-04-02
EP1166905B1 true EP1166905B1 (en) 2005-10-05

Family

ID=26643193

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01202510A Revoked EP1166905B1 (en) 2000-06-29 2001-06-29 Method for producing an aluminium sheet and aluminium sheet

Country Status (5)

Country Link
EP (1) EP1166905B1 (en)
AT (1) ATE305826T1 (en)
DE (1) DE60113772T2 (en)
DK (1) DK1166905T3 (en)
ES (1) ES2246997T3 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10345934B4 (en) * 2002-10-18 2005-03-10 Corus Aluminium Nv Metal blank for molding and process for its production
PT2665842E (en) * 2011-01-17 2015-03-30 Hydro Aluminium Rolled Prod Exterior wall metal sheet made of aluminium having a high surface roughness
ES2610971B1 (en) * 2015-09-30 2018-02-09 Acr Ii Aluminium Group Cooperatief U.A. ALUMINUM SURFACE RECORDING PROCESS

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE634213A (en) * 1961-07-17
DE3008679C2 (en) * 1980-03-06 1983-08-18 Vereinigte Metallwerke Ranshofen-Berndorf AG, 5282 Braunau am Inn, Oberösterreich Deep-drawable sheet metal or strip made of non-ferrous metal or an alloy thereof, in particular made of aluminum, as well as a method for its production
DE3705100A1 (en) * 1987-02-18 1988-09-01 Benecke Gmbh J METHOD FOR PRODUCING A SURFACE STRUCTURE OF IMPELLING ROLLERS, AND PRINCING ROLLER PRODUCED BY THE METHOD
JPH0441003A (en) * 1990-06-07 1992-02-12 Furukawa Alum Co Ltd Exterior use aluminum or aluminum alloy plate and its manufacture

Also Published As

Publication number Publication date
EP1166905A8 (en) 2002-05-08
DK1166905T3 (en) 2005-11-21
DE60113772D1 (en) 2006-02-16
ES2246997T3 (en) 2006-03-01
EP1166905A3 (en) 2003-04-02
DE60113772T2 (en) 2006-06-22
ATE305826T1 (en) 2005-10-15
EP1166905A2 (en) 2002-01-02

Similar Documents

Publication Publication Date Title
CA2899991C (en) Aluminium alloy for producing semi-finished products or components for motor vehicles, method for producing an aluminium alloy strip from said aluminium alloy, and aluminium alloystrip and uses therefor
US6528183B2 (en) Clad aluminum alloy sheet for aircraft structural parts
CN101437677B (en) Clad sheet product
CA2889954C (en) Aluminium composite material and forming method
CN109415782B (en) Anodized quality aluminum alloys and related products and methods
CN105543573A (en) 1100-H24 aluminum alloy plate used for car door and preparation method thereof
EP1166905B1 (en) Method for producing an aluminium sheet and aluminium sheet
US7846277B2 (en) Planar, rolled semi-finished product of aluminum alloys
US2995808A (en) Composite plated alloy material
US5985046A (en) Process for making clear coated aluminum alloy lighting sheet
JP2648679B2 (en) Manufacturing method of painted aluminum plated steel sheet with excellent corrosion resistance and workability
JP2007146236A (en) Surface treated steel sheet for liquid crystal front frame, its production method and liquid crystal front frame produced by the production method
US5725683A (en) Manufacturing clear coated aluminum alloy lighting sheet
JP3107915B2 (en) Aluminum alloy rolled sheet for phosphating automotive
JP2001303162A (en) Automotive aluminum alloy sheet and its producing method
JPH03271379A (en) Stainless steel sheet to be coated and coated steel sheet
JP3457298B2 (en) Stripping-type resin-coated titanium material excellent in processability, method for producing the same, and method for stripping the film
JP2640057B2 (en) Single side coated steel sheet for DI can
JP2007146235A (en) Surface treated steel sheet for liquid crystal front frame, its manufacturing method, and liquid crystal front frame manufactured by the manufacturing method
JP3270710B2 (en) Method for producing resin-coated aluminum alloy sheet for drawn ironing can
JP3134919B2 (en) Method for producing hot-dip coated steel sheet with excellent roll formability
US20240229197A9 (en) Durable aluminium alloy sheet for decorative applications
US20050139296A1 (en) Aluminum alloy for producing roll-shaped products
JP3688763B2 (en) Antiglare management method for cold rolling roll for manufacturing thin sheet made of titanium or stainless steel having excellent antiglare property and method for manufacturing thin sheet for building
JP2007146234A (en) Surface treated steel sheet for liquid crystal front frame, its production method and liquid crystal front frame produced by the production method

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

RIN1 Information on inventor provided before grant (corrected)

Inventor name: DENS, JOSEPHUS MARIA THEOPHIEL

Inventor name: BAEKELANDT, JEAN PIERRE JULES

Inventor name: VERBOOM, ELS

Inventor name: GEIBEL, ANSGAR MARIA

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

17P Request for examination filed

Effective date: 20031002

AKX Designation fees paid

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

17Q First examination report despatched

Effective date: 20040517

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RTI1 Title (correction)

Free format text: METHOD FOR PRODUCING AN ALUMINIUM SHEET AND ALUMINIUM SHEET

RIN1 Information on inventor provided before grant (corrected)

Inventor name: VERBOOM, ELS

Inventor name: BAEKELANDT, JEAN PIERRE JULES

Inventor name: GEIBEL, ANSGAR MARIA

Inventor name: DENS, JOSEPHUS MARIA THEOPHIEL

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: E. BLUM & CO. PATENTANWAELTE

REG Reference to a national code

Ref country code: DK

Ref legal event code: T3

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: GR

Ref legal event code: EP

Ref document number: 20050403725

Country of ref document: GR

REF Corresponds to:

Ref document number: 60113772

Country of ref document: DE

Date of ref document: 20060216

Kind code of ref document: P

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2246997

Country of ref document: ES

Kind code of ref document: T3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060306

ET Fr: translation filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060629

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060630

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

26 Opposition filed

Opponent name: ALCAN TECHNOLOGY & MANAGEMENT AG

Effective date: 20060627

PLAX Notice of opposition and request to file observation + time limit sent

Free format text: ORIGINAL CODE: EPIDOSNOBS2

26 Opposition filed

Opponent name: ALCAN TECHNOLOGY & MANAGEMENT AG

Effective date: 20060627

Opponent name: NOVELIS, INC.

Effective date: 20060704

PLAF Information modified related to communication of a notice of opposition and request to file observations + time limit

Free format text: ORIGINAL CODE: EPIDOSCOBS2

PLBB Reply of patent proprietor to notice(s) of opposition received

Free format text: ORIGINAL CODE: EPIDOSNOBS3

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

REG Reference to a national code

Ref country code: CH

Ref legal event code: PFA

Owner name: CORUS ALUMINIUM N.V.

Free format text: CORUS ALUMINIUM N.V.#A. STOCLETLAAN 87#2570 DUFFEL (BE) -TRANSFER TO- CORUS ALUMINIUM N.V.#A. STOCLETLAAN 87#2570 DUFFEL (BE)

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060629

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

RDAF Communication despatched that patent is revoked

Free format text: ORIGINAL CODE: EPIDOSNREV1

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DK

Payment date: 20090622

Year of fee payment: 9

Ref country code: ES

Payment date: 20090629

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20090622

Year of fee payment: 9

Ref country code: SE

Payment date: 20090623

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20090623

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20090624

Year of fee payment: 9

Ref country code: FR

Payment date: 20090618

Year of fee payment: 9

RDAG Patent revoked

Free format text: ORIGINAL CODE: 0009271

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT REVOKED

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20090616

Year of fee payment: 9

Ref country code: GB

Payment date: 20090623

Year of fee payment: 9

Ref country code: GR

Payment date: 20090629

Year of fee payment: 9

27W Patent revoked

Effective date: 20090618

GBPR Gb: patent revoked under art. 102 of the ep convention designating the uk as contracting state

Effective date: 20090618

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF THE APPLICANT RENOUNCES

Effective date: 20051005

Ref country code: CH

Free format text: LAPSE BECAUSE OF THE APPLICANT RENOUNCES

Effective date: 20051005

REG Reference to a national code

Ref country code: SE

Ref legal event code: ECNC

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20090627

Year of fee payment: 9