WO2012098060A1

WO2012098060A1 - Exterior wall metal sheet made of aluminium having a high surface roughness

Info

Publication number: WO2012098060A1
Application number: PCT/EP2012/050516
Authority: WO
Inventors: Rolf Meyer; Timo WEIHBERGER; Martin Jahnke; Michael RÖSNER-KUHN; Ulrich Hampel; Andreas Siemen; Wilhelm Schenkel; Sandra Eberhard; Volker Denkmann
Original assignee: Hydro Aluminium Rolled Products Gmbh
Priority date: 2011-01-17
Filing date: 2012-01-13
Publication date: 2012-07-26
Also published as: PL2665842T3; DK2665842T3; PT2665842E; DE202012012923U1; ES2533054T3; EP2665842A1; EP2665842B1

Abstract

The invention relates to an exterior wall metal sheet or strip made of aluminium or an aluminium alloy of the type AA 5005 and a process for the production thereof. The problem of providing an alternative to the steel sheets used hitherto in the field of exterior walls of buildings is solved according to the teaching of the present invention by an exterior wall metal sheet or strip made of aluminium or an aluminium alloy of the type AA 5005 by means of the exterior wall metal sheet having a thickness of from > 2 mm to 4 mm and an average roughness R_a of from 1.2 to 1.7 µm, where the average peak-to-valley height R_zis from 7 to 12 µm measured in accordance with DIN EN ISO 4287.

Description

EXTERNAL FACADE SHEET ALUMINUM WITH HIGHER

surface roughness

The invention relates to a Fassendenblech or -band made of aluminum or an aluminum alloy of the type AA 5005 and a process for its preparation.

Exterior facades of buildings are often clad with brushed steel sheets, which due to their rough

Surface have a special look. The problem with the use of steel sheets, however, is that they have a high weight and therefore an increased effort in terms of mounting structure and overall higher strength requirements for the facade to which they are attached, provide. Furthermore, steel sheets corrode, so expensive stainless steels must be used. In the field of furniture production, for interior ceiling panels or in the kitchen area, the use of anodized and anodized aluminum sheets is known, which have a so-called "butler-finish" structure due to the grinding structure of the rolls. The furniture, ceiling panels, im

Kitchens, sheet metal used for stand construction and trade fair construction as well as for doors and window accessories usually have a thickness of up to 1.5 mm or significantly less and are supplied with a maximum of 10 pm thick anodizing layer on the visible side. A use of this

Aluminum alloy sheets for facades were previously not possible due to the low thicknesses. In addition, the use of aluminum or aluminum alloys in the field of

Exterior facades problematic, since in particular problems were observed with a constant surface appearance under the influence of the weather.

The object of the present invention is to that extent

underlying, an alternative to the previously used

To propose steel sheets in the area of the outer facades of buildings.

The object indicated is achieved according to the teachings of the present invention by a cladding sheet or strip made of aluminum or an aluminum alloy of type AA 5005 in that the cladding sheet has a thickness of more than 2 mm to 4 mm and an average roughness R _a of 1 , 2 to 1.7 μπι, the mean roughness R _z 7 to 12 μπι measured according to DIN EN ISO 4287.

The mentioned Rautiefewerte ensure an attractive appearance, which is similar to that of steel sheets.

In addition, ensure sheet metal or strip thicknesses of more than 2 mm and a maximum of 4 mm sufficient strength of the cladding sheet or strip, for example compared

Wind influences, preferably sheet metal or strip thicknesses of 2.5 mm to 4 mm are used. On the other hand, even a cladding sheet or strip with the maximum thickness of 4 mm ensures a significant weight advantage over steel sheets with similar strength, so that elaborate

Fixing structures on the facade can be omitted. According to a first embodiment of the facade sheet or bands, the stroke length, ie the length of the roll structures pressed in on the sheet or strip, is preferably 6 mm to 15 mm, preferably 8 mm to 12 mm, particularly preferably 10 mm. The selected parameters provide the surface of the aluminum alloy strip or sheet with a

brushed steel almost identical surface appearance.

According to a further embodiment of the facade sheet, the cladding sheet has an anodized layer with a thickness of 15 μm to 30 μm, preferably 18 μm to 22 μm or 20 μm to 25 μm. It has been shown that the previously applied anodized layers of 10 pm thickness are not sufficient in the

Scope of the exterior facades sufficient

To ensure corrosion protection and a permanently attractive appearance. If cladding sheets with an anodized layer with a thickness of 18 to 22 pm are used, a cladding sheet or strip optimized in terms of production costs can be provided while, at the same time, surface appearance on exterior facades remains constant. Also advantageous is an Eloxalschichtdicke of more than 20 m to 25 pm, because these ensure at low overhead in production a further improved corrosion protection and thus improved longevity of the cladding especially in high air pollution. Eloxalschichten with more than 30 pm thickness, however, again show a lower

Protection. The Fasssadenbleche or bands are then ideally suited for an external facade.

Finally, the facade sheet can be additionally colored during the anodization, so that even colored optics can be provided.

The cladding sheet or strip preferably consists of an aluminum alloy of the type AA 5005 with a maximum of 0.30% by weight. Si, at most 0.7 wt.% Fe, at most 0.20 wt.% Cu, at most 0.20 wt.% Mn, 0.50 wt.% To 1.1 wt 0.10% by weight Cr, at most 0.25% by weight Zn and unavoidable

Impurities maximum 0.05 wt .-% individually and a maximum of 0.15 wt .-%. This aluminum alloy provides sufficient strength with good corrosion resistance and can easily become one

Façade sheet or strip to be processed. According to a second teaching of the present invention, the object is achieved by a method comprising the following method steps:

- a rolling billet of aluminum or one

Aluminum alloy of type AA 5005 is cast,

- The ingot is scalped, hot and then cold rolled, with the last cold roll pass of the

Abwalzgrad 15% to 30% and the work rolls have a surface structure which a medium

Roughness R _a of 1.2 μηα to 1.7 μτχι produce with a surface roughness R _z of 7 to 12 μπι on the strip surface.

It has been found that in particular the production of the strip or sheet by casting a rolled bar and

Hot rolling of the rolling ingot and subsequent cold rolling of the hot strip a homogeneous surface roughness on the finished facade sheet or facade tape can be achieved. As already stated above, the cladding sheet produced from a corresponding strip not only has sufficient strength and lighter weight than a steel sheet, but also a very similar one Surface appearance. It also ensures a very good

Transfer of the surface structure of the work rolls to the aluminum alloy strip in the last cold rolling pass

Rolling degree of preferably 20% in the last cold rolling pass.

If the surface structure produced on the belt has a stroke length of 6 to 15 mm, preferably 8 to 12 mm and particularly preferably 10 mm, a surface very similar to the brushed steel can be produced in the belt.

According to a further variant of the method only one work roll is used in the last cold rolling pass, which has a surface structure having a mean roughness R _a of 1.2 ^μ η τι μνα to 1.7 with an average roughness depth R _z of 7 μπι to 12 μπι generated on the tape surface. In this case, a distinction can be clearly made between the inner side and the outward-facing, facade-forming side of the facade panel. The aluminum strip produced in this way is preferably reshaped and then first, ie anodized in the formed state, so as not to damage the anodized layer during forming.

As previously stated, the reshaped

Facade sheet with an anodizing layer thickness of 15 to 30 μπι, preferably 18 to 22 μπι or 20 μηα to 25 μιη anodized to meet the specific requirements of the environment of the cladding panels. In addition, the invention is based on

Embodiments in conjunction with the drawing

be set out. The drawing shows in Fig. 1 is a schematic view of an outer facade of a

Building, Fig. 2 sectional view of an embodiment

of a facade sheet and

Fig. 3a) b) is a schematic perspective view of the

Strippers of two different ones

Cold rolling stands for the production of

Surface structure of the facade sheet.

Fig. 1 shows in a highly schematic perspective view of an outer facade 1 of a building, which is clad with cladding sheets 2 according to the invention. The

Facade panels consist of an aluminum alloy of the type AA 5005 and have a thickness of more than 2 mm to a maximum of 4 mm, preferably 2.5 to 4 mm in thickness. Due to the sheet thickness and the resulting low weight, the inventive

Aluminum sheets are easily attached to a facade and also provide sufficient

Strength, for example against wind load

evoked forces.

The surface of the facade panels 2 is with the

according to the invention and has a very similar to a brushed steel surface

Surface appearance. The surface of the cladding sheet has an average roughness R _a of 1.2 μτ to 1.7 μπι, wherein the roughness R _z of 7 μτ to 12 μιτι measured according to DIN EN ISO 4287. In addition, the stroke length of the roughness structure is 8 mm to 12 mm, preferably the stroke length is 10 mm. Nevertheless, the facade panel 2 is much lighter than a brushed steel sheet. That in Figure 2 in a sectional view

Facade plate 2 shown has an Eloxalschicht of 15 μηα to 30 μπι, preferably 18 μηα to 22 μιη on. These

Eloxalschicht ensures that the

Aluminum alloy sheet is corrosion resistant and

can have an individual color at the same time. An improved corrosion protection can be achieved by a preferably 20 μ ^η α to 25 μηα thick anodized layer.

Painting this facade sheet is not necessary because it is extremely corrosion resistant. In addition, it can be colored during the anodization, wherein the color penetrates into the pores remaining in the anodized layer and there

remains. The facade panel 2 according to the invention is also significantly lighter than a running in steel, brushed facade panel.

Since a forming process can possibly damage the anodized layer, the anodized layer is preferably applied after the forming of the sheet or strip. Figures 3a) and 3b) show in a schematic, perspective view of the work rolls 3, 3 ', 4, 4' of the cold rolling mill of the last cold rolling pass, which bring the surface structure in the aluminum alloy strip 5, 5 'and to a final thickness of more than 2 mm to 4 mm, preferably cold rolled to 2.5 mm to 4 mm. In contrast to the work rolls 3, 4 in FIG. 3 a), in FIG. 3 b) only one work roll 3 'has the necessary surface structure for the facade sheet on. The sheet thus produced therefore has a clearly visible, provided with the surface structure preferred side for the facade. A process-reliable impression of the surface structure in the band is by a

Rolling degree of 15% to 30%, preferably 20% achieved in the last cold rolling pass.

Claims

Patent claims

Façade sheet or strip consisting of aluminum or an aluminum alloy of type AA 5005, the

Facade sheet has a thickness of more than 2 mm to a maximum of 4 mm and the surface of the cladding sheet has an average roughness R _a of 1.2 μηα to 1.7 pm and the surface roughness R _z of 7 pm to 12 pm. measured according to DIN EN ISO 4287.

Facade sheet or strip according to claim 1,

The stroke length of the roughness structure is 6 mm to 15 mm.

Façade sheet or strip according to claim 1 or 2,

The aluminum strip or sheet has an anodized layer with a thickness of 15 μm to 30 μm, preferably a thickness of 18 μm to 22 μm or 20 μm to 25 μm.

A method of manufacturing a cladding sheet or strip according to any one of claims 1 to 3,

d a d u r c h e s e n c i n e s, d a s s

- a rolling billet of aluminum or one

Aluminum alloy of type AA 5005 is cast,

- The scalped ingot warm and then cold rolled to a final thickness of more than 2 mm to 4 mm, in the last cold rolling the degree of rolling 15% to 30%, preferably 20% and the work rolls of the last cold roll pass a surface texture which produce an average roughness R _a of 1.2 pm to 1.7 pm at a mean roughness R _z of 7 pm to 12 pm on the strip surface. 5. The method according to claim 4,

The stroke length of the roughness structure formed on the cold-rolled strip is 6 mm to 15 mm. 6. The method according to claim 4 or 5,

characterized in that only one work roll has a surface structure which produces an average roughness R _a of 1.2 pm to 1.7 pm with an average roughness R _z of 7 pm to 12 pm on the strip surface.

Method according to one of claims 4 to 6,

From the cold-rolled aluminum alloy strip, sheets are cut, which are formed into a facade sheet and anodized after forming.

Method according to one of claims 4 to 7,

The converted drum sheet is anodized with an anodization layer thickness of 15 pm to 30 pm, preferably 18 pm to 22 pm or 20 pm to 25 pm.