Method and installation for the production of an aluminum sheet with a textured surface

Abstract

A method for producing a sheet made of aluminum or an aluminum alloy, which is provided with a textured surface. According to the method, a cold rolled sheet is fed through the gap between two texturing rollers which are provided with a roughness pattern immediately after exiting a cold rolling mill, and the textured sheet is wound. The roughness pattern is transferred to the surface of the sheet by means of a force acting from the texturing rollers on the sheet. The installation for producing a cold rolled sheet made of aluminum or an aluminum alloy, which is provided with a textured surface, comprises a texturing rolling mill that encompasses texturing rollers and is disposed immediately after the cold rolling mill in the running direction (x) of the sheet. The method and installation make is possible to save a separate texturing pass and therefore one roller pass as opposed to methods known in prior art.

Description

BACKGROUND OF THE INVENTION [0001] The invention relates to a process and unit for producing a cold rolled strip of aluminium or an aluminium alloy with a textured surface comprising passing a cold rolled strip immediately after cold rolling through a roll gap of two textured rolls bearing a roughness pattern, wherein the roughness pattern is transferred to the surface of the strip as a result of the force of the textured rolls acting on the strip, and, thereafter, coiling the textured strip. [0002] In the automotive industry strips and sheets of aluminium alloys are employed for the manufacture of bodywork parts, whereby the sheets are shape-formed by deep drawing or stretch drawing. Lubricants have to be employed to carry out this deep drawing and other shape-forming steps. By pre-coating the strips or sheets in the rolling mill not only is the forming procedure simplified, but also optimal protection during transportation achieved. [0003] In a procedure commonly used today the st...

AI Technical Summary

Benefits of technology

[0010] The object of the invention is achieved by providing a process comprising passing a cold rolled strip immediately after cold rolling through a roll gap of two textured rolls bearing a roughness pattern, wherein the roughness pattern is transferred to the surface of the strip as a result of the force of the textured rolls acting on the strip, and, thereafter, coiling the textured strip.

[0013] In order to adjust the thickness as uniformly as possible over the whole breadth of the strip, the texturing rolls are preferably set at a constant roll force.

[0014] To endow the strip surface with the above mentioned property whereby it acts as substrate for a dry lubricant, the texturing rolls are—to advantage—roughened using electrical discharge texturing (EDT).

[0015] It has been found that the process according to the invention is also suitable for smoothing cold rolled strips. To that end it can also be proved advantageous to provide the texturing rolls with the conventional, simple roll grind that results in the so called “mill finish” surface quality. The rolls are only ground over their outer surface direction, i.e. the roll grind comprises a plurality of parallel grooves distrib-uted over the outer surface of the rolls.

[0010] The object of the invention is achieved by providing a process comprising passing a cold rolled strip immediately after cold rolling through a roll gap of two textured rolls bearing a roughness pattern, wherein the roughness pattern is transferred to the surface of the strip as a result of the force of the textured rolls acting on the strip, and, thereafter, coiling the textured strip.

[0016] Preferred is an arrangement in which the texturing rolls in the texturing roll stand are supported by intermediate rolls, which are in turn supported by backing rolls. The backing rolls may be arranged in several sets of rolls across the width of the intermediate rolls.

[0017] The backing rolls are preferably joined up in co-action to hydraulic pistons set at a constant force.

Problems solved by technology

In the case of an aluminium strip that has been produced in the normal manner using work rolls with a roll finish corresponding to a mill-finish surface texture, the lubricants exhibit relatively poor adhesion and distribution.

In practice this additional cold rolling pass incurs correspondingly greater production costs.

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