METHOD FOR MANUFACTURING AN ALUMINIUM TUBE, A METHOD FOR MANUFACTURING AN ALUMINIUM SLUG, AN ALUMINIUM TUBE AND AN ALUMINIUM SLUG

Abstract

A method for manufacturing an aluminium tube, including providing a slug of an aluminium alloy consisting of >98.4% by weight of Al, 0.10% by weight to 0.30% by weight of Si, 0.25% by weight to 0.45% by weight of Fe, 0.01% by weight to 0.08% by weight of Cu, 0.15% by weight to 0.40% by weight of Mn, at most 0.15% by weight of Mg, at most 0.05% by weight of Zn, at most 0.05% by weight of Cr, at most 0.05% by weight of Ni, at most 0.05% by weight of Ti and at most 0.05% by weight of other impurities, wherein the aforementioned ingredients of the aluminium alloy add to 100% by weight, and impact extrusion of the slug to form an aluminium tube having a shoulder and a neck.

Claims

1. A method for manufacturing a collapsible or squeezable aluminium tube comprising the steps of: a) providing a slug comprising or consisting of an aluminium alloy consisting of >98.4% by weight of Al, 0.10% by weight to 0.30% by weight of Si, 0.25% by weight to 0.45% by weight of Fe, 0.01% by weight to 0.08% by weight of Cu, 0.15% by weight to 0.40% by weight of Mn, at most 0.15% by weight of Mg, at most 0.05% by weight of Zn, at most 0.05% by weight of Cr, at most 0.05% by weight of Ni, at most 0.05% by weight of Ti and at most 0.05% by weight of other impurities, with the proviso that the aforementioned ingredients of the aluminium alloy add to 100% by weight, and b) impact extrusion of the slug to form an aluminium tube having a shoulder and a neck.

2. The method according to claim 1, wherein the aluminium alloy consists of: >98.7% by weight of Al, 0.15% by weight to 0.25% by weight of Si, 0.30% by weight to 0.40% by weight of Fe, 0.02% by weight to 0.06% by weight of Cu, 0.20% by weight to 0.30% by weight of Mn, at most 0.05% by weight of Mg, at most 0.05% by weight of Zn, at most 0.05% by weight of Cr, at most 0.05% by weight of Ni, at most 0.05% by weight of Ti and at most 0.05% by weight of other impurities, with the proviso that the aforementioned ingredients of the aluminium alloy add to 100% by weight.

3. The method according to claim 1, wherein the slug is produced by using post-consumer recycled aluminium scrap.

4. The method according to claim 1, wherein the slug is produced of >60% by weight, in particular >75% by weight, preferably >90% by weight, of post-consumer recycled aluminium scrap, based on the total weight of the slug.

5. The method according to claim 1, wherein the slug is produced by blending at least one fraction of post-consumer recycled aluminium scrap with at least one fraction of primary aluminum alloy and/or at least one fraction of post-industrial recycled aluminium scrap.

6. The method according to claim 3, wherein the post-consumer recycled aluminium scrap is produced from aluminium cans, in particular aluminium aerosol cans, and/or aluminium tubes.

7. The method according to claim 1, wherein the slug is produced carrying out the following steps, expediently in chronological order: a.sub.1) providing at least one fraction of post-consumer recycled aluminium scrap or providing at least one fraction of post-consumer recycled aluminium scrap and at least one fraction of post-industrial recycled aluminium scrap and/or at least one fraction of primary aluminium alloy, a.sub.2) melting the at least one fraction of post-consumer recycled aluminium scrap to a molten mass or melting the at least one fraction of post-consumer recycled aluminium scrap and the at least one fraction of post-industrial recycled aluminium scrap and/or the at least one fraction of primary aluminium alloy to a molten mass, a.sub.3) controlling the composition of the molten mass and optionally adding alloying elements to the molten mass, a.sub.4) casting of the molten mass to a strip or casting of a remolten mass to a strip, a.sub.5) hot rolling of the strip, a.sub.6) cold rolling of the hot rolled strip and a.sub.7) forming a slug from the cold rolled strip, wherein the steps/step a) and/or b) and/or c) are/is carried out such that the molten mass comprises or consists of an aluminium alloy consisting of >98.4% by weight of Al, 0.10% by weight to 0.30% by weight of Si, 0.25% by weight to 0.45% by weight of Fe, 0.01% by weight to 0.08% by weight of Cu, 0.15% by weight to 0.40% by weight of Mn, at most 0.15% by weight of Mg, at most 0.05% by weight of Zn, at most 0.05% by weight of Cr, at most 0.05% by weight of Ni, at most 0.05% by weight of Ti and at most 0.05% by weight of other alloying elements or other impurities, with the proviso that the aforementioned ingredients of the aluminium alloy add to 100% by weight, and the molten mass has a proportion of the post-consumer recycled aluminium scrap >60% by weight, in particular >75% by weight, preferably >90% by weight, based on the total weight of the molten mass.

8. The method according to claim 1, wherein the method further comprises the following steps, expediently in chronological order: c) cutting the aluminium tube, expediently at a rear end of the aluminium tube, wherein the rear end is arranged opposite to an aluminium tube's end having a shoulder and a neck, d) forming a thread, in particular an external thread, preferably an external circular thread or external oval thread, on or around the neck of the aluminium tube, e) annealing the aluminium tube, f) applying a coating, in particular lacquer, on an interior surface of the aluminium tube, g) curing of the coating, in particular lacquer, applied on the interior surface of the aluminium tube, h) applying a coating, in particular base coating, on an exterior surface of the aluminium tube, i) drying the coating, in particular base coating, applied on the exterior surface of the aluminium tube, j) printing the coating, in particular base coating, applied and dried on the exterior surface of the aluminium tube, k) capping the aluminium tube, l) applying a latex coating or a heat-sealable varnish on an interior surface of the aluminium tube which is close to the rear end of the aluminium tube, i.e. the end of the aluminium tube which is arranged opposite to the aluminium tube's end having the shoulder and neck, and m) optionally packaging the aluminium tube.

9. A squeezable or collapsible aluminium tube, wherein the aluminium tube is produced or producible by means of a method according to claim 1 and/or comprises or consists of an aluminium alloy consisting of: >98.4% by weight of Al, 0.10% by weight to 0.30% by weight of Si, 0.25% by weight to 0.45% by weight of Fe, 0.01% by weight to 0.08% by weight of Cu, 0.15% by weight to 0.40% by weight of Mn, at most 0.15% by weight of Mg, at most 0.05% by weight of Zn, at most 0.05% by weight of Cr, at most 0.05% by weight of Ni, at most 0.05% by weight of Ti and at most 0.05% by weight of other impurities, with the proviso that the aforementioned ingredients of the aluminium alloy add to 100% by weight.

10. The squeezable or collapsible aluminium tube according to claim 9, wherein the aluminium alloy consists of: >98.7% by weight of Al, 0.15% by weight to 0.25% by weight of Si, 0.30% by weight to 0.40% by weight of Fe, 0.02% by weight to 0.06% by weight of Cu, 0.20% by weight to 0.30% by weight of Mn, at most 0.05% by weight of Mg, at most 0.05% by weight of Zn, at most 0.05% by weight of Cr, at most 0.05% by weight of Ni, at most 0.05% by weight of Ti and at most 0.05% by weight of other impurities, with the proviso that the aforementioned ingredients of the aluminium alloy add to 100% by weight.

11. The squeezable or collapsible aluminium tube according to claim 9, wherein the aluminium tube is made of >60% by weight, in particular >75% by weight, preferably >90% by weight, of post-consumer recycled aluminium scrap, based on the total weight of the aluminium tube.

12. The squeezable or collapsible aluminium tube according to claim 9, the aluminium tube has a shoulder thickness from 0.2 mm to 0.7 mm, in particular 0.2 mm to 0.5 mm, preferably 0.15 mm to 0.4 mm.

13. The squeezable or collapsible aluminium tube according to claim 9 the aluminium tube has: a shoulder thickness <0.7 mm and a diameter from >40 mm to 50 mm or a shoulder thickness <0.6 mm and a diameter from >32 mm to 40 mm or a shoulder thickness <0.5 mm and a diameter from >25 mm to 32 mm or a shoulder thickness <0.4 mm and a diameter from 11 mm to 25 mm.

14. An aluminium slug comprising or consisting of an aluminium alloy consisting of: >98.4% by weight of Al, 0.10% by weight to 0.30% by weight of Si, 0.25% by weight to 0.45% by weight of Fe, 0.01% by weight to 0.08% by weight of Cu, 0.15% by weight to 0.40% by weight of Mn, at most 0.15% by weight of Mg, at most 0.05% by weight of Zn, at most 0.05% by weight of Cr, at most 0.05% by weight of Ni, at most 0.05% by weight of Ti and at most 0.05% by weight of other impurities, with the proviso that the aforementioned ingredients of the aluminium alloy add to 100% by weight, wherein the aluminium slug is made of >60% by weight, in particular >75% by weight, preferably >90% by weight, of post-consumer recycled aluminium scrap, based on the total weight of the aluminium slug.

15. The aluminium slug according to claim 14, wherein the aluminium alloy consists of: >98.7% by weight of Al, 0.15% by weight to 0.25% by weight of Si, 0.30% by weight to 0.40% by weight of Fe, 0.02% by weight to 0.06% by weight of Cu, 0.20% by weight to 0.30% by weight of Mn, at most 0.05% by weight of Mg, at most 0.05% by weight of Zn, at most 0.05% by weight of Cr, at most 0.05% by weight of Ni, at most 0.05% by weight of Ti and at most 0.05% by weight of other impurities, with the proviso that the aforementioned ingredients of the aluminium alloy add to 100% by weight.

Description

EXAMPLE SECTION

[0234] 95% by weight of post-consumer recycled aluminium scrap from used aerosol aluminium cans and used aluminium tubes was supplied as ingots together with 5% by weight of post-industrial recycled aluminium scrap from the production of collapsible tubes made out of EN-AW 1070A alloy. The blended scrap material was molten and the melt composition was adjusted to the following composition (in % by weight):

[0235] Al: 99.15

[0236] Si: 0.18

[0237] Fe: 0.37

[0238] Cu: 0.03

[0239] Mn: 0.24

[0240] Mg: <0.01

[0241] Cr: <0.01

[0242] Zn: 0.01

[0243] Ti: 0.01

[0244] The melt was then casted to an aluminium strip from which slugs were stamped out. Subsequently, the slugs were annealed at a temperature of around 500° C. to 520° C. for around 2 hours to 3 hours, followed by a cooling step at a cooling rate of lower than 0.05 K/s. The slugs prepared in such a way had a diameter of 24.7 mm and a thickness of 3.6 mm each.

[0245] From these slugs, tubes were formed by means impact extrusion (press type Herlan CP55) with a final length of 125 mm and a diameter of 25 mm, with two different shoulder thickness values (0.64 mm as reference and 0.22 mm as reduced thickness).

[0246] After the annealing process at about 380° C., an internal coating comprising a solvent-based epoxy-phenolic lacquer was applied by spraying which was then cured in a continuous polymerization oven at about 260° C. Subsequently, an external coating based on a solvent-based modified polyester lacquer was applied and then dried in a drying furnace at about 110° C. After a further printing step, the external coating was cured together with a printing layer in another furnace at about 175° C.

[0247] The following physical properties/dimensions of the tubes were compared: [0248] diameter measured according to DIN EN 13046 [0249] length measured according to DIN EN 13046 [0250] shoulder thickness measured according to DIN EN 13046 [0251] thickness membrane measured according to DIN 5059-1 [0252] porosity measured according to DIN EN 15384-1, DIN EN 15384-2 and [0253] annealing grade measured according to DIN EN 16285.

[0254] The obtained results are shown in the below table 1:

TABLE-US-00001 TABLE 1 summary of the obtained results Comparative Specification example Example Standard Diameter 24.8-25.1 mm  24.9 mm  24.89 mm DIN EN 13046 Length 124.5-125.5 125.06 mm 124.92 mm DIN EN 13046 shoulder  0.5-0.8 mm  0.64 mm  0.22 mm DIN EN 13046 thickness thickness 0.06-0.14 mm  0.12 mm  0.11 mm DIN 5059-1 membrane porosity    <=25 mA  11.66 mA  7.27 mA DIN EN 15384-2 Deformation   8-13 mm  10.38 mm  9.33 mm DIN EN 16285 of tube body

[0255] It can be seen that the tubes with the lower shoulder thickness also showed a lower deformation of the tube body in the “guillotine test” (according to DIN EN 16285) which is equivalent to a lower hardness compared to the comparative example (9.33 mm compared to 10.38 mm)