Aluminum alloy container end and sealed container thereof

Claim 2

IN AN ALUMINUM ALLOY CONTAINER END HAVING A REMOVABLE PORTION DEFINED BY AT LEAST ONE SCORE LINE IN THE OUTER SURFACE OF SAID CONTAINER END CAN END SAID SCORE LINE DESCRIBING A CLOSED PERIMETER FOR SAID REMOVABLE PORTION AND EXTENDING SUFFICIENTLY THROUGH ITS THICKNESS TO LOCALLY WEAKEN IT TO RENDER SAID PORTION DEFINED THEREBY MANUALLY REMOVABLE SUBSTANTIALLY BY TEARING TO PROVIDE AN ACCESS OPENING IN SAID CONTAINER END, THE CONTAINER END BEING PRODUCED FROM AN ALUMINUM ALLOY SHEET, THE IMPROVEMENT WHEREIN SAID ALUMINUM ALLOY SHEET IS PROVIDED AS A COMPOSITE SHEET COMPOSED OF A CORE ALLOY LAYER CONTAINING AT LEAST 90 PERCENT ALUMINUM, 4 TO 6 PERCENT MG AND UP TO 1% MN AND AN INSIDE CLADDING LAYER COMPOSED OF AN ALLOY CONSISTING ESSENTIALLY OF 1 TO 1.5 PERCENT ZN, THE BALANCE AL OF AT LEAST 99.2 PERCENT PURITY, SAID IMPROVEMENT SERVING TO IMPROVE RESISTANCE TO PERFORATION ATTACK IN THE REGION OF SAID SCORE LINE.

Claim 3

In the container end according to claim 1 the further improvement wherein the cladding of said composite sheet contains 1.1 to 1.4 percent Zn and not more than 0.2 percent of elements other than Al and Zn.

Claim 4

In the container end according to claim 1 the further improvement wherein the core alloy of said composite sheet contains 4 to 5.5 percent Mg and 0.2 to 0.7 percent Mn.

Claim 5

In the container end according to claim 1 the further improvement wherein the cladding of said composite sheet constitutes from 2 to 10 percent of the total composite thickness.

Claim 6

In the container end according to claim 1 the further improvement wherein the core of said composite sheet is clad on both sides with said cladding.

Claim 7

In the container end according to claim 1 the further improvement wherein the composite sheet is in a strain hardened and partially relaxed condition resulting from a cold rolling reduction of at least 90 percent in thickness followed by a thermal exposure which partially relaxes the strains.

Claim 8

In an aluminum alloy container end having a removable portion defined by at least one score line in the outer surface of said container end can end said score line describing a closed perimeter for said removable portion and extending sufficiently through its thickness to locally weaken it to render said portion defined thereby manually removable substantially by tearing to provide an access opening in said container end, the container end being produced from an aluminum alloy sheet, the improvement wherein said aluminum alloy sheet is provided as a composite sheet composed of a core layer containing at least 90 percent aluminum, 4 to 6 percent Mg and up to 1 percent Mn, an inside cladding layer composed of an alloy consisting essentially of 1 to 1.5 percent Zn, the balance aluminum of at least 99.2 percent purity, said container end having a protective organic coating applied to the underside surface beneath said score line, said coating being disturbed in the region beneath the score line, said improvement serving to improve resistance to perforation attack in the region of said score line.

Claim 9

In an aluminum alloy container end having a removable portion defined by at least one score line in the outer surface of said container end can end said score line describing a closed perimeter for said removable portion and extending sufficiently through its thickness to locally weaken it to render said portion defined thereby manually removable substantially by tearing to provide an access opening in said container end, the container end being produced from an aluminum alloy sheet, the improvement wherein said aluminum alloy sheet is provided as a composite sheet composed of a core layer containing at least 90 percent aluminum, 4 to 6 percent Mg and up to 1 percent Mn, an inside cladding layer composed of an alloy consisting essentially of 1 to 1.5 percent Zn, the balance aluminum of at least 99.2 percent purity, said container end having a protective organic coating applied to the underside surface beneath said score line, said coating being disturbed in the region beneath the score line, said improvement serving to improve resistance to perforation attack in the region of said score line.

Claim 10

In a container end of an aluminum alloy of the type containing 4 to 6 percent magnesium and having a removable portion defined by at least one score line in the outer surface of said container end can end said score line describing a closed perimeter for said removable portion and extending sufficiently through its thickness to locally weaken it to render said portion defined thereby manually removable substantially by tearing to provide an access opening in said container end, said core layer having Mg-Al precipitate particles situated preferentially along grain boundaries and <111> planes in the region of said score line, said particles being more closely spaced in said region than in the remainder of said core alloy layer of said container end and being anodic with respect to the matrix of said core, the container end being produced from sheet of said type of aluminum alloy, the improvement wherein said sheet is provided as a composite sheet composed of a core alloy layer consisting essentially of at least 92.5 percent Al, 4 to 6 percent Mg and 0.2 to 0.7 percent Mn and an inside cladding layer composed of an aluminum base alloy consisting essentially of aluminum and 1 to 1.5 percent Zn and not more than 0.8 percent of elements other than Al and Zn, said improvement serving to improve resistance to perforation attack in the region of said score line.

Claim 11

In a container end of an aluminum alloy of the type containing 4 to 6 percent magnesium and having a removable portion defined by at least one score line in the outer surface of said container end can end said score line describing a closed perimeter for said removable portion and extending sufficiently through its thickness to locally weaken it to render said portion defined thereby manually removable substantially by tearing to provide an access opening in said container end, said core layer having Mg-Al precipitate particles situated preferentially along grain boundaries and <111> planes in the region of said score line, said particles being more closely spaced in said region than in the remainder of said core alloy layer of said container end and being anodic with respect to the matrix of said core, the container end being produced from sheet of said type of aluminum alloy, the improvement wherein said sheet is provided as a composite sheet composed of a core alloy layer consisting essentially of at least 92.5 percent Al, 4 to 6 percent Mg and 0.2 to 0.7 percent Mn and an inside cladding layer composed of an aluminum base alloy consisting essentially of aluminum and 1 to 1.5 percent Zn and not more than 0.8 percent of elements other than Al and Zn, said improvement serving to improve resistance to perforation attack in the region of said score line.

Claim 12

In a hermetically sealed container the contents of which are corrosive to aluminum, said container having end and side wall portions to define said container and including an aluminum alloy panel having a removable portion defined by at least one score line in the outer surface of said panel and extending sufficiently through its thickness to locally weaken it to render said portion defined thereby manually removable substantially by tearing to provide an access opening in said panel, said aluminum alloy panel being produced from an aluminum alloy sheet, the improvement wherein said sheet is provided as a composite sheet composed of a core alloy layer containing at least 90 percent aluminum, 4 to 6 percent magnesium and up to 1 percent manganese and an inside cladding layer composed of an alloy consisting essentially of 1 to 1.5 percent zinc, the balance aluminum of at least 99.2 percent purity, said improvement serving to improve resistance to perforation attack in the region of said score line.

Claim 13

In a hermetically sealed container the contents of which are corrosive to aluminum, said container having end and side wall portions to define said container and including an aluminum alloy panel having a removable portion defined by at least one score line in the outer surface of said panel and extending sufficiently through its thickness to locally weaken it to render said portion defined thereby manually removable substantially by tearing to provide an access opening in said panel, said aluminum alloy panel being produced from an aluminum alloy sheet, the improvement wherein said sheet is provided as a composite sheet composed of a core alloy layer containing at least 90 percent aluminum, 4 to 6 percent magnesium and up to 1 percent manganese and an inside cladding layer composed of an alloy consisting essentially of 1 to 1.5 percent zinc, the balance aluminum of at least 99.2 percent purity, said improvement serving to improve resistance to perforation attack in the region of said score line.

Claim 14

In the container according to claim 9 wherein a food or beverage commodity occupies the container.

Claim 15

In a hermetically sealed container, housing a food or beverage commodity corrosive to aluminum having end and side wall portions to define said container and including an aluminum alloy panel, said panel having a removable portion defined by at least one score line in the outer surface of said panel and extending sufficiently through its thickness to locally weaken it to render said portion defined thereby manually removable substantially by tearing to provide an access opening in said panel, said panel being produced from aluminum alloy sheet, the improvement wherein the said sheet is provided as an aluminum composite sheet composed of a core alloy layer containing at least 90 percent aluminum, 4 to 6 percent magnesium and up to 1 percent manganese and a cladding layer metallurgically bonded to the core alloy and composed of an alloy consisting essentially of 1 to 1.5 percent zinc, the balance aluminum of at least 99.2 percent purity, said improvement serving to improve resistance to perforation attack in the region of said score line.

Claim 16

In a hermetically sealed container, housing a food or beverage commodity corrosive to aluminum having end and side wall portions to define said container and including an aluminum alloy panel, said panel having a removable portion defined by at least one score line in the outer surface of said panel and extending sufficiently through its thickness to locally weaken it to render said portion defined thereby manually removable substantially by tearing to provide an access opening in said panel, said panel being produced from aluminum alloy sheet, the improvement wherein the said sheet is provided as an aluminum composite sheet composed of a core alloy layer containing at least 90 percent aluminum, 4 to 6 percent magnesium and up to 1 percent manganese and a cladding layer metallurgically bonded to the core alloy and composed of an alloy consisting essentially of 1 to 1.5 percent zinc, the balance aluminum of at least 99.2 percent purity, said improvement serving to improve resistance to perforation attack in the region of said score line.