Can end formed from laminated metal sheet

A process for producing a can end comprising forming a laminate of metal sheet and polyester, the metal sheet comprising an aluminium alloy having a magnesium content of 0.8 to 2%, by weight and manganese content 0.6 to 1.5%, by weight wherein the process comprises thermally laminating a coextruded polyester film to a major surface of the metal sheet heated to a temperature T1 to form an initial laminate and reheating the initial laminate to a temperature T2, the coextruded polyester film comprising an inner layer and an outer layer with the inner layer adjacent to the metal sheet, wherein for melting temperatures Tm(i) and Tm(o) of the inner and outer layers respectively, Tm(i)<=T1<=Tm(o)+15.degree. C. and Tm(o)-3.degree. C.>=T2>=Tm(o)-16.degree. C., and the crystallinity factor of the polyester in the outer layer of the laminate is in the range of 0.05 to 0.5 as measured by X-ray diffraction and wherein the process further comprises forming the laminate into an end wherein the can end comprising central panel, a panel wall dependent from the periphery of the central panel, an annular countersink bead extending outwardly from the panel wall, a chuck wall extending upwardly from the periphery of the countersink bead and an annular seaming panel extending radially from the chuck wall such that the distance between the chuck wall and panel wall is between 0.85 mm and 1.0 mm measured at a height of 0.45 mm above the lowest part of the upper surface of the countersink bead.

A process for producing a can end comprising forming a laminate of metal sheet and polyester, the metal sheet comprising an aluminium alloy having a magnesium content of 0.8 to 2%, by weight and manganese content 0.6 to 1.5%, by weight wherein the process comprises thermally laminating a composite polyester film to a major surface of the metal sheet heated to a temperature T1 to form an initial laminate and reheating the initial laminate to a temperature T2, the composite polyester film comprising an inner layer and an outer layer With the inner layer adjacent to the metal sheet, wherein, for melting temperatures Tm(i) and Tm(o) of the inner and outer layers respectively, Tm(i)<=T1<=Tm(o)+15.degree. C. and Tm(o)-3.degree. C.>=T2>=Tm(o)-16.degree. C., and the crystallinity of the polyester in the outer layer of the laminate is in the range 0.05 to 0.5 as measured by X-ray diffraction;

• and wherein the process further comprises forming the laminate into a can end wherein the can end comprises a central panel, a panel wall dependent from the periphery of the central panel, an annular countersink bead extending outwardly from the panel wall, a chuck wall extending from the periphery of the countersink bead and annular seaming panel extending radially from the chuck wall such that the distance between the chuck wall and panel wall is between 0.85 mm and 1.0 mm as measured at a height of 0.45 mm above the lowest part of the upper surface of the countersink bead.