Seaming apparatus and method for cans

A method of joining a metal can body to a can end, said can end having a peripheral curl, said can body defining a longitudinal axis and having a peripheral flange, comprising the steps of:

• placing the can end over the can body;
• receiving a seaming chuck in said can end, said chuck having an anvil portion and a peripheral upper anvil wall, wherein said upper anvil wall is inclined relative to said longitudinal axis at an angle α greater than 6 degrees;
• and
• performing a seaming operation on said can end and can body with a seaming roll to form a seam, said seaming roll having a seaming surface for engaging said peripheral curl in a seaming operation to compress said peripheral curl against said peripheral flange and peripheral upper anvil wall to form a seam between said can end and said can body;
• wherein said seaming surface is inclined relative to said longitudinal axis by an angle β, wherein β is greater than about 4 degrees, and wherein β=α±up to about 4 degrees;
• and
• wherein said seaming roll and seaming chuck are arranged relative to each other such that said seam is formed such that thinning of the metal in said can body is substantially avoided.

An apparatus for use in forming a seam joining a can end to a can body, said can end having a peripheral curl, said can body defining a longitudinal axis and having a peripheral flange, comprising:

• a seaming roll having a seaming surface adapted for engaging said peripheral curl in a seaming operation to compress said peripheral curl against said peripheral flange and against a seaming chuck to form a seam therebetween;
• wherein said seaming surface is inclined relative to said longitudinal axis by an angle β of between 6 and 14 degrees;
• and wherein
• the seaming surface comprises a curved surface having a cross-sectional profile having upper and lower peripheral points at which said curved surface transitions to adjacent surfaces of said seaming roll, and wherein the measurement of the inclination of said seaming surface is measured by constructing a chord on said profile connecting said upper and lower points and measuring the inclination of said chord relative to the longitudinal axis.