Patent ID: 8813535

Claim:
A method for producing a band-shaped metal foil using a progressive tool carrier with individual tools being mounted in a common tool carrier, said metal foil being of a thickness less than 0.2 mm, and said metal foil having a primary structure comprising U-shaped waves and at least one secondary structure, the method comprising the following steps: stamping the metal foil; bending the metal foil to form the primary structure in the metal foil and wherein a part of the primary structure is formed in its final dimension; bending the metal foil to completely form the primary structure; bending the metal foil at least twice by 180 degrees to form a first secondary structure in its final dimensions and said first secondary structure having a shorter wavelength than the primary structure; bending the metal foil to form a second secondary structure in its final dimensions and said second secondary structure having a shorter wavelength than the primary structure; and whereby the first and second secondary structures are molded into the primary structure during the bending steps.