Method and device for expanding a metal element

A method of expanding an elongated and at least regionally planar metal element that has two respective marginal regions oppositely disposed and extending in a longitudinal direction and a central region arranged therebetween and including cuts, the marginal regions of the metal element are moved apart transversely to the longitudinal direction and in parallel with a planar extent of the metal element such that connection portions of the central region formed by the cuts and connecting the two respective marginal regions to one another are folded, the method comprising:

• applying a force transverse to the planar extent of the metal element to displace the two respective marginal regions with respect to one another transversely to the planar extent of the metal element to form a displaced state;
• and
• subsequently moving apart the two respective marginal regions in the displaced state,
• the two respective marginal regions displaced with respect to one another by a shape corrected displacement that corresponds to at least three times a thickness of the metal element.

A method of expanding an elongated and at least regionally planar metal element that has two respective marginal regions oppositely disposed and extending in a longitudinal direction and a central region arranged therebetween and including cuts, the marginal regions of the metal element are moved apart transversely to the longitudinal direction and in parallel with a planar extent of the metal element such that connection portions of the central region formed by the cuts and connecting the two respective marginal regions to one another are folded, the method comprising:

• applying a force transverse to the planar extent of the metal element to displace the two respective marginal regions with respect to one another transversely to the planar extent of the metal element to form a displaced state;
• and
• subsequently moving apart the two respective marginal regions in the displaced state,
• an embossed pattern embossed in the central region before or during the displacing of the two respective marginal regions.