Process for the production of thin-walled hollow profiles which are composed of nonferrous metals and have small diameters

A process for the continuous production of radially closed hollow profiles having a wall thickness of less than 0.15 mm and a diameter smaller than 4 mm and which are composed of nonferrous metals, comprising:

• supply of a flat strip of the nonferrous metal at a first supply speed to a forming apparatus, where the thickness of the flat strip corresponds to the wall thickness of the radially closed hollow profile to be produced,
• continuous forming of the flat strip supplied into a shape corresponding to the radially closed hollow profile, where two opposite edges of the flat strip rest flush against one another in a contact region extending in the longitudinal direction of the radially closed hollow profile after forming,
• continuous welding of the edges resting flush against one another in the contact region without prior treatment to reduce reflections, where the edges to be welded are conveyed at the first supply speed past a welding region which is fixed in relation to an apparatus implementing the process, wherein an area in the welding region is heated by means of a laser which emits light having a wavelength of less than 600 nm and the heated area has a diameter which is less than 20% of the cross-sectional dimension of the radially closed hollow profile,
• taking-off of the welded radially closed hollow profile from the welding region, determining of a longitudinal tensile force on the flat strip of the nonferrous metal and/or the welded radially closed hollow profile,
• regulating a drive which supplies the flat strip and/or a drive which supplies the welded radially closed hollow profile to forming, and/or a drive which supplies the welded radially closed hollow profile to welding and/or a drive which supplies the welded radially closed hollow profile to taking-up in an uptake apparatus, and
• taking-up of the welded radially closed hollow profile in an uptake device.