Production of a hollow body e.g. fence posts with fixed struts from a plastic-coated metal strip material, comprises bringing final cross-sectional shape to the hollow body by cold-rolling

摘要

The production of a hollow body (1) e.g. fence posts with fixed struts from a plastic-coated metal strip material, comprises bringing final cross-sectional shape to the hollow body by cold-rolling. The longitudinal edges of the metal strip are guided on joints next to one another and are connected by a laser welding. During the shaping of the hollow body, the joint edge of the metal strip is positioned on a profile surface eccentric to middle surface in such a manner that projections and/or holes are bringable into a welding joint (3) free planer region. The production of a hollow body (1) e.g. fence posts with fixed struts from a plastic-coated metal strip material, comprises bringing final cross-sectional shape to the hollow body by cold-rolling. The longitudinal edges of the metal strip are guided on joints next to one another and are connected by a laser welding. During the shaping of the hollow body, the joint edge of the metal strip is positioned on a profile surface eccentric to middle surface in such a manner that projections and/or holes are bringable into a welding joint (3) free planer region. Before the laser welding, the free joint edges of the metal strip are subjected to a pre-treatment step. The free joint edges are straightened for cutting merged guidance by a mechanical shaving, -milling or -grinding. A partial removing of the plastic coating and/or the lacquer coating is carried out on the surfaces of the free joint edges. The welding joint area is subjected to a sealing after the laser weld. The sealing is made with a hot-melt adhesive sealing and/or a lacquer coating. A masking tape is applied in the hot-melt adhesive sealing. The sealing strip is kept in paint different from the color of the metal band. A lacquer hardened quickly under UV light, is sprayed by a spray head.