Abstract: A method for generating an electric control signal driving apparatus to produce a topological structure on a workpiece, in particular to produce a leather structure. Initially, at least, two different signal components are generated and the control signal is then formed by their addition. One signal component may correspond to a fine structure and another for instance to a coarse structure or to a line structure. In this manner, the portions of the structure can be determined and processed one at a time to imitate a natural leather surface.

Abstract: To make a velour needle felt, an optionally pre-needled staple fiber non-woven web is applied to a revolving brushlike support and is then needled to form a pile on the side which faces the support. To increase the resistance of the velour needle felt to distortion, it is proposed that a layer which has a higher resistance to distortion than the staple fiber non-woven web and consists particularly of a spun-bonded web is applied to the brushlike support before the staple fiber non-woven web is applied thereto and that the pile fibers are pulled in the needling operation through the layer which has the higher resistance to distortion.