Abstract: One aspect is a device for processing a filament in a process stream, including at least one processing beam source, designed and arranged for emitting at least one processing beam which is suitable for processing a segment of the filament by interaction of the at least one processing beam with the segment of the filament, thereby obtaining a processed filament. The device includes a guide, including a filament feed which is arranged upstream of the at least one processing beam source, and is designed to feed the filament from a feed reel. The guide is designed and arranged to guide the filament so that during the processing the segment of the filament inclines an angle with a vertical axis in the range from 0 to 45°.

Abstract: One aspect is a device for processing a filament in a process stream, including at least one processing beam source, designed and arranged for emitting at least one processing beam which is suitable for processing a segment of the filament by interaction of the at least one processing beam with the segment of the filament, thereby obtaining a processed filament. The device includes a guide, including a filament feed which is arranged upstream of the at least one processing beam source, and is designed to feed the filament from a feed reel. The guide is designed and arranged to guide the filament so that during the processing the segment of the filament inclines an angle with a vertical axis in the range from 0 to 45°.

Abstract: One aspect refers to a method for preparing a processed filament, including providing a filament, which comprises a multitude of segments, which follow one another in a longitudinal direction of the filament, wherein each of the segments of the multitude of segments comprises a multitude of sections, which are disposed circumferentially around the filament; and processing the filament in n processing steps, thereby obtaining the processed filament. For each integer i in the range from 1 to n, the ith processing step comprises, for each integer j in the range from 1 to m, processing the jth section of the (i+j?1)th segment. N and m are integers which are, independent from one another, at least 2. Sections of different number are at different circumferential locations of the filament. The processing of each section of each segment of the filament comprises an interaction of the section of the segment of the filament with at least one processing beam.