Device with processing beam source and a guide for processing a filament

A device for processing a filament in a process stream, the device comprising:

• a) 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;
• and
• b) a guiding means, comprising a filament feed which is
• i) arranged upstream of the at least one processing beam source, and
• ii) designed to feed the filament from a feed reel;
• wherein the guiding means is designed and arranged to guide the filament so that during the processing with the at least one processing beam source the segment of the filament inclines an angle with a vertical axis in the range from 0 to 45°.