Abstract: A toothed strip or forming a clothing on a roller is formed of a plurality of teeth disposed along a front face of the face in alternating relation with a plurality of troughs. Each tooth has an equilateral triangle shaped front face with a flat apex and an equilateral triangle shaped back which extends from the apex of the front face of the tooth. Each trough is inclined upwardly from the front face of the strip towards the rear and merges into the backs of adjacent teeth. During operation, fibers are able to fold about the teeth without the free ends of the fibers coming together and coiling.