Method of producing opened fiber bundle, method of producing cleaning member, apparatus which opens fiber bundle, and system which produces cleaning member

A method of continuously producing an opened fiber bundle for a cleaning member, said method comprising the steps of:

• (a1) providing
• (i) first nip rolls,
• (ii) second nip rolls, which are disposed downstream in a machine direction from the first nip rolls and have a faster peripheral velocity compared with the first nip rolls,
• (iii) third nip rolls, which are disposed downstream from the second nip rolls and have a slower peripheral velocity compared with the second nip rolls, and
• (iv) an opening facilitator, which is disposed between the first nip rolls and the second nip rolls and comprises an edge extending orthogonal to the machine direction, an upstream portion adjacently located upstream from the edge, and a downstream portion adjacently located downstream from the edge;
• (a2) conveying a fiber bundle using the first nip rolls and the second nip rolls to apply a tensile force to the fiber bundle, the fiber bundle being pushed onto the upstream portion and the edge of the opening facilitator while being conveyed;
• and
• (a3) conveying the fiber bundle using the second nip rolls and the third nip rolls to relax the fiber bundle and form a belt-shaped fiber bundle,
• wherein the edge of the opening facilitator is not rounded.