PROCÉDÉ DE RETOURNEMENT ET APPAREIL DE RETOURNEMENT POUR UN ENROULEUR POUR LE DÉROULAGE DE TOILES DE FIBRES

摘要

The invention relates to a turn-up method for a reel-up for reeling of fiber webs, a fiber web travelling in direction (S) is cut by means of two water jet nozzles moving substantially in transverse direction in relation to the travelling direction (S) of the fiber web (W), in the method two cuts (C1, C2) are formed by two water jet nozzles starting their movement at latest from edges of the fiber web (W) and moving with cutting pressure of the water jet nozzles on towards center area of the fiber web (W) and at the center area of the fiber web (W) the cuts (C1, C2) cross or meet and a substantially V-shaped tail end (V1) to the fiber web (W) is formed, after the cuts (C1, C2) of the tail end (V1) of the fiber web (W) are finished the cutting by the water jet nozzles and the movement of the waterjet nozzles is stopped and after the stop the return movement of the water jet nozzles and the cutting by the water jet nozzles is started again from the center area of the fiber web (W) and the water jet nozzles are moved by return movement towards the edges of the fiber web so that the fiber web W is cut by two cuts (C3, C4) and a substantially V-shaped beginning end (V2) to the fiber web W is formed and between the cuts (C1, C2) for the tail end (V1) and the cuts (C3, C4) for the beginning end (V2) one reject part (R) of the fiber web (W) with two substantially V-shaped cuts is formed. The invention also relates to a turn-up device for a reel-up for reeling of fiber webs comprising two water jet nozzles. The turn-up device comprises means (14) to stop the cutting by the water jet nozzles (10,12) between cutting of a tail end (V1) and cutting of a beginning end (V2) for a selected time for forming only one reject part (R) in the turn-up and that travel distance (L1, L2) of each nozzle in cross-direction of the fiber web (W) is substantially shorter than width (L) of the fiber web (W).