Abstract: The invention discloses an apparatus for treating fabrics which comprises a first chamber for forming a reserve of infeed fabric, a second chamber for forming a reserve of outfeed fabric, first means for slowly infeeding the fabric into the first chamber, second means for slowly removing the fabric from the second chamber, a duct allowing for the passage therethrough of the fabric between the first chamber and the second chamber, fabric transport means capable of forward and backward operation which generates a forward and backward movement of the fabric between both chambers, and control means, operation of which causes inversion of the forward and backward movement, and collision members adapted to be impacted by the fabric, which move between a collision position and a free passage position in synchronism with the forward and backward movement of the fabric.