Patent ID: 7802705

Claim:
A method for forming a pleat on a folded-up portion of a fabric comprising a polylactic acid yarn of 100 mass %, the method comprising: a step of weaving or knitting the fabric comprising the polylactic acid yarn of 100 mass %; and a step of folding up the fabric and imparting a pressure thereon in a dry heat by heating rolls, wherein, in the step of imparting the pressure on the fabric by the heating rolls in the dry heat, temperatures of the surfaces of the upper and lower rolls of the heating rolls are set at 100 to 130° C., and a line pressure between the upper and lower rolls is set at 0.1 to 1.0 kg/cm; and the fabric is passed between the rotating upper and lower rolls of the heating rolls in atmospheric ambience, and the pleat is thereby formed on the folded-up portion of the fabric by the state of being heated and pressed in the dry heat when the fabric is passed between the heating rolls and the state of being in atmospheric ambience after the fabric has been passed therebetween.