METHOD FOR PRODUCING POLYLACTIC ACID-BASED AIR-THROUGH NONWOVEN FABRIC, AND POLYLACTIC ACID-BASED AIR-THROUGH NONWOVEN FA

摘要

The invention provides a method of producing an air-through nonwoven fabric comprising the steps of: forming a web comprising composite fibers comprising a first polylactic acid and a second polylactic acid having a lower melting point than the melting point of the first polylactic acid; a step of exposing the web to a first air-through treatment in the temperature range of the following temperature T₁: glass transition temperature of second polylactic acidT₁melting point of second polylactic acid; and a step of exposing the web that has been exposed to the first air-through treatment, to a second air-through treatment in the temperature range of the following temperature T₂: melting point of second polylactic acid−5° C.≦T₂≦melting point of second polylactic acid+15° C., to produce an air-through nonwoven fabric, wherein the degree of crystallinity of the air-through nonwoven fabric is in the range of 44% to 68%.