Nonwoven fabrics comprising polylactic acid and surface-treated calcium carbonate

A process for producing a nonwoven fabric, the process comprising the following steps:

• a) providing a surface-treated calcium carbonate-containing filler material, the surface-treated calcium carbonate-containing filler material being a calcium carbonate-containing filler material and a surface-treatment layer on at least a part of the surface of said calcium carbonate-containing filler material, wherein the surface-treatment layer is formed by contacting the calcium carbonate-containing filler material with a surface treatment agent, wherein the surface treatment agent comprises at least one mono-substituted succinic anhydride and/or mono-substituted succinic acid and/or a salt thereof;
• b) providing a first polylactic acid polymer;
• c) providing a second polylactic acid polymer being different from the first polylactic acid polymer;
• d) forming a masterbatch consisting of the surface-treated calcium carbonate-containing filler material of step a) in an amount of from 20 to 80 wt.-%, based on the total weight of the masterbatch, with the first polylactic acid polymer of step b);
• e) mixing the masterbatch of step d) with the second polylactic acid polymer of step c) to obtain a mixture, the mixture consisting of the masterbatch of step d) and the second polylactic acid polymer of step c);
• f) forming the mixture of step e) into fibers;
• g) forming a fibrous web from the fibers of step f);
• and
• h) forming the non-woven fabric by calendering or hydroentanglement of the fibrous web of step g).