The present disclosure provides a process for producing a flexible container. In an embodiment, the process includes (A) providing a flexible container. The flexible container has (i) a body, and (ii) a neck. The process includes (B) positioning a fitment into the neck. The fitment has a top portion and a base. The fitment is composed of a polymeric material. The process includes (C) inserting a mandrel into the fitment. The mandrel includes an expandable collar composed of an elastomeric material. The process includes (D) expanding the collar radially outward to contact an inner surface of the base. The process includes (E) sealing, with a pair of opposing seal bars, the base to the neck.

A coated fabric (11), comprising a fabric (12) from polymer tapes (12a, 12b), wherein the fabric (12) is coated with a sealing layer (13), wherein at least a portion of the polymer tapes (12a, 12b) have a breaking tenacity of less than 45 cN/tex, preferably 15 to 40 cN/tex and an elongation at break of more than 30%, preferably of 40 to 90%, and/or wherein the sealing layer (13) is formed from a composition A comprising at least one ethylene/-olefin interpolymer, and wherein the composition has a density from 0.905 to 0.930 g/cc, preferably from 0.910 to 0.930 g/cc (1 cc=1 cm.sup.3), and a melt index (12) from 3 to 20 g/10 min and a bag comprising said fabric; a packaging machine (100) for filling gusseted (220) bags (10, 200) wherein the bag walls (202) of the bags (10, 200) consist of a woven fabric (11) of polymer tapes (12a, 12b) at least in part and wherein each of the ends (203, 204) of the bag wall (202) is provided with a filling mouth (211) for filling, wherein a closing device (125) is provided which is structured such that as the filling mouth (211) is closed a welding temperature of at least 50 Kelvin higher in the region of the gussets (220) than in a center region (223) of the bag wall (202) can be generated.