a method for manufacturing a liner having baffles therein for use in flexible bulk containers , having the steps of : positioning a baffle strip of thermoplastic material adjacent to a continuous sheet of thermoplastic film ; heat sealing the baffle strip to the continuous sheet of film at spaced apart intervals ; alternately varying the length of continuous sheet film adjacent to the length of baffle strip material between adjacent heat seals to form pockets of excess continuous sheet film between alternating pairs of heat seals ; cutting the continuous sheet to a length substantially equal in length to the circumference of the flexible bulk container and ; folding the continuous film sheet in half with the attached baffle strip on the inside of the fold and with the fold extending perpendicular to the length of baffle strip ; and heat sealing the ends opposite the fold to form a tubular shaped liner with the pockets of the excess film sheet forming corners therein .