Method for manufacturing a bag by means of blown film extrusion

A method for manufacturing a bag by means of blown film extrusion, said bag comprising main walls each comprising, on an internal face, a closing assembly comprising at least three complementary profiles which extend in parallel in a main direction extending according to a longitudinal axis, the manufacturing method comprising the following steps:

• extruding plastic material so as to form an annular film comprising the closing assemblies, said annular film being intended to form the walls of the bag, and
• blowing the annular film at an inflation rate of less than 1.3 so as to form a jacket, wherein, the extrusion step further comprises integrally forming the at least three complementary profiles of each of the closing assemblies with one same base connected to the annular film extending a connecting rod in parallel to the longitudinal axis between the annular film and the base, and
• wherein the connecting rod is configured to keep the base at a distance from the annular film.