Patent ID: 7007441

Claim:
A sterilizing unit for sterilizing a web of packaging material on a machine for packaging pourable food products, the sterilizing unit comprising: a bath containing a sterilizing agent, in which said web is fed continuously; an aseptic environment comprising a process chamber connected to an outlet of said bath and housing drying means for removing residual sterilizing agent from said web; and an aseptic chamber communicating with said process chamber via an opening for the passage of said web, and in which said web is folded and sealed longitudinally to form a tube which is filled continuously with the product for packaging; and an air processing circuit for controlling the process conditions in said aseptic environment, and comprising suction means for drawing air from said process chamber, air processing means, and means for feeding processed air into said aseptic chamber; comprising valve means interposed between said process chamber and said suction means of said air processing circuit, and which can be activated during operation of said machine to control the pressure conditions in said aseptic environment.