Aseptic filling lines are used when both the beverage and the bottle must remain free from microorganisms until the bottle is capped. They are widely used for dairy drinks, juice, tea, functional beverages, and other products that can spoil easily. The beverage and bottles are sterilized before filling. Then the bottles move into an aseptic filling area, where a steam barrier and HEPA-filtered sterile air maintain aseptic conditions around the filling valves. When a bottle reaches the filling station, the valve seals around its opening and releases the beverage into the bottle. Once the required level is reached, the valve stops the flow and closes before the cap is applied. This prevents small product leaks and reduces the chance of air and microorganisms entering the bottle, which helps prevent mould growth during storage.