Dosing unit, a dosing method, and a machine for producing unit dose articles

A machine for producing unit dose articles, comprising:

• a movable surface having a plurality of cavities, continuously movable in a machine direction,
• a first feeding assembly configured for feeding a first continuous water-soluble film on said movable surface at a first position,
• a retaining system configured for retaining said first continuous water-soluble film adherent to said cavities as it moves in said machine direction,
• a dosing unit located downstream of said first position and configured for dispensing dosed quantities of at least one fluid composition into said cavities,
• a second feeding assembly configured for feeding a second continuous water- soluble film on said movable surface at a second position located downstream of said dosing unit so as to enclose said dosed quantities of at least one fluid composition between said first and second continuous water-soluble films, and
• a wetting unit configured for wetting a surface of said second continuous water-soluble film upstream of said second position,
• wherein said dosing unit comprises:
• a stationary guide defining a closed-loop guide path having a lower section and an upper section,
• a plurality of movable elements movable along said stationary guide,
• a transmission system configured for continuously moving said plurality of movable elements along said closed-loop guide path,
• a plurality of nozzles carried by respective movable elements and associated to respective dosing chambers,
• a plurality of plungers reciprocally movable into the respective dosing chambers between respective retracted and advanced positions,
• a rotary fluid distributor comprising at least one stationary inlet and a plurality of movable outlets fluidically connected to the respective dosing chambers, and
• a driving system configured for moving said plurality of plungers from the retracted position to the advanced position when the respective movable elements move along said lower section of the closed-loop guide path and for moving said plurality of plungers from the advanced position to the retracted position when the respective movable elements move along said upper section of the closed-loop guide path.

A method for dosing fluid products, comprising:

• continuously moving a plurality of movable elements along a closed-loop guide path having a lower section and an upper section,
• providing on said plurality of movable elements a plurality of nozzles associated to respective dosing chambers,
• providing a plurality of plungers reciprocally movable into respective dosing chambers between respective retracted and advanced positions,
• supplying at least one fluid composition to said dosing chambers through a rotary fluid distributor comprising at least one stationary inlet and a plurality of movable outlets connected to the respective dosing chambers, and
• moving said plurality of plungers from the retracted position to the advanced position while the respective movable elements move along said lower section of the closed-loop guide path and moving said plurality of plungers from the advanced position to the retracted position when the respective movable elements move along said upper section of the closed-loop guide path.