Sealing system for containers

Abstract

A sealing system is for containers, in particular of the type that envisages sealing with an aluminum cap. Forming equipment (12) of a cap or seal (0) of weldable sealing material (S) is for the application on the mouth of a container (B), the equipment (12) including a service portion (12a) outside a controlled atmosphere chamber (2) and an operating portion (12b) inside the controlled atmosphere chamber (2). The operating portion (12b) includes a positioning roll (29) which is tangential, in the direction of rotation of the positioning roll (29), with a cutting roll (30) adapted to cut a sheet of sealing material (S) from a web of the sealing material (S) and with a forming roll (31) adapted to shape the sheet of sealing material (S) in the cap or seal (O).

1 . A forming equipment for a cap or seal of weldable sealing material for application on a mouth of a container, said equipment comprising a service portion outside a controlled atmosphere chamber and an operating portion within said controlled atmosphere chamber;
 wherein the operating portion comprises a positioning roll which is tangential, in a direction of rotation of said positioning roll, with a cutting roll adapted to cut a sheet of sealing material from a web of said sealing material, and with a forming roll adapted to shape said sheet of sealing material in said cap or seal.   
     
     
         2 . The equipment according to  claim 1 , wherein the positioning roll is connected to a vacuum adapted to retain the web of sealing material on the an outer surface of the positioning roll up to the cutting roll, the sheet of sealing material between a tangency point with the cutting roll and a tangency point with the forming roll and the seal or cap between the tangency point with the forming roll and a release point of said seal or cap on said container. 
     
     
         3 . The equipment according to  claim 1 , wherein at the tangency point between the positioning roll and the cutting roll a scrap tape is formed, wherein said scrap tape is dragged by the cutting roll, passing between the cutting roll and a counter-pressure roll. 
     
     
         4 . The equipment according to  claim 3 , wherein the counter-pressure roll is swinging around a hinge and is operated pneumatically, through a pneumatic cylinder, or by elastic systems, so as to ensure a predetermined pressure on the cutting roll and thus favour the traction of the scrap tape. 
     
     
         5 . The equipment according to  claim 1 , wherein the positioning roll comprises, at a release point of the seal or cap on the container, a sector in which the vacuum is blocked, so that the cap or seal, once reaching vertical above the mouth of the container can be released so as to position the cap or seal thereon. 
     
     
         6 . The equipment according to  claim 1 , wherein the positioning roll comprises along an outer surface thereof a plurality of mould elements of said seal or cap, each mould element comprising a mould profile which reproduces in negative a shape of the seal or cap, and wherein the mould profile comprises a central hole in which a duct is fitted which leads into the central portion of the positioning roll, and the central portion, with the exclusion of the sector, is connected to a vacuum, and wherein, around an outer hole of the duct, a ring made of ferromagnetic material is positioned. 
     
     
         7 . The equipment according to  claim 6 , wherein the cutting roll is motorized and comprises a plurality of cutting devices along a perimeter of the cutting roll, each cutting device comprising a blade element which reproduces the shape of the outline of the sheet of sealing material for the formation of the seal or cap, said blade element being adapted to interact with a corresponding bas-relief profile of the positioning roll in order to cut said sheet of sealing material from said web of sealing material. 
     
     
         8 . The equipment according to  claim 1 , wherein the forming roll comprises a plurality of forming devices along a perimeter of the cutting roll, each forming device being mounted in a swinging manner to a first end of a rod, wherein the rod is fitted in a seat formed inside the forming roll, so that said first end protrudes outwards while the second end opposite the first end is facing a cavity and pushes against a pre-calibrated spring. 
     
     
         9 . The equipment according to  claim 8 , wherein the rod has a recessed portion with a lower shoulder and an upper shoulder, the lower shoulder and the upper shoulder forming a stroke limiter of the rod by interaction with a corresponding internally protruding section of the seat, said internally protruding section having a lengthwise extension smaller than an extension of said recessed portion. 
     
     
         10 . The equipment according to  claim 8 , wherein, at the first end of the rod, a pin is transversely fitted, which supports in a swinging manner the forming device and wherein the forming device comprises a body having a support end, facing outwards, and a coupling end with the rod, a punch being removably fixed at the support end of the body. 
     
     
         11 . The equipment according to  claim 10 , wherein the punch is made of a non-ferromagnetic material and comprises a hollow body which houses a magnet therein, the magnet being positioned in a central position and having a cylindrical shape and a perpendicular axis with respect to a basis of the cylinder aligned with a radius of the forming roll. 
     
     
         12 . The equipment according to  claim 10 , wherein the coupling end of the body of the forming device has a widened V shape with two ends and has, at the two ends of the V, two fixed pins, the body centrally having a slot arranged horizontally, in which the pin of the rod is fitted, and wherein a spring is arranged between each of the fixed pins, and the pin of the rod. 
     
     
         13 . The equipment according to  claim 8 , wherein the first end of the rod ends with a convex profile when viewed in a direction perpendicular to a plane of the forming roll. 
     
     
         14 . The equipment according to  claim 8 , wherein the cutting roll is fixed to a toothed wheel hinged on a support plate of the equipment and is coupled with an actuator, for movement, the toothed wheel being connected by a driving member with the positioning and forming rolls, so that the positioning roll, the cutting roll and the forming roll move in a synchronized manner and a cutting device cyclically is at a respective mould element and a mould element cyclically is at a respective forming device during an operating step of the equipment. 
     
     
         15 . The equipment according to  claim 1 , wherein the operating portion comprises a sterilizer arranged upstream of said positioning roll with respect to a sliding direction of said web of sealing material. 
     
     
         16 . The equipment according to  claim 15 , wherein a sterilizer comprise a tank containing a sterilizing liquid, rolls being placed in said tank so as to create a tortuous path for the web of sealing material. 
     
     
         17 . The equipment according to  claim 15 , wherein the operating portion comprises a series of spray nozzles, arranged downstream of said sterilizer and upstream of said positioning roll. 
     
     
         18 . The equipment according to  claim 1 , wherein the service portion comprises at least one reel of sealing material and a series of return rolls for moving the web of sealing material unwound from the at least one reel, wherein the at least one reel is provided with a brake system or a servo drive associated with a respective unwinding spindle so as to prevent uncontrolled unwinding of the web of sealing material. 
     
     
         19 . The equipment according to  claim 18 , wherein downstream of the at least one reel a buffer chamber is arranged, having a bottom wall and side walls, a vacuum being applied to the buffer chamber through suitable suction, so as to create a loop of the web of sealing material, the buffer chamber comprising a series of detection sensors arranged along one side wall so as to detect a length of the loop between respective return rolls and a bottom of the loop, wherein the detection sensors are connected to a command and control unit which in turn is connected to the unwinding spindle so as to adjust the extent of a spindle brake according to the length of the loop, so as to maintain a constant length of the loop in case of possible decelerations or accelerations of operational steps downstream and maintain a constant tensioning of the web of sealing material as determined by a value of the vacuum in the buffer chamber. 
     
     
         20 . The equipment according to  claim 1 , wherein the service portion comprises a rewinding reel operated by a motorized rewinding spindle, which provides for recovery of the scrap tape of sealing material. 
     
     
         21 . The equipment according to  claim 1 , wherein the controlled atmosphere chamber comprises a roll inlet port comprising two opposing rolls through which the web of sealing material passes and a roll outlet port through which the scrap tape passes. 
     
     
         22 . A filling and sealing equipment for containers, comprising a forming equipment according to  claim 1 , wherein in said controlled atmosphere chamber the following is arranged in sequence:
 a sterilization unit,   a rinsing or activation unit,   a filling unit,   a unit for receiving the seal or cap,   a heat sealing unit of said container, and   a capping unit of said container,   wherein said receiving unit is arranged underneath said positioning roll, at a release point of a seal or cap on the mouth of a container in transit on said receiving unit, wherein the receiving unit comprises a conveyor having a plurality of plates, each of the plurality of plates holds a container to be sealed, or a common sliding surface on which transit of said receiving unit is directed.   
     
     
         23 . Method of sealing containers with a seal or cap, said method comprising the steps of:
 a) introducing a web of sealing material (S) into a controlled atmosphere chamber;   b) sterilizing said web of sealing material;   c) moving said web of sealing material on a positioning roll;   d) passing said web of sealing material at a cutting roll so as to single out a disc or sheet of sealing material;   e) passing said disc or sheet of sealing material on said positioning roll at a forming roll having at least one punch so as to form said seal or cap;   f) releasing said seal or cap on a mouth of a container, where steps b) to f) are carried out continuously inside said controlled atmosphere chamber.