Equipment for the finishing of flexible containers in a continuous cycle

Abstract: Method for the production and finishing of containers made of flexible material and corresponding equipment for the production, filling and sealing of containers (400) made of flexible material, comprising a unit (100) for producing the said containers (400) and feeding them to a machine (200) for the filling and sealing of the containers, wherein the said filling and sealing machine (200) is of the type with continuously rotating carousels (201, 202, 203, 204) with individual stations for filling (201c, 201d), sealing (203d) and cooling rotating continuously in synchronization with the continuous rotary advance of each container (400), additional means (300) of synchronizing the feed of the containers from external equipment (100; 500) being provided.

Description: The present invention relates to equipment for the finishing of the flexible containers in a continuous cycle. It is known that the technique of packaging both liquid and solid products has been in part directed towards the production and finishing of flexible containers made in packet form and provided with bases which can be enlarged as a result of filling to form a stable supporting base for the filled package. The known art also includes automatic equipment capable of producing the said packets from a roll of plastic sheet material and of filling and hermetically sealing the packets thus produced, such equipment substantially consisting of a first unit for forming the packet and a second unit disposed in series with the first, in which the packet is filled and sealed; an example of this type of machine is described, for example, in patent application IT-68.032 A/90. Such types of equipment with totally discontinuous cycles, while enabling the containers to be formed by operations executed from a stopped position, which provides better results, have considerable disadvantages, particularly due to the fact that their operation is discontinuous or step-by-step throughout the production cycle; in particular, the unit for filling and sealing the individual containers made with step-by-step advance does not permit a substantial increase in line with the design, since the cycle time is dependent on the time of the transfer of each individual packet from each fixed station to the next, which is also fixed. In these conditions, with fixed operating stations and step-by-step advance, it is necessary, in order to reduce the said advance time, to divide the filling, for example, among a number of stations, although this entails a certain loss of capacity, and in any case it is necessary to wait until the longest operation has been completed before it is possible to continue in the operating sequence. Moreover, any significant increase in the speed of advance to compensate for the cycle time should be prevented: the abrupt accelerations and stops would cause the liquid to leak from the packet, resulting in an unacceptable increase in wasted production owing to the failure to maintain the guaranteed mean filling level. This situation is even more serious if the waste is detected only at the end of the cycle in the final control operations. From US-4 353 198, on which document claim 1 is based, an equipment comprising a discontinuous part of forming the containers and a continuous part of filling and sealing the containers is known. The continuous part includes a feeding system consisting of an endless belt that is subject to elongation phenomena, and obliges to greater overall dimensions of the plant and to a greater number of clamping means, that make onerous changing of the means themselves on varying of the dimensions of the containers necessary. Consequently there arises the technical problem of producing equipment for automatic production and filling of containers in packet form made of flexible material, which provides a high output with minimum design work, does not causes wasted production due to the leakage of liquid from the containers, is easy and economical to install and can be supplied either from step-by-step machines for producing flexible containers in packet form, or from machines for feeding individual packets already prepared for filling. These results are achieved with the present invention, which provides an equipment for the finishing of containers made of flexible material according to claim 1. In a preferred embodiment the said means of capturing the containers consist of suction cups disposed at the extremities of radial arms movable linearly in a direction perpendicular to the lateral surfaces of the containers to enable said lateral surfaces to be captured and separated to create a filling aperture. Preferably the said means of capturing and sealing the containers consist of jaws movable in both vertical directions for lowering and raising, and also in both horizontal directions for closing and re-opening of the jaws, said jaws being provided with resistances capable of heat-welding the top aperture of the container and with ducts for the passage of cooling liquid capable of cooling the container. Further details may be obtained from the following description, with reference to the attached drawings, which show: in Figure 1, a schematic plan view of the equipment according to the invention; in Figure 2, a schematic section through a vertical plane of the equipment in Fig. 1; in Figure 3, a plan view of the continuous filling and sealing equipment with the station for cutting and synchronization of the feed; in Figure 4, an enlarged detail of the plan view of the station for cutting and synchronization of the feed of the filling and sealing machine; in Figure 5a, a general schematic section in the plane of the line VA-VA in Figure 3; in Figure 5b, a detail of the capturing and filling station of the machine in Fig. 5a; in Figure 5c, a detail of the sealing station of the machine in Fig. 5a; and in Figure 6, the machine in Fig. 3 illustrated with a feed by an automatic loader of individual packets. In Figure 1, an embodiment of the invention is shown. The equipment substantially consists of a unit 100 for forming a continuous strip 101 divided into individual containers 400, operating with a discontinuous step-by-step advance, and a machine 200 for filling and sealing the individual containers 400, operating with a continuous cycle as will be described in greater detail subsequently; a unit 300 for cutting the strip into individual containers and for synchronizing the feed of the said individual containers 400 to the finishing machine 200 is interposed between the unit 100 with discontinuous advance for the formation of the strip of containers and the machine 200 with a continuous cycle for finishing the said containers. In greater detail, the unit 100 for forming the continuous strip 101, known in itself as regards its general characteristics and therefore described only with respect to its essential components, has a reel 102 for feeding a sheet 101 of plastic or like material which is unwound by a motor 102a with feedback control provided by means of a compensator 102b which accumulates and keeps in tension a certain quantity of film to ensure the correct feeding of the film to the subsequent processing stations. In the subsequent advance provided by driven rollers 103, the film passes through the station for bringing the strip into a vertical position; the strip is then half bent to form the two lateral flaps 101a and 101b of the container 400. Continuing in its advance, the film undergoes the bending of its base into a double "W" so that the base is prepared for the subsequent operations of sealing and cooling performed at corresponding stations 104 and 105 disposed in series along the path of the strip 101. In this way a continuous strip 101 of individual containers 400, still joined together in a chain and open at their tops, is formed, and is made to proceed in a longitudinal direction from the advance station 106 which, in synchronization with the station 103, causes the step-by-step advance of the strip at a rate determined by the longest of the periods required by the sealing station 104 and cooling station 105 to perform their operations. On leaving the forming machine 100 described above, the strip 101 is fed, and drawn by the latter, to a unit 300 (Fig. 4) comprising a compensator 301 which is required to keep the strip 101 taut in its passage from the forming unit 100 to the machine for filling and sealing 200, while compensating for the different stage of advance of the strip 101 which in the example is to be transformed from the two-step advance of the forming unit 100 into a single-step advance for the subsequent cutting station 303 which is supplied by the step-by-step feed device 302 (Fig. 4). The strip fed in this way by single steps corresponding to the width of each individual packet enables the strip 101 to be divided into individual containers 400 which are introduced into the machine for filling and sealing 200 through a synchronizing device 304 which sends the said containers 400 to the first wheel 201 of the machine 200 in which the continuous advance and processing cycle commences. In greater detail (Fig. 5a), the machine for filling and sealing 200 has a driving mechanism 210 capable of imparting a continuous motion to the said first wheel 201, on which the filling of the container 400 takes place; to the star wheel 202 for conveying the container 400, which is filled but still open at its top, to the second wheel 203, on which the upper extremity of the container 400 is heat-welded and cooled; and to the star wheel 204 for discharging the finished container to the output conveyor 205. With reference to Fig. 5b, the wheel 201 is mounted rotatably about a vertical axis consisting of a sleeve 201a inside which and coaxially with which is disposed the tube 201b for feeding the liquid to be metered and injected into the packets 400. Inside the sleeve 201a there is also disposed the air suction tube 201c which provides a pressure drop at the suction cups 201d disposed at the extremities of radial arms 201e which have the function of retaining the two lateral flaps 400a and 400b of the container 400, enabling them to be separated to form an upper aperture through which the metered liquid can be injected. The said separation takes place by the symmetrical separation of the suction cups 201d as a result of a corresponding traversing movement executed by the movable supports 201f of the suction cups 201d. The liquid is metered by metering devices 201g supplied through the duct 201b, which send the programmed dose to the injector 201h which injects the dose into the container 400 which is in the form of an open packet. It should be emphasized that the whole sequence of capturing of the container 400 by the suction cups 201d, symmetrical separation of the lateral surfaces 400a and 400b, metering and injection of the metered liquid into the container is executed continuously during the rotation of the wheel 201 which moves the container from the angular position entry into the wheel to that of exit to the transfer star wheel 202; this sequence being executed by individual devices for capture 201d, separation 201f, metering 201g, and injection 201h, disposed next to each container 400 and rotating together with the container in synchronization with the rotation of the wheel 201. When the container 400 has arrived at the position of transition to the transfer star wheel 202, the pressure drop at the suction cups 201d is eliminated to leave the container 400 free to pass to the star wheel 202 and from this, after a corresponding rotation, to the second wheel 203, substantially like the wheel 201, on which the operations of sealing the container 400 are executed as described below. The wheel 203 (Fig. 5c) rotates on a central shaft 203a coaxially with which is disposed, in an upper position, a second rotating mechanism formed by a central hub 203b from which branch radial arms 203c, on the free ends of which are disposed the heat-welding mechanisms, each of which comprises two jaws 203d mounted on guides which permits two-way movement either vertically, for lowering and raising, or horizontally, for closing and re-opening. The jaws 203d are integral with an electrical resistance 203e and ducts 203f for the supply of a cooling liquid for a rapid cooling of the container after the sealing by heat-welding. Thus, during the rotation of the wheel from the angular position of capturing the container 400 from the star wheel 202 to the position of passage of the container to the discharge star wheel 204, the following operations are executed simultaneously for each container: lowering of the jaws 203d, closing of the jaws with consequent closing of the lateral flaps 400a and 400b of the container, connection of the resistances 203e for the sealing of the container 400, circulation of cooling liquid for the cooling of the container, re-opening and raising of the jaws 203d which are then ready for another cycle, and passage of the finished container to the discharge star wheel 204. From the star wheel 204 the container 400 can then be sent to the output conveyor belt or the like. Many variations may be made in the practical embodiment of the constructional details of the equipment without departure from the scope of the present invention as defined in the following claims; in particular, the filling and sealing machine 200 could be supplied through a loading device known in itself and therefore shown purely schematically (Fig. 6) as a block 500. In this case, the compensating device 301, synchronizing device 302 and cutting device 303 would he superfluous and could be removed or neutralized while keeping the configuration of the synchronizing device 304 unchanged.

Claims: Equipment for the finishing of containers (400) made of flexible material, comprising a container supplying machine (100,500), a machine for filling and sealing (200), and a unit (304) for synchronization of the feeding of the containers, wherein said supplying machine for supplying the containers to said machine for filling and sealing is a unit (100) for producing the containers (400), or a loading device (500) for supplying preformed containers (400), said machine for filling and sealing (200) comprising at least one first wheel (201) for the continuous rotary advance of said containers, having individual means for capturing (201c,201d) and filling (201g,201h) for each container, said means continuously rotating coaxial and in synchronization with said advance of each container on said first wheel (201), characterised in that, said machine for filling and sealing (200) further comprises at least one second wheel (203) for the continuous rotary advance of said containers, having individual means for capturing (203d), sealing (203e) and cooling (203f) for each container, said means continuously rotating coaxially and in synchronization with each container at said second wheel (203). Equipment according to Claim 1, characterised in that said machine for filling and sealing (200) comprises at least one further wheel (202) for transporting the filled containers from said first wheel (201) to said second wheel (203). Equipment according to Claim 1, characterised in that the said means of capturing the containers rotating in synchronisation with said first wheel (201) consists of suction cups (201d) disposed at the extremities of radial arms (201f) which are movable linearly in a direction perpendicular to the lateral surfaces (400a,400b) of the container to enable said lateral surfaces to be captured and separated to create a filling aperture. Equipment according to Claim 1, characterised in that said means of capturing and sealing the containers preferably consists of jaws (203d) movable in both vertical directions for lowering and raising, and also in both horizontal directions for closing and reopening of the jaws, said jaws being provided with resistances (203e) capable of heat-welding the top aperture of the container and with ducts (203f) for the passage of cooling liquid capable of cooling the container. Equipment according to Claim 1, characterised in that the said filling means comprises a metering device (201g) which feeds the programmed quantity of liquid to an injector (201h) which forces the dose into the container. Equipment according to Claim 1, characterised in that the supplying machine consists of a loading device (500) for supplying individual preformed containers.

Inventors: RONCHI MARIO, RONCHI, MARIO
Applicants: RONCHI MARIO S R L, RONCHI MARIO S.R.L.
Application year: 1993
Main classification: B65B3
IPC codes: B65B3