WO2004074103A1

WO2004074103A1 - Apparatus and method for obtaining closed containers

Info

Publication number: WO2004074103A1
Application number: PCT/EP2004/001758
Authority: WO
Inventors: Flavio Traldi; Andrea Bartoli
Original assignee: Green-Pack S.R.L.
Priority date: 2003-02-24
Filing date: 2004-02-23
Publication date: 2004-09-02
Also published as: ITMO20030042A0; ITMO20030042A1

Abstract

An apparatus comprises advance means for advancing a container cavity (2) along an advance direction (F) and applying means (15) for applying closure means (4) to said container cavity 5 (2), said applying means (15) being movable parallelly to an edge zone (5) of said container cavity (2) so as to associate said closure means (4) to said container cavity (2) while said container cavity (2) is substantially stationary. A method comprises filling a container cavity (2) with a spillable product (3) and applying closure means (4) to said container cavity (2), said container cavity (2) being kept substantially stationary during said applying.

Description

Apparatus and method for obtaining closed containers

The invention relates to an apparatus and a method for filling containers with a spillable product and for subsequently closing such containers. The apparatus and the method according to the invention are particularly suitable for filling tub-like containers, i.e. containers provided with a cavity accessible through an opening having relatively large dimensions. Such containers can be filled with various products, for example food, pharmaceutical, cosmetic or detergent products.

The tub-like containers are usually obtained by thermoforming a web of sheet material, for example made of plastics, advanced along a horizontal plane. The web is shaped by means of a punch cooperating with a die, so as to obtain on the sheet material an upwardly open cavity. The sheet material, once shaped by the punch, is conveyed towards a filling station, in which the sheet material stops and a product is introduced into the container cavity until the desired filling level is obtained. The sheet material is then advanced towards a welding station in which the sheet material stops again and a closure web is welded to an edge zone of the container cavity. The closure web is laid over the underlying sheet material while the latter is advancing from the filling station to the welding station. A process of this kind is disclosed in US 2003/0014945 and in DE 3111537.

US 3838550 discloses a method and an apparatus for packaging products in containers while the containers are continuously moved along a path. The containers are sequentially dropped from a nested stack towards an apertured conveyor that defines the path for the containers and a negative pressure is produced below the conveyor to assist in drawing the container in the apertures of the conveyor. The conveyor moves the containers to a filling station where the product is flowed into the containers at several different locations, so that the containers are filled in stages while being moved by the conveyor. The filled containers then progress to a welding station in which a continuous web of heat-weldable cover film is heat-welded to the filled containers.

A drawback of the forming technique described above is that the product filling the containers, particularly if it is a liquid product, can accidentally spill, due to the high inertial forces acting on the container when the latter is moved from the filling station to the welding station.

The inertial forces can produce splashes of liquids that, besides dirtying the surrounding regions of the apparatus, compromise the filling precision of the single containers. In addition, the liquid spilled from the container cavities can contaminate the edge zone thereof, on which the closure web has to be welded. If the edge zone of the container cavity is contaminated, it is difficult to properly weld the closure web to the container cavity and to obtain leakproof containers. In order to avoid spillage of a liquid from a container cavity, US 3965656 discloses an apparatus in which the containers are continuously travelled through the container receiving, filling, welding and discharge stations. A filling means at the filling station travels forwardly with a group of containers while discharging a liquid through nozzles into the group of containers . A movable heat welder means heat welds a cover to an edge zone of each container while travelling forward therewith.

Although the apparatus disclosed in US 3965656 has some advantages over the discontinuous apparatuses disclosed in US 2003/0014945, DE 3111537 and US 3838550, spillage may still occur in certain circumstances.

In fact, if the apparatus disclosed in US 3965656 stops for whatever reason, for example in case of jams or other troubles, the filled containers are suddenly decelerated. Similarly, when the apparatus restarts working after the stop, the filled containers are subjected to high accelerations. Thus, the liquid can spill out of the container cavities that have not yet been closed. Furthermore, a complicated control system is required to ensure that the filling means and the heat welding means travel in a registered position with the underlying moving container cavities. An object of the invention is to improve the apparatuses and methods for obtaining filled and closed containers, particularly formed from sheet material.

A further object of the invention is to improve the filling and closing operations of container cavities and reduce the risks of accidental leakages of the product with which the container cavities are filled.

A still further object of the invention is to obtain an apparatus for filling and closing containers which has a particularly simple structure. In a first aspect of the invention, there is provided an apparatus comprising advance means for advancing a container cavity along an advance direction and applying means for applying closure means to said container cavity, characterized in that said applying means is movable parallelly to an edge zone of said container cavity so as to associate said closure means to said container cavity while said container cavity is substantially stationary.

Owing to this aspect of the invention, an apparatus can be obtained in which the product that fills the cavity cannot be easily spilled from the cavity. In fact, owing to the movable applying means, no movement of the container cavity is required to associate the closure means to the edge zone of the container cavity. It is therefore possible to completely fill each cavity without contaminating the edge on which the closure means has to be applied and thereby without compromising a proper sealing of the container. Furthermore, even if the apparatus stops for whatever reason, no acceleration or deceleration acts on the container cavity filled with the spillable product. A sudden stop of the apparatus does not imply a sudden stop of the container cavity to which the closure means is being associated, because the container cavity is already stationary while the closure means is being associated thereto. Finally, there is no need to use a complicated control system, because the applying means does not have to travel in a registered position with the simultaneously moving container cavity. On the contrary, the applying means acts on a stationary container cavity. In a second aspect of the invention, there is provided a method, comprising filling a container cavity with a spillable product and applying closure means to said container cavity, characterized in that said container cavity is kept substantially stationary during said applying. Owing to this aspect of the invention, accidental leakages of the spillable product from the container cavity can be avoided. In fact, no inertial forces act on the container while the closure means is applied. The splashes of spillable product occurring in the prior art when the container cavity is transferred from the filling station to the welding station in order to associate the closure web to an edge zone thereof are therefore substantially eliminated.

The invention will be better understood and carried out with reference to the attached drawings, that illustrate an exemplifying and not limitative embodiment thereof, in which: Figure 1 is a schematic cross-section of a container filled with a spillable product;

Figure 2 is a schematic front view of an apparatus for obtaining containers; Figures 3 to 5 are schematic front views, partially sectioned, of a portion of the apparatus of Figure 2, highlighting subsequent steps of the filling and closing operations of the containers of Figure 1. Figure 1 shows a tub-like container 1, comprising a container cavity 2, filled with a spillable product 3, for example a liquid or a pasty product with relatively low viscosity. The container cavity 2 may also be filled with a granular product or with a solid product that was spillable during the filling operations and then solidified during cooling.

The container cavity 2 has an upwardly opening closed by a closure member 23, fixed to an edge zone 5 of the container cavity 2, for example by heat-welding. The container 1 can be filled and closed in an apparatus 6 of the type shown in Figure 2. A sheet material 7 in the form of a web is indexed in an advance direction F through the apparatus 6. A plurality of container cavities 2 has been obtained on the sheet material 7, for example by thermoforming. The apparatus 6 is provided with filling means comprising, in the particular case of Figure 2, three nozzles 8; obviously, a different number of nozzles 8 may be provided, according to the specific requirements of the user. The nozzles 8 are connected to a plate 9 mounted on a trolley 20, which also supports welding means 16 for closing the container cavities 2 with a closure web 4 unwound from a reel 10. The welding means 16 comprises a lower mould 11, provided with a recess 12 into which the container cavity 2 is received, and an upper mould 13, provided with a protruding welding profile 14 along which the closure web 4 is welded to the edge zone 5 of the container cavity 2.

The lower mould 11 and the upper mould 13 are movable perpendicularly to the advance direction F one in relation to the other, as indicated by the arrow Fl, between a spaced configuration, shown in Figure 2, in which the moulds 11 and 13 do not interact with the container cavity 2, and a cooperation configuration, not shown, in which the moulds 11 and 13 are in contact one with another so as to weld the closure web 4 on the edge zone 5 of the container cavity 2.

The trolley 20, on which the filling means and the welding means 16 are mounted, is movable parallelly to the edge zone 5, as shown by the arrow F2, between a first position A, shown in Figure 2 with continuous line, and a second position B, shown with hatched line. In the particular case shown in Figure 2, the trolley 20 is movable horizontally. The operation of the apparatus 6 is described hereinafter with reference to Figures 3, 4 and 5. As shown in Figure 3, a group of container cavities 2 obtained on the sheet material 7 and comprising for example three container cavities 2 , is partially filled by means of the nozzles 8 in a position of preliminary filling. In this position, the nozzles 8 introduce into the container cavities 2 the spillable product 3 up to a level corresponding to about the half capacity of the container cavities 2.

The partially filled container cavities 2 are then indexed in the advance direction F towards a position in which complete filling of the container cavities 2 occurs, as shown in Figure 4. It is noted that, since the container cavities 2 are only partially filled, they can be easily moved away from the preliminary filling position even at relatively high speed without undesired spillage of the spillable product 3. The nozzles 8 are also advanced in the advance direction F towards the position shown in Figure 4, in which the nozzles 8 completely fill the container cavities 2 with the spillable product 3. In order to move the nozzles 8, the trolley 20 is also advanced in the advance direction F, together with the welding means 16, so as to move from the first position A to the second position B. After completely filling the container cavities 2, the nozzles 8 are brought backwards in the preliminary filling position, as indicated by the arrows F3 in Figure 5, and may start filling a new group of empty container cavities 2. The trolley 20 moves with the nozzles 8 in the direction F3 towards the first position A, and brings backwards the closure web 4. To this end, the trolley 20 is provided with a redirecting roller 15, movable parallelly to the edge zone 5 of the container cavities 2, on which the closure web 4 is partially wound. While the redirecting roller 15 is moving in the direction F3 together with the trolley 20, the closure web 4 is progressively associated to the edge zone 5 of the container cavity 2, which is in a stationary position. In particular, the closure web 4 is progressively associated to adjacent edge portions of the container cavity 2, starting from a forward edge portion 21 towards a backward edge portion 22 opposite to the forward edge portion 21.

After associating the closure web 4 to the filled container cavities 2, the upper mould 13 and the lower mould 11 can move one in relation to the other perpendicularly to the advance direction F, in order to reach the cooperation configuration and weld the closure web 4 to the edge region 5 of the filled container cavities 2. It is noted that, after the container cavities 2 have been filled to the desired level, they remain stationary until the closure web 4 is applied onto the container cavities 2 and welded to the edge zone 5 thereof. Undesired leakages of the spillable product 3 are therefore avoided, even if the whole volume of the container cavities 2 is filled with the spillable product 3.

In addition, the mode of operation described above allows the productivity of the apparatus 6 to be optimised, since while the welding means 16 close a group of container cavities 2, the nozzles 8 partially fill an upstream group of container cavities 2.

The sheet material 7, on which the container cavities 2 have been filled and closed, is then moved away from the welding means 16 and advanced towards a severing station 17, of known type, in which single containers 1 or groups of containers 1 are severed from the sheet material 7.

Claims

CLAIMS 1. An apparatus comprising advance means for advancing a container cavity (2) along an advance direction (F) and applying means (15) for applying closure means (4) to said container cavity (2), characterized in that said applying means (15) is movable parallelly to an edge zone (5) of said container cavity (2) so as to associate said closure means (4) to said container cavity (2) while said container cavity (2) is substantially stationary.

2. An apparatus according to claim 1, wherein said applying means comprises redirecting means (15) for directing a closure web (4) of said closure means in a direction parallel to said edge zone (5) .

3. An apparatus according to claim 2, wherein said redirecting means comprises roller means (15).

4. An apparatus according to any one of the preceding claims, and further comprising filling means (8) movable parallelly to said edge zone (5) .

5. An apparatus according to claim 4, wherein said filling means (8) is mounted on a trolley (20) which supports said applying means (15) .

6. An apparatus according to any one of the preceding claims, and further comprising welding means (16) for welding said closure means (4) to said edge zone (5), said welding means (12, 14) being movable parallelly to said edge zone (5) .

7. An apparatus according to claim 6, as appended to claim 5, wherein said welding means (12, 14) is mounted on said trolley (20) .

8. A method comprising filling a container cavity (2) with a spillable product (3) and applying closure means (4) to said container cavity (2), characterized in that said container cavity (2) is kept substantially stationary during said applying.

9. A method according to claim 8, wherein said applying comprises laying a closure web (4) onto said container cavity (2) .

10. A method according to claim 9, wherein said laying comprises progressively associating said closure web (4) to adjacent edge portions of said container cavity (2) from a first edge portion (21) towards a second edge portion (22) opposite to said first edge portion (21).

11. A method according to any one of claims 8 to 10, wherein said filling is completed in a closure position in which said applying occurs .

12. A method according to claim 11, wherein said filling comprises partially filling said container cavity (2) in a preliminary filling position and moving said container cavity (2) from said preliminary filling position to said closure position.

13. Δ method according to claim 12, wherein said partially filling comprises introducing said spillable product (3) into said container cavity (2) up to about half the volume of said container cavity (2).

14. A method according to claim 12, or 13, wherein while a first container cavity (2) is affected by said partially filling, a second container cavity (2) is affected by said applying.

15. A method according to any one of claims 11 to 14, and further comprising, after said applying, welding said closure means (4) on said container cavity (2) in said closure position.