EP1368237B1 - Method and apparatus for filling and vacuum sealing pairs of bags - Google Patents

Abstract

A method and an apparatus for filling and closing pairs of containers (3; 3') in the form of envelopes or bags provided or not with side and/or bottom bellows, made of flexible material, connected with each other by a central union strip, at which strip are their openings opposite to and facing each other for filling the containers with the products so as to form a continuous web (2) of paired containers; in said method the step of sealing the paired containers takes place under vacuum or under a strong negative pressure. For this operation a station (30) is inserted downstream of the filling station (25) which comprises a chamber (32) with a lid (34) for hermetic closure, which can be opened in the surroundings atmosphere and inside which chamber the vacuum or a strong negative pressure can be created after insertion thereinto of the filled containers, said chamber (32) being internally provided with electrically heatable jaws for sealing the containers in the absence of air, and a transport unit (10) is provided.

Description

The present invention relates to a method and an apparatus for fully-automatically carrying out the filling and vacuum sealing of pairs of opposite envelope-type or bag-type containers fed in the form of a continuous web to filling stations.

In the field of packages, above all as far as goods of large consumption are concerned, widely used are envelopes of flexible plastic material that are directly heat-sealable or envelopes of aluminium foil made heat-sealable by the presence of a thin coating of plastic material.

In both cases the surface designed to remain externally visible is usually printed with inscriptions for the identification of the contained goods.

Of the different products marketed in containers of this type, a great number of them requires aseptic envelopes or bags to be vacuum sealed for better conservation in the course of time of the product held therein.

It is an object of the present invention to provide a method and an apparatus for feeding and filling with goods in a liquid state, in powder or in pieces, pairs of containers of flexible material open at the top and having their respective openings specularly facing each other, connected to each other by a joining strip, and to carry out the vacuum sealing of the opening of the thus filled containers.

According to the invention, the intended object is achieved by modifying a simple and relatively convenient automatic apparatus of a type already available on the market, see EP-A-487 788, which discloses a method and apparatus according to the preambles of appended claims 1 and 2 in which a device is inserted apt to receive within a chamber that can be hermetically closed, a limited number of containers previously filled with the products whereafter the vacuum is created in said chamber and the container opening heat-sealed in the chamber itself, as defined in claims 1 and 2.

The webs of paired containers facing each other that can be used in the filling and vacuum-sealing method according to the present invention can consist of any known type of paired containers, i.e. bags or simple envelopes, envelopes with bellows-like bottom, envelopes with two side bellows, or envelopes with side bellows and simplified bottom bellows to allow vertical self-support of the container.

Envelopes with side bellows are preferred because they allow a greater automatic opening out of the flaps of the upper container opening on filling.

Since the invention particularly aims at meeting the requirements of business concerns even of limited size that carry out the filling of containers with products, the containers are supplied by firms specialised in manufacturing bags in the form of a continuous web of paired containers having upper openings facing each other and wound up in the form of a bobbin or concertina-folded in packaging boxes. This feature makes the production by the user customer easier because the latter must only attend to carrying out the final hermetic seal for closing the container after having filled the same. Thus also the final controls are reduced in favour of a more practical operation. From the point of view of surface contamination too, the closed bag is more reliable than the material on a reel.

The invention is described herebelow in more detail having reference to the accompanying drawings that show the arrangement of the sequence of characteristic stations in an apparatus using said webs of paired containers, apt to carry out vacuum sealing of the containers in accordance with the contemplated method.

In the drawings:

• Fig. 1 is a schematic perspective top view of the apparatus for feeding, filling and vacuum sealing containers embodying the method according to the invention;
• Fig. 2 is a perspective side view, by way of example only, of a pair of bags of the type with side bellows, joined to each other by an intermediate connecting strip, which are part of a continuous web of bags to be fed to the apparatus schematically shown in Fig. 1 in which, for illustrative purposes, the right bag has a filling opening which is only partly raised whereas in the left bag the opening is completely open;
• Fig. 3 is a plan view, by way of example, of a length of the bag web of the type shown in Fig. 2, yet in which the bags are sealed at the bottom in such a manner that a bellow is formed which is apt to keep the filled and sealed bag in a vertical position on the display shelves; and
• Figs. 4 and 5 show, in a plan and perspective view and still by way of example, a length of web of a further type of bags also provided with side bellows and a bottom bellows apt to keep the filled and sealed bag in a vertical position on the display shelves.

In Fig. 1 the apparatus altogether identified by A, is in its general features of known type.

In the case under review, the apparatus is fed with a web 2 of paired containers 3, 3' of flexible material joined to each other by an intermediate strip 20 and concertina-folded inside a packaging box 5, as supplied from the manufacturer of the containers.

The apparatus is provided with a rod-shaped support 6 descending gradually until close to the packaging box 5 where is centred the strip 20 that keeps in a connected relationship the web of paired containers 3, 3' folded up in the box itself (see also Figs. 2 and 3). On proceeding towards the filling and sealing stations, the containers 3, 3' moved by a drive or transport unit 10 are arranged on either side of support 6 which, downstream, at position 8, progressively widens out until it becomes, at the transport unit 10, a track of practically the same transverse width as strip 20.

The transport unit 10 is preferably made up of an upper roller 11 provided with linear jutting out elements opposite which are the corresponding cavities of an underlying nip-roller so as to pluck the material of the union strip 20 as shown under reference 14 in Figs 2 and 3, thereby achieving a positive and regular forward movement of the containers 3-3'. The containers reach the filling stations 25 with the flaps of their respective openings that already having been widened out upstream through the action of opening-out members 24 of a known type.

According to the invention, between the filling station 25 and the end station 40 for recovery of the strip 20 and the collection of the filled and sealed containers released from each other, the insertion of an additional work station is provided, which station, identified by 30 in Fig. 1, usefully completes the task of the existent apparatus in accordance with the intended object.

The additional station 30, shown only schematically, consists of a chamber 32 which can be opened and re-closed with a hermetic-seal lid 34 and in which a vacuum condition can be created.

Chamber 30 is provided with a relatively limited capacity, i.e. 1 to 4 pairs of containers at the most, depending on their transverse size, so as to limit the creation of the vacuum condition within conveniently reduced periods of time, and it is internally provided with one or more pairs of thermoelectric jaws to operate the hermetic sealing of the filled pairs of containers inside which, as desired, the products remain protected under the condition of a very limited presence of air. Once the vacuum sealing of the upper opening of the containers has been carried out, the lid 34 is removed and a pliers device draws the sealed envelopes out of the chamber and introduces therein other just filled envelopes. The pairs of already sealed envelopes reach the end station 40 where the union strip 20 can be recovered and the individual or paired envelopes fall into the respective packaging boxes for despatch.

As already stated, the containers for use in this apparatus can be of various types, among which there are those provided with side bellows as shown in Fig. 2, or those of the vertical self-supporting type, as shown in Fig. 3 or in Fig. 4.

For obtaining the type of envelope shown in Fig. 3, the side ends of the web can be pressed by heatable jaws in order to perform, at the bottom of each container, the conjunction of all heat-sealable facing surfaces, thereby forming two inclined sealing connections 23, 23' that, starting from the sealing closure 22 of the bottom of the final bag, connect with the side sealing closures 21, 21' of same so as to form a bellows in replacement of known bellows of curved conformation.

To obtain a bag as shown in Fig. 4, the four sides of the bottom have a sealing closure 22 involving the whole perimeter of the bottom itself and the lower edge of the four sealing closures 21 of the upright walls so that the bottom rest surface essentially corresponds to the whole surface of the bottom itself.

Claims (3)

1. A method of filling and sealing pairs of containers (3,3') in the form of envelopes or bags provided or not with side and/or bottom bellows, made of flexible material, connected with each other by a central union strip (20) and presenting at said central union strip, their facing and opposite openings for filling the containers with the products, so as to form a continuous web of paired containers, comprising the following steps:

   a) feeding a filling and sealing apparatus with pairs of such containers connected with each other in the form of a continuous web (2) taken from a bobbin on which such web is wound or from a packaging box (5) in which the web is concertina-folded;

   b) causing the web of paired containers hung by said central union strip from a horizontal rod-shaped support (6) with their respective openings facing upwards, to move forward;

   c) spreading apart the upper openings of the pairs of containers of the continuous web;

   d) filling each pair of containers in a filling station (25), as said containers move under appropriate filling devices, with the products in a liquid or granular form or in pieces;

   e) heat-sealing the openings of the pairs of filled containers;

   f) separating the sealed containers from each other; and

   g) collecting the individual containers in packaging means,

      characterised in that in step e) the sealing of the pairs of containers takes place in a chamber (32) which is opened to receive some couples of paired containers, whereafter the chamber is hermetically closed, the vacuum or a strong negative pressure is created therein and the container openings are heat-sealed.
2. An apparatus for filling and sealing pairs of containers (3, 3') in the form of envelopes or bags provided or not with side and/or bottom bellows, made of flexible material, connected with each other by a central union strip (20) and presenting to said central union strip, their facing and opposite openings for filling the containers with the products, so as to form a continuous web (2) of paired containers, suitable for implementing the method as claimed in claim 1, this apparatus comprising:

   a feeding source for supplying pairs of containers, such as a bobbin or a storage (5) of pairs of concertina-folded containers from which the web (2) of paired containers (3, 3') is unwound or taken;

   a support (6) for feeding the web (2) of paired containers the free end of which is centred on the centre line of a central strip (20) for union of the pairs of containers (3, 3') in order to arrange said paired containers on either side of the feeding support, which are vertically suspended with their respective openings facing upwards;

   a drive or transport unit (10) apt to direct the web (2) of paired containers towards a station (24) for the spreading out of the openings of the containers (3, 3'), and to a subsequent filling station (25);

   a station (40) for separating the containers above the sealing lines and eliminating the upper scraps together with the union strip (20),

      characterised in that downstream of the filling station (25) a station (30) is arranged which comprises a chamber (32) with a lid (34) for hermetic closure, adapted to receive some couples of paired containers which can be opened at ambient atmosphere, and inside which a vacuum or a strong negative pressure can be created, said chamber (32) being internally provided with electrically heatable jaws for sealing the containers in the absence of air.
3. An apparatus according to claim 2, characterised in that the transport unit (10) preferably consists of an upper roller (11) provided with linear jutting-out elements opposite corresponding cavities of an underlying nip-roller which are capable of plucking the material of the union strip (20) to achieve a positive and regular forward movement of the containers (3, 3').

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