NO172793B - GASKET FOR LIQUID MATERIAL - Google Patents

Abstract

The package for flowable contents consists of side walls (1), which are connected to each other in tubular form via a longitudinal sealing seam, and end walls which are mounted at the ends of the tube and form the bottom (2) and lid (5) of the package. In this case, the side walls (1) consist of cardboard coated with thermoplastic and the bottom (2) of the package consists of a separate, essentially flat wall piece and is sealed onto the bottom edge (3) of the tubular side walls (1). In order to provide a lightweight, sturdy and inexpensive package, the material of which can be exploited better for the contents and can also be better prepared for reuse, provision is made for the bottom (2) and the lid (5) to consist of glass and to be welded fluid-tightly to the tubular side walls (1) and for the lid (5) to have a closable pouring opening (10). <IMAGE>

Description

The invention relates to a packing for liquid material, comprising side walls which are connected in a tube shape by means of at least one longitudinal sealing seam, and end walls which are arranged towards the ends of the tube and which form the bottom and top of the packing, the side walls comprising a carrier material, e.g. . cardboard, which is coated with thermoplastic material on at least one side, and the bottom of the package is formed by a separate, substantially flat wall piece and is sealed on the lower edge of the tubular side walls.

Such and similar gaskets are known. In one case, the top of the known gasket comprises thermoplastic material without a carrier material, is sprayed on the side walls along its outer edge, and has a pouring device.

Another package is also known where, although the side walls also comprise coated cardboard, the top and bottom comprise thermoplastic material without a carrier material. This known packing is, in the fillable state, designed so that the lid is sprayed on along its four edges, while, however, the bottom for filling the packing is only sprayed on along one edge against the side wall. The cross-section of this gasket, as well as the top and bottom, is substantially square.

Also with the known gasket described above, the bottom is square, so that opposite the round top there is a certain volume reduction, so that the gasket material for the liquid material is not yet optimally utilized. It has been found that all packages with plastic bottoms or tops have the disadvantage that a gas permeability cannot be avoided so that easily perishable liquid materials are exposed during longer storage times. In special cases, sterilization of the known packages has so far only been possible with significant costs. Although the side walls are formed from flat material webs which can relatively easily be coated with gas-impermeable materials, for example metal foils, this method is associated with significant difficulties at top and bottom.

Therefore, certain liquid materials are transported in known glass bottles which, however, have several known disadvantages, for example those relating to cleaning, packing and opening and the expenses associated with the weight. The professional must choose a glass container with a large wall thickness so that the container exposed to careless treatment during transport, washing and filling is not damaged. On the other hand, glass is considered a very ideal packaging material, especially if you take into account the environmental impact and the high reuse value, i.e. the recycling value. For economic reasons, a paper wrapper is often preferred to a glass bottle, when one considers the large weight difference and the associated transport costs; also the stock of reusable glass bottles. Typically, the weight of a solid 1 liter bottle is about 360g.

The purpose of the present invention is therefore to provide a light, stable and reasonable packing with the initially mentioned characteristics of known packings, while the material is better utilized for the filling volume and is also easier to prepare again. The invention should also enable a gas-tight package that is easily sterilizable and remains aseptic for a long time.

According to the invention, the purpose is achieved by the bottom

and the top consists of glass and is fluid-tight welded to the tube-shaped side walls and that the top has a closable pouring opening.

The invention offers an unusual combination of materials, namely paper and glass. Instead of the usual plastic materials for top and bottom, the invention uses glass which was previously and partly still today by experts in the field considered not to be weldable with plastic-coated paper. However, it is known that glass bottles can also be closed with thermoplastic materials, instead of crown caps or the like.

In that case, a tackifier was applied to the edge of the bottle neck, but improvements were deemed absolutely necessary,

on the one hand because of the difficult process steps and on the other hand the contamination of the foodstuffs in the bottles. A heat sealing adhesive was therefore found with which durable connections are achieved, for example between glass and a plastic material. Even with liquid materials, bottles could therefore mainly be closed by sealing. However, it is not known to date to provide a package which mainly comprises plastic-coated paper with a top

or bottom made of glass. Even if a paper sleeve has already been closed by means of aluminum at its ends, it should be noted that metals are deformable, so that the tops and bottoms which are made of metal can also be connected to the paper sleeve by overflanging and clamping. Such methods cannot be used when glass is used instead of metal. In addition, a professional will fear breakage in the glass top or bottom when pressing on the paper sleeve.

The invention here follows a new path for providing a substantially lighter (less weight) but none the less stable package. A tubular paper sleeve which is open at the ends is produced in a known manner from a paper web which is coated with plastic material on at least one side. At a closing station, the tops and bottoms, which are kept in stock and are made of glass, are connected with the sleeve, adjusted and welded. Here, for example, an induction welding device can be used. As the top has the pouring opening, the gasket when produced in this way can be filled and then closed.

The materials used for the tubular side walls, i.e. the sleeve, namely paper or cardboard, coated on at least one side with the plastic material, provide, so to speak, a soft suspension for the two rigid glass discs or plates so that the packing can not only be satisfactorily manufactured, but also filled , transported and handled by the end consumer without risk. The two glass plates are suspended on the tubular side walls in a manner similar to a vibration damper. With the help of this unexpected combination of glass and paper, a high degree of stability also appears in the new packaging.

In an advantageous embodiment of the invention, the pouring opening on the top of the gasket has an annular collar that extends outwards in the axial direction of the gasket and the sealing surface lying in the axial direction is placed on the outer periphery of the top and/or bottom. The above-described design of the pouring opening not only provides a good way to fill the packing through the open pouring opening, but in addition the closing is significantly simplified because the outwardly projecting annular collar on the pouring opening can easily be reached by a closing device. In this way, the construction of the closing device can be simplified and the method can be developed with a higher performance. The fact that a sealing surface is provided on the outer periphery of the top and/or bottom improves the adhesion between the glass part and the paper sleeve. The sealing surface is essentially annular in the usual quart, pint, one liter and two liter packs, and will have a length of from 1 to 7 mm, preferably 2 to 5 mm. It is thereby ruled out that the glass top or glass bottom of the filled or empty package detaches from the paper side walls, respectively only possible with a certain application of force in case of destruction of the package.

According to the invention, the tubular side walls can be internally coated with a metal foil. The pouring opening can also be closed by an optionally coated metal foil. Aluminum is preferably used. For aseptic milk packs, it is known in and of itself to cover the paper side walls with aluminum foil, so that the side walls are also made gas-tight. For aseptic packs, one therefore often has

used the known parallelepiped-shaped gaskets which consist entirely of this coated paper. Due to material consumption, tightness and opening problems, however, one would like to switch to other types of packing. Especially with gaskets where at least one of the ends is closed by a plastic top or bottom, problems have already arisen due to gas ingress into the gasket through the plastic material. If, according to the teachings of the present invention, glass is used instead of plastic materials, these problems associated with making the packing gas-tight will be overcome. The features according to the invention therefore also make it possible to produce a gas-tight and sterilizable package. In the manufacturing process described above, the sterilization operation is carried out after the operation of producing the gasket, i.e. after the glass plates or disks have been welded into the soft paper sleeve, i.e. the tubular side walls comprising plastic-coated cardboard, and before the filling operation.

The features shown above can be used in accordance with the invention in a particularly advantageous way when the cross-section of the tube-shaped side walls as well as the top and bottom are circular. Such a packing provides the optimal filling volume in relation to the packing material used, i.e. it provides an even better utilization than in the case of a square bottom.

Nowadays, rubbish is already collected separately, and it will therefore also be possible to make the packaging according to the invention comprising glass and paper recyclable with a small number of processing operations (cutting off the top and bottom with a knife) because the separated materials and especially the glass are very suitable for recycling. With the new packing for liquid material according to the invention, an environmentally friendly and transport-friendly packing is provided which at the same time has a high advertising effect because advertising printing can be arranged on the paper web for producing the tubular side walls in a known manner.

By using different shapes of the glass top <p>g the glass bottom, they can be made with such a shape in itself that they can be easily stacked, so that they can be delivered from magazines to the finished paper sleeves which are, for example, carried on a conveyor belt, on a practical and compact way.

The invention shall be described in more detail below

in connection with some design examples and with reference to the drawings, where fig. 1 is a perspective view of a milk package according to a first embodiment of the invention with the closure cover removed, fig. 2 is a sectional view through the gasket shown in fig. 1 with a metal foil placed on the pouring opening, fig. 3, 4, 6 and 7 are interrupted and schematic sectional views through the upper part of the tubular side walls with the top welded in position, in an open condition, fig. 5 shows three open separated tops stacked on top of each other, fig. 8 is an interrupted sectional view of another embodiment, with a metal foil placed on top, fig. 9 is a similar view to that shown in FIG. 8 but shows a further modified embodiment of the top and with the closing cover shown separately in section above,

and fig. 10 is an interrupted sectional view through the tubular side walls with the longitudinal sealing seam and the edge protection.

Fig. 1 is a perspective view of the finished milk package in the open state. It comprises side walls 1 which are connected to form a tubular shape by means of a longitudinal sealing seam 4 (see fig. 10), and end walls of glass of which fig. 1 shows only the top 5 while fig. 2 also shows the bottom 2. The side walls 1 comprise paper or cardboard which is coated with thermoplastic material on both sides and they are formed from a flat web which preferably has pressure on it. The web is shaped into a tube and is closed to provide the tube shape by means of the longitudinal sealing seam 4, in the manner shown in fig. 10. A plastic band 6 is sealed on the inside of the tube and extends longitudinally in the axial direction of the tube and forms the edge protection so that fluid cannot penetrate to the small inner edge of the paper which is without plastic protection, and which could therefore damage the paper .

Both the bottom 2 and the top 5 comprise a separate, predominantly flat wall portion which has a disc-like shape in the case of the round embodiment and has a plate-like shape in the case of other embodiments. The base 2 is sealed to the lower edge 3 of the side walls 1. The ring-shaped sealing surface ,7 is placed on the inside of the tubular side wall 1, at the bottom at the edge 3 thereof on one side and at the outer periphery of the base 2 on the other side . In order for the above-mentioned sealing surface which extends in the direction of the gasket's axis 8 to have a given height or length of e.g. from 1 to 7 mm, preferably 2 to 5 mm, a depression or channel is formed in the bottom 2, out of the plane which is placed across the axis 8. The depression-like channel 9 also provides a stiffening effect of the bottom 2 as an addition.

The bottom 2 and the top 5 comprise glass which is preferably colored for the purpose of protecting against light and is preferably prestressed pressed glass.

The top 5 could also have such a V-shaped or trapezoidal annular recess 9 as the bottom 2, but such an embodiment is not shown in the drawings. On the contrary, the top 5 is braced by other annular edges or the pouring opening 10. The pouring opening 10 is placed centrally in the circular top 5 and is formed by an annular collar 11 which projects upwards and outwards in the direction of the axis 8 and as at its top, at its outer end, has a bead 12 (see fig. 7) or a sealing surface 13 which is arranged transversely with respect to the axial direction 8. It is also possible to explain the bead 12 in fig. 7 in such a way that it forms such a sealing surface as indicated by reference number 13 in the other embodiments.

Upwards and outwards, the pouring opening is closed by an aluminum foil 14 which is coated on both sides with thermoplastic material. The aluminum foil 14 is only shown in fig. 2, 8 and 9.

In fig. 2, the aluminum foil 14 is shown bent downwards on the outside on the periphery of the annular collar 11. This is effected by the closing cover 15 of polyethylene which is releasably mounted on the annular collar 11 by snapping the closing cover over the inwardly projecting annular bead 16 shown in fig. . 9 onto the annular collar 11 and over its bead 12 or annular outer edge of the sealing surface 13.

In fig. 9 shows, for example, the condition where the aluminum foil 14 still lies flat on the sealing surface 13, namely before the closing cover 15 is snapped onto the annular collar 11 and engaged. When the closing cover 15 is then removed, it is obtained in fig. 2 shown condition.

It will be clear that in order to pour out material from the packing, the aluminum foil 14 must be broken open, and if the packing is only partially emptied, the closing cover 15 can be used to reseal the packing.

Fig. 3 shows a first embodiment of the cross-section of the top 5, which can also be seen in the representations shown in fig. 1 and 2. Here, the sealing surface 13 is shown, which is arranged perpendicularly or transversely with respect to the axis 8 of the gasket, with its outer edge 17 over which the internal bead 16 on the closing cover 15 can be engaged. In a downward direction, the annular collar 11 transitions from the cylindrical shape to a truncated cone shape and then again in the lower region to transition into a plane so that an annular surface 18 is formed which is found again essentially in all peaks 5 , except for the embodiment shown in fig. 8. On the outer periphery of the top 5, the sealing surface 19 is formed which is arranged in the direction of the axis 8 and which is annular and which has a height or length of approximately 1 to 7 mm and preferably 2 to 5 mm in the direction of the axis 8 . It provides adhesion between the glass top 5 and the paper wall 1.

In the embodiments shown in fig. 4, 7, 8 and 9, there is also an annular surface 20 which covers the edge of the paper and which is next to the sealing surface 19 and outside this. There, too, there is a welded connection between glass and paper. Liquid cannot therefore penetrate into the open edge of the paper side wall 1.

Fig. 5 shows the good stacking possibility for the top 5 according to the second embodiment shown in fig. 4. Other tops are also stackable in a similar manner.

Claims (5)

1. Packing for liquid material, comprising side walls (1) which are connected in a tubular shape by means of at least one longitudinal sealing seam (4), and end walls which are arranged towards the ends of the tube and which form the bottom (2) and the top (5) of the gasket, as the side walls (1) comprise a carrier material, e.g. cardboard, which is coated on at least one side with thermoplastic material, and the bottom (2) of the package is formed by a separate, substantially flat back piece and is sealed on the lower edge (3) of the tubular side walls (1), CHARACTERIZED BY that the bottom (2) and the top 5) consist of glass and are fluid-tightly welded to the tubular side walls (1) and that the top (5) has a closable pouring opening (10). 2. Gasket according to claim 1, CHARACTERIZED IN THAT the pouring opening (10) in the top (5) has an annular collar (11) which extends out in the axial direction (8) of the gasket and that the sealing surface (19) which lies in the axial direction (8) is placed on the outer periphery of the top (5) and/or bottom (2). 3. Packing according to claim 1 or 2, CHARACTERIZED IN THAT the tubular side walls (1) are coated with a metal foil on the inside. 4. Packing according to one of claims 1-3, CHARACTERIZED IN THAT the pouring opening (10) is closed by an optionally coated metal foil (14). 5. Gasket according to one of claims 1-4, CHARACTERIZED IN THAT the cross-section of the tubular side walls (1) and the top (5) and the bottom (2) is circular.