WO2007067029A1

WO2007067029A1 - Plastic spout for a flexible pouch and flexible pouch provided with such a spout

Info

Publication number: WO2007067029A1
Application number: PCT/NL2005/000839
Authority: WO
Inventors: Laurens Last
Original assignee: Ipn Ip B.V.
Priority date: 2005-12-07
Filing date: 2005-12-07
Publication date: 2007-06-14

Abstract

A sealable plastic spout (1) adapted to be sealed by means of a sealing technique between film walls of a flexible pouch, said spout having a plastic body and a channel (2) therein for dispensing a substance from the flexible pouch and/or feeding a substance to the flexible pouch. The body has sealing surfaces (7, 8) on opposed sides thereof, said sealing surfaces being meltable for establishing a connection to an adjoining film wall of the flexible pouch. The body has a main body part through which the channel extends and two elongated wings (10, 11) extending over a length thereof in diametrically opposed directions outward from the main body part, each wing having a height at right angles to its length, each wing having a solid cross-section, each wing (10, 11) having opposed faces forming part of the sealing surfaces of the spout, and wherein each wing further has a significant length.

Description

PLASTIC SPOUT FOR A FLEXIBLE POUCH AND FLEXIBLE POUCH PROVIDED WITH SUCH A SPOUT.

The present invention relates to a plastic spout adapted to be fitted by means of a sealing technique between film walls of a flexible pouch, comprising a plastic body which forms a channel for dispensing a substance from the flexible pouch and/or feeding a substance to the flexible pouch.

From the prior art it is known to manufacture spouted flexible pouches, wherein a plastic spout is sealed between film walls of the flexible pouch, commonly by pressing the film walls against the spout with heated sealing jaws of a suitable heat sealing device. The production of such flexible pouches with spouts sealed into the pouch is a high-speed process. Both the sealing process and the use of the pouches by end users result in a number of criteria associated with plastic spouts. These criteria include sealing quality and sealing conditions (time to establish seal during the sealing process, strength, appearance, absence of leaks or weak spots) , strength during load testing of filled flexible pouch (e.g. drop tests), user-friendliness of produced pouch, etc.

The present invention aims to propose improved spouts or at least alternative designs.

According to a first aspect thereof the present invention provides a spout according to claim 1.

When a spout having the design according to claim 1 is sealed into a pouch, the two elongated wings extend between the film walls at either side of the central body part over a length of at least 8, preferably at least 12 millimetres. These "lengthy" wings serve to provide additional sealing surface between the film walls and spout. Also the wings provide a mechanical connection between the central body part and the adjacent areas of the upper end of the flexible pouch. This is in particular advantageous in an embodiment wherein the spout is provided with a screw cap, wherein the lengthy wings then provide the user with a "hold" for holding the spout while unscrewing or thightening the cap.

The inventive spout is efficient in view of the use of plastic material, which positively affects the injection moulding and cost price, when compared to prior art sealable plastic spouts. Prior art spouts are known having a solid lower part to be sealed into the pouch which requires much plastic anyway. More sophisticated prior art spouts, e.g. as proposed by the present applicant, have a lower part almost entirely formed by two sealing walls defining an opening between them which requires less plastic than the solid version.

Nonetheless, if one considers the sealing of a spout into an opening between the film walls of a certain lenght (e.g. into the top opening of an already prepared pouch) than it will become clear that the spout according to the present invention allows to "cover" a major part of said length via the two wings, which can contain a reduced amount of plastic material in comparison to a prior art spout having a wide ^Nλeye- or boat shaped lower part" of the spout with no wings or with only short melting fins sealed between the film walls .

It is noted that in prior art spout short meltable fins are present on diametrically opposed positions of the central body part of the spout. These meltable fins have a minimal length in a direction away from the central body part and when viewed from above an essentially triangular cross-section. The short meltable fins are provided in order to fill the triangular area between the film walls at the position where the film walls diverge from one another near the spout and thus prevent leakage at this position. These short fins neither provide a "hold" for the user of the pouch nor allow to arrive at the reduction of plastic material for the spout as explained above . The lengthy wings also can contribute to an easier handling of the spouts prior to their sealing into a pouch, e.g. on vibratory feed equipment leading to the heat sealing device. Preferably the sealing surfaces of the spout, including the sealing faces of the wings, have a rough surface structure, which produces a good connection with the film walls of the flexible pouch.

It also appears that producing the sealed connection between the film walls and the spout of claim 1 with the aid of a suitable sealing technique can proceed at a very high speed without

complications. Furthermore, the sealed connections perform very well if they are subjected to mechanical stress, for example in a drop test with a flexible pouch filled with liquid. The sealing is preferably conducted using heated sealing jaws, but ultrasonic sealing or other suitable methods are also envisaged.

The first aspect of the invention further relates to a flexible pouch provided with such a spout.

The first aspect of the invention further relates to a method for manufacturing a flexible pouch with such a spout.

The first aspect of the invention further relates to the method of claim 28, wherein a flexible pouch is provided with a winged spout, which is sealed between film walls of the flexible pouch, and wherein the film walls are sealed directly to each other along the bottom edges of the wings. This is preferably done at the same time as sealing the spout into the pouch, in practice e.g. using the same heated sealing jaws which are provided with a zone for sealing the film walls against one another.

By sealing the film walls directly against one another below said wing edges a very leak tight flexible pouch is obtained. Also any barrier properties, e.g. oxygen barrier, provided by the film walls (e.g. by a metallic layer in the film or foil) are now present in the areas below the wings, which enhances the barrier property of the entire flexible pouch.

A second aspect of the present invention relates to a spout

according to claim 29. The design of the anti-nesting members with flange panels along the vertical sides of the central curved section allows for a high stability of these members. This also contributes to the stability of the entire spout, e.g. of the upper channel member, which protrudes from the pouch and is subjected to

mechanical loads and impacts, e.g. as a result of shipping, storage, or use of the pouch by the end-user.

Preferred embodiments of the spout according to claim 29 are described in the subclaims 30-31.

A third aspect of the present invention relates to a spout according to claim 32. In this design the array of parallel ribs provides stability of the sealing walls, which allows for a thin design of the sealing walls themselves. This is advantageous for the heat sealing process.

By choosing the cross-section of the ribs and the spacing the flexibility/stability of the sealing walls can be optimised without having to resort to thicker sealing walls.

The spacing of the ribs can be substantially uniform, (e.g. in the range from 3 to 5 millimetres apart from each other) , but non uniform spacing, e.g. a dense arrangement near the centre of the array and further apart near the ends of the array is also possible.

The parallel arrangement of the sealing walls and their position essentially at right angles to the lower edge of the sealing walls allows for a practical embodiment of the related part of the injection mould in which the spout is manufactured.

In a practical embodiment the ribs can have a tapering cross-section to allow for easier release from the mould. A further aspect of the present invention provides for a spout, possibly a spout having no or less long wings than in claim 1, wherein the body of the spout is made of LLDPE or a blend including LLDPE, and wherein the film walls of the flexible pouch each contain a layer to be heat sealed to the sealing surfaces of the spout, possibly an inner layer of a multiple layer film, of LLDPE or a blend thereof, e.g. a blend with HDPE (High Density Polyethylene).

In an advantageous embodiment a polyolefin including Metalozene, e.g. LLDPE including Metalozene is used as thermoplastic material for the spout. Providing a combination of LLDPE elements (spout and inner layer of pouch) to be heat sealed against one another provides for excellent sealing. The reduced rigidity of the spout is e.g. compensated for preferably by providing the wings, preferably wings having a reinforcement element, or the internal ribs on the sealing walls as disclosed herein.

A yet further aspect of the present invention provides for a spout to be sealed between the film walls of a pouch, wherein the body and an integral, user openable closure element of the spout are made of a first plastic material, e.g. HDPE or LLDPE, and the hinge

structure of a second, different plastic material, preferably PP, and the spout with hing structure and preferably integral closure element is manufactured using the co-injection plastic moulding technique .

The man skilled in the art will appreciate that the above aspects can be integrated in various combinations in the design of a sealable plastic spout. The various aspects of the invention will be explained in greater detail below with reference to the drawing, in which: In the drawings :

Fig. la,b,c,d show in perspective view from above and from below, and further in vertical cross-section from two sides, an example of a spout according to the first aspect of the present invention

Fig. 2a, b, c shows in vertical side view, in part cross-section and from below a further example of a spout according to the first aspect of the present ^' invention,

Fig. 2d in vertical cross-section a wing of the spout of figure 2a- c,

Fig. 3 shows a detail of the spout of figures la-c sealed into a flexible pouch,

Fig. 4 an example of a spout according to the second aspect of the invention,

Figs. 5a-d in side elevational view, in side view from a different direction, view from below and in perspective view respectively an example of a spout according to the third aspect of the present invention.

Figures la,b,c and d show an example of a sealable plastic spout 1 according to the first aspect of the present invention. This spout 1 is adapted to be sealed by means of a sealing technique between film walls of a flexible pouch, which is commonly done by placing the spout with its sealing surfaces between the film walls of the pouch and then pressing the film walls against the sealing surfaces using sealing jaws (which are suitably heated) . The combination of heat and pressure results in the melting of the pressed together surfaces and their integration/adherence. Upon cooling a firm heat seal is obtained. In general the pace of suitable heat-sealing equipment is very high and the duration of the heat sealing process can in practice be less than 1 second.

The spout 1 has in this example a unitary plastic body made of a single suitable thermoplastic material, e.g. (linear low density) polyethylene. The spout 1 has a channel 2 therein for dispensing a substance from the flexible pouch and/or feeding a substance to the flexible pouch (e.g. while filling the pouch on suitable filling equipment). The substance can be all sorts, e.g. liquid, pasty, powdery, a food product, a beverage, detergent, fragrance, soap, etc.

The body of the spout 1 shown here has a transverse wall 4 with a central opening therein which opening forms the lower mouth part of the channel 2. Here the transverse wall 4 is directed at right angles to the longitudinal axis of the channel 2. The wall 4 has essentially the form of an annular disc.

Protruding upward from the transverse wall 4 is tubular part 5. This part 5 forms the major part of the channel 2. A closure member, here a screw cap (not shown) can be fitted on the tubular member, here via a screw thread 6 on the tubular part 5. Other closure members, e.g. a peelable foil seal, a flip-top cap, etc are also possible.

Below the transverse wall 4 the spout 1 here has two sealing walls 7,8 which project downward and form a space between them, here an essentially circular space but other shapes of the space, such as oval or canoe-shaped, are also possible. In this design, just as in an essentially oval or canoe-shape, the sealing walls 7, 8 are symmetrical with respect to a vertical plane of symmetry.

The outer side of the sealing walls 7, 8 form exterior meltable sealing surfaces of the spout 1, which are fused to the film walls of the pouch, wherein the pouch preferably has a plastic (inner) layer engaging the sealing walls. In this manner a connection to an adjoining film wall of the flexible pouch is established.

The body of the spout 1 also has two elongated wings 10, 11

extending over a length thereof in diametrically opposed directions outward from the main body part, here in the plane of symmetry of the sealing walls 7,8 as is preferred. Each wing 10,11 has a height at right angles to its length. In general terms the sealing walls 7,8 are at the greatest distance from each other in a central area and join each other at end junctions located in the plane of symmetry, wherein each of the wings 10, 11 extends in said plane of symmetry from an end junction outward.

Each wing 10,11 has a solid cross-section and faces on opposite vertical side thereof forming part of the sealing surfaces of the spout 1. Here the faces are essentially parallel to each other.

As can be seen in the example of figures la-d the wings 10,11 are of a significant length, here at least 8 millimetres, more preferably at least 12 millimetres. That is significantly longer than the short meltable fins on these locations as seen in prior art plastic spouts, e.g. as in WO 2005/066037.

Figure 2 shows a pouch 15, having left and right vertical side edges 16, 17 (here obtained by heat sealing the two film walls) , a bottom (not shown) and a top having an opening extending the full stretch between the left and right vertical side edges 16,17. The spout 1 with wings 10, 11 in this example spans the entire width of the opening of the top between the vertical side edges 16, 17. This is the preferred embodiment of the long winged spout 1 in combination with such a pouch 15, but a pouch could also be wider at the top than the width of the wing span of the wings.

The wings 10, 11 add stability to the upper part of the spouted pouch 15 and improve the adherence of the spout 1 onto the pouch 15. Also a user can easily grip the pouch when opening or closing the pouch with a user openable closure element, such as with a screw cap. Also the wings 10, 11 serve to position the spout 1 with respect to the opened pouch prior to the sealing action.

As can be seen in this example for each elongated wing 10, 11 the length is greater than the height thereof, preferably at least twice the height. In order to obtain an additional stability of the spouted pouch and to obtain a stable design of the wings 10, 11 it is preferred that the height of the wings 10, 11 is at least 4 millimetres, preferably greater than 6 millimeters, e.g. between 4 and 15 millimeters.

In the embodiment shown in figures 3a-d same or similar parts of the spout as in the embodiment of figures la-d have been given the same reference numeral. As can be seen in figure 3b and also in figure 3d each wing 10 has top edge 10a and a bottom edge 10b, wherein the main side faces of each wing 10 define a wing thickness of solid cross-section, here tapering from said top edge towards said bottom edge. As is

preferred here each wing 10 has an essentially triangular cross- section tapering from the top edge towards said bottom edge. This provides a stable design of the wing while at the same time allowing for improved sealing of the spout into the pouch (as will be discussed later) and allowing for a favourable behaviour under load (e.g. on impact testing of a filled pouch).

Also in figures 3a-d a reinforcement member 25 extends along the top edge 10a of each wing 10, 11. This reinforcement member 25 is integrally moulded with the wing 10,11 here of the same

thermoplastic material.

The reinforcement member 25 is designed to lie outside from the film walls, actually covering the top ends of the film walls. As such the reinforcement members 25 contribute to the stability of the wings 10, 11 as they add plastic material and increase the cross-section.

As is preferred the reinforcement members 25 have a width at right angles to the wing which is greater the thickness of said wing near said top edge 10a. due to the greater width of the member 25 an increase resistance against bending sideways of the wing is

obtained. Preferably, as shown here, each reinforcement member 25 extends beyond said wing 10, 11 at both sides thereof. This results in the "covering" of the top ends of the film walls. Preferably in practice each reinforcement member 25 has a width in the range from 1 millimetre to 5 millimetre as a maximum. More preferably in the range from 2 millimetres to 4 millimetres .

In a practical embodiment a reinforcement member 25 has an

essentially uniform cross-section over its length, e.g. a

rectangular cross-section. An additional effect provided by the elongated reinforcement members 25 is that - when the pouch is intended for a beverage or the like (drink-yoghurt) and the consumer is expected to drink directly from the pouch - the reinforcement members 25 cover the usually sharp top ends of the film walls so that the "mouth-feel" is improved. A suitable design of the elongated reinforcement members 25, e.g. with a cross-section with a rounded top face, can add to this effect. Also one can envisage that said reinforcement member 25, or the upper or other layer thereof is moulded from a different

thermoplastic material, e.g. to obtain better "(mouth) feel

characteristics", e.g. by co-injection moulding, e.g. from an elastomer.

The figures 3a-d also show that the wings 10, 11 each have a top edge which slopes downward from the main body part towards the ends of the wings. This also contributes to the "mouth-feel" of the pouch.

The figures 3a-d show that the wings have a top edge which is straight, but other shapes, e.g. curved downward are also possible as shown in figures la-d. It is advantageous for the handling of the spout, e.g. in conveyor equipment that the lower edges of the sealing walls lie in a plane below the remote end of the wings.

In figures 3a-d each wing extends in longitudinal direction beyond the reinforcement member 25, e.g. by at least 2 millimetres, so that a reduced sideways stiffness of the wing is obtained at its far end. This is favourable in view of tensions in the film walls near the wing ends, e.g. when impact testing a filled pouch.

For stability the wings 10, 11 have an increased height portion at the junction with the main body part (see at 26) .

In a variant the spout can be fitted with an integral, user openable closure element for closing the channel 2 the spout, e.g. a hinged closure element, which is hinged to the central body part via a hinge structure.

In a possible embodiment the long winged spout 1 is made entirely as a monolithic body from a first thermoplastic material, e.g. a polyethylene (blend) such as with HDPE and/or LLDPE, in a suitable injection mould. When a hinge structure for a closure element is present it can be envisaged that said hinge structure is made of a second, different plastic material, preferably PP, and the spout, hinge structure and preferably the closure member is manufactured using the co-injection plastic moulding technique. E.g. a

combination of LLDPE for the main body and PP for the hinge is used.

In combination with the lengthy wings 10,11, and even without reinforcement member 25 if desired, it is proposed that the film walls of the bag are also sealed directly to each other in a zone 27 extending along the bottom edges 10b, lib of the wings 10, 11. This can be seen in figure 2.

Via this direct interconnection via sealing of the film walls an improved robustness of the pouch is obtained. Also, e.g. when the film walls include a specific barrier layer, e.g. a metallic layer to prevent oxygen, the barrier properties of the film walls are used to prevent migration of e.g. colorant, gas (air, oxygen), via the material of the spout. This sealing of the film walls in said zone can be obtained by suitable design of the heat sealing jaws of the heat sealing equipment. When present in the spout the reinforcement member 25 preferably extends along the top edge of the film walls, and the film walls have top edges touching against the reinforcement members. This prevents any melted material (e.g of the inner layer of the pouch and/or of the sealing walls) from being pressed "upward" from between the film wall and the spout and thereby forming a

undesirable rough edge on the topside of the film walls.

Figure 4 shows a sealable plastic spout 30 according to the second aspect of the invention.

In general this spout 30 has a plastic body with a central part 31, here include a transverse wall 31a and a tubular part or upper channel member 31b as explained with reference to figures 1 and 2, and sealing walls 33, 34 downward projecting from said central part and delimiting a space between them. The sealing walls 33, 34 form sealing surfaces on both sides of the exterior of the spout. These sealing surfaces are meltable for establishing a connection to an adjoining film wall of the flexible pouch. The sealing surface shown are of a flat design, in particular without horizontal ribs, but the surface could include such ribs. Preferably the sealing surface are rough.

The upper channel member 31b extends upward from said central part and delimits at least a part of the channel 35 of the spout 30.

The lower end of the spout body further has two opposed anti-nesting members 36, 37, which each extend downward from said central part into the space between the sealing walls 33, 34. The anti-nesting members 36, 37 in general avoid nesting of the spouts, e.g. in conveyor equipment. Also they contribute to the stability of the spout body.

The anti-nesting members 36, 37 in this design each include a curved section 36a, 37a having vertical side edges, when seen in horizontal cross-section (here along the axis of the channel 35) . The anti-nesting members 36, 37 further each include a flange panel 36b, c and 37b, c along each vertical side of the curved section thereof. It can be seen that opposed flange panels 36a, 37a and 36b, 37b of said opposed anti-nesting members leave an open space between them.

In the preferred embodiment shown here the sealing walls 33, 34 are symmetrical with respect to an imaginary vertical central plane of symmetry of the spout, said sealing walls having integral ends located in said plane and having a greatest distance between the centre between the ends. The anti-nesting members 36, 37 are in this embodiment arranged symmetrical with respect to said plane of symmetry. In an embodiment not shown here essentially vertical end panels interconnect the opposed anti-nesting members 36, 37 at the vertical side edges of the flange panels 36b, c and 37b, c.

In a further variant the spout includes connecting bodies, possibly flexible connecting bodies, between each anti-nesting member 36, 37 and a neighbouring sealing wall 33, 34. The connecting bodies can be designed as panels, oriented vertically (here parallel to the axis of the channel of the spout) and at their upper ends integral with the transverse wall of the spout.

Referring to figures 5a-d now an example of a spout 60 according to the third aspect of the present invention will be explained.

The sealable plastic spout 60 is adapted to be sealed by means of a suitable sealing technique between film walls of a flexible pouch.

The spout 60 has been injection moulded and has a body and a channel therein for dispensing a substance from the flexible pouch and/or feeding a substance to the flexible pouch. The body has a main part 61 with tubular member 62 and channel 63 therein and downward projecting sealing walls 64, 65 having a lower edge 66. The sealing walls 64, 65 delimit an open space between their inner surfaces, essentially free of any interconnecting bodies between the sealing walls 64, 65. The sealing walls 64, 65 form sealing surfaces on the outward facing lower sides of the spout, said sealing surfaces being meltable for establishing a connection to an

adjoining film wall of the flexible pouch.

As mentioned before the heat-sealing process is basically governed by the combination of heat and pressure, which combination in the end .results in a sealing time required to establish a suitable heat sealing between the spout and the pouch.

The sealing walls 64, 65 depicted here have a curved central part 64a, 65a and on opposite sides thereof a straight part 64b, c and

65b, c (when seen from below) . These straight parts merge in jointed ends of the sealing walls, which lie in the plane of symmetry of the sealing walls. In particular in combination with such sealing walls 64, 65 having straight parts, the fourth aspect of the invention envisages that each sealing wall 64, 65 is provided on the inner surface thereof with an array of parallel inwardly protruding ribs 67, 68 extending essentially at right angles to said lower edge 66 of the sealing walls. The ribs each have an inner free edge, here having an incline outwardly when seen from the top of the rib to the lower end, which facilitates e.g. release from the mould.

These ribs 67, 68 provide stability of the sealing walls, whereas they allow that the section of the sealing walls between the ribs are kept quite thin. Thus, by providing the inward ribs 67, 68 the designer has the option to combine stability with a thin design of the sealing walls. The thin design is favourable for the heat sealing process as heating up of a thin sealing wall is faster than of a thick walled sealing wall. Until now the "straight parts including sealing walls" had to be made thick in order to prevent inward collapse under the pressures exerted during the heat sealing process .

It is preferred that the array includes ribs having different cross- sectional areas, preferably one or more ribs with a maximum cross- sectional area centrally in said array and one or more ribs of minimum cross-sectional area at the ends of the array (as shown in figure 6c) . In spout 60 a transverse wall covers the open space between the sealing walls 64, 65 and the sealing walls project downward. It is then advantageous that the ribs 67, 68 at their upper ends are integral with said transverse wall. Spout 60 here also includes very thin horizontal welding ribs 69 on the outer surface of the sealing walls, which can be provided to assist in the sealing process if desired.

Claims

C L A I M S

1. Plastic spout (1) adapted to be sealed by means of a sealing technique between film walls of a flexible pouch, said spout having a plastic body and a channel (2) therein for dispensing a substance from the flexible pouch and/or feeding a substance to the flexible pouch, which body has sealing surfaces (7,8) on opposed sides thereof, said sealing surfaces being adapted for establishing a Connection to an adjoining film wall of the flexible pouch, wherein the body has a main body part through which the channel extends, characterised in that said body has two elongated wings (10,11) extending over a length thereof in diametrically opposed directions outward from the main body part, each wing having a height at right angles to its length, each wing having a solid cross-section, each wing having faces forming part of the sealing surfaces of the spout, and wherein each wing (10,11) further has a length of at least 8 millimetres.

2. Spout according to claim 1, wherein for each elongated wing (10,11) the length is greater than said height, preferably at least twice the height.

3. Spout according to claim 2, wherein the height of the wings is at least 4 millimetres.

4. Spout according to one or more of the preceding claims, wherein each wing (10,11) has top edge and a bottom edge, and wherein the opposed faces of each wing define a wing thickness of solid cross- section.

5. Spout according to claim 4, wherein each wing has a tapering cross-section towards said bottom edge, e.g. an essentially triangular cross-section tapering from the top edge towards said bottom edge .

6. Spout according to one or more of the preceding claims, wherein each wing has a top edge and a bottom edge, wherein a reinforcement member (25) extends along said top edge, preferably having a solid cross-section.

7. Spout according to claim 6, wherein said reinforcement member (25) having a width at right angles to the wing which is greater the thickness of said wing near said top edge.

8. Spout■ according to claim 7, wherein said reinforcement member (25) extends beyond said wing at both sides thereof.

9. Spout according to claim 7 or 8, wherein said reinforcement member (25) has a width in the range from 1 millimetre to 5

millimetre as a maximum, preferably in the range from 2 millimetres to 4 millimetres.

10. Spout according to one or more of claims 6-9, wherein said reinforcement member (25) has an essentially uniform cross-section over its length, e.g. a rectangular cross-section or preferably a cross-section with a rounded top face.

11. Spout according to one or more of the preceding claims, wherein the wings (10,11) each have a top edge, which slopes downward from the main body part towards the ends of the wings.

12. Spout according to one or more of the preceding claims, wherein the wings (10,11) have a top edge which is straight, preferably with a downward sloping section near the end of the wing.

13. Spout according to claim 6, wherein each wing extends (10,11) in longitudinal direction beyond the reinforcement member.

14. Spout according to one or more of the preceding claims, wherein the main body part has a lower end in a plane below the wings .

15. Spout according to one or more of the preceding claims, wherein the wings have a increased height portion (26) at the junction with the main body part.

16. Spout according to one or more of the preceding claims, wherein the main body part has a transverse wall (4) with an opening (3) therein which forms part -of the channel, and also sealing walls (7,8) which project downward from the transverse wall and form a space between them, e.g. an essentially oval space, preferably the sealing walls being substantially symmetrical relative to a plane of symmetry of the sealing surfaces of the spout.

17. Spout according to claim 16, in which the sealing walls (7,8) are at the greatest distance from each other in a central area and join each other at end junctions located in the plane of symmetry, wherein each of the wings extends in said plane of symmetry from an end junction outward.

18. Spout according to one or more of the preceding claims, wherein the body has a tubular element (5) which delimits a part of the channel .

19. Spout according to claims 16 and 18, wherein the tubular element (5) extends from the side of the transverse wall facing away from the sealing walls.

20. Spout according to claim 18 or 19, wherein the tubular element (5) is provided with a screw thread (6) for receiving a screw cap.

21. Spout according to one or more of the preceding claims, wherein the spout further comprises an integral, user openable closure element for closing said channel of the spout.

22. Spout according to claim 21, wherein the spout comprises a hinged closure element, which is hinged to the central body part via a hinge structure.

23. Spout according to claim 22, wherein the body and the closure element are made of a first plastic material, e.g. HDPE- and/or LLDPE, and the hinge structure of a second, different plastic material, preferably PP, and the spout is manufactured using the co- injection plastic moulding technique.

24. A flexible pouch (15) having film walls provided with a sealable plastic spout (1) according to one or more of the preceding claims sealed between said film walls.

25. Flexible pouch (15) according to claim 24, wherein the film walls are also sealed directly to each other in a zone extending along the bottom edges of the wings.

26. Flexible pouch (15) according to claim 24 or 25, wherein the flexible pouch has left and right vertical side edges, a bottom and a top having an opening extending between the left and right vertical side edges, wherein the spout with wings spans the width of the opening of the top between the vertical side edges.

27. Flexible pouch (15) according to one or more of claims 24-27 provided with a spout (1) according to one or more of claims 6 - 13, wherein each wing has a top edge and a bottom edge, wherein a reinforcement member (25) extends along said top edge, and wherein the film walls have top edges touching against the reinforcement members.

28. Method of sealing a spout (1) according to one or more of the preceding claims 1-23 between film walls of a flexible pouch, wherein a seal connection is established directly between the film walls in a zone (27) directly beneath the bottom edges of the wings of the spout.

29. Sealable plastic spout adapted to be sealed by means of a sealing technique between film walls of a flexible pouch, said spout having a plastic body and a channel therein for dispensing a substance from the flexible pouch and/or feeding a substance to the flexible pouch, which body has a central part, sealing walls downward projecting from said central part and delimiting a space between them, which sealing wall form sealing surfaces on opposed sides of the spout, said sealing surfaces being adapted for establishing a connection to an adjoining film wall of the flexible pouch, which body has an upper channel member, which extends upward from said central part and delimits at least a part of the channel of the spout, which body further has two opposed anti-nesting members, which each extend downward from said central part into the space between the sealing walls, which anti-nesting members each include a curved section having vertical side edges - when seen in horizontal cross-section - characterised in that, said anti-nesting members (36,37) further each include a flange panel (36b, c; 37b, c) along each vertical side of the curved section (3βa,37a) thereof, opposed flange panels of said opposed anti- nesting members leaving a space between them.

30. Spout according to claim 29, wherein said sealing walls are symmetrical with respect to an imaginary vertical central plane of symmetry of the spout, said sealing walls having integral ends located in said plane and having a greatest distance between the centre between the ends .

31. Spout according to claim 30, wherein said anti-nesting members are arranged symmetrical with respect to said plane of symmetry.

32. Plastic spout (60) adapted to be sealed by means of a sealing technique between film walls of a flexible pouch, said spout being injection moulded and having a body and a channel therein for dispensing a substance from the flexible pouch and/or feeding a substance to the flexible pouch, which body has a main part and downward projecting sealing walls

(64,65) having a lower edge, said sealing walls delimiting an open space between their inner surfaces, which sealing wall form sealing surfaces on opposed outer sides of the spout, said sealing surfaces being adapted for establishing a connection to an adjoining film wall of the flexible pouch, wherein said channel extends in said main part, characterised in that, each sealing wall (64,65) is provided on the inner surface thereof with an array of parallel inwardly protruding ribs (67,68) extending essentially at right angles to said lower edge.

33. Spout according to claim 32, wherein said array includes ribs having different cross-sectional areas, preferably one or more ribs with a maximum cross-sectional area centrally in said array and one or more ribs of minimum cross-sectional area at the ends of the array.

34. Spout according to claim 32 or 33, wherein said main part includes a transverse wall (70) from which said sealing walls project downward, said ribs at their upper ends being integral with said transverse wall.