WO1997010152A1

WO1997010152A1 - A bag or pouch and a method of producing the same

Info

Publication number: WO1997010152A1
Application number: PCT/DK1996/000379
Authority: WO
Inventors: Jørgen HYLDGAARD; Lars Holm Frydenlund
Original assignee: Plum Kemi Produktion A/S
Priority date: 1995-09-15
Filing date: 1996-09-11
Publication date: 1997-03-20
Also published as: AU6923196A

Abstract

A bag or pouch (10) is formed by a pair of superposed, substantially rectangular layers of plastic sheet material. These layers are sealingly interconnected along their contour so as to form transverse first and second heat seal seams (12, 13). A substantially rectangular bottom wall (14) and/or top wall is defined by folding corner portions (28) inwardly towards the bottom wall or outwardly towards side walls. Adjacent parts of heat seal seams on the corner portions (28) and on the bottom wall (14) or the side walls of the pouch are directly interconnected so as to maintain corner portions in their folded condition. Such interconnections do not weaken the walls of the pouch and they may be made subsequent to filling the bag or pouch, if desired.

Description

A bag or pouch and a method of producing the same

The present invention relates to a bag or pouch formed by a pair of superposed, substantially rectangular layers of plastic sheet material, which layers are sealingly intercon- nected along their contour.

A bag of this type, which is usually pillow shaped when filled with a liquid product, may be adapted to be arranged in a dispenser such that a discharge spout of the bag extends in a downward direction, for example as disclosed in the international patent application WO 94/17712.

The international patent application WO 95/13224, GB 1141714, and GB 1463579 disclose a bag or pouch formed by superposed layers of plastic sheet material and having a flat bottom surface so that in a filled condition the bag may be supported by this bottom surface. However, the flat bottom walls of the known bags or pouches are being made by forming heat sealing seams in pouch walls being in direct contact with the product contained therein, whereby the strength of the bags or pouches may be substantially reduced.

The present invention provides a bag or pouch of the above type having a flat bottom or end surface which may be pro¬ duced without weakening the walls of the bag or pouch defin¬ ing the product containing space thereof.

Thus, the present invention provides a bag or pouch formed by a pair of superposed, substantially rectangular layers of plastic sheet material, which layers are sealingly intercon¬ nected along their contour so as to form a transverse first heat seal seam extending between a first pair of corner portions of the interconnected layers of sheet material, said first pair of corner portions being folded towards each other, or each first corner portion being folded outwardly and towards a possible adjacent side seam of the bag or pouch, so as to form a substantially rectangular first end surface in a distended condition of the bag or pouch, each of the first pair of corner portions being retained in its folded condition by direct interconnection between adjacent parts of the first heat seal seam or between the first heat seal seam and an adjacent side seam, respectively. By folding the corner portions a substantially rectangular, such as square first end surface may be formed when the bag or pouch is distended for example by a fluid or particulate product arranged within the bag or pouch. When the bag or pouch is of the type having a pair of opposite, longitudinally extending side seams the said first corner portions may be folded outwardly away from each other and attached to the respective side seams, if desired.

The sections of the first heat seal seam formed on the folded first pair of corner portions may be interconnected in any suitable manner, for example by means of an interconnecting adhesive tape section or another interconnecting part of sheet material which is glued or otherwise attached to the folded first corner portions. The folded corner portions may, alternatively, be individually attached to an adjacent seal¬ ing seam along the contour of the bag or pouch, and in that case part of such seam functions as the interconnecting part. In the preferred embodiment, however, the said first pair of adjacent folded corner portions may be mutually overlapping, and the overlapping parts of the transverse first heat seal thereon corner portions may then be directly interconnected, for example by means of an adhesive, by heat sealing, stapl¬ ing, or by any other suitable means.

The rectangular layers of sheet material from which the bag or pouch is made define four corner portions, namely one at each corner at the rectangular shape. Consequently in addi¬ tion to the above first pair of the corner portions the bag or pouch comprises a second pair of adjacent corner portions. These second corner portions may also be folded and intercon- nected as described above in connection with the first corner portions so as to form a second rectangular end surface. Alternatively, each of these second pair of corner portions may comprise fastening means for fastening the corner portion to a dispenser for dispensing a liquid or particulate product from the bag or pouch. As explained below, according to the present invention the second pair of corner portions may be fastened to the dispenser in such a manner that a substan¬ tially parallelepiped-shaped product containing space is defined within the bag or pouch. The fastening means for fastening the corner portions to the dispenser may be of any suitable type. As an example, the fastening means may com¬ prise openings, preferably defined in a second transverse heat seal seam, for receiving pins or stud members formed on the dispenser.

The invention further relates to a method of producing a bag as that described above, said method comprising forming a tubular body of superposed layers of plastic sheet material, forming a first heat seal seam transversely to the longitudi¬ nal axis of the tubular body so as to define an end seam or a bottom seam of the bag or pouch, folding corner portions at opposite ends of the transverse end or bottom seam inwardly toward the longitudinal axis of the tubular body or outwardly towards a possible side seam of the bag or pouch, and inter¬ connecting the folded corner portions by directly intercon¬ necting adjacent parts of the first heat seal seam so as to retain them in their folded condition, or by directly inter¬ connecting adjacent parts of the first heat seal seam.

The folded corner portions may be mutually spaced and as mentioned above, they may be indirectly interconnected by means of a separate interconnecting sheet part which may be glued, stapled, or otherwise attached to parts of the first heat seal seam of the respective corner portions. However, in case the corner portions are long enough to mutually overlap they may be interconnected in their overlapping condition, for example by means of a glue or staples. In the preferred embodiment, however, the overlapping parts of the corner portions are mutually interconnected by heat sealing. If the corner portions do not overlap adjacent parts of the folded first heat seal seam may be directly interconnected, for example by heat sealing.

The substantially rectangular end surface of the bag or pouch according to the invention filled with a liquid or particulate product is defined by folds (not seams) forming the edges of the rectangular shape, and such folds do not reduce the strength of the sheet material from which the bag or pouch is made to any substantial extent.

The tubular body from which the bag or pouch is made, may be a hose-like extruded seamless body. Alternatively, the tubu¬ lar body may be made by fusing or sealing overlapping longi¬ tudinal edge portions of superposed layers of plastic sheet material.

In a preferred embodiment of the method according to the invention a mandrel defining a substantially rectangular cross-sectional outline corresponding to the shape of the desired rectangular end or bottom surface of the bag or pouch and having a pair of flaps hinge-connected or rotatably connected to opposite sides of the mandrel, is inserted into the inner space of the tubular body so that the substantially axially extending flaps are positioned into engagement with the corner portions of the bag or pouch at opposite ends of the end or bottom seam, the corner portions being folded inwardly by moving the hinge flaps of the mandrel inwardly towards the longitudinal axis of the tubular body. When the folded corner portions have been interconnected as described above, the mandrel with the moveable flaps may be removed from the bag or pouch thus formed. Each of the moveable flaps may have a substantially triangular outline.

The mandrel may be in the form of a filling tube which may have any cross-sectional shape, such as circular or polygonal. In the preferred embodiment, however, the filling tube has a rectangular shape, and a fluid or particulate product may be being filled into the bag or pouch through the filling tube when the corner portions have been folded and interconnected. The mandrel may then gradually be moved out from the bag or pouch while product is being filled into the bag, or the mandrel may be moved out from the bag when all of the content has been filled into the bag via the tubular mandrel. When the bag has been filled it may be closed and sealed by forming a transversely extending top seam on the tubular body. A long hose-like tubular body may be threaded around the mandrel or filling tube in a longitudinally col¬ lapsed condition, and each time a bag or pouch has been filled and completed, it may be moved downwardly from the mandrel. It should be understood that the top seam of a completed bag or pouch and the bottom seam of a succeeding bag or pouch may be made in one and the same step.

It should be noted that because the folded corner portions of the bag according to the invention are maintained in their folded position by interconnecting adjacent seam portions of the bag and not wall portions which are in contact with the content of the filled bag, the corner portions may be folded and fastened after filling the bag or pouch, if desired. Furthermore, the interconnections of the adjacent seam por¬ tions retaining the folded corner portions in position may be made so weak that they will break before the wall parts of the filled bag when the filled bag or pouch is exposed to excessive inner or outer forces.

The bag or pouch according to the invention may be provided with a discharge spout or discharge tube, which is preferably extending from the rectangular bottom surface of the bag. The filled bag or pouch may then be arranged in a dispenser with the discharge spout extending downwardly from the downwardly facing rectangular bottom surface. When the filled bag or pouch is arranged within a dispenser the product defining space of the bag or pouch should preferably be substantially parallelepipedly shaped so that the filled bag or pouch may substantially occupy a box-shaped or parallelepiped shaped space defined within the dispenser.

Alternatively, the upper end of the bag or pouch according to the invention may be provided with a spout or discharge passage of the types disclosed in the published international patent applications WO 94/22731 and WO 96/11854. Such dis¬ charge passage or spout, which is self-sealing, may be opened by inserting a suitable tubular member, such as a drinking straw, therein. Then, a liquid content, such as a drink, may be discharged from the bag or pouch by compressing the same.

When an open ended bag or pouch with a substantially rec¬ tangular end wall has been made in a manner as described above the inside of the bag may be turned out. In its filled condition the bag or pouch then obtains a smooth outer sur- face without protruding seams or folded corner portions.

Therefore, according to a further aspect the present inven¬ tion provides a method of arranging a bag or pouch of the type formed by a pair of superposed, substantially rectangu¬ lar layers of plastic sheet material sealingly interconnected along their contour, in a dispenser chamber comprising means defining a pair of transversely spaced edge portions, said method comprising folding each of a pair of adjacent corner portions of the bag or pouch around an adjacent edge portion of said pair of edge portions and fastening the folded corner portion to the dispenser in its folded condition so as to form a substantially rectangular, such as a square, end wall of the bag or pouch. By this method of arranging the bag or pouch in the dispenser a substantially rectangular upper and/or lower end surface of the bag or pouch may be defined, the substantially parallel edge portions of the dispenser chamber defining opposite edges of the rectangular shape.

The edge portion defining means which may be arranged at the upper and/or at the lower end of the dispenser chamber, may be of any suitable type. Thus, the edge portion defining means may comprise a pair of transversely spaced, substan¬ tially parallel rails or wires, the upper or lower edge portions of a pair of transversely spaced, upright walls defining the dispenser chamber, and opposite end portions of a top wall portion and/or bottom wall portion defining the dispenser chamber.

The bag or pouch being inserted into a dispenser chamber may be of the type described above having a substantially rec¬ tangular (including substantially square) bottom wall, and a substantially rectangular top wall may then be formed by folding the upper corner portions of the bag or pouch around a pair of upper edge portions defined in connection with the dispenser chamber.

The corner portion of the bag or pouch may be attached to the outer surfaces of the chamber walls in any suitable manner, for example by gluening or by mechanical means. As an example, each folded corner portion of the bag or pouch may be fastened to the outer surface of an adjacent chamber wall by inserting a pin or stud member extending from said outer surface into a corresponding opening defined in the corner portion.

The present invention also provides a dispenser for dispens¬ ing a liquid or particulate product from a bag or pouch of the type described above, said dispenser comprising edge defining means arranged at the upper and/or lower end of a dispenser chamber for receiving the bag or pouch and defining a pair of transversely spaced, substantially parallel free edge portions, and means for fastening each of adjacent opposite corner portions of the bag or pouch when such corner portion has been folded around the adjacent free edge por¬ tion.

The edge defining means may be of any suitable type defining a pair of transversely spaced, substantially parallel free edge portions. Thus, the edge defining means may, for example, comprise a pair of spaced, parallel rails or wires, upper and/or lower edge portions of a pair of upright chamber defining walls, and opposite edge portions of a top and/or bottom wall portion defining the dispenser chamber.

The dispenser may further comprise a cover, which is moveable between an open and a closed position and which in its closed position is in engagement with or closely spaced from the outer surfaces of walls defining the dispenser chamber, the spaced walls in its closed position, the fastening means being formed on an inwardly recessed part of said walls. The corner portions of a bag or pouch, which is folded around the edge portions of the chamber walls, may then be received in the recessed parts of the walls so that they do not interfere with the movement of the dispenser cover.

The invention will now be further described with reference to the drawings, wherein

Fig. 1 shows a bag or pouch of the known pillow-shaped type, Fig. 2 is an embodiment of the bag or pouch according to the invention, Fig. 3 is a diagrammatic front view of part of a dispenser for receiving the bag or pouch shown in Fig. 2, Fig. 4 illustrates the bag or pouch shown in Fig. 2 being arranged in the dispenser shown in Fig. 3, Figs. 5a-8a and Figs. 5b-8b illustrate various stages of a method of producing a bag or pouch of the type illustrated in Fig. 2 shown in side and bottom views, respectively, Fig. 9 is a front view of an alternative embodiment of the dispenser part shown in Figs. 3 and 4, and Fig. 10 is a front view of the dispenser part shown in Fig. 9 with a filled bag or pouch mounted therein.

Fig. l shows a conventional pillow-shaped package or pouch 10 made from a plastic film or sheet material and filled with a liquid or particulate product. The pouch 10 may be made from a tubular body or hose having a longitudinally extending seam 11, and the pouch or package 10 is defined between transverse bottom and top seams 12 and 13, respectively. The seams may, for example, be made by heat sealing. The tubular body or hose from which the package or pouch 10 is produced may be made by seamless extrusion, so that the longitudinal seam 11 may be dispensed with.

Fig. 2 shows an embodiment of a bag or pouch according to the invention, which has been made by modifying the bag shown in Fig. 1 so as to form a substantially flat end wall or bottom wall 14 thereon. The substantially rectangular bottom wall 14 is defined by a first pair of parallel bottom folds or pleats 15 and by a second pair of substantially parallel bottom folds or pleats 16 extending transversely and substantially at right angles to the folds or pleats 15. Substantially triangular side surfaces 17 are defined between a pair of folds or pleats 18 extending from opposite ends of the top seem 13 and by the bottom folds or pleats 15. A downwardly extending discharge spout or outlet 19 may be formed on the bottom wall 14, and in the top seam 13 openings or holes 20 for mounting the filled package or pouch shown in Fig. 2 in a dispenser frame 21 of the type shown in Figs. 3 and 4 may be formed at opposite ends of the seam.

The dispenser body 21 shown in Figs. 3 and 4 comprises a pair of mutually spaced, substantially parallel side walls 22 and an interconnecting pouch supporting bottom structure 23 with a downwardly extending spout passage 24 defined therein. The upper end portions 25 of the dispenser side walls 22 are offset inwardly in relation to the remaining part of the side walls so as to define a recess 26. Pins or stud members 27 extent transversely from the outer surfaces of the upper end portions 25 of the side walls 22 into the recesses 26.

A package or pouch of the type shown in Fig. 2 may be arranged in the dispenser frame 21 so that the rectangular bottom wall 14 is supported by the bottom structure 23 of the dispenser, and the discharge spout 19 extends through the passage 24. Thereafter, a pair of upper, opposite corner portions 28 in which the openings 20 are formed, may be folded outwardly above the upper edges 29 of the dispenser side walls 22 as shown in Fig. 4, and the corner portions 28 may be retained in their folded condition by moving them into engagement with the outer surfaces of the upper end portions 25 of the side walls 22 so that the stud members 27 are received in the openings 20 formed in the top seam 13 of the packing or pouch.

By folding the upper corner portions 28 of the pouch as described above, the upper part of the pouch is formed into a substantially rectangular top wall 30, whereby the upwardly converging folds or pleats 18 are caused to extent substan¬ tially parallel. This means that the pouch shown in Fig. 2 is converted into an almost parallelepipeded shape filling the dispenser chamber defined between the opposite side walls 22 almost completely. The corner portions 28 are received in the recesses 26 so that a dispenser cover (not shown) moveable between closed and open positions and being in engagement with or positioned closely adjacent to the outer surfaces of the side walls 22 would not interfere with the corner por¬ tions 28 or damage the same.

A method of forming the flat, substantially, rectangular end wall or bottom wall 14 of the pouch shown in Fig. 2 will now be explained with reference to Figs. 5-8 of the drawings:

Packages or pouches according to the invention and as shown in Fig. 2 may be made from an elongated tubular body or hose 31 of a plastic film or laminate. The tubular body 31 may be made seamless by extrusion, or may have a longitudinally extending seam 11 preferably made by heat sealing. The tubu- lar body or hose 31 may be supplied from a stock of material (not shown in the drawings) and passed around a stationary mandrel or filling tube 33 having a substantially rectangular outer cross-sectional shape corresponding to the desired cross-sectional shape of the filled bag or pouch to be pro- duced. As shown in Fig. 5, the lower free end portion of the tubular body or hose 31 is sealed by a transverse bottom seam 12 which is relatively broad, and which may be made by heat sealing. The tubular mandrel 33 contains a pair of substan- tially triangular folding flaps 35 mounted on a pair of opposite inner wall surfaces of the rectangular mandrel 33. The flaps 35 are mounted so as to be longitudinally displaceable in relation to the stationary filling tube 33 from a retracted position shown in Fig. 5 to an extended position shown in Fig. 6. In their retracted position the flaps 35 are completely received within the mandrel 33. In their extended position, however, the flaps extend below the lower end of the mandrel 33 and are mounted so as to be rotatable towards each other about hinge connection 36 posi- tioned at the bottom end of the mandrel 33.

When the hose 31 has been moved downwardly around the mandrel or filling tube 33 so that a predetermined length of the free end portion of the hose extends from the bottom end of the mandrel 33, the folding flaps 35 are moved downwardly in relation to the filling tube or mandrel 33 as indicated by an arrow 37 in Fig. 6a, whereby the folding flaps 35 come into engagement with the inner surfaces of a pair of corner por¬ tions 28 of the sealed end of the hose 31 at opposite ends of the bottom seam 12. Preferably, the flaps are directed down- wardly and slightly outwardly so that each flap defines a small angle with the longitudinal axis of the mandrel. The flaps 35 may now be rotated about the hinge connections 36 from the position shown in Fig. 6, via the position shown in Fig. 7, and into a position shown in Fig. 8 in which the corner portions 28 are partly overlapping and in mutual abutting engagement in a zone 39 of overlapping. In this position the overlapping parts of the corner portions 28 may be interconnected, for example by heat sealing. Furthermore, the corner portions 28 by be sealed to the bottom seam 12. By these steps a substantially rectangular, preferably square flat end surface or end wall 14 shown in Fig. 8b has been formed on the free end of the tubular body or hose 31. The flaps 35 may now be withdrawn from the interconnected corner portions 28, and a liquid or particulate product may be filled into the lower end portion of the hose 31 via the filling tube 33 while the tubular body or hose 31 is moved downwardly in relation to the filling tube or mandrel 33. When the desired amount of product has been filled into the free end of the hose or tube 31 extending below the mandrel or filling tube 33, a transverse top seam 13 (Figs. 1 and 2) may be formed between the upper part of the liquid or particulate product filled into the tube or hose 31 and the lower edge portion of the mandrel or filling tube 33. Now, the filled bag or pouch thus formed may be cut from the hose 31. A new bottom seam 12 is preferably formed at the lower end of the tubular body or hose 31 at the same time as the top seam 13 of the preceding bag or pouch is being made.

Therefore, the operation described above may now be repeated to form a new filled bag or pouch.

It should be understood, that the corner portions of the pouch at opposite ends of the top seam 13 may be folded toward each other and interconnected, or folded outwardly and attached to opposite, longitudinal side seams replacing the seam 11, so as to also form a substantially rectangular, flat end wall at the top seam 13.

Fig. 9 diagrammatically illustrates a dispenser frame com- prising a back wall 41 with a bottom structure 23 defining a spout receiving passage 24 as described above in connection with Fig. 3 and 4. A pair of transversely spaced, substan¬ tially parallel rods or rails 42 extend substantially at right angles from the back wall 41, and a bar or arm 43 extending from the back wall 41 and positioned between the rods 42 has an upwardly extending pin or stud member 44.

Fig. 10 illustrates how a bag or pouch of the type shown in Fig. 2 may be arranged in the dispenser shown in Fig. 9. As explained above in connection with Figs. 3 and 4 the bottom wall 14 of the pouch may be supported by the bottom structure 23 and the discharge spout 19 may extend through the passage 24. Thereafter opposite corner portions 38 may be folded around the rods 42 and inwardly, and the openings or holes 20 formed in the top seam 13 of the pouch may be threaded on the pin or stud member 44, whereby the corner portions 38 may be retained in their folded condition. In this manner a substan¬ tial rectangular upper end wall of the pouch may be formed.

It should be understood, that various modifications and changes of the embodiments described above may be made with- out departing from the scope of the present invention. As an example, a bag or pouch of the type shown in Fig. 1 may be arranged in dispensers of the type shown in Fig. 3, 4, 9, and 10. In this case the bottom structure 23 could be replaced by edges defining means, such as edge portions formed at the lower ends of the side walls 22 shown in Figs. 3 and 4, or by a pair of spaced rods corresponding to the rods or rails 42 shown in Figs. 9 and 10.

Furthermore, the bag or pouch described above and shown in the drawings needs not necessarily be made from plastic film material, but may also be made from paper, cardboard, or another suitable sheet material.

Claims

1. A bag or pouch formed by a pair of superposed, substan¬ tially rectangular layers of plastic sheet material, which layers are sealingly interconnected along their contour so as to form a transverse first heat seal seam extending between a first pair of corner portions of the interconnected layers of sheet material, said first pair of corner portions being folded towards each other, or each first corner portion being folded outwardly and towards a possible adjacent side seam of the bag or pouch, so as to form a substantially rectangular first end surface in a distended condition of the bag or pouch, each of the first pair of corner portions being retained in its folded condition by direct interconnection between adjacent parts of the first heat seal seam or between the first heat seal seam and an adjacent side seam, respect¬ ively.

2. A bag or pouch according to claim l, wherein said first pair of adjacent folded corner portions are mutually overlap¬ ping and the overlapping parts of the transverse first heat seal thereon may then be directly interconnected by heat sealing.

3. A bag or pouch according to claim 1 or 2, wherein each of a second pair of adjacent corner portions comprises fastening means for fastening the corner portion to a dispenser for dispensing a liquid or particulate product from the bag or pouch.

4. A bag according to claim 3, wherein the fastening means comprises an opening for receiving a pin or stud member formed on the dispenser.

5. A method of producing a bag or pouch according to any of the claims 1-4, said method comprising forming a tubular body of superposed layers of plastic sheet material, forming a first heat seal seam transversely to the longi¬ tudinal axis of the tubular body so as to define an end seam or a bottom seam of the bag or pouch, folding corner portions at opposite ends of the trans- verse end or bottom seam inwardly toward the longitudinal axis of the tubular body, or outwardly towards a possible adjacent side seam of the bag or pouch, and interconnecting the folded corner portions by directly interconnecting adjacent parts of the first heat seal seam so as to retain them in their folded condition, or by directly interconnecting parts of the first heat seal seam to adjacent side seams, respectively.

6. A method according to claim 5, wherein the corner portions are folded so as to mutually overlap and adjacent parts of the first heat seal seam are subsequently interconnected in their overlapping condition.

7. A method according to claim 5 or 6, wherein a mandrel having a pair of flaps hinge-connected or rotatably connected to opposite sides of the mandrel is inserted into the inner space of the tubular body so that the substantially axially extending flaps are positioned into engagement with the corner portions of the bag or pouch at opposite ends of the transverse end bottom seam, the corner portions being folded inwardly by moving the hinged flaps of the mandrel inwardly towards the longitudinal axis of the tubular body.

8. A method according to claim 7, wherein the mandrel is a filling tube having a substantially rectangular outer cross- sectional shape, a fluid or particulate product being filled into the bag or pouch through the filling tube when the corner portions have been folded and interconnected.

9. A method according to any of the claims 5-7, further comprising turning the inside of the bag or pouch out before filling the bag.

10. A method of arranging a bag or pouch of the type formed by a pair of superposed, substantially rectangular layers of plastic sheet material sealingly interconnected along their contour, in a dispenser chamber comprising means defining a pair of transversely spaced edge portions, said method com¬ prising folding each of a pair of adjacent corner portions of the bag or pouch around an adjacent edge portion of said pair of edge portions and fastening the folded corner portion to the dispenser in its folded condition so as to form a sub- stantially rectangular end of the bag or pouch.

11. A method according to claim 10, wherein the dispenser chamber is defined by a pair of transversely spaced upright walls each having an upper edge portion, each of the adjacent corner portions of the bag or pouch being folded outwardly and above the upper edge portion of the adjacent chamber wall and being fastened to the outer surface of the wall.

12. A method according to claim 10, wherein the dispenser chamber is defined by a top wall having opposite edges, each of the adjacent corner portions of the bag or pouch being folded inwardly and above the adjacent top wall edge and being fastened to the upper surface of the top wall.

13. A method according to claim 11 or 12, wherein each folded corner portion of the bag or pouch is fastened to the outer surface of the adjacent chamber wall by inserting a pin or stud member extending from said outer surface into a corre¬ sponding opening defined in a heat seal seam of the corner portion.

14. A dispenser for dispensing a liquid or particulate pro¬ duct from a bag or pouch of the type formed by a pair of superposed, substantially rectangular layers of plastic sheet material sealingly interconnected along their contour, said dispenser comprising edge, defining means arranged at the upper and/or lower end of a dispenser chamber for receiving the bag or pouch and defining a pair of transversely spaced, substantially parallel free edge portions, and means for fastening each of adjacent opposite corner portions of the bag or pouch when such corner portion has been folded around the adjacent free edge portion.

15. A dispenser according to claim 14, wherein the edge defining means comprise a pair of spaced, parallel rails or wires, upper and/or lower edge portions of a pair of upright chamber defining walls, or opposite edge portions of a top and/or bottom wall portion defining the dispenser chamber.

16. A dispenser according to claim 15, further comprising a cover, which is moveable between an open and a closed posi¬ tion and which in its open position is in engagement with or closely spaced from the outer surfaces of walls defining the dispenser chamber, the fastening means being formed on an inwardly recessed part of said walls.