Production of collapsible pouches having a fitment

1. A production machine for the production of collapsible pouches having a fitment, said pouches each having walls made from a heat-sealable film material, wherein the production machine comprises a fitment sealing station that is configured to heat seal a plastic fitment having an attachment portion in a non-bonded edge region between opposed first and second walls made from the heat-sealable film material, wherein the non-bonded edge region has a length and a height, wherein the fitment sealing station comprises:

an impulse sealing device comprising a first jaw and a second jaw,

an actuator device configured to move the first and second jaws relative to one another between an opened position and a clamped position, and

a cooling device configured to cool each of the first and second jaws,

wherein the first jaw has a first contoured front surface configured to contact the edge region of a respective first wall of the pouch,

wherein the second jaw has a second contoured front surface configured to contact the edge region of a respective second wall of the pouch,

wherein the first and second contoured front surfaces each have a recessed face portion defining a recess configured to receive therein a half of the attachment portion of the fitment, and wherein the first and second contoured front surfaces each define, on opposite sides of the respective recessed face and adjoining said recessed face, coplanar face portions,

wherein each of the first and second jaws comprises at the respective contoured front surface thereof at least one elongated, impulse heatable member that extends along the recessed face portion and the coplanar face portions of the respective front surface and that is covered by a heat-resistant non-stick covering,

wherein the production machine is configured such that, in operation, the fitment is positioned with the attachment portion thereof in the non-bonded edge region, between the opposed first and second walls made from heat-sealable film material, and

wherein the fitment sealing station is configured to perform an impulse sealing cycle, wherein the actuator device is configured to bring the first and second jaws into the clamped position, so that—in the edge region—the first and second walls are clamped against the attachment portion of the fitment by the recessed faces of the first and second jaws and so that—in the edge region—the first and second walls on opposite sides of the fitment are clamped against one another by the coplanar faces of the first and second jaws, and wherein the fitment sealing station is configured to, in the clamped position, temporarily energize the impulse heatable members so as to generate an impulse of heat that is emitted by each of the impulse heatable members, which impulses of heat seal the edge region of the first and second walls to the attachment portion of the fitment and to each other on opposite sides of the attachment portion, wherein the first and second jaws, at least the impulse heatable members thereof, cool down after termination of the energizing assisted therein by operation of the cooling device, and wherein the actuator device is configured to move the first and second jaws into the opened position after the impulse heatable members have cooled down,

wherein each impulse heatable member is a susceptor element comprising electrically conductive material, said susceptor element having a rear side facing away from the respective contoured front surface, and

wherein each of the first and second jaws comprises an inductor which is electrically insulated from the respective susceptor element, wherein the inductor comprises an elongated inductor section that extends along the respective contoured front surface at the rear side of the respective at least one susceptor element, and

wherein the fitment sealing station comprises a high frequency electric current source, which is connected to the inductor of each of the first and second jaws, and

wherein the fitment sealing station is configured so that, in the impulse sealing cycle, the electric current source is operated to temporarily feed a high frequency electric current to the inductors, thereby generating a high frequency electromagnetic field with the inductors, wherein the high frequency electromagnetic field induces eddy currents in the respective susceptor element generating an impulse of heat that is emitted by the susceptor element, which impulses of heat seal the edge region of the walls to the attachment portion of the fitment and to each other.

2. The production machine according to claim 1 , wherein the at least one elongated inductor section is a solid cross-section metal inductor section, having a constant cross-section over its length along the contoured front surface of the respective jaw.

3. The production machine according to claim 1 , wherein the elongated inductor section has, seen in a top view onto the jaw, a shape corresponding to the contoured front surface of the jaw and maintains a uniform distance between the susceptor element and the elongated inductor section.

4. The production machine according to claim 1 , wherein the inductor of a jaw comprises multiple elongated inductor sections that are parallel to one another.

5. The production machine according to claim 1 , wherein the inductor of a jaw comprises multiple elongated inductor sections that are parallel to one another and vertically spaced from one another by a horizontal slit.

6. The production machine according to claim 5 , wherein said slit between neighbouring inductor sections that are arranged above one another has a height between 0.01 and 5 mm.

7. The production machine according to claim 5 , wherein the susceptor element, seen in a view onto the front of the jaw, extends over the slit between parallel elongated inductor sections and overlaps in said view with each of the parallel inductor sections.

8. The production machine according to claim 5 , wherein the susceptor element is embodied as one strip that extends over the slit between parallel elongated inductor sections and overlaps in said view with each of the parallel inductor section.

9. The production machine according to claim 1 , wherein the inductor of a jaw is embodied so that in a pair of adjacent and parallel inductor sections arranged at the rear side of the susceptor element, the current flows in opposite directions through the inductor sections.

10. The production machine according to claim 1 , wherein the at least one elongated inductor section has a thickness of between 1.0 and 4.0 mm, seen perpendicular to the front surface of the jaw.

11. The production machine according to claim 1 , wherein at least one cooling fluid duct extends along the at least one inductor section that extends along the rear side of the susceptor element.

12. The production machine according to claim 1 , wherein the susceptor element is made of metal material.

13. The production machine according to claim 1 , wherein the susceptor element is embodied as a strip having opposed front and rear main faces that define the thickness of the strip between them.

14. The production machine according to claim 1 , wherein the susceptor element has a thickness of between 0.01 and 5 mm.

15. The production machine according to claim 1 , wherein the jaw is provided with a single continuous susceptor element embodied as a strip having a height of the strip between 3 and 10 millimetres.

16. The production machine according to claim 1 , wherein the jaw is provided with a resilient backing layer behind the susceptor element, thereby allowing for the jaw front to accommodate for a local variation of the number of film material walls.

17. The production machine according to claim 1 , wherein the spacing between the rear of the susceptor element and the neighbouring inductor section(s) is at a minimum 0.025 mm, and at a maximum 3.0 mm.

18. The production machine according to claim 1 , wherein the spacing between the front surface of the jaw and the susceptor element is at a minimum 0.025 mm.

19. The production machine according to claim 1 , wherein the contoured front surface of the jaw is smooth in a region of contact with the walls of film material, at least in the recessed portion thereof.

20. The production machine according to claim 1 , wherein the jaws are configured so that the entire non-bonded edge region in which the fitment is inserted is sealed in one cycle by the operation of the jaws.

21. The production machine according to claim 1 , wherein the sealing device is configured to provide a heat impulse with the susceptor element of between at least 150° C. and at most 500° C. measured on the susceptor element.

22. The production machine according to claim 1 , wherein the heat impulse duration lies between 10 and 1000 milliseconds.

23. The production machine according to claim 1 , wherein the cycle includes a clamped cooling phase directly following the heat impulse during which the jaws are maintained in clamped position.

24. The production machine according to claim 1 , wherein the production machine comprises a conveyance mechanism that is configured to convey individual pouches or a string of interconnected pouches along a path of conveyance in a continuous motion, said path at least extending along the fitment sealing station, and wherein the sealing station comprises a motion device that is configured to move the first and second jaws in synchronicity with the continuously moving pouch or string of pouches during the impulse sealing cycle.