A method for filling a package with a liquid food product
By employing servomotors and synchronized piston pumps to control outlet valves, the method addresses the issue of food residues and air incorporation in low viscosity liquid food filling, enhancing sealing reliability and efficiency.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- TETRA LAVAL HOLDINGS & FINANCE SA
- Filing Date
- 2025-10-29
- Publication Date
- 2026-06-25
Smart Images
Figure EP2025081202_25062026_PF_FP_ABST
Abstract
Description
[0001] A METHOD FOR FILLING A PACKAGE WITH A LIQUID FOOD PRODUCT
[0002] Technical Field
[0003] The invention relates to packaging technology. More particularly, it is related to a method for filling a package with a liquid food product using a filing device, as well as a filling device.
[0004] Background Art
[0005] Today, most filling stations comprised in packaging machines or packaging lines have been configured to make sure that filling of a liquid food product can be filled into a package in a time-efficient manner. In addition to reducing the time it takes for filling, the filling station may be arranged such that splashing, foaming and air incorporation can be reduced. Reducing splashing has two positive effects. First, by reducing a risk of having food residues in sections of the package that are to be sealed, the risk of having inadequate sealings, sometimes referred to as welds, can be reduced. This holds true for gable-top packages, but also other forms of packages being sealed downstream the filling station. Another benefit of reducing splashing is that there is less risk that food residues end up on an outside of the package. Regarding foaming and air incorporation, these side-effects of filling may negatively affect the food product and should therefore be avoided to the extent possible.
[0006] Several techniques for filling has been developed and there are variety of different solutions available. An overall guide to the current state of filling technology for carton gable-top packages has been provided by Tetra Pak™ in the white paper “Optimized filling”, published by AB Tetra Pak in April 2022, which is hereby incorporated by reference.
[0007] The prior art successfully provides a process for efficient filling resulting in packaging machines with high output in terms of packages produced as well as a low risk of failures caused by e.g. splashing of food product into sealing sections of the packages. Even though the current filling stations perform well, there is room for further improvement such that the filling process can be made even more efficient and also even more reliable.
[0008] Summary
[0009] It is an object of the invention to at least partly overcome one or more of the above-identified limitations of the prior art. In particular, it is an object to provide a method and a device for filling liquid food product into a package that can be used also for products, having a dynamic viscosity of less than 1000 mPas, such as drinking yoghurt.
[0010] When using some of the current filling devices comprising pneumatic cylinders for actuating the outlet valves, there is a risk that food residues get stuck under a filling pipe, sometimes referred to as filamentation, after an outlet valve has been closed, i.e. after the filling has been performed. Since packages are usually subsequently provided to the filling station along a conveyor belt, if product residue filaments are formed, these may end up on a subsequent package provided below the filling device. In case the residues end up on the sealing sections, this may result in insufficient sealing of this package.
[0011] By having the pneumatic cylinder replaced by a servomotor, the outlet valve can be closed quicker, which in turn results in an abrupt stop, or abrupt closure. This abrupt stop, caused by using the servomotor, provides for that the food product filaments, or more generally residues, are disjoined from the filling pipe by the mechanical shock and fed down into the package. Thus, by using the servomotor, the risk of having food product residues ending up on the subsequent package can be reduced. In addition, by having the product residue filaments shaken off, a more well defined filling volume control can be achieved.
[0012] According to a first aspect, it is provided a method for filling a package with a liquid food product using a filling device comprising a filling pipe having an outlet valve placed in a lower end, a pump, which may be a piston pump, arranged to feed the liquid food product into the filling pipe, and a servomotor for controlling the outlet valve, said method comprising placing the package below the filling device, feeding the liquid food product into the filling pipe using the pump, opening the outlet valve, using the servomotor, such that the liquid food product is allowed to pass the lower end of the filling pipe into an interior space of the package, and closing the outlet valve, using the servomotor, such that the liquid food product is hindered from passing the lower end of the filling pipe and surrounding air is hindered from being sucked into the filling pipe.
[0013] By using the servomotor, a closing duration of the outlet valve is shortened compared to using the pneumatic cylinder, thereby reducing a risk that air is sucked into the filling pipe. Still an advantage, as an effect of having a faster closing of the outlet valve, is that a mechanical shock can be provided. This shock may provide for that food residues, e.g. filaments, hanging from the lower end of the filling pipe after closure is shaken down into the package. This provides for that the risk that these food residues end up on the subsequent package is reduced, but also that an improved volume control can be achieved.
[0014] A dynamic viscosity of the liquid food product (FP) may be less than 1000 mPas.
[0015] The dynamic viscosity of the liquid food product may be above 40 mPas.
[0016] The lower end of the filling pipe may be provided with a circular opening formed as a conical-shaped recess, sometimes referred to as countersunk hole, wherein the outlet valve may comprise a cone-shaped element placed inside the filling pipe, connected to the servomotor and arranged to interact with the conical-shaped recess, wherein a combination of using the servomotor for closing the outlet valve and having the conical-shaped recess interacting with the cone-shaped element further reduces the risk that air is sucked into the filling pipe during the step of closing the outlet valve.
[0017] The servomotor may be set to be moved between a lower and an upper end position, wherein in the lower end position, a distance between the servomotor and the circular opening of the lower end of the filling pipe may be less than a length of the cone-shaped element, thereby providing for an abrupt stop of the cone-shaped element during closing.
[0018] A difference between the distance and the length may be at least 1 mm.
[0019] The pump may be a piston pump, and the step of closing the outlet valve may be timely aligned, e.g. synchronized, with respect to a reciprocating motion of a piston of the piston pump.
[0020] Since using the piston pump comes with the effect that there is a risk that air is sucked into the filling pipe if the outlet valve opening and closing is not in tune with the reciprocating motion of the piston pump, having these two operations depending on each other reduces the risk that air is sucked in, which in turn provides a more efficient process in terms of filling, e.g. less foaming, and also that the food product is less affected. Having air sucked into the filling pipe may namely result in that air is incorporated into the food product, which may result in that the properties of the food product is negatively affected.
[0021] The liquid food product may comprise particles, such as berries or seeds. The step of closing the outlet valve using the servomotor may further result in that the liquid food product attached to the lower end of the filling pipe is separated and fed into the package placed below.
[0022] A positive effect of using the servomotor, in addition to reducing the time for closing the outlet valve compared to using a pneumatic cylinder, is that when closing, a mechanical shock may be formed. This shock may provide for that food residues attached to a lower end of the filling pipe or a lower end of the element controlled by the servomotor are disjoined and fed into the package.
[0023] The filling device may further comprise a package lifter, and the method may further comprise lifting the package, using the package lifter, towards the filling device such that the lower end of the filling pipe is placed in an interior space of the package, and lowering the package, using the package lifter, away from the lower end of the filling pipe during the step of opening the outlet valve.
[0024] By moving the package downwards during the filling of package, that is, during a period when the outlet valve is opened, the foaming and splashing can be further reduced.
[0025] According to a second aspect it is provided a filling device for filing liquid food product into a package, said filling device comprising a filling pipe provided with an outlet valve in a lower end, a pump and a servomotor for actuating the outlet valve between an open state and a closed state, a control circuitry communicatively connected to the pump and the servomotor, and configured to feed the liquid food product into the filling pipe using the pump, open the outlet valve using the servomotor, such that the liquid food product is allowed to pass the lower end of the filling pipe into an interior space of the package, and close the outlet valve, using the servomotor, such that the liquid food product is hindered from passing the lower end of the filling pipe and surrounding air is hindered from being sucked into the filling pipe.
[0026] The lower end of the filling pipe may be provided with a circular opening formed as a conical-shaped recess, wherein the outlet valve may comprise a cone-shaped element placed inside the filling pipe, connected to the servomotor and arranged to interact with the conical-shaped recess.
[0027] The pump may be a piston pump, and the step of closing the outlet valve may be timely aligned with respect to a reciprocating motion of a piston of the piston pump. The filling device may further comprise a package lifter, wherein the control circuitry may be further configured to lift the package, using the package lifter, towards the filling device such that the lower end of the filling pipe is placed in an interior space of the package, and lower the package, using the package lifter, away from the lower end of the filling pipe while opening the outlet valve.
[0028] The same features and advantages described above with respect to the first aspect also apply to this second aspect.
[0029] According to a third aspect it is provided a computer program product, loadable in the memory of at least one processing unit and comprising instructions suitable for performing the steps of the method according to the first aspect.
[0030] Still other objectives, features, aspects and advantages of the invention will appear from the following detailed description as well as from the drawings.
[0031] Brief Description of the Drawings
[0032] Embodiments of the invention will now be described, by way of example, with reference to the accompanying schematic drawings, in which
[0033] Fig. 1 generally illustrates a cross-sectional view of a filling device.
[0034] Fig. 2 is a series of four photos showing a filling process using the filling device.
[0035] Fig. 3 is a general illustration of another filing device arranged to fill two packages simultaneously.
[0036] Fig. 4A is a graph showing the bottom valve position, fill pump position and upper Universal Product Valve (UPV) position over a filling cycle according to a first example.
[0037] Fig. 4B is another graph showing the bottom valve position, fill pump position and upper Universal Product Valve (UPV) position over a filling cycle according to a second example.
[0038] Fig. 5 is a flowchart illustrating a method for filling a package with a liquid food product.
[0039] Detailed
[0040] Fig. 1 illustrates a filling device 100 forming part of a filling station in a packaging machine or packaging line. As illustrated, the filling device 100 comprises a filling pipe 102 extending vertically. In a lower end 106 of the filling pipe 102, an outlet valve 104 is provided. In a closed state, as illustrated, when food product FP can be held inside the filling pipe 102. The food product FP can be fed into the filling pipe 102 by using a pump 108. The outlet valve 104 can be controlled via a servomotor 110. As illustrated, the servomotor 110 may be placed above the filling pipe and be connected to a cone-shaped element via a rod such that the outlet valve 104 can be closed by lowering the cone-shaped element and opened by lifting the cone-shaped element.
[0041] The pump 108 and the servomotor 110 may be communicatively connected to a control circuitry 112, which may be provided with one or more processors and one or more memories. By having the pump as well as the servomotor both connected in this way provides for that movements of the servomotor may be aligned with movements of the pump. For instance, in case the pump is a piston pump, by aligning these movements, a risk of having air sucked into the filling pipe when retracting a piston of the pump can be reduced. In this context, using the servomotor 110 and not the pneumatic cylinder provides for that the outlet valve 104 can be closed quicker and with improved control, thereby reducing the risk of having the air sucked into the filing Pipe.
[0042] Another benefit of using the servomotor 110 and the quick closing of the outlet valve 104 that comes with using the servomotor 110 is that the outlet valve 104 can be closed abruptly. Put differently, the servomotor 100, providing for about four times the speed of a pneumatic cylinder, is not only capable of providing a quick closing and opening of the outlet valve 104, but also that the closing comes with a mechanical shock. The mechanical shock has the effect that any food residues hanging down from the filling pipe or the outlet valve are shaken off such that these fall down into the package. This is especially most relevant for low viscous products having a dynamic viscosity being less than 1000 mPas, e.g. drinking yoghurt. To secure that this mechanical shock is provided, the filling device 100 can be arranged such that this is closed abruptly. For instance, the servomotor may be set to be moved between a lower and an upper end position. In the lower end position, a distance D between the servomotor 110 and a circular opening of the lower end of the filling pipe 102 may be less than a length L of the cone-shaped element, i.e. the element attached to the servomotor and forming part of the outlet valve, thereby providing for an abrupt stop of the cone-shaped element during closing. By way of example, a difference between the distance D and length L can be at least 1 mm.
[0043] When filling a package 114 placed under the filling device 100, different techniques may be used. As illustrated, a package lifter 116 may be used for lifting the package 114 towards the filling pipe 102 and while filling the package, that is, opening the outlet valve, the package can be lowered. By combining these two operations, foaming, splashing and air inclusion can be reduced. Another option is to fill the package without using the package lifter, that is, having the package standing still while being filled. Still an option is to lower the filling pipe into the package and having the filling pipe lifted during filling.
[0044] Fig. 2 is a series of photos illustrating a filling process using the filling device 100 illustrated in fig. 1 . As can be seen in the leftmost photo, the food product FP, in this example yoghurt, can be filled into the package 114 via the filling pipe 102 while lowering the package 114 using the package lifter 116. As can be seen in the two photos placed in the middle, after having the outlet valve 104 closed, the viscosity of the food product results in that there is an after-dripping into the package after the outlet valve is closed. In the rightmost photo, this after-dripping is close to be finished. In line with the description above, by using the servomotor 110 for controlling the outlet valve 104, this valve can be closed faster, thereby providing for that the filing process can be made more time efficient. Further, by closing the outlet valve abruptly, product residues, sometimes referred to as filaments, may be shaken off from the lower end of the filling pipe such that these are fed into the package.
[0045] Fig. 3 illustrates another example of the filling device 100 illustrated in fig. 1. While the example illustrated in fig. 1 is filling one package at a time, a filling arrangement illustrated in fig. 3 is filling two packages at a time.
[0046] As illustrated, the food product may be stored in a tank 300 placed above the filling device 100. Two pipes connected to a lower section of the tank are connected to inlet valves 302a, b, sometimes referred to as inlet Universal Product Valves (UPVs) or upper UPVs. Below the inlet valves, on the pipes, two pumps 108a,b are provided. During the filling sequence, the two inlet valves 302a, b, the pumps 108a,b and the outlet valves 104, illustrated in fig. 1 , are coordinated such that the food product FP can be time efficiently filled into the packages 114a,b in a controlled manner such that splashing and foaming can be reduced. As illustrated in fig. 1 and described above, by having the outlet valve 104, in this example one for each pipe, low viscous products can be filled without the risk, at least a reduced risk, of having the filaments causing sealing issues or other unwanted side effects. The concept of using the upper UPV, the pump and a lower valve is generally known in the field of packaging, see for instance the white paper “Optimized filling”, published by AB Tetra Pak in April 2022, which is hereby incorporated by reference. In fig. 4A, a normalized graph comprising three lines is illustrated. A first line 400a illustrates a bottom valve position, i.e. a position of the outlet valve 104, a second line illustrates a fill pump position 402a and a third line illustrates an upper UPV position 404a, i.e. a position of the inlet valve 302a, b illustrated in fig. 3. As described, by abruptly closing the outlet valve 104, the mechanical shock that shakes off the product filaments down into the package can be achieved. This abrupt closure can be seen in fig. 4A by a small upward movement on the first line 400a after the bottom valve has been closed. In addition, this can also be seen in that the line 400a in fig 4A is steeper than the line 400b in fig. 4B. Further, in the figure it can also be seen that the fill pump position, illustrated by the second line 402a, is coordinated with the bottom valve position, illustrated by the first line 400a, thereby reducing the risk that air is sucked into the filling pipe. It can also be seen in the figure that the upper UPV is opened after the bottom valve, i.e. outlet valve, is closed.
[0047] In fig. 4B, another normalized graph comprising the same three lines - a bottom valve position 400b, a fill pump position 402b, and an inlet valve position 404b - is illustrated. Unlike the graph illustrated in fig. 4A, the bottom valve position 400b in fig. 4B is closed without any lift, i.e. no upward movement appearing after the closer of the bottom valve.
[0048] Further, as can be seen to the left of both fig. 4A and 4B, in the line 402a and the line 402b, when the UPV has closed, the filling pump makes a small stroke backwards to release built in static pressure from the product tank.
[0049] Fig. 5 is a flowchart illustrating a method 500 for filling the package 114, 114a-b with the liquid food product FP using the filling device 100 illustrated by way of example in fig. 1 and 2. The method can comprise placing 502 the package 114, 114a-b below the filling device 100, feeding 504 the liquid food product FP into the filling pipe 102 using the pump 108, opening 504 the outlet valve 104, using the servomotor 110, such that the liquid food product FP is allowed to pass the lower end 106 of the filling pipe 102 into an interior space of the package 114, and closing 506 the outlet valve 104, using the servomotor 110, such that the liquid food product FP is hindered from passing the lower end 106 of the filling pipe 102 and surrounding air is hindered from being sucked into the filling pipe 102. By using the servomotor, or any other actuator capable of providing a comparable closing time of the outlet valve, the risk of having air sucked into the filling pipe can be reduced.
[0050] The method may further comprise lifting 510 the package 114, 114a,b, using the package lifter 116, towards the filling device 100 such that the lower end 106 of the filling pipe 102 is placed in the interior space of the package 114, 114a,b, and lowering 512 the package 114, 114a,b, using the package lifter 116, away from the lower end 106 of the filling pipe 102 during the step of closing 508 the outlet valve 104. By having the package lifter 116, and coordinating a vertical movement of the package with the opening and closing of the outlet valve, it is possible to further reduce splashing and foaming.
[0051] From the description above follows that, although various embodiments of the invention have been described and shown, the invention is not restricted thereto, but may also be embodied in other ways within the scope of the subject-matter defined in the following claims.
Claims
CLAIMS1 . A method (500) for filling a package (114, 114a-b) with a liquid food product (FP) using a filling device (100) comprising a filling pipe (102) having an outlet valve (104) placed in a lower end (106), a pump (108, 108a-b) arranged to feed the liquid food product into the filling pipe (102), and a servomotor (110) for controlling the outlet valve (104), said method comprising placing (502) the package (114, 114a-b) below the filling device (100), feeding (504) the liquid food product (FP) into the filling pipe (102) using the pump (108), opening (504) the outlet valve (104), using the servomotor (110), such that the liquid food product (FP) is allowed to pass the lower end (106) of the filling pipe (102) into an interior space of the package (114), and closing (506) the outlet valve (104), using the servomotor (110), such that the liquid food product (FP) is hindered from passing the lower end (106) of the filling pipe (102) and surrounding air is hindered from being sucked into the filling pipe (102).
2. The method according to claim 1 , wherein a dynamic viscosity of the liquid food product (FP) is less than 1000 mPas.
3. The method according to claim 2, wherein the dynamic viscosity of the liquid food product is above 40 mPas.
4. The method according to any one of the preceding claims, wherein the lower end of the filling pipe (102) is provided with a circular opening formed as a conical-shaped recess, wherein the outlet valve (104) comprises a cone-shaped element placed inside the filling pipe (102), connected to the servomotor (110) and arranged to interact with the conical-shaped recess, wherein a combination of using the servomotor (110) for closing the outlet valve (104) and having the conical-shaped recess interacting with the cone-shaped element further reduces the risk that air is sucked into the filling pipe (102) during the step of closing the outlet valve.
5. The method according to claim 4, wherein the servomotor is set to be moved between a lower and an upper end position, wherein in the lower end position, adistance (D) between the servomotor (110) and the circular opening of the lower end of the filling pipe (102) is less than a length (L) of the cone-shaped element, thereby providing for an abrupt stop of the cone-shaped element during closing.
6. The method according to claim 5, wherein a difference between the distance (D) and the length (L) is at least 1 mm.
7. The method according to any one of the preceding claims, wherein the pump (108, 108a,b) is a piston pump, and wherein the step of closing (508) the outlet valve (104) is timely aligned with respect to a reciprocating motion of a piston of the piston pump.
8. The method according to any one of the preceding claims, wherein the liquid food product (FP) comprises particles, such as berries or seeds.
9. The method according to any one of the preceding claims, wherein the step of closing (508) the outlet valve (104) using the servomotor (110) further results in that the liquid food product (FP) attached to the lower end (106) of the filling pipe (102) is separated and fed into the package (114) placed below.
10. The method according to any one of the preceding claims, wherein the filling device (100) further comprises a package lifter (116), said method further comprising lifting (510) the package (114, 114a,b), using the package lifter (116), towards the filling device (100) such that the lower end (106) of the filling pipe (102) is placed in an interior space of the package (114, 114a,b), and lowering (512) the package (114, 114a,b), using the package lifter (116), away from the lower end (106) of the filling pipe (102) during the step of opening (506) the outlet valve (104).
11. A filling device (100) for filing liquid food product into a package (114,114a, b), said filling device (100) comprising a filling pipe (102) provided with an outlet valve (104) in a lower end (106), a pump (108, 108a,b) and a servomotor (110) for actuating the outlet valve (104) between an open state and a closed state, a controlcircuitry (112) communicatively connected to the pump (108, 108a,b) and the servomotor (110), and configured to feed the liquid food product (FP) into the filling pipe (102) using the pump (108, 108a,b), open the outlet valve (104) using the servomotor (110), such that the liquid food product (FP) is allowed to pass the lower end (106) of the filling pipe (102) into an interior space of the package (114, 114a,b), and close the outlet valve (104), using the servomotor (110), such that the liquid food product (FP) is hindered from passing the lower end (106) of the filling pipe (102) and surrounding air is hindered from being sucked into the filling pipe (102).
12. The filling device () according to claim 11 , wherein the lower end of the filling pipe (102) is provided with a circular opening formed as a conical-shaped recess, wherein the outlet valve (104) comprises a cone-shaped element placed inside the filling pipe (102), connected to the servomotor (110) and arranged to interact with the conical-shaped recess.
13. The filling device (100) according to claim 11 or 12, wherein the pump (108, 108a,b) is a piston pump, and wherein the step of closing the outlet valve (104) is timely aligned with respect to a reciprocating motion of a piston of the piston pump.
14. The filling device (100) according to any one of the claims 11 to 13, wherein the filling device (100) further comprises a package lifter (116), wherein the control circuitry (112) is further configured to lift the package (114, 114a, b), using the package lifter (116), towards the filling device (100) such that the lower end (106) of the filling pipe (102) is placed in an interior space of the package (114, 114a,b), lower the package (114, 114a, b), using the package lifter (116), away from the lower end (106) of the filling pipe (102) while opening the outlet valve (104).
15. A computer program product, loadable in the memory of at least one processing unit and comprising instructions suitable for performing the steps of the method according to any of claims 1 to 10.