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(11) | EP 4 108 578 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 153(4) EPC |
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| (54) | DEVICE FOR THE EXTRACTION OF GAS FROM THE UPPER PART OF A BAG CONTAINING A POWDERY MATERIAL, MACHINE AND CORRESPONDING PROCEDURE |
| (57) The invention relates to a device (1) for extracting gas from the upper part of a
bag (100) containing a powdered material, corresponding machine and method. The device
(1) comprises cannulas (2) with gas driving means (4) at a distal end (6) and first
clamps (10). The cannulas (2) are movable along a first direction (A) for being inserted
into the opening (102) of a bag (100), and along a second direction (B), perpendicular
to said first direction (A), for holding the opening of the bag (100) in a spaced
position. The clamps (10) can be moved between an open position and a closed position
in which the opening (102) is pressed between the first clamps (10). When the cannulas
(2) are in said spaced position and the first clamps (10) are in said closed position
of the first clamps, the first clamps (10) are movable along said first direction
(A), in the direction moving away from the opening of the bag for extracting gas from
said bag (100) . |
Field of the invention
[0001] The invention relates to a device for extracting gas from the upper part of a bag containing a powdered material.
[0002] More specifically, the invention relates to a device a device comprising cannulas comprising gas driving means, said cannulas having a distal end and a proximal end, said gas driving means being provided at least at said distal end, said cannulas being movable along a first direction for being inserted into the opening of a bag, and along a second direction, perpendicular to said first direction between: a close cannula position, wherein said cannulas are close to one another, such that said cannulas can be introduced in the opening of said bag along said first direction, and a spaced cannula position, wherein said cannulas are spaced apart from one another such a distance that said bag can be held by said opening through said cannulas, and first clamps movable between: an open position of the first clamps, wherein said first clamps are spaced apart from one another, such that said opening of said bag is arranged between said first clamps, in the open state, and a closed position of the first clamps, wherein said first clamps are close to one another, such that said opening of said bag is pressed between said first clamps.
[0003] Likewise, the invention relates to a machine for filling bags, and to a method for extracting gas from the upper area of a bag containing a powdered material.
State of the art
[0004] Devices for extracting gas from bags filled with bulk products, both in preformed bag filling machines, as well as in form, fill, and seal machines are known. These latter machines form their own bag and are known in the art by their acronym FFS (form, fill, and seal).
[0005] In the filling station of any of these machines, while the bag is being filled up with the powdered material, the powdered material is also being compacted by tapping or vibration. Finally, a step for extracting gas from the upper area of the bag is envisaged. Normally, this gas is usually residual air. Extracting gas from the bag causes the bag to adopt a parallelepipedic shape, thereby facilitating its transport and storage.
[0006] In machines for filling bags with a fine product, and particularly with a powdered product, air is commonly extracted by suction. Nevertheless, this extraction system is very slow, thus affecting the productivity of the machine in which it is installed.
[0007] One of the techniques used for extracting gas from the bag is by introducing cannulas in the bag, forming a vacuum. However, this technique has the drawback of not extracting enough gas.
Summary of the invention
[0008] The object of the invention is to provide a device of the type indicated above, having a more robust configuration and better operation for the purpose of extracting the air from bags.
[0009] This object is achieved by means of a device of the type indicated above, characterized in that when said cannulas are in said spaced cannula position and said first clamps are in said closed position of the first clamps, said first clamps are movable along said first direction, in the direction of said proximal end towards said distal end, moving away from said proximal end, between: an initial extraction position, a final extraction position, for extracting gas from said bag.
[0010] This allows moving the clamps in the closed position from the proximal end of the cannulas to the distal end thereof, thus extracting the gas from the bag while at the same time the suspended powdered material is compacted. The bag thereby adopts the desired parallelepipedic shape.
[0011] In the invention, preferably the cannulas are two cannulas with a substantially rectangular or elongated cross-section, said cannulas being oriented such that the longest sides of said cannulas are arranged parallel to the longest sides of the bag.
[0012] The invention further includes a number of preferred features that are object of the dependent claims and the utility of which will be highlighted hereinafter in the detailed description of an embodiment of the invention.
[0013] Preferred embodiments the features of which are described in the dependent claims have been provided based on the invention defined in the main claim.
[0014] Preferably, said first clamps have a length greater than the separation between said cannulas when they are in said spaced cannula position. This allows extracting the air from the bag in a more uniform and controlled manner.
[0015] Preferably, said device further comprises second clamps arranged between said proximal end of said cannulas and said first clamps, said second clamps being movable between: [i] an open position of the second clamps, wherein said second clamps are spaced apart from one another, such that said opening of said bag is arranged between said second clamps, in the open state, and [ii] a closed position of the second clamps, wherein said second clamps are close to one another, such that said opening of said bag is held between said second clamps. The second clamps improve the hold on the opening of the bag.
[0016] Preferably, said gas driving means of said cannulas further comprise gas blowing means, arranged for insufflating gas into said bag in the area of said opening when said first clamps are in said closed position of the first clamps. This allows eliminating any powdered material residue from the opening of the bag for it to be clean, thereby facilitating the welding of the opening of the bag.
[0017] Even more preferably, said gas driving means comprise gas suction means. The gas suction means can be used to complement the gas extraction performed by the first clamps, thereby assuring that the most amount of gas possible is extracted.
[0018] Preferably, said first direction of said cannulas is a vertical direction defined by the longitudinal axis of said cannulas, such that the step of extracting gas is more easily performed because the direction is parallel to the direction of gravity.
[0019] Preferably, said device comprises at least one motor for operating said first clamps and further comprises torque sensing means functionally associated to said first clamps for detecting the end of travel of said first clamps, corresponding to said final extraction position. The sensing means prevent the device from working under overload conditions, since when the first clamps exceed the setpoint value, the sensing means send instructions to the motor to stop the air extraction movement of the first clamps.
[0020] The invention also relates to a machine for filling bags which has the device according to the invention.
[0022] The invention also relates to a method for extracting gas from the upper area of a bag containing a powdered material with a device according to the invention. The method is characterized in that it comprises the following steps:
- [a] placing said cannulas comprising gas driving means in said close cannula position, wherein said cannulas are close to one another,
- [b] introducing said cannulas in the opening of said bag, and then
- [c] moving said cannulas to said spaced cannula position, wherein said cannulas are spaced apart from one another such a distance that it allows said bag to be held by said opening through said cannulas,
- [d] moving said first clamps, which are in said open position of the first clamps, to said closed position of the first clamps, such that said opening of said bag is pressed between said first clamps along the entire width of said opening, and then
- [e] moving said first clamps in the longitudinal direction of said cannulas in the
direction of said proximal end toward said distal end, moving away from said distal
end between:
- [i] said initial extraction position,
- [ii] said final extraction position, for extracting gas from said bag,
- [f] moving said cannulas to said close cannula position and
- [g] extracting said cannulas from said opening of said bag.
[0023] This method allows extracting most of the gas from said bag in a more efficient and robust manner while at the same time, it also compacts the suspended powdered material.
[0024] Preferably, in the method said cannulas are introduced in said opening of said bag without contacting the powdered material contained in said bag, thereby facilitating the first clamps extracting the air from the bag.
[0025] In another preferred embodiment of the method, when said torque sensing means detect a torque greater than a setpoint value, said first clamps reach said final extraction position.
[0026] Preferably, after the step of moving said cannulas to said spaced cannula position, the method further comprises a step of moving second clamps, which are in said open position of the second clamps, to said closed position of the second clamps, such that said opening of said bag is held between said second clamps, and after extracting the gas from said bag, said second clamps return to their open position of the second clamps. The use of the second clamps reinforces the hold on the opening of the bag.
[0027] Preferably, after said step of extracting gas and while said first clamps are in said final extraction position, the method comprises the step of insufflating a gas over the opening of said bag through said cannulas to thereby cleaning the opening of the bag before performing welding.
[0028] Preferably, said gas that is insufflated over said opening of said bag is air. This provides for eliminating any powdered material residue from the opening of the bag for it to be clean, thereby facilitating the welding of the opening of the bag.
[0029] The invention also comprises other detail features illustrated in the detailed description of an embodiment of the invention and in the attached figures.
Brief description of the drawings
[0030] The advantages and features of the invention will become apparent from the following description in which a preferred embodiment of the invention in reference to the figures is provided in a non-limiting manner with respect to the scope of the main claim.
Figure 1 is front view of a bag form, fill, and seal machine according to a first embodiment, wherein the cannulas of the machine are in the proximal position.
Figure 2 is another front view of the same machine, wherein the cannulas of the machine are in the spaced position.
Figure 3 is a side view of the same machine, wherein the first clamps are in the open position.
Figure 4 is another side view of the machine, wherein the first clamps are in the closed position.
Figure 5 is another side view of the machine.
Figure 6 depicts the method of extracting gas from a bag.
Detailed description of embodiments of the invention
[0031] Figures 1 to 5 show an embodiment according to the invention of a device 1 for extracting gas, which is usually residual air, from the upper part of a bag 100 containing a powdered material.
[0032] The device 1 comprises cannulas 2 having a distal end 6 and a proximal end 8. At the distal end 6, the cannulas 2 have gas driving means 4 in turn comprising gas blowing means and gas suction means. In the figures, the gas driving means are indicated as gas outlet ports of the cannulas 2. The operating and blowing means can be, for example, a reversible pneumatic cylinder, or the like. As will be described below, the gas blowing means can be used for cleaning the opening 102 of the bag, and the gas suction means can be used for suctioning air from the bag 100. It is important to point out that the gas driving means 4 described in the figures do not refer to devices that move the cannulas, but rather to the means which move the gas for the purpose of cleaning the opening 102 of the bag.
[0033] As can be seen in Figures 1 and 2, the cannulas 2 can be moved along a first vertical direction A, defined by the longitudinal axis C of the cannulas 2, and along a second direction B, perpendicular to the first direction A. To move the cannulas along directions A and B in the device according to the invention, for example, a range of devices such as an asynchronous motor, a servomotor, or a pneumatic cylinder are provided.
[0034] The possibility of movement in these two directions allows the cannulas 2 to be placed in a close cannula position and in a spaced cannula position. On one hand, in the close cannula position, the cannulas 2 are close to one another. Therefore, as depicted in Figure 1, the cannulas can be introduced, at the distal end 6 and along the first direction A, in the opening 102 of the bag 100. On the other side, as can be seen in Figure 2, in the spaced cannula position, the cannulas 2 are spaced apart from one another such a distance that it allows the bag 100 to be held by the opening 102 through the cannulas 2. To that end, the cannulas grip the bag 100 on the inside and retain it by pulling it tight between the outer sides 14 of the cannulas 2.
[0035] Despite the fact that the gas driving means 4 can help extract the residual air from the bag 100, the device 1 furthermore has first clamps 10 suitable for extracting the air from the bag 100 which, in fact, are the part extracting most of the air. As can be seen in Figure 1, these first clamps 10 have a length greater than the separation existing between the cannulas 2 when the latter are in the spaced cannula position.
[0036] As shown in Figures 3 and 4, the first clamps 10 can be moved between an open position and a closed position. On one hand, in the open position the opening 102 of the bag 100 is arranged between the first clamps 10, in the open state. On the other hand, in the closed position the opening 102 of the bag 100 is pressed by the first clamps 10 in a non-tight manner. Therefore, despite the fact that the first clamps 10 press the bag 100, the air in the bag 100 can get out thereof. This is important because for extracting the air from the bag 100, the first clamps 10 can be moved along the first direction A, in the direction going from the proximal end 8 toward the distal end 6. Namely, the first clamps 10 can be placed between an initial air extraction position, wherein the first clamps 10 are placed below the distal end 6 of the cannulas 2 and spaced from the powdered material of the bag, and a final air extraction position, wherein the first clamps 10 are close to the powdered material of the bag. For this reason, if the first clamps 10 tightly pressed the entire opening 102 of the bag 100, the air in the bag 100 could not be extracted therefrom.
[0037] The device 1 also has torque sensing means linked to a motor 18 operating the first clamps 10. Therefore, when the torque sensing means detect the end of travel of the first clamps 10, corresponding to the final extraction position, they send a signal to the motor 18 to stop moving the first clamps 10.
[0038] Likewise, for the purpose of better holding the opening 102 of the bag, the device 1 comprises second clamps 12, which are arranged between the proximal end 8 of the cannulas 2 and the first clamps 10. The second clamps 12 can be moved between an open position, wherein the opening 102 of the bag 100 is arranged between the second clamps 12, in the open state, and a closed position, wherein the opening 102 of the bag is held by the second clamps 12, such that they can exert can pressure on the bag 100 to thereby hold it. The second clamps 12 allow holding the bag 100 while at the same time they allow air in the bag 100 to get out.
[0039] Next, the method of extracting gas of the machine described according to the first embodiment is described based on Figure 6. The left part of Figure 6 shows the steps of the method in a side view, while the right side shows the corresponding front view of this same step.
[0040] As can be seen in Figure 6A, before starting the method of extracting the air, the first clamps 10 and the second clamps 12 are in their open position, and the cannulas 2 are spaced from the bag 100, such that a bag 100 can be placed in the station.
[0041] As can be seen in Figure 6B, the method starts by placing the cannulas 2 in their close cannula position and introducing them in the opening 102 of the bag 100 at their distal end 6. Next, as depicted in Figure 6C, the cannulas 2 are moved to their spaced cannula position to hold the bag 100, and the second clamps 12, which also help to hold the opening 102 of the bag, are closed. Subsequently, the first clamps 10 are closed, pressing the bag 100, and are moved, as shown in Figure 6D, in the direction defined by the longitudinal axis C of the cannulas 2, in the direction going from the proximal end 8 of the cannulas 2 toward the distal end 6 of the cannulas 2, thereby successfully extracting the air from the bag 100. As discussed above, the first clamps 10 press the bag 100 such that the air in the bag 100 can get out through the opening 102 thereof. Likewise, the gas driving means 4 can suction the air from the bag 100 before, during, or after the first clamps 100 have extracted the air from the bag 100.
[0042] Next, as shown in Figure 6E, for cleaning the opening 102 of the bag 100, before performing welding corresponding, the first clamps 10 are opened. Then the cannulas 2 are moved toward the proximal end 8, i.e., upwards, and the first clamps 10 are closed below the cannulas 2. Once the first clamps 10 have been closed, the gas blowing means insufflate a gas over the opening 102 of the bag, thereby eliminating any powdered material residues there may be. The gas used is preferably dry air, but inert gases with a low percentage of moisture and having protective properties with respect to the product in the bag can be used.
1. A device (1) for extracting gas from the upper part of a bag (100) containing a powdered
material, said device (1) comprising:
[a] cannulas (2) comprising gas driving means (4), said cannulas (2) having a distal end (6) and a proximal end (8), said gas driving means (4) being provided at least at said distal end (6), said cannulas (2) being movable along a first direction (A) for being inserted into the opening (102) of a bag (100), and along a second direction (B), perpendicular to said first direction (A) between:
[i] a close cannula position, wherein said cannulas (2) are close to one another, such that said cannulas (2) can be introduced in the opening (102) of said bag (100) along said first direction (A), and
[ii] a spaced cannula position, wherein said cannulas (2) are spaced apart from one another such a distance that said bag (100) can be held by said opening (102) through said cannulas (2), and
[b] first clamps (10) movable between:
[i] an open position of the first clamps (10), wherein said first clamps (10) are spaced apart from one another, such that said opening of said bag is arranged between said first clamps (10), in the open state, and
[ii] a closed position of the first clamps (10), wherein said first clamps (10) are
close to one another, such that said opening (102) of said bag is pressed between
said first clamps (10),
characterized in that when said cannulas (2) are in said spaced cannula position and said first clamps
(10) are in said closed position of the first clamps, said first clamps (10) are movable
along said first direction (A), in the direction of said proximal end (8) towards
said distal end (6), moving away from said proximal end (8), between:
[i] an initial extraction position,
[ii] a final extraction position, for extracting gas from said bag (100).
2. The device (1) according to claim 1, characterized in that said first clamps (10) have a length greater than the separation between said cannulas
(2) when they are in said spaced cannula position.
3. The device (1) according to any one of claims 1 to 2, characterized in that it further comprises second clamps (12) arranged between said proximal end (8) of
said cannulas (2) and said first clamps (10), said second clamps (12) being movable
between:
[i] an open position of the second clamps, wherein said second clamps (12) are spaced apart from one another, such that said opening (102) of said bag is arranged between said second clamps (12), in the open state, and
[ii] a closed position of the second clamps, wherein said second clamps (12) are close to one another, such that said opening (102) of said bag is held between said second clamps (12).
4. The device (1) according to any one of claims 1 to 3, characterized in that said gas driving means (4) of said cannulas (2) further comprise gas blowing means,
arranged for insufflating gas into said bag (100) in the area of said opening (102)
when said first clamps (10) are in said closed position of the first clamps.
5. The device (1) according to any one of claims 1 to 4, characterized in that said gas driving means (4) comprise gas suction means.
6. The device (1) according to any one of claims 1 to 5, characterized in that said first direction (A) of said cannulas (2) is a vertical direction defined by
the longitudinal axis (C) of said cannulas (2).
7. The device (1) according to any one of claims 1 to 6, characterized in that it comprises at least one motor (18) for operating said first clamps (10) and further
comprises torque sensing means functionally associated to said first clamps (10) for
detecting the end of travel of said first clamps (10), corresponding to said final
extraction position.
8. A machine for filling bags, characterized in that it comprises a device (1) according to any one of claims 1 to 7.
9. The machine according to claim 8, characterized in that it is a form, fill, and seal machine.
10. A method for extracting gas from the upper area of a bag (100) containing a powdered
material with a device (1) according to any one of the preceding claims, characterized in that it comprises the following steps:
[a] placing said cannulas (2) comprising gas driving means (4) in said close cannula position, wherein said cannulas (2) are close to one another,
[b] introducing said cannulas (2) in the opening (102) of said bag, and then
[c] moving said cannulas (2) to said spaced cannula position, wherein said cannulas (2) are spaced apart from one another such a distance that it allows said bag (100) to be held by said opening (102) through said cannulas (2),
[d] moving said first clamps (10), which are in said open position of the first clamps, to said closed position of the first clamps, such that said opening (102) of said bag is pressed between said first clamps (10) along the entire width of said opening (102), and then
[e] moving said first clamps (10) in the longitudinal direction of said cannulas (2) in the direction of said proximal end (8) toward said distal end (6), moving away from said distal end (6) between:
[i] said initial extraction position,
[ii] said final extraction position, for extracting gas from said bag (100),
[f] moving said cannulas (2) to said close cannula position and
[g] extracting said cannulas from said opening (102) of said bag.
11. The method according to the claim 10, characterized in that said cannulas (2) are introduced in said opening (102) of said bag (100) without
contacting the powdered material contained in said bag (100).
12. The method according to claim 10 or 11, characterized in that when said torque sensing means detect a torque greater than a setpoint value, said
first clamps (10) reach said final extraction position.
13. The method according to any one of claims 10 to 12, characterized in that after the step of moving said cannulas (2) to said spaced cannula position, the method
further comprises a step of moving second clamps (12), which are in said open position
of the second clamps, to said closed position of the second clamps, such that said
opening (102) of said bag is held between said second clamps (12), and in that after extracting the gas from said bag (100), said second clamps (12) return to their
open position of the second clamps.
14. The method according to any one of claims 10 to 13, characterized in that after said step of extracting gas and while said first clamps (10) are in said final
extraction position, the method comprises the step of insufflating a gas over the
opening (102) of said bag (100) through said cannulas (2).
15. The method according to claim 14, characterized in that said gas that is insufflated over said opening (102) of said bag (100) is air.