A valve that provides air pulses

Abstract

A valve (30) is provided for providing a pulse of sterile air to a roll of packaging material (20). The valve includes a rotatable valve stem (31) having an inlet portion (32) with a circular cross-section, wherein the inlet portion (32) is provided with a radial groove (33) connecting to an axial cavity (34) of the valve stem (31). The valve (30) also includes a valve member (35) including a bent end (36) adapted to engage with an outer surface of the inlet portion (32) of the valve stem (31) during rotation of the valve stem (31), and a fluid passage (37) extending through the valve member (35) such that air can flow through the valve (30) via the valve member (35) and the valve stem (31) when the valve stem (31) is rotated to a position where the radial groove (33) of the inlet portion (32) aligns with the fluid passage (37) of the valve member (35).

Description

TECHNICAL FIELD

[0001] The present invention relates generally to the field of air pulse technology and valves therefor. More specifically, the present invention proposes a valve, device and method capable of removing excess sterilizing agent from a web of packaging material. BACKGROUND

[0002] It is known to use a roll-fed packaging machine to produce individual packages of different types of food products, such as milk. One advantage of using such a packaging machine is that the continuous production of packages makes it possible to achieve high speeds.

[0003] To ensure that the packaging material is free from unwanted bacteria and other microorganisms, the packaging can be sterilized using a sterilizing agent, such as hydrogen peroxide. For various reasons, it is desirable to remove the sterilizing agent before the package is filled with product.

[0004] During the production of such packages, a web of packaging material is fed through different stations for sterilization, tube forming, filling, sealing and final forming. When passing through the sterilization station, the web of packaging material is immersed in the sterilizing agent. The web of packaging material is then transported through a nip formed by two rollers, which spreads the sterilizing agent onto an even film covering both sides of the web of packaging material. The web is then exposed to heat for efficient sterilization and subsequent evaporation of the sterilizing agent.

[0005] The web of packaging material can have protruding structures, such as injection-molded opening devices. At these protruding structures, the sterilizing agent can not spread onto the even film, resulting in an excess of sterilizing agent around these structures. This excess of sterilizing agent can not evaporate properly in the heating step, leaving unwanted residues of sterilizing agent inside and outside the packaging material.

[0006] Therefore, when the packaging material has protruding structures such as the opening devices described above, there is a need to provide a solution that allows for an even distribution of the sterilizing agent. SUMMARY

[0007] It is an object of the present invention to at least partly overcome one or more of the above-mentioned limitations of the prior art.

[0008] An idea of the present invention is to remove the sterilizing agent from areas having protruding structures by pulsing sterile air to blow on the web of packaging material. The pulsed blowing can be precisely positioned on the web, for example, in areas where there is an excess of sterilizing agent. This also serves to avoid undesirably removing sterilizing agent from areas where the sterilizing agent is properly spread.

[0009] Although air pulse technology exists today, there is a need for improved technology in order to more effectively achieve this, for example, in terms of speed to allow the roll-fed packaging machine to be run at maximum capacity, the amount of air used, the durability of the components and hygiene.

[0010] It is an object of the present invention to provide a valve capable of producing a fast pulse of sterile air.

[0011] According to a first aspect, there is provided a valve for providing a pulse of sterile air to a web of packaging material. The valve comprises:

[0012] a rotatable valve stem having an inlet portion with a circular cross section, wherein the inlet portion is provided with a radial slot connected to an axial cavity of the valve stem. The valve further comprises:

[0013] a valve member comprising a curved end adapted to cooperate with an outer surface of the inlet portion of the valve stem during rotation of the valve stem, and a fluid passage extending through the valve member such that air can flow through the valve via the valve member and the valve stem when the valve stem is rotated to a position in which the radial slot of the inlet portion is aligned with the fluid passage of the valve member. One advantage of these features of the valve is that a fast and distinct air pulse can be produced.

[0014] According to an embodiment, the valve comprises a drive unit connected to the valve stem to rotate the valve stem. By operating the valve at different rotational speeds using the drive means, the opening time (length) of the valve can be adjusted when the slot passes through the opening of the valve.

[0015] According to an embodiment, the valve member comprises a drain slot for allowing air to escape when the radial slot of the valve stem is aligned with the drain slot. One advantage of having a drain slot is to prevent air from leaking to the web of packaging material immediately after the air pulse.

[0016] According to an embodiment, the circumferential width of the radial slot is in the range of 1-10%, preferably in the range of 1-5% of the total circumference of the inlet portion. According to an embodiment, the circumferential width of the radial slot is smaller than the width of the fluid passage of the valve member. One advantage of these features regarding the circumferential width is to provide a fast opening and closing time of the valve, resulting in a distinct square air pulse.

[0017] According to an embodiment, the inlet portion 32 comprises a plurality of spaced-apart radial slots, each radial slot being connected to the axial cavity of the valve stem. One advantage of this feature is to provide a plurality of air pulses per rotation of the shaft member, to minimize wear of the components, and to require less power.

[0018] According to a second aspect, an apparatus is provided for providing a sterile air pulse to a package material roll, wherein the package material roll comprises a plurality of sequentially arranged portions configured to form individual packages, wherein at least a subset of these portions includes a positioning element. The apparatus includes: a positioning element reader arranged to determine when a positioning element passes by the positioning element reader; a valve according to the first aspect described above for providing a sterile air pulse; and a control unit configured to control the operation of the valve based on the output of the positioning element reader.

[0019] According to one embodiment, the device may further include nozzles arranged to provide air pulses on one or both sides of the packaging material roll. Thus, air pulses are simultaneously applied inside and outside the packaging material roll.

[0020] According to one embodiment, the device may also include a pressure sensor positioned downstream of the valve stem. One advantage of doing so is that the correct timing and pressure of the air pulse can be verified.

[0021] According to a third aspect, a method for removing excess sterilizing agent from a package material roll is provided. The method includes providing a valve member having a rotatable valve stem and a valve component adapted to engage with the valve stem, and rotating the valve stem such that a radial groove of the valve stem is in fluid communication with a fluid passage of the valve component, thereby allowing air to flow through the valve via the valve component and the valve stem.

[0022] One advantage of this approach is its high efficiency in terms of speed, allowing the packaging material rolls to pass through the valve at high speed, and allowing the roll feeder packaging machine used for producing packaging from the rolls to operate at maximum capacity.

[0023] According to one embodiment, a packaging material roll comprises a plurality of continuously arranged portions configured to form a package, wherein at least a subset of these portions includes a positioning element. In such an embodiment, the method further includes the steps of: determining when the positioning element passes through a positioning element reader, and calculating, based on the output of the positioning element reader, the time it takes for a desired area of ​​the packaging material roll to pass through the valve, wherein the step of rotating the valve stem is performed at the calculated time. The opening time (length) of the valve can be adjusted by using different rotational speeds as the groove passes through the opening of the valve.

[0024] Other objects, features, aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings. Attached Figure Description

[0025] Embodiments of the invention will now be described by way of example with reference to the accompanying schematic diagrams, wherein:

[0026] Figure 1aThis is a perspective view of components of a roll-feed packaging machine equipped with a device for providing sterile air pulses, according to one embodiment.

[0027] Figure 1b This is a top view showing an example of a packaging material roll used with a valve according to various implementation schemes.

[0028] Figure 2 yes Figure 1a A perspective view of a portion of the device shown.

[0029] Figure 3 It is a perspective view of a portion of the apparatus according to one embodiment.

[0030] Figure 4 yes Figure 3 The diagram shows a perspective view of the valve assembly, with some components omitted.

[0031] Figure 5 This is a cross-sectional view of a valve for providing a sterile air pulse in the open position, according to one embodiment.

[0032] Figure 6 yes Figure 5 A cross-sectional view of the valve, shown here in the closed position.

[0033] Figures 7-9 This is a cross-sectional view of a valve for providing sterile air pulses according to one embodiment, shown in the open, closed, and vented positions.

[0034] Figure 10 This is a flowchart illustrating a method for removing excess sterilizing agent from packaging material rolls according to one embodiment. Detailed Implementation

[0035] refer to Figure 1a The components of a roll-feed packaging machine 10 equipped with device 40 are shown by way of example.

[0036] During the production process, the packaging material roll 20 is fed into and passes through machine 10. To ensure that the packaging material 20 is free of bacteria and other unwanted microorganisms, a sterilizing agent can be used to sterilize the packaging. According to one example, the sterilizing agent may include hydrogen peroxide. The roll-feed packaging machine 10 is equipped with a sterilization tank 11. When passing through the sterilization tank 11, the packaging material roll 20 is immersed in the sterilizing agent.

[0037] The packaging material roll 20 is then conveyed through a gap formed by two rollers 12a-b, where excess sterilizing agent is removed by distributing the sterilizing agent onto a uniform film covering both sides of the packaging material roll 20. The packaging material roll 20 is then exposed to heat in a heating tower 13 for effective sterilization and subsequent sterilizing agent evaporation prior to tube forming, filling, sealing, and final shaping. These steps, which transform the sterilized packaging material roll 20 into individual packages, are performed by additional components (not shown) of the roll-feed packaging machine 10 and will not be described further herein.

[0038] Packaging material roll 20 may have protruding structures 22a-f, such as injection molding opening devices, as shown in reference. Figure 1b For example, Figure 1b An example of packaging material roll 20 is shown.

[0039] The packaging material roll 20 may include a plurality of continuously arranged portions 21a-f. Each of the plurality of continuously arranged portions 21a-f may include an opening device 22a-f attached thereto. At least one subset of the plurality of continuously arranged portions 21a-f may include positioning elements 23a-f. For example, positioning elements 204a-f may be integrated into the packaging material 20 such that their position remains unchanged during production.

[0040] Positioning elements 23a-f can be used to provide the packaging machine 10 with information about the position of the roll 20. Positioning elements 23a-f can be marks and / or codes that can be read by an element reader 45 (e.g., a photocell, camera, or tape reader) (see [link to documentation]). Figure 1a Alternatively, for example, positioning elements 23a-f may be disposed on the packaging material roll 20 as optical reference marks, such as printed marks provided thereon. Alternatively, positioning elements 23a-f may be printed magnetic marks detectable by a magnetic reading device internal or external to device 40. Positioning elements 23a-f are not limited to this example, but may be any reference location providing information about the position of the roll 20. One of the positioning elements 23a-f may be used to estimate the position of multiple portions 21a-f.

[0041] At these protruding structures 22a-f, sterilizing agent may accumulate and may not be distributed evenly to the film by the rollers 12a-b, resulting in excess sterilizing agent remaining at or near the protruding structures 22a-f. This excess sterilizing agent may not evaporate properly at the heating tower 13, thus leaving undesirable sterilizing agent residues inside and outside the packaging material roll 20.

[0042] It has been recognized that excess sterilizing agent in areas of the packaging material roll 20 with protruding structures 22a-f can be removed by pulse-blowing sterile air over the packaging material roll 20 before it is exposed to heat. Pulsed air blowing allows for precise targeting over the packaging material roll 20, for example, in areas with excess sterilizing agent. This offers several advantages. It avoids removing sterilizing agent from other areas where it is actually properly distributed. It also minimizes the amount of air used and the turbulence generated. By using pulsed air instead of a continuous airflow, the total airflow and energy used can be significantly lower. Furthermore, since the air is directed only to a small portion of the roll 20, it does not affect the temperature distribution of the packaging material 20 and thus could not potentially reduce the efficiency of the sterilization process.

[0043] Back to Figure 1a The roll-feed packaging machine 10 is equipped with a device 40 for providing sterile air pulses to the packaging material roll 20 to remove excess sterilizing agent.

[0044] Device 40 includes a valve 30 for providing sterile air pulses. Valve 30 includes a valve member 35 and a valve stem 31, which will be referenced... Figures 5-9 Further description. In one embodiment, valve 30 is further provided with a drive unit 41 for adjusting the position of the rotatable valve stem 31 of valve 30. In one embodiment, drive unit 41 is a servo motor. In another embodiment, drive unit 41 is an electric motor.

[0045] In the illustrated embodiment, device 40 further includes a positioning element reader 45, which is arranged to determine the positioning elements 23a-f of the packaging material roll 20 (see [link]). Figure 10 When does the positioning element reader 45 pass? The control unit 46 is configured to control the operation of the valve 30 based on the output of the positioning element reader 45. The positioning element reader 45 and the control unit 46 are able to determine when the positioning elements 23a-f pass the positioning element reader 45, and the control unit 46 is configured to calculate the time it takes for the desired area of ​​the packaging material roll 20 (i.e., the position of the protruding structures 22a-f) to pass through the valve 30. This calculation is preferably based on the positioning element reader 45 (i.e., the detection time), the speed of the packaging material roll 20, the distance between the positioning elements 23a-f and the protruding structures 22a-f, and the time distance between the positioning element reader 45 and the nozzle of the valve 30 (given the speed of the packaging material roll 20). The valve stem 31 is rotated at the calculated time to open the valve 30 at the desired time.

[0046] In one implementation, the protruding structures 22a-f can be detected using other devices, such as a camera. In this way, the valve 30 can be synchronized with the precise blowing position used to blow air onto the protruding structures 22a-f.

[0047] In one embodiment, the device 40 further includes a pressure sensor 44 disposed downstream of the valve stem 31. The determination of the air pressure at different time points can be used as part of the quality control of the device 40, verifying the correct air pressure at the correct time.

[0048] The device 40 also includes an air source 42 for supplying sterile air to the valve 30. In one embodiment, the air source 42 supplies air at a pressure of 1.5 to 5.0 bar, preferably 2.0 bar. The valve 30 is positioned in direct fluid communication with the outlet of the air source 42.

[0049] refer to Figure 2 The diagram illustrates an apparatus 40 for providing sterile air pulses to a packaging material roll 20. The apparatus includes a valve 30 for providing sterile air pulses, a drive unit 41 for adjusting the position of a valve stem 31, an air source 42 for providing sterile air to the valve 30, and nozzles 43 arranged to provide air pulses from the valve 30 to both sides of the packaging material roll 20.

[0050] Nozzle 43 includes air outlets facing both sides of the packaging material web 20. The air outlets may be formed, for example, as narrow channels that allow air leaving valve 30 to exit through.

[0051] refer to Figure 3 The device 40 is described in more detail. The device includes a valve 30 for providing sterile air pulses, a drive unit 41 for adjusting the position of a valve stem 31 disposed within a valve housing 30b, an air source 42 for providing sterile air to the valve 30, and a pressure sensor 44 disposed downstream of the valve stem 31.

[0052] refer to Figure 4 Valve 30 is shown without housing 30b. Valve 30 is provided with a rotatable valve stem 31 having an inlet portion 32 with a circular cross-section and an axial cavity 34. Valve 30 is also provided with a valve member 35, which includes a bent end 36 adapted to engage with the outer surface of the inlet portion 32 of the valve stem 31 during rotation of the valve stem 31. A drive unit 41 is drivenly connected to the valve stem 31 for adjusting the position of the valve stem 31. Air pressure from an air source 42 presses the valve member 35 against the valve stem 31.

[0053] The valve component 35 and valve stem 31 are preferably made of durable materials, such as stainless steel or aluminum. This is also advantageous for use with packaging machines 10, which, as described above, require hygienic and food-safe materials.

[0054] refer to Figure 5The diagram shows a cross-sectional view of a valve 30 in the open position for providing a pulse of sterile air to a roll of packaging material 20. A rotatable valve stem 31 has an inlet portion 32 with a circular cross-section, wherein the inlet portion 32 has a radial groove 33 communicating with an axial cavity 34 of the valve stem 31. The valve also includes a valve member 35 having a bent end 36 adapted to engage with the outer surface of the inlet portion 32 of the valve stem 31 during rotation of the valve stem 31. The radial groove 33 is axially aligned with a fluid passage 37 extending through the valve member 35, such that when the valve stem 31 is rotated to the open position, the radial groove 33 of the inlet portion 32 is circumferentially aligned with the fluid passage 37 of the valve member 35, allowing air to flow through the valve member 35 and the valve stem 31 through the valve 30. The rotation of the valve stem 31 is driven by a drive unit 41. The opening time (length) of the valve 30 can be adjusted by using different rotational speeds as the groove 33 passes through the fluid passage 37 in the valve 35.

[0055] Valve 30 in Figure 6 The valve is shown in its closed position. Here, the radial groove 33 of the inlet portion 32 is rotated to a circumferential position that is not aligned with the fluid passage 37 of the valve member 35, thereby preventing air from flowing through the valve member 35 and through the valve stem 31.

[0056] refer to Figure 7 Valve 30 is shown in the open position. It can be seen that the radial groove 33 of the inlet portion 32 is aligned with the fluid passage 37 of the valve member 35, allowing air to flow continuously through the valve member 35 and the valve stem 31.

[0057] The circumferential width of the radial groove 33 is preferably in the range of 1-10% of the total circumference of the inlet portion 32, more preferably in the range of 1-5%. Even more preferably, the circumferential width of the radial groove 33 is smaller than the width of the fluid passage 37 of the valve member 35. These features provide rapid opening and closing times for the valve, resulting in a rapid and pronounced opening time, square, air pulse. The valve stem 31 can rotate at a constant speed, resulting in the valve stem 31 being in the open position for a much shorter time than in the closed position. Variation in rotation speed during rotation is also possible, thereby adjusting the time the valve stem is in the open and closed positions.

[0058] According to one embodiment, the inlet portion 32 may include a plurality of spaced radial grooves 33, each radial groove being connected to an axial cavity 34 of the valve stem 31. The advantage of this feature is that the valve stem 31 may have more air pulses per revolution, thereby minimizing component wear and requiring less power.

[0059] The valve component 35 can be sealed by an O-ring 50 on the outside of the valve component 35 to ensure that there is no leakage of the air source 42 around the valve component 35.

[0060] refer to Figure 8 The valve is displayed as being in the closed position. In the closed position, the valve stem 31 rotates such that the radial groove 33 of the inlet portion 32 has passed through the fluid passage 37 of the valve member 35, preventing air from flowing through the valve member 35 and the valve stem 31.

[0061] refer to Figure 9 Valve 30 is shown in the venting position. In the closed position, the axial cavity 34 and / or radial groove 33 of the inlet portion will contain overpressurized air from the air source 42, which may leak through the nozzle after the valve is closed. To prevent this leakage, valve stem 31 is rotated to the venting position. In the venting position, valve stem 31 rotates such that the radial groove 33 of the inlet portion 32 aligns with the discharge groove 38 of the valve member 35. The discharge groove 38 extends to the outer surface of the valve member 35 (also shown in the figure). Figure 4 (In the middle), allowing air to exit from the axial cavity 34 and radial groove 33 of the inlet portion 32, thereby reducing air leakage. The exhaust groove preferably extends to the outer surface of the valve member 35 in a direction parallel to the axial cavity 34 of the valve stem 31. Housing 30b (see...) Figure 3 It includes an air outlet 39 that is in fluid communication with the exhaust channel 38.

[0062] refer to Figure 10 The diagram schematically illustrates a method 100 for removing excess sterilizing agent from a roll of packaging material 20. Method 100 includes a first step 102 of providing a valve 30 having a rotatable valve stem 31 and a valve member 35 adapted to cooperate with the valve stem 31, and a step 104 of rotating the valve stem 31 such that a radial groove 33 of the valve stem 31 is in fluid communication with a fluid passage 37 of the valve member 35, thereby allowing air to flow through the valve 30 via the valve member 35 and the valve stem 31.

[0063] Method 100 may also include optional steps 106 and 108. In step 106, the time it takes for the positioning elements 23a-f to pass through the positioning element reader 45 is determined. In step 108, the time it takes for the desired area of ​​the packaging material roll 20 to pass through the valve 30 is calculated based on the output of the positioning element reader 45, as shown with reference to FIG1. ​​In embodiments involving steps 106 and 108, step 104 of rotating the valve stem 31 is performed at the calculated time.

[0064] The required area can be the opening device 22a-f of the packaging material roll 20, and the positioning elements 23a-f can be a reference. Figure 1b The type described. Control unit 46 is configured to control the operation of valve 30, thereby performing step 104 of rotating valve stem 31 at a calculated time based on the output of positioning element reader 45, as further explained above.

[0065] As can be seen from the above description, although various embodiments of the present invention have been described and shown, the present invention is not limited thereto, but may be embodied in other ways within the scope of the subject matter defined by the appended claims.

Claims

1. An apparatus (40) for providing sterile air pulses to a web of packaging material (20), wherein, The device (40) comprises: a valve (30) comprising: a rotatable valve stem (31) having an inlet portion (32) with a circular cross section, wherein the inlet portion (32) is provided with a radial slot (33) connected to an axial cavity (34) of the valve stem (31); a valve member (35) comprising a curved end (36) adapted to cooperate with an outer surface of the inlet portion (32) of the valve stem (31) during rotation of the valve stem (31), and a fluid passage (37) extending through the valve member (35) such that air can flow through the valve (30) via the valve member (35) and the valve stem (31) when the valve stem (31) is rotated to a position in which the radial slot (33) of the inlet portion (32) is aligned with the fluid passage (37) of the valve member (35); wherein the device (40) further comprises: a drive unit (41) to adjust the position of the valve stem (31); an air source (42) for providing sterile air to the valve (30); and a nozzle (43) arranged to provide air pulses from the valve (30) to one or both sides of the web of packaging material (20).

2. The apparatus (40) of claim 1, wherein, The drive unit (41) is connected to the valve stem (31) for rotating the valve stem (31).

3. The apparatus (40) of claim 2, wherein, The drive unit (41) is a servo motor or an electric motor.

4. The apparatus (40) according to any one of the preceding claims 1-3, wherein, The valve member (35) comprises a drain slot (38) for allowing air to escape when the radial slot (33) of the valve stem (31) is aligned with the drain slot (38).

5. The apparatus (40) according to the preceding claim 4, wherein The drain slot (38) extends to an outer surface of the valve member (35).

6. The apparatus (40) according to any one of the preceding claims 1-3, wherein, The circumferential width of the radial slot (33) is in the range of 1-10% of the total circumference of the inlet portion (32).

7. The apparatus (40) of claim 6, wherein, The circumferential width of the radial slot (33) is in the range of 1-5% of the total circumference of the inlet portion (32).

8. The device (40) according to any of the preceding claims 1-3, wherein the circumferential width of the radial slot (33) is less than the width of the fluid passage (37) of the valve member (35).

9. The device (40) according to any of the preceding claims 1-3, further comprising a plurality of spaced apart radial slots (33), each connected to the axial cavity (34) of the valve stem (31).

10. The device (40) according to any of the preceding claims 1-3, wherein the web of packaging material (20) comprises a plurality of successively arranged portions (21a-21f) arranged as individual packages, wherein at least a subset of the portions (21a-f) comprises a positioning element (23a-f), the device (40) further comprising: a positioning element reader (45) arranged to determine when a positioning element (23a-f) passes the positioning element reader (45), a control unit (46) configured to control operation of the valve (30) based on output from the positioning element reader (45).

11. The apparatus (40) according to claim 10, further comprising a pressure sensor (44) arranged downstream of the valve stem (31).

12. The apparatus (40) according to the preceding claim 10 or 11, further comprising an air source (42) connected to the valve (30), wherein the air pressure provided by the air source (42) is 1.5 to 5.0 bar.

13. The apparatus (40) according to the preceding claim 12, wherein the air pressure provided by the air source (42) is 2.0 bar.

14. A method (100) for removing excess sterilizing agent from a web of packaging material (20), the method (100) comprising: providing an apparatus (40) according to any of the preceding claims 1-13, and rotating the valve stem (31) such that the radial groove (33) of the valve stem (31) is in fluid communication with the fluid passage (37) of the valve member (35), thereby allowing air to flow through the valve (30) through the valve member (35) and the valve stem (31).

15. The method (100) according to claim 14, wherein the web of packaging material (20) comprises a plurality of successively arranged portions (21a-21f) arranged to form a package, wherein at least a subset of the portions (21a-f) comprises a positioning element (23a-f), the method (100) further comprising: determining when the positioning element (23a-f) passes the positioning element reader (45), calculating a time for a desired area of the web of packaging material (20) to pass the valve (30) based on output from the positioning element reader (45), and wherein the step (104) of rotating the valve stem (31) is performed at the calculated time.

16. The method of claim 15, wherein, the desired area is an opening device (22a-f) of the web of packaging material (20).

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