Food packaging method and packaging machine

Abstract

A method (600) for packaging food is provided. The method may include receiving (602) at least one sheet of packaging material (PM) in a packaging machine (500), the packaging material (PM) including a cellulose-based middle layer (400), an inner layer (404) arranged to face the food (FP), and an outer layer (402), wherein an ink-based print is provided on the outer layer (402), curing (604) the inner layer (404) of at least one sheet of packaging material (PM) such that ink particles (302) released from the outer layer (402) to the inner layer (404) bind to the inner layer (404), thereby preventing the ink particles (302) from being released into the food (FP), processing (606) at least one sheet of packaging material (PM) into a package (110), and filling (608) the package (110) with food (FP).

Description

Technical Field

[0001] The present invention generally relates to liquid food packaging technology. More specifically, it relates to a method for reducing the risk of ink particles related to the printing of packaging materials from transferring to food. Background Art

[0002] Today, roll-fed packaging machines are common. Tetra Pak TM sold by Tetra Pak TM A3 is an example of such a packaging machine (sometimes also called a filling machine). Briefly, in a roll-fed packaging machine, a roll of packaging material is received. The packaging material is unwound and then the packaging material web is fed into the machine. To ensure that no or at least very few unwanted microorganisms are transmitted from the packaging material to the food, the web is treated with a hydrogen peroxide bath or a low-voltage electron beam (LVEB) device. Once the microorganisms on the web are killed, the web can be processed into a vertically placed tube. The food is filled into the tube from above, and the tube is continuously sealed and cut at the lower end, enabling the production of packages at an astonishing speed, such as 30,000 packages per hour.

[0003] Before the packaging material is supplied to the packaging machine, the packaging material is printed. Generally, the packaging material is produced and printed in a so-called processing factory. Briefly, in such a factory, laminates including different layers are produced, and printing, sometimes also called a decorative pattern, is provided on the outer layer of the packaging material.

[0004] When the packaging material is wound on a roll, the printed outer layer abuts against the inner layer. In this way, it is possible for ink particles to transfer from the outer layer to the inner layer, and the inner layer faces the food after the package is formed. To reduce the impact of ink particles on the inner layer, food-grade inks that are safe for consumers have been developed, that is, even if the ink particles eventually enter the food, they will not cause harm to consumers. Optionally or additionally, a covering layer can also be provided on top of the printing, which can eliminate or at least mitigate the risk.

[0005] Another possible solution is to perform printing in the packaging machine after the packaging material is unrolled from the roll, that is, by changing the order of steps and not performing printing when the packaging material is on the roll, thereby eliminating the risk of printing particles transferring from the outer layer to the inner layer.

[0006] Although there have been some solutions to avoid or at least reduce the negative impact of ink particle transfer from the outer layer to the inner layer during the transportation of the packaging material, the problem of ink particle migration still exists. Therefore, there is a need for a solution to reduce the negative impact caused by the transfer of ink particles between the outer layer and the inner layer without affecting the cost-effectiveness and versatility of the packaging machine. Summary of the Invention

[0007] The object of the present invention is to overcome at least in part one or more limitations of the above-mentioned prior art. In particular, the object of the present invention is to provide a safe, low-cost and general method to reduce the influence of ink particles transferring from the outer layer of the printed packaging material to the inner layer of the packaging material facing the food once the packaging is formed.

[0008] According to a first aspect, there is provided a method for food packaging, the method comprising

[0009] receiving at least one sheet of packaging material in a packaging machine, the packaging material comprising a cellulose-based middle layer, an inner layer and an outer layer arranged to face the food, wherein an ink-based print is provided on the outer layer,

[0010] curing the inner layer of the at least one sheet of packaging material such that ink particles released from the outer layer bind to the inner layer, thereby preventing the ink particles from being released into the food,

[0011] processing the at least one sheet of packaging material into a package, and

[0012] filling the package with the food.

[0013] The advantage of curing the packaging material after receiving it in the packaging machine is that even if ink particles transfer from the outer layer to the inner layer, for example during transportation from the printing machine to the packaging machine, these particles will be bound to the inner layer, so that these particles will not transfer from the inner layer to the food at a later stage. By placing the curing device in this way, different measures do not need to be taken to avoid ink particles eventually entering the inner layer, thereby improving cost-effectiveness.

[0014] Curing can be carried out by an ultraviolet (UV) lamp, an electron beam device and / or a light emitting diode (LED) device.

[0015] While curing the inner layer, the method may further comprise

[0016] using an ultraviolet lamp, an electron beam device and / or a light emitting diode device to reduce the number of microorganisms on the inner layer.

[0017] The energy (usually in the form of light) used to cure the ink particles on the inner layer can also be used to kill the microorganisms on the inner layer. Therefore, the energy emitted onto the inner layer can achieve a dual purpose: curing the ink particles so that they do not eventually enter the food; killing the microorganisms so that they do not transfer to the food.

[0018] A light barrier layer may be provided on the packaging material, the light barrier layer being arranged to allow light of a transmissible wavelength to pass through, and the method may further comprise

[0019] Emitting light of a transmission wavelength from an ultraviolet lamp, an electron beam device, and / or an LED device, and

[0020] Reducing the number of microorganisms on the outer layer of the web by light of a transmission wavelength passing through the packaging material.

[0021] The advantage that the light barrier layer allows light of a transmission wavelength to pass through is that it can not only protect the food from sunlight, thereby reducing the risk of food spoilage, but also allow light of a limited wavelength to pass through the packaging material, so that the energy emitted by the ultraviolet lamp, LED lamp, and / or electron beam device can not only reduce the number of microorganisms on the inner layer, but also reduce the number of microorganisms on the outer layer.

[0022] The light emitted by the LED device has an ink-specific wavelength adapted to the characteristics of the ink used.

[0023] The packaging material may not have a cover layer provided outside the printed outer layer.

[0024] Since the ink particles transferred to the inner layer are restricted by the curing device, the risk of ink particles transferring from the outer layer to the inner layer is reduced. Therefore, there is no reason or at least less reason to take measures to prevent the transfer of ink particles from the outer layer to the inner layer. Since the cover layer can be not used, a more cost-effective packaging material can be provided, and the printing machine device does not have to provide a cover layer after printing.

[0025] The packaging material may not have an ink migration prevention layer, thereby allowing ink particles to migrate from the outer layer to the inner layer through the packaging material.

[0026] The transfer of ink particles from the outer layer to the inner layer is not necessarily due to the web of the packaging material being wound on a reel, making the inner layer adjacent to the outer layer, but may also be due to the ink particles passing through the packaging material. To avoid this transfer, it is common practice to use an ink migration prevention layer. However, since the ink particles on the inner layer can be processed in the packaging machine, there is no need or at least a reduced need for such an ink migration prevention layer. Therefore, this layer can be omitted, making the packaging material more cost-effective.

[0027] The curing step can be divided into a first-stage curing and a second-stage curing. The first-stage curing uses a first range of wavelengths, and the second-stage curing uses a second range of wavelengths, where the second range of wavelengths is wider than the first range of wavelengths.

[0028] The first-stage curing can be completed by an LED device, and the second-stage curing can be completed by an ultraviolet lamp.

[0029] The advantage of using an LED device in combination with a subsequent ultraviolet lamp is that, in the first step, light of a specific range of wavelengths can be used to meet the characteristics of the ink used; in the second step, light of a wide range of wavelengths can be used to ensure that ink particles that are not properly bonded by the LED device are firmly bonded after passing through the ultraviolet lamp.

[0030] The packaging machine can be a roll-fed packaging machine and supply packaging material to the packaging machine in the form of a web wound on a reel, such that the outer layer is adjacent to the inner layer.

[0031] After the printing press device has completed printing and before the packaging is processed and filled in the packaging machine, the printed packaging material can be stored on a reel, thereby improving the storage efficiency of the packaging material and improving the supply chain.

[0032] According to a second aspect, there is provided a packaging machine for packaging food, the packaging machine comprising

[0033] a packaging material receiver configured to receive packaging material, the packaging material comprising a cellulose-based middle layer, an inner layer and an outer layer configured to face the food, wherein an ink print is provided on the outer layer,

[0034] a curing device configured to cure the inner layer, bonding ink particles placed on the inner layer to the inner layer, thereby preventing the ink particles from being released into the food,

[0035] a packaging former configured to process the packaging material into a package, and

[0036] a product filling device configured to fill food into the package.

[0037] The features and advantages of the first aspect described above apply equally to the second aspect.

[0038] The curing device can include an ultraviolet (UV) lamp, an electron beam device, and / or a light emitting diode (LED) device.

[0039] The curing device can be a curing and microbe-reducing device for simultaneously curing and reducing the number of microbes on the inner layer.

[0040] The packaging material can have a light-blocking layer that allows light of a transmission wavelength to pass through, wherein the ultraviolet lamp, the electron beam device, and / or the LED device can be arranged to emit light of the transmission wavelength, thereby allowing the light of the transmission wavelength passing through the packaging material to reduce the microbes on the outer layer of the web.

[0041] The packaging material receiver is a packaging material reel receiver arranged to receive packaging material in the form of a reel having a wound packaging material web, wherein the packaging machine further includes a web feeder arranged to unwind the web from the reel and feed the web downstream in the packaging machine.

[0042] Other objects, features, aspects, and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Embodiments of the present invention will now be described by way of example, with reference to the schematic drawings, in which

[0044] Figure 1 is a perspective view of a roll-fed packaging machine.

[0045] Figure 2 generally shows a printer device.

[0046] Figure 3 shows in detail a web of packaging material wound on a reel.

[0047] Figure 4A -C shows three cross-sectional views of different packaging materials.

[0048] Figure 5 generally shows a packaging machine with a built-in curing device.

[0049] Figure 6 shows a flowchart of a food packaging method. DETAILED DESCRIPTION

[0050] Figure 1 Generally shows a packaging machine 100. In the illustrated embodiment, the packaging machine 100 is a roll-fed cardboard packaging machine. The general principle of such a machine is that starting from a roll of packaging material PM, a web 102 is formed. Although not shown, if required to meet food safety regulations, the web 102 can be sterilized using a hydrogen peroxide bath, a low-voltage electron beam (LVEB) device, or any other device capable of reducing the number of unwanted microorganisms. After sterilization, the web 102 can be processed into a tube 106 by a longitudinal sealing device 104. When processed into a tube, food FP (such as milk) can be fed into the tube 106 through a product conduit 108 that is at least partially located inside the tube 106.

[0051] To process the tube 106 of the filled food FP into the package 110, a transverse sealing device 112 can be used to perform a transverse seal at the lower end of the tube. Generally speaking, the transverse sealing device 112 has two main functions: 1) providing a transverse seal, that is, welding two opposite sides of the tube together, so that the product in the lower part of the tube (below the sealing device) is separated from the product in the tube (above the sealing device); 2) cutting off the lower part of the tube in the transverse seal portion 114, thus forming the package 110. Optionally, the step of cutting off the lower part can also be completed by different components of the device in a subsequent step, rather than, as shown, completing the transverse seal and cutting off the lower part in the same device 112, or if the package is intended to be sold in multi-packs, the step of cutting off the lower part is completed by the consumer.

[0052] Figure 2 A printer device 200 is shown. Such a device can be installed at a food production base, such as a dairy production base, so that packaging materials PM without printing or with certain printed parts can be provided to the production base. The advantage of such an arrangement is that it is possible to decide later what products to produce. Another advantage is that the required storage volume of the packaging material PM is less, especially for a production base that produces multiple products. In other words, the supply chain can be improved.

[0053] In the illustrated embodiment, a reel 202a containing unprinted packaging material PM is provided to the printer device 200. After being unwound, the packaging material PM is fed along the feed direction FD to the printing device 204. This device 204 provides ink Ink on the packaging material PM. Downstream of the printing device 204, a curing device 206 is placed. In order to harden the ink Ink and properly attach it to the packaging material PM, energy E (usually in the form of light) needs to be emitted to the packaging material PM. After printing and curing, the packaging material PM is wound onto a reel 202b with printed PM.

[0054] Even if not shown, printing can be directly performed on the web 102, that is, the web 102 is directly fed from the production workshop into the printer device 200, rather than being wound onto the reel 202a first.

[0055] As Figure 3 shown, by applying energy E to the ink Ink through the curing device 206, cured ink particles 300 will be formed and attached to the outer layer, and at the same time, the transferred ink particles 302 will be placed on the inner layer. As shown, the transfer of ink particles may be due to the web being wound up, but the transfer may also occur in other ways. For example, in some cases, although not shown, due to the air flow in the printer device 200, the ink particles may enter the inner layer of the packaging material. This may occur in Figure 2On the coils shown, it can also occur on polyethylene terephthalate (PET) bottles.

[0056] Figure 4A A cross-sectional view of the packaging material PM is generally illustrated. The packaging material PM includes a cellulose-based intermediate layer 400, an outer layer 402 provided with ink Ink, an inner layer 404 arranged to face the food FP, a cover layer 406 placed outside the outer layer 402, a light-blocking layer 408, and an ink migration prevention layer 410. As shown, the light-blocking layer 408 and the ink migration prevention layer 410 can be placed between the inner layer 404 and the cellulose-based middle layer 400, but other configurations can also be adopted.

[0057] Placing the cover layer 406 on top of the outer layer 402 can reduce the risk of ink migration. However, setting such a layer will not only increase costs and make the packaging material more complex, but the printer device 200 must also have the function of adding an additional layer after printing. Therefore, in order to achieve cost-effectiveness and versatility, that is, to make in-situ printing attractive to more food producers, it is beneficial to omit the cover layer 406.

[0058] As shown, the ink migration prevention layer 410 can itself be a single layer, but its function can also be achieved through the combination of different layers, and it does not exist solely for preventing ink migration. Even if the ink migration prevention layer 410 is not added to the printer device 210, it will increase the cost of the packaging material. If this layer can be omitted, cost-effectiveness can be improved.

[0059] Figure 4B The packaging material PM without the cover layer 406 is shown, but it is consistent with the Figure 4A packaging material PM shown. One way to overcome the increased risk of ink migration due to the absence of the cover layer 406 is not to roll up the web on the reel, but since this requires placing the printer device close to the packaging machine, there are deficiencies in terms of versatility.

[0060] Figure 4C The packaging material PM without the cover layer 406 and the ink migration prevention layer 410 is generally shown. If the ink migration prevention layer 410 is not used, part of the ink Ink may migrate through the packaging material PM. Therefore, when using the Figure 4C packaging material PM shown, there is a risk that the ink Ink migrates from the outer layer 402 to the inner layer 404 when rolled up, but there is also a risk that the ink Ink passes through the packaging material PM. The advantage of omitting the ink migration prevention layer 410 is that a more cost-effective packaging material PM can be obtained.

[0061] In Figure 4CIn the packaging material PM shown, the light blocking layer 408 is replaced by a light blocking layer 412, which is arranged to allow light 414 of a transmission wavelength to pass through. In other words, the light blocking layer 412 does not block all light, but allows light 414 of certain transmission wavelengths to pass through. The advantage of this arrangement is that the food can be fully shielded from sunlight, thereby reducing the risk of microbial growth in the food FP, but the light 414 allowed to pass through the packaging material PM is used to kill microorganisms on the outer layer 402 when the packaging material PM is treated before filling the food FP.

[0062] To use Figure 4B and Figure 4C The packaging material PM shown can be used Figure 5 The packaging machine 500 shown in FIG. 5 may include a packaging material receiver 502, which is illustrated in the form of a roll receiver. Figure 2 After the roll 202b for printing (printed) is placed in the printer device 200 shown, the packaging material can be unwound and the roll 102 is fed in a feeding direction FD by the roll feeder 504. The roll feeder 504 generally includes a plurality of components for feeding and guiding the roll 102.

[0063] In the filling machine 500, a curing device 506 may be provided for emitting energy E to cure the transfer ink particles 302 located on the inner layer 404 of the packaging material PM, i.e., to adhere to the packaging material PM. The curing device 506 may include a light emitting diode (LED) device, an ultraviolet (UV) lamp, and / or an electron beam device. Figure 5 As shown, the curing device 506 may include a combination of an LED device and an ultraviolet lamp. With this combination, the web 102 may first be exposed to the energy E emitted by the LED device and then to the energy E emitted by the ultraviolet lamp downstream in the feeding direction FD. With this arrangement, a first range of wavelengths may be provided first and then a second range of wavelengths may be provided, wherein the second range of wavelengths is wider than the first range of wavelengths. The first range may be adjusted according to the characteristics of the ink Ink used, thereby providing reliable and efficient curing.

[0064] By curing the inner layer 404 of the packaging material PM in the filling machine 500, the transferred ink particles 302 (which may eventually risk entering the food FP) are cured and attached to the packaging material PM. In other words, the curing device 506 will solve this problem instead of avoiding the generation of transferred particles 302 as has been done so far. Figures 4A to 4CDescriptions of different packaging materials, which not only have advantages in terms of how to handle the packaging material PM between the printer device 200 and the packaging machine 500, but also allow the use of more cost-effective packaging materials PM, such as packaging materials without the cover layer 406 and / or packaging materials without the ink migration prevention layer 410.

[0065] After the web 102 is cured, it is processed in the packaging former 508 (as Figure 1 shown), and the package 110 is filled with the food FP in the product filling device 510 (also as Figure 1 shown). Although a roll-fed cardboard packaging machine is shown in the figure, the same principle can be applied to other food packaging, because in other food packaging, ink particles may eventually enter the food.

[0066] Although the curing device 506 is shown integrated with other components of the packaging machine 500 in the figure, other embodiments are also possible. For example, the packaging material receiver 502, the partial web feeder 504, and the curing device 506 can be installed in a separate component connected to the packaging machine 500. This embodiment may be useful when upgrading an existing packaging machine without a curing device.

[0067] Figure 6 is a flowchart illustrating a method 600 for packaging food FP. In the first step 602, at least one sheet of packaging material PM can be received in the packaging machine 500. The packaging material PM can include a cellulose-based middle layer 400, an inner layer 404 arranged to face the food FP, and an outer layer 402, where ink-based printing is provided on the outer layer 402.

[0068] In the second step 604, the inner layer 404 of at least one sheet of packaging material PM can be cured so that the ink particles 302 released from the outer layer 402 bind to the inner layer 404, thereby preventing the ink particles 302 from being released into the food FP.

[0069] In the third step 606, at least one sheet of packaging material PM can be processed into a package 110.

[0070] In the fourth step 608, the food FP can be filled into the package 110.

[0071] Optionally, the second step 604 can be divided into a first-stage curing 610 and a second-stage curing 612. In the first-stage curing 610, a first range of wavelengths can be used, and in the second-stage curing 612, a second range of wavelengths can be used, where the second range of wavelengths can be wider than the first range of wavelengths.

[0072] Optionally, in a fifth step 614 that can be performed in parallel with the second step 604, the number of microorganisms on the inner layer 404 can be reduced by using an ultraviolet lamp, an electron beam device, and / or an LED device. In other words, the transferred ink particles can be bound to the inner layer 404 at the same time, thereby reducing the risk of these particles ultimately entering the food and reducing the number of microorganisms on the inner layer 404.

[0073] Optionally, in a sixth step 616, an ultraviolet lamp, an electron beam device, and / or an LED device can emit light with a transmission wavelength of 414, and in a seventh step 618, the light with a transmission wavelength of 414 passes through the packaging material PM, thereby reducing the number of microorganisms on the outer layer 402 of the web 102.

[0074] 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 and can be embodied in other ways within the scope of the subject matter defined by the following claims.

Claims

1. A method (600) for packaging food, the method comprising receiving (602) at least one sheet of packaging material (PM) in a packaging machine (500), the packaging material (PM) comprising a cellulose-based middle layer (400), an inner layer (404) arranged to face the food (FP), and an outer layer (402), wherein an ink-based print is provided on the outer layer (402), curing (604) the inner layer (404) of the at least one sheet of packaging material (PM) such that ink particles (302) released from the outer layer (402) to the inner layer (404) bind to the inner layer (404), thereby preventing the ink particles (302) from being released into the food (FP), processing (606) the at least one sheet of packaging material (PM) into a package (110), and filling (608) the package (110) with the food (FP).

2. The method according to claim 1, wherein the curing (604) is accomplished by an ultraviolet (UV) lamp, an electron beam device, and / or a light-emitting diode (LED) device.

3. The method according to claim 2, further comprising, while curing (604) the inner layer (404), reducing the microbial count (614) on the inner layer (404) by utilizing the ultraviolet lamp, the electron beam device, and / or the LED device.

4. The method according to claim 3, wherein the packaging material (PM) is provided with a light-blocking layer (412), the light-blocking layer (412) being arranged to allow light of a transmission wavelength (414) to pass through, the method (600) further comprising emitting (616) the light of the transmission wavelength (414) from the ultraviolet lamp, the electron beam device, and / or the LED device, passing the light of the transmission wavelength (414) through the packaging material (PM), thereby reducing the microbial count (618) on the outer layer (402) of the web (102).

5. The method according to any one of claims 2 to 4, wherein The light emitted by the LED device has an ink-specific wavelength adapted to the characteristics of the ink (Ink) used.

6. The method according to any one of claims 1 to 4, wherein the packaging material (PM) is not provided with a cover layer (406) on the outer side of the outer layer (402) where the print is provided.

7. The method according to any one of claims 1 to 4, wherein the packaging material (PM) does not have an ink migration prevention layer (410), thereby allowing ink particles to migrate from the outer layer (402) to the inner layer (404) through the packaging material (PM).

8. The method according to any one of the preceding claims 1 to 4, wherein the curing (604) step is divided into a first-stage curing (610) and a second-stage curing (612), a first range of wavelengths being used in the first-stage curing (610) and a second range of wavelengths being used in the second-stage curing (612), wherein the second range of wavelengths is wider than the first range of wavelengths.

9. The method according to claim 8, wherein the first stage curing (610) is accomplished by an LED device, and the second stage curing (612) is accomplished by an ultraviolet lamp.

10. The method according to any one of the preceding claims 1 to 4, wherein the packaging machine (500) is a rolling feed type packaging machine, and provides the packaging material (PM) in the form of a web (102) wound on a reel, such that the outer layer (402) is adjacent to the inner layer (404).

11. A packaging machine (500) for packaging food (FP), the packaging machine (500) comprising a packaging material receiver (502) configured to receive a packaging material (PM), the packaging material comprising a cellulose-based middle layer (400), an inner layer (404) configured to face the food (FP), and an outer layer (402), wherein an ink printing is provided on the outer layer (402). a curing device (506) configured to cure the inner layer (404), causing ink particles (302) located on the inner layer (404) to bond to the inner layer (404), thereby preventing the ink particles (302) from being released into the food (FP). a packaging former (508) configured to process the packaging material (PM) into a package (110), and a product filling device (510) configured to fill the food into the package (110).

12. The packaging machine (500) according to claim 11, wherein the curing device (506) comprises an ultraviolet (UV) lamp, an electron beam device, and / or a light emitting diode (LED) device.

13. The packaging machine (500) according to claim 11 or 12, wherein the curing device (506) is a curing and microorganism reducing device configured to simultaneously cure and reduce the number of microorganisms on the inner layer (404).

14. The packaging machine (500) according to claim 12, wherein, The packaging material (PM) is provided with a light blocking layer (412), the light blocking layer (412) being configured to allow light of a transmission wavelength to pass through, wherein the ultraviolet lamp, the electron beam device, and / or the LED device are configured to emit the light (414) of the transmission wavelength, thereby allowing the reduction of microorganisms on the outer layer (402) of the web (102) by the light (414) of the transmission wavelength passing through the packaging material (PM).

15. The packaging machine (500) according to claim 11 or 12 or 14, wherein the packaging material receiver (502) is a packaging material reel receiver arranged to receive the packaging material (PM) in the form of a reel (202b) having a wound web of packaging material (PM), wherein the packaging machine (500) further comprises a web feeder (504) arranged to unwind the web (102) from the reel (202b) and feed the web (102) downstream in the packaging machine (500).

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