Apparatus and method for digitally printing carton-based packaging material for packaging that holds liquid food products.
A compact apparatus and method for integrating digital printing into existing packaging machines addresses the challenge of modifying packaging machines by using a web supply assembly and shielding configuration to orient and cure ink on packaging materials, facilitating efficient production with minimal disruption.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TETRA LAVAL HOLDINGS & FINANCE SA
- Filing Date
- 2020-05-06
- Publication Date
- 2026-06-30
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing packaging machines require expensive modifications to integrate digital printing capabilities, limiting the flexibility and cost-effectiveness of transitioning from flexographic to digital printing for packaging materials.
A compact apparatus and method for digitally printing carton-based packaging materials that can be integrated into existing packaging machines with minimal modifications, utilizing a web supply assembly, print heads, curing devices, and a shielding configuration to orient and cure food-grade ink on the packaging material without disrupting the machine's operation.
Enables seamless integration of digital printing on existing packaging machines, reducing the need for extensive modifications and allowing for efficient production of printed packaging materials with minimal disruption to the production process.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention generally relates to the field of packaging technologies such as food packaging technology. More particularly, a method and apparatus for digitally printing a carton-based packaging material for a package that holds a liquid food product are presented.
Background Art
[0002] Today, it is generally known to use roll-fed packaging machines for various types of food products, such as milk. Roll-fed packaging machines, also called filling machines, have several advantages. One is that by continuously producing packages, a higher speed can be achieved compared to blank-fed packaging systems. Another advantage is that by continuously filling a tube of packaging material and forming packages at the lower end of the tube, the risk of unwanted microorganisms entering the packages can be reduced.
[0003] Packaging materials are today very often printed using so-called flexographic printing at packaging material production centers, sometimes called converting factories, for carton-based packaging materials. After being printed and prepared in other ways to hold food products, for example laminated such that an inner plastic layer is formed between the carton layer of the packaging material and the food product, the packaging material is wound onto a reel and transported to where the packaging machine is located.
[0004] For example, it has been proposed to use digital printing to print packaging materials instead of using flexographic printing and preparing the packaging materials at a packaging material production center. The advantage of using digital printing instead of flexographic printing is that smaller batches may be printed in a cost-effective manner.
[0005] While the use of digital printing for printing packaging materials is well-known, several challenges must be overcome. One of these challenges is designing equipment for digital printing so that it can be added to existing lines without requiring expensive modifications and reconstructions of the packaging machines and / or the buildings in which they are located. [Overview of the Initiative] [Problems that the invention aims to solve]
[0006] The objective is to overcome at least partially one or more of the limitations of the prior art identified above. Specifically, the objective is to provide a compact device for digitally printing packaging materials that can be added to existing packaging machines with little to no modification required. [Means for solving the problem]
[0007] According to a first aspect, an apparatus is provided for digitally printing carton-based packaging material for a package that holds a liquid food product, the packaging material having a first side adapted to form the outer surface of the package and a second side adapted to form the inner surface of the package, the apparatus comprising an inlet configured to receive a web of the packaging material with the normal vector of the first side oriented in a first direction, a web supply assembly arranged to supply the web from the inlet and through the apparatus, the web supply assembly comprising at least one drive unit and at least one web orientation device, and a print head arranged to supply food-grade ink onto the first side of the web A plurality of print bars, wherein the web supply assembly is arranged to rotate the web after it has been received through an inlet, with the normal vector of the first side facing a second direction and the first side facing the print head; a plurality of curing devices, each having a curing head arranged to cure food-grade ink supplied on the first side, wherein the web supply assembly is arranged to rotate the web after the food-grade ink has been supplied by the print head, with the normal vector of the first side facing a third direction and the first side facing the curing head; and an outlet configured to move the web of packaging material out of the device.
[0008] The print heads of multiple print bars may be oriented downwards, and / or the curing head of a curing device may be oriented upwards.
[0009] The apparatus may further include a shielding configuration that physically separates the print head and the hardening head so as to prevent energy radiated from the hardening head from reaching the print head.
[0010] The shielding configuration may form part of a web tension configuration that can provide the web being tensioned when ink is supplied by multiple printing bars and / or when the ink is cured by multiple curing devices.
[0011] At least some of the printing bars may be positioned above at least some of the curing devices.
[0012] The web supply assembly may be positioned such that a first slack of the web is formed downstream of the inlet and upstream of the multiple print bars, and / or a second slack of the web is formed downstream of the multiple curing devices and upstream of the outlet.
[0013] The curing head may use ultraviolet (UV) light.
[0014] According to a second aspect, a method is provided for digitally printing a carton-based packaging material for a package that holds a liquid food product, the packaging material having a first side adapted to form the outer surface of the package and a second side adapted to form the inner surface of the package, the method comprising receiving a web of the packaging material through an inlet with the normal vector of the first side oriented in a first direction, and supplying the web from the inlet and through the device by using a web supply assembly from the inlet and through the device, the web supply assembly comprising at least one drive unit and at least one web orientation device, and the normal vector of the first side The method includes: reorienting the web after it has been received through an inlet such that the culvert is oriented in a second direction and the first side faces the print heads of a plurality of print bars; providing food-grade ink onto the first side of the web by using a plurality of print bars equipped with print heads; reorienting the web after the food-grade ink has been provided by the print heads such that the normal vector of the first side is oriented in a third direction and the first side faces the curing heads of a plurality of curing devices; curing the food-grade ink provided onto the first side by using a plurality of curing devices equipped with curing heads; and moving the web out of the apparatus through an outlet.
[0015] The print heads of multiple print bars may be oriented downwards, and / or the curing head of a curing device may be oriented upwards.
[0016] The method may further include preventing energy radiated from the hardening head from reaching the print head by using a shielding configuration that physically separates the print head and the hardening head.
[0017] The method may further include stretching the web when ink is supplied by multiple printing bars and / or when the ink is cured by multiple curing devices by using a web tension configuration, wherein the shielding configuration forms part of the web tension configuration.
[0018] At least some of the printing bars may be positioned above at least some of the curing devices.
[0019] The method may further include compensating for changes in the speed of the apparatus by forming a first slack downstream of the inlet and upstream of the multiple print bars by using a web supply assembly, and / or by forming a second slack downstream of the multiple curing devices and upstream of the outlet by using a web supply assembly.
[0020] The curing head may use ultraviolet (UV) light.
[0021] According to a third aspect, a computer program product is provided which, when executed on a computer, includes instructions that cause the computer to perform the method according to the first aspect.
[0022] Further purposes, features, embodiments, and advantages will become apparent from the detailed description and drawings below.
[0023] Here, an embodiment will be described as an example with reference to the attached schematic diagram. [Brief explanation of the drawing]
[0024] [Figure 1] It is a general view of a roll - feeding packaging machine. [Figure 2a-2b] It is a side view of two embodiments of an apparatus for digitally printing a carton - based packaging material for a package holding a liquid food product. [Figure 3] It is a flowchart showing a method for digitally printing a carton - based packaging material.
Embodiments for Carrying out the Invention
[0025] Referring to FIG. 1, the packaging machine 100, which may also be called a filling machine, is generally shown as an example. The packaging machine 100 is a roll - feeding packaging machine used for packaging liquid food products in carton - based packages. Since the 1940s, this type of packaging machine has been introduced by Tetra Pak and is now a well - known method for packaging milk and other liquid food products in a safe and cost - effective manner. The general method can also be used for non - liquid food products such as potato chips.
[0026] Today, the packaging material is often printed and prepared at a packaging material production center, also called a converting factory, and transported to the location where the packaging machine 100 is placed, such as a dairy product manufacturing plant. Usually, the packaging material is wound onto a reel before being moved. After arriving at the site, the reel is placed inside the packaging machine as shown in FIG. 1.
[0027] During production, the web 102 of the packaging material can be fed from a reel through a packaging machine in the web feeding direction A. Although not shown in Figure 1, the packaging material may pass through a sterilization device, such as a hydrogen peroxide bath or an LVEB (low voltage electron beam) station, to ensure that the web 102 is free of unwanted microorganisms. Before serving the food product, the tube can be formed from the web 102 by forming a longitudinal seal. The food product may be fed into the tube via a pipe 104, and a valve 106 may be used to regulate the flow through the pipe 104. The lower end 108 of the tube can be fed into a folding device 110 where a transverse seal is created, and the tube is cut so that it can be folded along fold lines, also called weakening lines or creasing lines, to produce the package 112. Although the folding device 110 is shown as a single device, the folding device 110 may include multiple different devices.
[0028] Instead of printing the packaging material web 102 at a packaging material production center, i.e., printing it off-site, the web 102 can be printed on-site using digital printing within the apparatus 200, for example, as shown in Figures 2a and 2b. The apparatus 200 can be configured so that the web 102 is supplied into the packaging machine 100 via the apparatus 200.
[0029] The packaging material may be supplied into the apparatus 200 via a reel 202. The packaging material may be partially printed, that is, part of the packaging material may be printed at a packaging material production center, or the packaging material may not be printed so that all printing is performed by the apparatus 200.
[0030] The packaging material may be stacked on the reel 202 such that a first side 204, adapted to form the outer surface of the package 112, faces outward, and a second side 206, adapted to form the inner surface of the package 112, faces inward. The web 102 can be fed into the apparatus 200 through the inlet 207 with the first side 204 facing downward.
[0031] In apparatus 200, the web 102 may be fed forward by a web feeding assembly. The web feeding assembly may include a first roller 208a, a second roller 208b, a third roller 208c or any other type of web oriented device and a first drive unit 210, which together provide that the web is not only fed through apparatus 200 but also removed from reel 202. To compensate that different steps in apparatus 200 may be required over different periods of time on different occasions, the web 102 may form a first slack 212 downstream of the first drive unit 210. The first slack 212 may be formed between the inlet 207 and the pre-processing device 214.
[0032] From the first slack 212, the web 102 may be fed into a pre-processing device 214, where the packaging material is pre-processed so that printing can be performed at a series of stations downstream of the pre-processing device 214. As shown, printing may be provided by using a plurality of print bars, four print bars 216a, 216b, 216c, and 216d as an example herein, in combination with a plurality of pinning devices that provide initial curing, four pinning devices 217a, 217b, 217c, and 217d as an example herein. The print bars 216a, 216b, 216c, and 216d may be equipped with downward-facing print heads so that they can provide that the first side 204 is printed with food-grade ink as it passes through the print bar.
[0033] As shown in Figure 2a, after printing, the web may be rotated so that the first side 204 faces downward. Food-grade ink provided by printing bars 216a, 216b, 216c can be cured by using multiple curing devices, three curing devices 218a, 218b, and 218c as an example herein. Curing devices 218a, 218b, and 218c may have an upward-facing curing head so that the curing head faces the first side 204 of the packaging material. The curing energy of the curing devices 218a, 218b, and 218c may be, for example, an electron beam or UV light.
[0034] The web 102 may be rotated by using a fourth roller 219 or any other type of web orientation device positioned downstream of the print bars 216a, 216b, 216c, 216d and upstream of the curing devices 218a, 218b, 218c. The fourth roller 219 may also form part of a web tension configuration 220 that can be used to provide tension to the web 102 as it is printed, pinned, and / or cured, and / or the fourth roller 219 may also form part of a web supply assembly.
[0035] The web tension configuration 220 may include a shielding configuration 222 that prevents, for example, UV light radiation from the curing devices 218a, 218b, 218c from reaching the print heads of the print bars 216a, 216b, 216c, 216d. The shielding configuration 222 may be, for example, a metal plate placed between the curing head and the print head.
[0036] The web tension configuration 220 may be implemented in various ways. For example, as shown in Figures 2a and 2b, the web 102 is tensed or relaxed.
[0037] After curing, the web 102 is fed into a second slack 226 via a second drive unit 224 which can form part of the web supply assembly, and can then exit the device 200 via an outlet 227. The advantage of the second slack 224 is that it allows for compensation of not only slight stops in the downstream packaging machine 100, but also speed changes within the device 200.
[0038] A general advantage of the apparatus 200 is that the printing bars 216a, 216a, 216c, and 216d can be placed above the curing devices 218a, 218b, and 218c, thereby enabling a compact design. Furthermore, by reorienting the web twice, the packaging material can be supplied in the same manner as today, i.e., supplied onto the reel 202 with the first side 204 facing outward, and the packaging machine 100 can also supply in the same manner as today, i.e., receive the web with the first side 204 facing downward. Thus, another advantage of the design is that little to no modifications are needed in the packaging machine 100 and the packaging material production center.
[0039] As shown in Figure 2a and as described above, the web 102 may be rotated 180 degrees after passing the print head and before passing the curing head so that, for example, the print bars 216a, 216b, 216c, and 216d can be positioned above the curing devices 218a, 218b, and 218c. In other words, the normal vector of the first side 204 may be directed in a first direction D1 when supplied into the apparatus 200 via the inlet 207. By using the web supply assembly, the web 102 may be reoriented so that its normal vector is directed in a second direction D2 when it reaches the print heads of the print bars 216a, 216b, 216c, and 216d. After printing, i.e., downstream of the print head, the web 102 may be reoriented so that the normal vector of the first side 204 is directed in a third direction D3. If the printing bar is positioned above the curing device as shown in Figure 2a, the second direction D2 and the third direction D3 may be presented as two opposing directions, i.e., 180 degrees apart from each other.
[0040] Figure 2b shows another example of how the apparatus may be designed. In the example shown in Figure 2b, the print bars 216a, 216b, 216c, and 216d may be positioned so that the print heads are facing downwards, alongside the print heads of the apparatus 200 shown in Figure 2a. However, unlike the apparatus 200 shown in Figure 2a, the curing devices 218a, 218b, and 218c are positioned so that the curing heads are facing horizontally, so that the web 102 can be cured while it is moving vertically, and more specifically downwards in this example. In other words, instead of reorienting the web 102 so that the normal vector of the first side 204 is moved 180 degrees, as shown in Figure 2a, the normal vector is reoriented by 90 degrees.
[0041] Furthermore, although not shown, it is also possible to position both the print bars 216a, 216b, 216c, 216d and the curing devices 218a, 218b, 218c horizontally and facing each other, and to reorient the web by 180 degrees downstream of the print bars 216a, 216b, 216c, 216d and upstream of the curing devices 218a, 218b, 218c.
[0042] The above example relates to reorienting the normal vector by 90 or 180 degrees downstream of the print head and upstream of the hardening head, but this is merely an example, and it should be understood that the web 102 may be oriented in ways other than these specific examples, e.g., by a few small steps less than 90 degrees.
[0043] Figure 3 presents a flowchart illustrating a method for digitally printing carton-based packaging material for a package 112 that holds a liquid food product, as an example. In the first step 302, the web 102 may be received with the normal vector of the first side 204 oriented in a first direction D1. In the second step 304, the web may be supplied through the apparatus 200. In the third step 306, the web 102 may be reoriented so that the normal vector of the first side oriented in a direction D2. In the fourth step 308, ink may be supplied onto the first side 204 by print bars 216a, 216b, 216c, 216d equipped with print heads. Then, in the fifth step 310, the web 102 may be reoriented so that the normal vector of the first side oriented in a third direction D3. In the sixth step 312, the ink applied to the first side 204 may be cured by curing devices 218a, 218b, 218c equipped with curing heads. In the seventh step 314, the web may be moved out of the apparatus 200.
[0044] Optionally, in the eighth step 316, the energy radiated from the curing devices 318a, 318b, and 318c may be prevented from reaching the print head by the shielding configuration 222.
[0045] Optionally, in step 9 318, the web may be stretched during printing and / or curing by the web tension configuration 220. The shielding configuration 222 may form part of this web tension configuration 220.
[0046] Optionally, in the tenth step 320, the first slack 212 may be formed such that changes in velocity within the apparatus 200 can be compensated for.
[0047] Optionally, in the eleventh step 322, the second slack 226 may be formed such that changes in velocity within the apparatus 200 can be compensated for.
[0048] While the steps are listed in a specific order, please understand that the stopping process does not necessarily have to follow this sequence.
[0049] While various embodiments of the present invention have been described and demonstrated above, the present invention is not limited thereto and may be embodied in other ways within the scope of the subject matter defined in the following claims.
Claims
1. Apparatus (200) for digitally printing on carton-based packaging material for a package (112) that holds liquid food products, The packaging material has a first side surface (204) adapted to form the outer surface of the package (112) and a second side surface (206) adapted to form the inner surface of the package (112). The aforementioned device (200) An inlet (207) configured to receive the web (102) of the packaging material with the normal vector of the first side surface (204) oriented in a first direction (D1), A web supply assembly (208a, 208b, 208c, 210, 219, 224) arranged to supply the web (102) from the inlet (207) and through the device (200), the web supply assembly (208a, 208b, 208c, 210, 219, 224) comprising at least one drive unit (210, 224) and at least one web orientation device (208a, 208b, 208c, 219), A plurality of print bars (216a, 216b, 216c, 216d) having print heads positioned to supply food-grade ink onto the first side surface (204) of the web (102), wherein the web supply assembly (208a, 208b, 208c, 210, 219, 224) is positioned to rotate the web (102) after it has been received through the inlet (207) such that the normal vector of the first side surface (204) is oriented in a second direction (D2) and the first side surface (204) faces the print head, A plurality of curing devices (218a, 218b, 218c) having curing heads arranged to cure the food-grade ink provided on the first side surface (204), wherein the web supply assembly (208a, 208b, 208c, 210, 219, 224) is arranged to rotate the web (102) after the food-grade ink has been supplied by the print head such that the normal vector of the first side surface (204) is oriented in a third direction (D3) and the first side surface (204) faces the curing head, An outlet (227) configured to move the web (102) of the packaging material out of the device (200). Includes, The shielding configuration (222) further includes a shielding configuration that physically separates the print head and the hardening head so as to prevent energy radiated from the hardening head from reaching the print head. Device (200).
2. The apparatus according to claim 1, wherein the print heads of the plurality of print bars (216a, 216b, 216c, 216d) are directed downward, and / or the curing head of the curing device (218a, 218b, 218c) is directed upward.
3. The apparatus according to claim 1, wherein the shielding configuration (222) forms part of a web tension configuration (220) that provides the web to be tensioned when the ink is provided by the plurality of printing bars or when the ink is cured by the plurality of curing devices.
4. The apparatus according to claim 1, wherein the shielding configuration (222) forms part of a web tensioning configuration (220) that provides tension to the web when the ink is provided by the plurality of printing bars and when the ink is cured by the plurality of curing devices.
5. The apparatus according to any one of claims 1 to 4, wherein at least a portion of the plurality of printing bars (216a, 216b, 216c, 216d) is placed above at least a portion of the plurality of curing devices (218a, 218b, 218c).
6. The apparatus according to any one of claims 1 to 5, wherein the web supply assemblies (208a, 208b, 208c, 210, 219, 224) are arranged such that a first slack (212) of the web (102) is formed downstream of the inlet (207) and upstream of the plurality of print bars (216, 216b, 216c, 216d), and / or a second slack (226) of the web (102) is formed downstream of the plurality of curing devices (218a, 218b, 218c) and upstream of the outlet (227).
7. The apparatus according to any one of claims 1 to 6, wherein the curing head is ultraviolet (UV) light.
8. A method (300) for digitally printing on carton-based packaging material for a package (112) that holds liquid food products, The packaging material has a first side surface (204) adapted to form the outer surface of the package (112) and a second side surface (206) adapted to form the inner surface of the package (112). The above method (300) is, The web (102) of the packaging material is received (302) through the entrance (207) with the normal vector of the first side surface (204) oriented in the first direction (D1), The web (102) is supplied (304) from the inlet (207) and through the device (200) using web supply assemblies (208a, 208b, 208c, 210, 219, 224), wherein the web supply assemblies (208a, 208b, 208c, 210, 219, 224) include at least one drive unit (210, 224) and at least one web orientation device (208a, 208b, 208c, 219), Reorienting the web (102) after it has been received through the inlet (207) (306) such that the normal vector of the first side surface (204) is oriented in the second direction (D2) and the first side surface (204) is oriented toward the print heads of the plurality of print bars (216a, 216b, 216c), By using the plurality of print bars (216a, 216b, 216c, 216d) equipped with the print head, food-grade ink is provided on the first side surface (204) of the web (102) (308), Reorienting the web (102) after the food-grade ink has been supplied by the print head (310) such that the normal vector of the first side surface (204) is oriented in a third direction (D3) and the first side surface (204) is oriented toward the curing heads of a plurality of curing devices (218a, 218b, 218c), By using the plurality of curing devices (218a, 218b, 218c) equipped with the curing head, the food-grade ink provided on the first side surface (204) is cured (312), Moving the web (102) out of the device (200) via the exit (227) (314) Includes, The further includes using a shielding configuration (222) that physically separates the print head and the hardening head, thereby preventing energy radiated from the hardening head from reaching the print head (316), Method (300).
9. The method according to claim 8, wherein the print heads of the plurality of print bars (216a, 216b, 216c, 216d) are pointed downward, and / or the curing head of the curing device (218a, 218b, 218c) is pointed upward.
10. The method of claim 8, further comprising tensing the web (102) by using a web tension configuration (224) when the ink is supplied by the plurality of printing bars (216a, 216b, 216c, 216d) or when the ink is cured by the plurality of curing devices (218a, 218b, 218c), wherein the shielding configuration (222) forms part of the web tension configuration (224).
11. The method of claim 8, further comprising tensing the web (102) by using a web tension configuration (224) when the ink is supplied by the plurality of printing bars (216a, 216b, 216c, 216d) and when the ink is cured by the plurality of curing devices (218a, 218b, 218c), wherein the shielding configuration (222) forms part of the web tension configuration (224).
12. The method according to any one of claims 8 to 11, wherein at least a portion of the plurality of printing bars (216a, 216b, 216c, 216d) is placed above at least a portion of the plurality of curing devices (218a, 218b, 218c).
13. The method according to any one of claims 8 to 12, further comprising compensating for changes in the speed of the apparatus (200) by forming a first slack (212) downstream of the inlet (207) and upstream of the plurality of print bars (216a, 216b, 216c, 216d) by using the web supply assemblies (208a, 208b, 208c, 210, 219, 224) and / or forming a second slack (226) downstream of the plurality of curing devices (218a, 218b, 218c) and upstream of the outlet (227) by using the web supply assemblies (208a, 208b, 208c, 210, 219, 224) (320).
14. The method according to any one of claims 8 to 13, wherein the curing head is ultraviolet (UV) light.
15. The apparatus according to claim 1, further comprising a plurality of pinning devices (217a, 217b, 217c, 217d) used in combination with the plurality of printing bars (216a, 216b, 216c, 216d).
16. The apparatus according to claim 1, wherein the shielding configuration (222) comprises a metal plate placed between the hardening head and the printing head, the plurality of printing bars (216a, 216b, 216c, 216d) are arranged on one side of the metal plate, and the plurality of hardening devices (218a, 218b, 218c) are arranged on the other side of the metal plate.
17. The apparatus according to claim 1, wherein the shielding configuration (222) comprises first and second metal plates placed between the hardening head and the printing head, the plurality of printing bars (216a, 216b, 216c, 216d) are arranged on one side of the first metal plate, the plurality of hardening devices (218a, 218b, 218c) are arranged on one side of the second metal plate, and the angle between the normal vector of the first metal plate and the normal vector of the second metal plate is 90 degrees.