Liquid packaging paperboard

Abstract

The utility model discloses a liquid packaging paperboard, which belongs to the technical field of packaging paperboards and comprises an inner protective layer, a blocking layer, a supporting layer and a printing layer which are sequentially arranged. The side face, making contact with the blocking layer, of the supporting layer is in a wave shape, the blocking layer and the inner protection layer are both in a wave shape, and the wave-shaped face of the supporting layer comprises wave crest parts and wave trough parts which are clamped and matched with each other. Two groups of first convex edges are arranged at transverse sealing positions, corresponding to two ends, of the corrugated surface of the supporting layer, are respectively positioned on the upper-layer paperboard and the lower-layer paperboard at the joint of the cylindrical liquid packaging paperboard, and are distributed in a staggered manner. When the end opening of the liquid packaging paperboard folded into the barrel shape is sealed, the corrugated surfaces of the two attached layers of liquid packaging paperboards are embedded with each other, a corrugated sealing surface is formed at the attaching position, tight attaching at the edge sealing position is achieved structurally, and the bonding stability can be improved by being matched with bonding of the inner protection layer.

Description

Technical Field

[0001] This utility model mainly relates to the field of packaging paperboard technology, specifically a liquid packaging paperboard. Background Technology

[0002] Liquid packaging paperboard is a multi-layered composite paperboard specifically designed for packaging liquid or semi-liquid products such as milk, juice, beverages, wine, soups, and oils. Traditionally, liquid packaging paperboard is typically composed of multiple layers, a design aimed at balancing cost, strength, printability, barrier properties, and processability.

[0003] Currently, most existing liquid packaging paperboards use a thermoforming process to seal the two ends of the cut and folded cylindrical liquid packaging paperboard. This process involves heating and applying pressure to melt the inner thermoplastic material of the sealing area of ​​the packaging paperboard. Under pressure, the material then impregnates, diffuses, and bonds with the material of adjacent sealing areas, forming a strong seal after cooling. However, the inner surface of existing liquid packaging paperboards is flat, and the connection and fixation of the two ends of the cylindrical liquid packaging paperboard relies solely on the inner layer adhesive, resulting in insufficient bonding stability. Utility Model Content

[0004] This utility model provides a solution that is significantly different from existing technologies, addressing the problem that existing solutions are too simplistic. It mainly provides a liquid packaging paperboard to solve the problem of insufficient port connection stability of existing liquid packaging paperboards mentioned in the background.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0006] A liquid packaging paperboard includes an inner protective layer, a barrier layer, a support layer, and a printing layer arranged sequentially; the side of the support layer that contacts the barrier layer is corrugated, and both the barrier layer and the inner protective layer are formed in a corrugated shape.

[0007] Furthermore, the waveform surface of the support layer includes mutually fitted crests and troughs.

[0008] Furthermore, on the wave surface of the support layer, there are two sets of first protrusions at the transverse sealing points at both ends. The two sets of first protrusions are located on the upper and lower cardboard at the bonding point of the cylindrical liquid packaging cardboard, respectively, and the two sets of first protrusions are staggered.

[0009] Furthermore, each group of first protrusions has at least one, and the length direction of the first protrusion is parallel to the extension direction of the support layer waveform.

[0010] Furthermore, the thickness of the first protrusion is less than the sum of the thicknesses of the barrier layer and the inner protective layer.

[0011] Furthermore, the first rib has a waveform in the transverse direction of the cardboard that adapts to the wave-shaped surface on the support layer.

[0012] Furthermore, a set of second protrusions is provided on the longitudinal sealing area on one side of the waveform surface of the support layer, and the number of second protrusions is at least one, with the length direction of the second protrusions perpendicular to the length direction of the first protrusions.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] (1) This utility model sets one side of the support layer in contact with the barrier layer as a wave shape. When the port of the liquid packaging cardboard folded into a cylindrical shape is sealed, the wave-shaped surfaces of the two layers of liquid packaging cardboard are interlocked, forming a wave-shaped sealing surface at the joint. Compared with the flat sealing surface in the prior art, this utility model achieves a tight fit at the sealing edge from a structural perspective. Combined with the bonding of the inner protective layer, it can improve the bonding stability. Furthermore, the wave structure extends the sealing contact area, which can disperse stress, improve peel strength and tear resistance, and better adapt to mechanical impacts in long-distance transportation or cold chain links.

[0015] (2) In the optimized solution of this utility model, a first protruding rib is provided at the transverse sealing and bonding point of the liquid packaging paperboard, forming a barrier perpendicular to the direction in which the liquid flows out from the port at the bonding point, and forming multiple "maze-like" sealing barriers in conjunction with the wave-shaped surface of the support layer, which can further ensure the sealing effect of the hot-pressed bonding point.

[0016] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the transverse cross-sectional structure of the present invention in Embodiment 1;

[0018] Figure 2 This is a schematic diagram showing the arrangement of the first protruding ridge in Embodiment 2 of the present invention;

[0019] Figure 3 This is a schematic diagram of the second protruding ridge in Embodiment 3 of this utility model.

[0020] Reference numerals: 1. Inner protective layer; 2. Barrier layer; 3. Support layer; 31. Crest; 32. Trough; 33. First ridge; 34. Second ridge; 4. Printed layer. Detailed Implementation

[0021] To facilitate understanding of this utility model, a more comprehensive description of the utility model will be given below with reference to the accompanying drawings, which show several embodiments of the utility model. However, the utility model can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the disclosure of the utility model more thorough and comprehensive.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] Example 1: Please refer to the appendix for details. Figure 1 A liquid packaging paperboard, comprising:

[0024] Inner protective layer 1, made of food-grade LDPE; its main functions are: direct contact with liquids to ensure food safety; heat sealing (lateral sealing) to form a packaging box; acid and oil resistance (to prevent milk components from corroding).

[0025] Barrier layer 2, made of aluminum foil, is used for long-term shelf-life packaging to block oxygen and light; or EVOH (ethylene-vinyl alcohol copolymer) is used for short-term shelf-life products to replace aluminum foil and improve recyclability; its main function is to completely block oxygen (the oxygen permeability of aluminum foil is <0.01 cm³ / m²·day), block ultraviolet rays, and prevent the oxidation of vitamins and fats in milk.

[0026] Support layer 3, made of bleached or unbleached chemical pulp paperboard, is used to maintain the rigid shape of the packaging box and provide mechanical strength (compression resistance, bending resistance).

[0027] Printed layer 4, consisting of a low-density polyethylene (LDPE) or polypropylene (PP) film plus a printed coating, is used to provide a colored printed surface (brand logo, product information, etc.) and to achieve moisture-proof and abrasion-proof protection. The LDPE / PP layer can be heat-sealed for longitudinal sealing of the packaging box.

[0028] In this embodiment, from the transverse cross-section of the cardboard, the side of the support layer 3 that contacts the barrier layer 2 is wavy, including a crest portion 31 and a trough portion 32, which fit together; the barrier layer 2 and the inner protective layer 1 are thus formed into a wavy shape.

[0029] In application, when sealing the ends (lateral sealing) of the liquid packaging cardboard folded into a cylindrical shape, the crest 31 of the upper cardboard at the bonding point is bonded to the trough 32 of the lower cardboard, and vice versa. The bonding is then achieved through the heat-sealing of the inner sheath 1, forming a corrugated sealing surface at the bonding point. On one hand, the corrugated surfaces of the two bonded liquid packaging cardboard layers interlock, structurally achieving a tight seal at the edge. Combined with the bonding of the inner sheath 1, this enhances bonding stability. On the other hand, by increasing the heat-sealing path length (the corrugated structure extends the sealing contact area), stress is dispersed, peel strength and tear resistance are improved, allowing for better resistance to mechanical impacts during long-distance transportation or cold chain processes.

[0030] Example 2: The difference between this example and Example 1 is that:

[0031] Please refer to the attached document carefully. Figure 2 In this embodiment, two sets of first ribs 33 are provided on the wave surface of the support layer 3 at the two ends of the cylindrical packaging box. The length direction of the first ribs 33 is parallel to the extension direction of the wave of the support layer 3. The two sets of first ribs 33 are respectively located on the upper and lower paperboards at the bonding point of the cylindrical liquid packaging paperboard. The number of each set of first ribs 33 is at least one, and the two sets of first ribs 33 are staggered. The thickness of the first ribs 33 is less than the sum of the thicknesses of the barrier layer 2 and the inner protective layer 1. The first ribs 33 have a wave shape in the transverse direction of the paperboard that is adapted to the wave surface of the support layer 3.

[0032] When applied, during heat-sealing of the ends of the liquid packaging cardboard folded into a cylindrical shape, the two layers of cardboard are bonded together. The first rib 33 forms a barrier perpendicular to the direction in which the liquid flows out from the end at the bonding point. At least two first ribs 33 and the corrugated surface of the support layer 3 cooperate to form multiple "maze-like" sealing barriers, which can further ensure the sealing effect of the heat-sealed bonding point.

[0033] Everything else is the same as in Example 1.

[0034] Example 3: The difference between this example and Example 2 is that:

[0035] Please refer to the attached document carefully. Figure 3 In this embodiment, a set of second ribs 34 is provided on the longitudinal sealing area on one side of the corrugated surface of the support layer 3. There is at least one set of second ribs 34, and the length direction of the second ribs 34 is perpendicular to the length direction of the first ribs 33. In application, when the overlap of a liquid packaging cardboard folded into a cylindrical shape is heat-sealed (longitudinal sealing), the two cardboard layers are bonded together. The second ribs 34 form a barrier at the bonding point, perpendicular to the direction in which the liquid flows out from the overlap, further ensuring the sealing effect of the heat-sealed joint.

[0036] Everything else is the same as in Example 2.

[0037] The present invention has been described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, shall be within the protection scope of the present invention.

Claims

1. A liquid packaging paperboard, comprising an inner protective layer (1), a barrier layer (2), a support layer (3), and a printing layer (4) arranged sequentially; characterized in that: The side of the support layer (3) that contacts the barrier layer (2) is wavy, and both the barrier layer (2) and the inner protective layer (1) are shaped as wavy.

2. The liquid packaging paperboard according to claim 1, characterized in that: The support layer (3) has a wave crest (31) and a wave trough (32) that fit together.

3. The liquid packaging paperboard according to claim 1, characterized in that: The support layer (3) has two sets of first ribs (33) on the wave surface corresponding to the transverse sealing points at both ends. The two sets of first ribs (33) are located on the upper and lower cardboard at the bonding point of the tubular liquid packaging cardboard, respectively, and the two sets of first ribs (33) are staggered.

4. A liquid packaging paperboard according to claim 3, characterized in that: The number of first protrusions (33) in each group is at least one, and the length direction of the first protrusions (33) is parallel to the extension direction of the waveform of the support layer (3).

5. A liquid packaging paperboard according to claim 4, characterized in that: The thickness of the first protrusion (33) is less than the sum of the thicknesses of the barrier layer (2) and the inner protective layer (1).

6. A liquid packaging paperboard according to claim 3, characterized in that: The first rib (33) has a waveform in the transverse direction of the cardboard that is adapted to the waveform surface on the support layer (3).

7. A liquid packaging paperboard according to claim 3, characterized in that: A set of second protrusions (34) is provided on the longitudinal sealing part of the corresponding side of the wave surface of the support layer (3). The number of second protrusions (34) is at least one, and the length direction of the second protrusion (34) is perpendicular to the length direction of the first protrusion (33).

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