Paper-plastic composite packaging bag and strength detection method thereof

Abstract

The application provides a paper-plastic composite packaging bag, which comprises a bag body, wherein the bag body comprises an outer paper layer and an inner paper layer, the outer paper layer is arranged on the outer side of the inner paper layer, and a reinforcing layer is arranged between the outer paper layer and the inner paper layer; a first plastic layer and a second plastic layer, the first plastic layer is arranged on the inner side of the inner paper layer, the second plastic layer is arranged on the inner side of the first plastic layer, and a buffer layer is arranged between the first plastic layer and the second plastic layer; and a film layer is arranged between the first plastic layer and the inner paper layer and is used for bonding the first plastic layer and the inner paper layer. The packaging bag has high strength and can provide collision buffering for products.

Description

Technical Field

[0001] This invention relates to the field of packaging bag design technology, and in particular to a paper-plastic composite packaging bag and its strength testing method. Background Technology

[0002] Packaging bags can be used to hold various media, such as sand and putty powder for building materials. There are many types of packaging bags on the market. Currently, paper-plastic composite packaging bags are the most common. These bags are made of paper and plastic. The paper material provides strength and printability, while the plastic material provides waterproof, moisture-proof, and oil-proof functions.

[0003] The existing invention patent, such as CN103407674A, entitled "A Method for Manufacturing Paper-Plastic Composite Packaging Bags", discloses the following steps: (1) preparing raw materials; (2) blown film process, through which resin particles are produced into PE film; (3) printing process, through which a substrate film is produced into a printed film; (4) labeling and laminating process, which includes a labeling process, a first laminating process, and a second laminating process. First, a labeling film is produced on the printed film through the labeling process to form a printed labeling film. Then, through the first laminating process, industrial typing paper and PE film are laminated for the first time. After natural curing, the printed labeling film is laminated with the first laminated film for the second time. After lamination, it is allowed to cure naturally; (5) slitting process, through which the naturally cured product is slitting and the finished product is put into storage.

[0004] Packaging bags produced in this way have low structural strength in actual use. They are prone to tearing, puncture, deformation and other damage during transportation, storage or use. Furthermore, they cannot effectively protect products from damage caused by external environmental factors such as pressure and impact when they are used to hold products. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a paper-plastic composite packaging bag and its strength testing method, which solves the technical problems mentioned in the background art regarding the low structural strength and relatively weak product protection of existing paper-plastic composite packaging bags.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] A paper-plastic composite packaging bag includes a bag body comprising an outer paper layer and an inner paper layer, the outer paper layer being disposed on the outer side of the inner paper layer, and a reinforcing layer being disposed between the outer paper layer and the inner paper layer; a first plastic layer and a second plastic layer, the first plastic layer being disposed on the inner side of the inner paper layer, the second plastic layer being disposed on the inner side of the first plastic layer, and a buffer layer being disposed between the first plastic layer and the second plastic layer; and a film layer, the film layer being disposed between the first plastic layer and the inner paper layer, and used to bond the first plastic layer and the inner paper layer together.

[0008] In a preferred embodiment of the present invention, the outer paper layer and the inner paper layer account for 50% to 60% of the bag body thickness, the first plastic layer and the second plastic layer account for 20% to 35% of the bag body thickness, and the film layer accounts for 5% to 15% of the bag body thickness.

[0009] In a preferred embodiment of the present invention, the reinforcing layer is made of glass fiber.

[0010] In a preferred embodiment of the present invention, the buffer layer is an expanded microsphere.

[0011] In a preferred embodiment of the present invention, the thin film layer is a PET film.

[0012] In a preferred embodiment of the present invention, an EVA layer is provided on the inner wall of the second plastic layer.

[0013] In a preferred embodiment of the present invention, the bottom of the bag is provided with a reinforcing seal.

[0014] In a preferred embodiment of the present invention, the side of the bag is provided with a plurality of windows, and the inner sidewall of the bag is provided with a plurality of transparent films, with each of the films corresponding to one of the windows.

[0015] In a preferred embodiment of the present invention, the diameter of the thin film is larger than the diameter of the window opening.

[0016] It also includes a method for testing the strength of paper-plastic composite packaging bags, performed in the following order:

[0017] S1. Pretreatment: Prepare several bags of the same size and shape, and clean and humidify the bags to ensure consistent test conditions.

[0018] S2. Tensile strength test: Use a universal testing machine to test the longitudinal and transverse tensile strength of the bag body, and record the tensile strength and elongation at break.

[0019] S3. Tear strength test: Use a tear strength tester to test the tear resistance of the bag when subjected to tearing force and record the tear strength index;

[0020] S4. Puncture resistance test: The puncture strength tester is used to test the puncture resistance of the bag when subjected to puncture force, and the puncture strength index is recorded.

[0021] S5. Leakage test: Use an airtightness testing machine to check the sealing and pressure resistance of the bag and record the leakage of the bag under different pressures.

[0022] Compared to the beneficial effects achieved by existing technologies:

[0023] The reinforcing layer effectively enhances the overall strength and compression resistance of the paper-plastic composite packaging bag, increasing its overall service life. The buffer layer not only further improves the overall strength and toughness of the packaging bag but also effectively protects the packaged product. The film layer effectively bonds the first plastic layer to the inner paper layer via thermal pressing.

[0024] This systematic strength testing method for paper-plastic composite packaging bags has advantages such as comprehensiveness, specificity, reliability, and continuity. This testing method can not only ensure product quality and safety, but also provide a scientific basis for continuous improvement and innovation of packaging technology, and has important practical value. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall external structure of an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the layered structure of the bag body of the present invention;

[0027] Figure 3 This is a partial structural diagram of the bag's interior.

[0028] Figure 4 This diagram illustrates the optimal thickness ratio between the packaging bag size and the various layers of the bag.

[0029] In the above figures: 1. Bag body; 2. Outer paper layer; 3. Inner paper layer; 4. Reinforcing layer; 5. First plastic layer; 6. Second plastic layer; 7. Buffer layer; 8. Film layer; 9. EVA layer; 10. Reinforcing seal; 11. Window; 12. Film sheet. Detailed Implementation

[0030] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Example:

[0032] Reference Figures 1-3This is a paper-plastic composite packaging bag, comprising a bag body 1. A reinforcing seal 10 is provided at the bottom of the bag body 1, which effectively increases the support strength of the bottom of the bag body 1 and helps users distinguish the top and bottom of the packaging bag. Several windows 11 are vertically opened on the side of the bag body 1, and several transparent films 12 are provided on the inner wall of the bag body 1. Each film 12 corresponds to one of the windows 11, and the diameter of the film 12 is larger than the diameter of the window 11. The vertical arrangement of multiple windows 11 allows personnel to directly observe the product contained inside the packaging bag from the outside. It is worth mentioning that the sidewall of the window 11 is covered with transparent sealant, preventing damage to the layered structure of the bag body 1 during use.

[0033] like Figure 2 As shown, the bag body 1 includes an outer paper layer 2 and an inner paper layer 3. The outer paper layer 2 is disposed on the outer side of the inner paper layer 3. A reinforcing layer 4 is provided between the outer paper layer 2 and the inner paper layer 3. The reinforcing layer 4 is made of glass fiber. It also includes a first plastic layer 5, a second plastic layer 6, and a film layer 8. The first plastic layer 5 is disposed on the inner side of the inner paper layer 3. The second plastic layer 6 is disposed on the inner side of the first plastic layer 5. A buffer layer 7 is provided between the first plastic layer 5 and the second plastic layer 6. The buffer layer 7 is an expandable microsphere. The expandable microsphere is a thermoplastic hollow polymer microsphere composed of a thermoplastic polymer shell and sealed liquid alkane gas. It is formed by extrusion and injection molding and added between the first plastic layer 5 and the second plastic layer 6. The film layer 8 is a PET film. The film layer 8 is disposed between the first plastic layer 5 and the inner paper layer 3 and is used to bond the first plastic layer 5 and the inner paper layer 3. The inner wall of the second plastic layer 6 is provided with a soft EVA layer 9. The EVA layer 9, as an inner lining, has good flexibility and elasticity, which can better conform to the surface of the package and enhance the wrapping effect. Except for the first plastic layer 5 and the inner paper layer 3, which are fixed by heat pressing with a film layer 8, the other layers are fixed by common adhesives.

[0034] like Figure 4 As shown, the outer paper layer 2 and the inner paper layer 3 account for 50% to 60% of the thickness of the bag body 1, the first plastic layer 5 and the second plastic layer 6 account for 20% to 35% of the thickness of the bag body 1, and the film layer 8 accounts for 5% to 15% of the thickness of the bag body 1. This arrangement allows for adjustment of the proportion of each layer according to different sizes of the packaging bag, so as to achieve the best overall strength and toughness of the packaging bag.

[0035] A method for testing the strength of paper-plastic composite packaging bags, comprising the following steps:

[0036] S1. Pretreatment: Prepare several bags 1 of the same size and shape, and clean and humidify the bags 1 to ensure that the test conditions are consistent.

[0037] S2. Tensile strength test: A universal testing machine is used, which mainly consists of a loading mechanism, a force measuring device, and a displacement measuring device. The loading mechanism is driven by an electric motor to apply tensile or compressive force. The force measuring device is used to monitor the force value acting on the bag body 1 in real time, and the displacement measuring device is used to record the deformation of the bag body 1. Its specific structure is existing technology and will not be described in detail in this article.

[0038] S3. Tear strength test: A tear strength tester is used, which mainly consists of a clamping device, a tearing fixture, and a force sensor. The clamping device fixes both ends of the bag body 1, the tearing fixture can apply a controlled tearing force to the bag body 1, and the force sensor monitors the force value change in real time during the tearing process and records the tear resistance of the bag body 1.

[0039] S4. Puncture resistance test: A puncture strength tester is used, including a puncture head, force sensor, support platform, etc. The puncture head impacts or punctures the bag body 1 vertically at a certain speed to test the puncture resistance of the bag body 1 when subjected to puncture force. The force sensor records the maximum puncture force during the puncture process.

[0040] S5. Leakage test: Using an airtightness testing machine, which mainly consists of a sealed cavity, a pressure regulating system, and a leakage detection device, bag 1 is placed in the sealed cavity. The pressure regulating system can apply or remove pressure, and the leakage detection device monitors the sealing performance of the sample under different pressures. The leakage situation of bag 1 under different pressures is recorded.

[0041] S6. Drop Test: Simulate the situation where bag 1, which carries products of different weights, is dropped during transportation. Check the structural integrity and record the damage to the appearance and contents of bag 1 after the drop.

[0042] S7. Dynamic fatigue test: Simulate the use of bag 1 under repeated stress or vibration, evaluate its durability, and record the deformation and damage of bag 1 under different cycles.

[0043] This systematic strength testing method for paper-plastic composite packaging bags has the following advantages:

[0044] Comprehensive: It includes tests for multiple key mechanical performance indicators such as tensile strength, tear strength, puncture resistance, sealing performance, drop resistance, and dynamic fatigue, which can comprehensively evaluate the overall strength performance of the packaging bag.

[0045] Targeted approach: Targeted test items and methods were designed based on the characteristics of paper-plastic composite packaging bags, which can more accurately reflect the strength requirements in actual use.

[0046] Reliability: Standardized testing equipment and procedures are used to ensure the repeatability and comparability of data, providing a reliable basis for product quality control.

[0047] Continuity: Testing is conducted in sequence from pretreatment to dynamic fatigue, which can better simulate the various mechanical loads that the packaging bag will experience throughout its entire life cycle.

[0048] Guidance: Through system testing, weak points in the packaging bag can be accurately identified, providing targeted improvement suggestions for optimizing design and material selection.

[0049] This comprehensive and standardized packaging bag strength testing system not only ensures product quality and safety, but also provides a scientific basis for continuous improvement and innovation of packaging technology, and has important practical value.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A paper-plastic composite packaging bag, characterized in that: Includes a bag body (1), said bag body (1) comprising, An outer paper layer (2) and an inner paper layer (3) are provided, wherein the outer paper layer (2) is disposed on the outer side of the inner paper layer (3), and a reinforcing layer (4) is provided between the outer paper layer (2) and the inner paper layer (3); A first plastic layer (5) and a second plastic layer (6), wherein the first plastic layer (5) is disposed on the inner side of the inner paper layer (3), and the second plastic layer (6) is disposed on the inner side of the first plastic layer (5), and a buffer layer (7) is provided between the first plastic layer (5) and the second plastic layer (6); A thin film layer (8) is disposed between the first plastic layer (5) and the inner paper layer (3) and is used to bond the first plastic layer (5) and the inner paper layer (3).

2. The paper-plastic composite packaging bag according to claim 1, characterized in that: The outer paper layer (2) and inner paper layer (3) account for 50% to 60% of the arc thickness of the bag body (1), the first plastic layer (5) and second plastic layer (6) account for 20% to 35% of the thickness of the bag body (1), and the film layer (8) accounts for 5% to 15% of the thickness of the bag body (1).

3. The paper-plastic composite packaging bag according to claim 1, characterized in that: The reinforcing layer (4) is made of glass fiber.

4. The paper-plastic composite packaging bag according to claim 1, characterized in that: The buffer layer (7) is an expanded microsphere.

5. A paper-plastic composite packaging bag according to claim 1, characterized in that: The film layer (8) is a PET film.

6. A paper-plastic composite packaging bag according to claim 1, characterized in that: The inner wall of the second plastic layer (6) is provided with an EVA layer (9).

7. A paper-plastic composite packaging bag according to claim 1, characterized in that: The bottom of the bag (1) is provided with a reinforcing seal (10).

8. A paper-plastic composite packaging bag according to claim 1, characterized in that: The bag body (1) has several vertically opened windows (11) on its side, and several transparent thin films (12) are provided on the inner wall of the bag body (1), with each of the several thin films (12) corresponding to one of the several windows (11).

9. A paper-plastic composite packaging bag according to claim 8, characterized in that: The diameter of the thin film (12) is directly larger than the diameter of the window (11).

10. The method for testing the strength of a paper-plastic composite packaging bag according to claim 1, characterized in that: Proceed in the following order: S1. Pretreatment: Prepare several bags (1) of the same size and shape, and clean and humidify the bags (1) to ensure that the test conditions are consistent. S2. Tensile strength test: Use a universal testing machine to test the longitudinal and transverse tensile strength of the bag body (1) and record the tensile strength and elongation at break. S3. Tear strength test: Use a tear strength tester to test the tear resistance of the bag (1) when subjected to tearing force and record the tear strength index. S4. Puncture resistance test: The puncture strength tester is used to test the puncture resistance of the bag (1) when subjected to puncture force, and the puncture strength index is recorded. S5. Leakage test: Use an airtightness tester to check the sealing and pressure resistance of the bag (1) and record the leakage of the bag (1) under different pressures.

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