Leakproof double-layered bulk bag

Abstract

The application discloses a leakproof double-layer packing bag, in particular to a packing bag for powder packaging. The application aims to provide a leakproof double-layer packing bag with simple structure and convenient processing. The packing bag comprises an outer bag (1) and an inner bag (2) arranged in the outer bag (1). The outer bag (1) is provided with an outer sling (6). The inner bag (2) is provided with a feeding port (4) and a discharging port (5). The inner bag (2) is composed of an upper inner bag (21) at the upper part and a lower inner bag (22) at the lower part. The upper inner bag (21) and the lower inner bag (22) are connected by a bonding surface (231) to form a connecting part (23). The connecting part (23) is sewn with the outer bag (1) by sewing thread (8). The leakproof double-layer packing bag has simple structure, low production cost and good leakproof effect on powder materials. The discharging speed is improved, and powder materials are not left in the inner bag.

Description

Technical Field

[0001] This invention relates to bulk bags, and more particularly to bulk bags for powder packaging. Background Technology

[0002] FIBCs (Flexible Intermediate Bulk Containers) are widely used for product packaging in industries such as metallurgy and chemicals. With the development and changes in market demand, powder products with high requirements for moisture and leakage prevention often use double-layer packaging: an inner plastic bag and an outer paper or woven material to meet the requirements of filling, transportation, and unloading. However, the inner and outer layers need to be connected to each other to prevent incomplete unloading of powder material during filling and unloading due to twisting or wrinkling between the inner and outer layers. Currently, there are two main methods for connecting the inner and outer layers:

[0003] Firstly, the inner and outer layers are sewn together, but for particularly fine powders, leakage can easily occur from the stitches. For example, in a leak-proof plastic container bag disclosed in CN212830437U, the side of the leak-proof layer is folded upward and sewn to the side wall of the bag body.

[0004] Secondly, CN218260026U discloses a leak-proof container bag with an inner bag layer and an outer bag layer structure. An adhesive layer and a leak-proof film are evenly arranged between the outer bag layer and the inner bag layer. Although it can achieve the purpose of preventing leakage, the container bag is complicated to process and harmful volatile gases are generated during the processing, which can harm the health of workers. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a leak-proof double-layer container bag that is simple in structure and easy to process.

[0006] The leak-proof double-layer container bag used in this invention to solve its technical problem includes an outer bag and an inner bag disposed therein. The outer bag is provided with an outer lifting strap, and the inner bag is provided with an inlet and an outlet. The inner bag is composed of an upper inner bag and a lower inner bag, which are connected by an adhesive surface. The connecting part is sewn together with the outer bag using sewing thread.

[0007] Furthermore, the adhesive surfaces are bonded using adhesive or heat sealing.

[0008] Furthermore, an inner sling is provided on the upper inner side of the outer bag 1; after the powder material is filled, the inner sling is looped or tied tightly to the feed inlet.

[0009] Furthermore, the inner slings are connected to the upper corner of the inner side of the outer bag, and there are 2 to 4 slings evenly distributed.

[0010] Furthermore, the adhesive surface of the inner bag is located below the center line of the inner bag.

[0011] Furthermore, the height ratio of the upper inner bag to the lower inner bag is 1:0.6 to 0.3.

[0012] Furthermore, the complete bag body is cut along the adhesive surface 231 to form an upper inner bag and a lower inner bag.

[0013] The leak-proof double-layer container bag of this invention has a simple structure, low production cost, and good leak-proof effect for powder materials. It improves unloading speed while ensuring complete unloading, preventing powder material from remaining in the inner bag. Attached Figure Description

[0014] Figure 1 This is a cross-sectional schematic diagram of the inner bag structure of the present invention;

[0015] Figure 2 This is a schematic diagram of the double-layer container bag structure of the present invention;

[0016] Figure 3 This is a schematic diagram of the loading status of double-layer container bags;

[0017] Figure 4 This is a schematic diagram of the unloading status of a double-layer container bag.

[0018] Explanation of reference numerals in the attached drawings: 1-Outer bag, 2-Inner bag, 21-Upper inner bag, 22-Lower inner bag, 23-Connecting part, 231-Adhesive surface, 31-Lower side of upper inner bag, 32-Upper side of lower inner bag, 4-Inlet, 41-Upper strap, 5-Outlet, 51-Lower strap, 6-Outer strap, 7-Inner strap, 8-Sewing thread. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings.

[0020] The container bag of the present invention, such as Figure 2 As shown, it includes an outer bag 1 and an inner bag 2. The upper part of the outer bag 1 is equipped with external lifting straps 6 for easy hoisting, and the inner bag 2 is equipped with an inlet 4 and an outlet 5. The inner bag 2 is as follows... Figure 1 As shown, the inner bag 21 consists of an upper inner bag 21 and a lower inner bag 22. A connecting portion 23, formed by the adhesive surfaces 231 of the lower inner bag 31 of the upper inner bag 21 and the upper inner bag 32 of the lower inner bag 22, connects the upper inner bag 21 and the lower inner bag 22 into a single unit with an internal cavity. The adhesive surfaces 231 are bonded using adhesive or heat sealing. The connecting portion 23 of the inner bag 2 is sewn to the outer bag 1 using sewing thread 8. Because the adhesive surface 231 of the connecting portion 23 has a certain width, and the sewing thread 8 is positioned in the middle of the adhesive surface 231, the powder material in the inner bag 2 is blocked by the adhesive surface 231 and cannot leak outwards through the sewing stitches of the sewing thread 8.

[0021] like Figure 3As shown, during the filling process of the double-layer container bag, the outlet 5 of the inner bag 2 is secured with the lower strap 51, and the powder material is poured into the cavity of the inner bag 2 through the inlet 4. After filling, the inlet 4 is secured with the upper strap 41, completing the packaging. The double-layer container bag can be lifted by lifting equipment or a forklift using the outer lifting strap 6 set on the outer bag 1 for easy transportation.

[0022] When double-layered container bags filled with powder materials are transported to the usage site, and the powder materials need to be unloaded, such as Figure 4 As shown, the double-layer container bag is lifted using hoisting equipment or a forklift via the outer sling 6. The discharge port 5 is opened, and the powder material is discharged downwards from the discharge port 5 by its own gravity using the lower strap 51. This completes the entire process of filling, transporting, and unloading the powder material.

[0023] During the unloading process described above, due to the weight of the powder material, the inner bag 2 will sink and collapse as the powder material decreases, thus reducing the unloading speed and potentially leaving some powder material in the inner bag 2, resulting in incomplete unloading. Therefore, an inner lifting strap 7 is installed on the upper inner side of the outer bag 1. During the unloading process, the inner lifting strap 7 is connected to the upper part of the inner bag 2, lifting the inner bag 2 to prevent it from sinking with the powder material, ensuring the outlet 5 remains unobstructed, increasing the unloading speed, and ensuring complete unloading. (See attached...) Figure 2 , 3 As shown in Figure 4, the outer bag 1 has a square cross-section, so the inner lifting strap 7 is connected to the upper corner of the inner side of the outer bag 1, and there are 2 to 4 evenly arranged straps. After the powder material is filled and the upper binding strap 41 is tightened, the inner lifting strap 7 is looped or tied to the feed inlet 4, which can both lift the inner bag 2 and enhance the tightening effect of the feed inlet 4.

[0024] When the powdered material is unloaded, the adhesive surface 231 of the upper inner bag 21 and the lower inner bag 22 of the inner bag 2 is subjected to the gravity of the powdered material, and the adhesive surface 231 is at risk of being torn. In order to reduce this risk, the adhesive surface 231 is set below the center line of the height of the inner bag 2. The preferred structure is that the height ratio of the upper inner bag 21 to the lower inner bag 22 is 1:0.6 to 0.3. In this way, the weight of the powdered material in the lower inner bag 22 is reduced accordingly, and the tension on the adhesive surface 231 is also reduced accordingly.

[0025] When making the upper inner bag 21 and the lower inner bag 22, the inner bag 2 is first made into a complete bag body using existing bag body production equipment and processes. The complete bag body is then cut along the adhesive surface 231 to form the upper inner bag 21 and the lower inner bag 22. Therefore, the production of the inner bag body does not require additional material costs.

Claims

1. A leak-proof double-layer container bag, comprising an outer bag (1) and an inner bag (2) disposed therein, wherein the outer bag (1) is provided with an outer lifting strap (6), and the inner bag (2) is provided with an inlet (4) and an outlet (5), characterized in that: The inner bag (2) consists of an upper inner bag (21) and a lower inner bag (22). The upper inner bag (21) and the lower inner bag (22) are bonded together by an adhesive surface (231) to form a ring-shaped connecting part (23). The connecting part (23) is located inside the outer bag (1) and is sewn together with the inner wall of the outer bag (1) by a sewing thread (8). The sewing thread (8) is located in the middle of the adhesive surface (231) and is arranged around the circumference of the connecting part (23). The outer bag (1) is an integral structure. The outer bag (1) has a cavity for accommodating the inner bag (2). The top of the outer bag (1) is provided with a first inlet communicating with the cavity, and the bottom of the outer bag (1) is provided with a first outlet communicating with the cavity. The two ends of the inner bag (2) extend from the first inlet and the first outlet respectively, and the inner wall of the outer bag (1) is attached to the two ends of the inner bag (2).

2. The leak-proof double-layer container bag as described in claim 1, characterized in that: The adhesive surface (231) is bonded by adhesive or by heat sealing.

3. The leak-proof double-layer container bag as described in claim 1 or 2, characterized in that: The upper inner side of the outer bag (1) is provided with an inner sling (7); after the powder material is filled, the inner sling (7) is wrapped or tied to the feed inlet (4).

4. The leak-proof double-layer container bag as described in claim 3, characterized in that: The inner strap (7) is connected to the upper corner of the inner side of the outer bag (1), and there are 2 to 4 straps evenly arranged.

5. The leak-proof double-layer container bag as described in claim 1, characterized in that: The adhesive surface (231) is located below the height center line of the inner bag (2).

6. The leak-proof double-layer container bag as described in claim 5, characterized in that: The height ratio of the upper inner bag (21) to the lower inner bag (22) is 1:0.6 to 0.

3.

7. The leak-proof double-layer container bag as described in claim 1, characterized in that: The complete bag body is cut along the adhesive surface (231) to form an upper inner bag (21) and a lower inner bag (22).

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