An asymmetric lamination valve port packaging bag

Abstract

This invention discloses an asymmetric stacked valve-sealed packaging bag, belonging to the field of packaging bag technology. It includes a bag body, the front side of which is composed of at least two layers of valve plates stacked together, including an inner valve plate on the inner side and an outer valve plate on the outer side. The lateral width of the inner valve plate is smaller than the total lateral width of the front side, covering only a portion of the front side. The lateral width of the outer valve plate is close to and slightly smaller than the total lateral width of the front side, essentially covering the entire front side. Both the inner and outer valve plates are vertically divided into an upper section and a lower section. In the lower section, the lower sections of the inner and outer valve plates are pressed together to form a sealing compression part, which contains a venting microchannel connecting the inner cavity of the bag to the outside. In the upper section, the upper sections of the inner and outer valve plates are in a non-sealed free contact state, forming a lateral feed inlet.

Description

Technical Field

[0001] This invention relates to the field of packaging bag technology, specifically to a valve-mouth packaging bag for filling powdery or granular materials, and more particularly to a packaging bag with an asymmetric stacked valve structure that also has automatic sealing and venting functions. Background Technology

[0002] Valve bags are widely used for packaging powdery or granular materials such as chemical raw materials, building materials, food ingredients, and pharmaceutical intermediates due to their advantages such as suitability for automated filling, accurate metering, and low labor costs. Existing valve bags are usually made of tubular film material through processes such as M-folding, edge insertion, and sealing. The valve opening is generally formed on the side of the bag body, which is formed by overlapping and partially sealing the upper film of the left and right halves of the bag body.

[0003] For example, patent document US4566131A discloses a plastic film side-valve bag, the bag body of which is composed of left and right M-shaped half-bags. The upper bag film of the left half-bag overlaps with that of the right half-bag and is partially sealed along the sealing strip, forming a lateral valve opening between the front sealing edge and the sealing point. During filling, the material is filled through the valve opening, and after the bag body expands, the upper bag film passively adheres to achieve automatic sealing. Patent document CN104590673A also discloses a similar side-valve bag and its bag-making equipment, which uses a complex folding mechanism and an inserting mechanism to fold the film material multiple times to form the valve opening structure.

[0004] However, the existing technologies mentioned above have the following shortcomings: First, the formation of the valve opening is highly dependent on the M-shaped folding process of the bag body, which requires the configuration of a complex folding frame and insertion mechanism. The bag making equipment is costly and difficult to debug, and the folding accuracy directly affects the consistency and sealing of the valve opening. Second, most existing valve bags lack a dedicated venting structure, making it difficult for gas inside the bag to be effectively discharged, resulting in the bag body bulging after filling. This not only affects the stability of stacking, but also makes the material susceptible to moisture and deterioration due to residual air. Although some solutions use multi-layer film staggered perforation to achieve air permeability, they require additional perforation and staggered bonding processes, which are complex. Furthermore, the straight-through venting holes are easily blocked by powdery materials or cause material leakage.

[0005] Therefore, it is necessary to provide a valve-type packaging bag that is simple in structure, low in manufacturing cost, and has both automatic sealing and reliable venting functions. Summary of the Invention

[0006] 1. Technical problem to be solved: The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and provide an asymmetric stacked valve-mouth packaging bag. This packaging bag uses an asymmetric stacking structure of valve plates of unequal width to form a lateral feed port, achieving the valve port construction without the need for a complex M-shaped folding process. Simultaneously, a venting microchannel is integrated within the lower sealing area, combining automatic sealing and venting functions, and preventing material leakage during the venting process.

[0007] 2. Technical Solution: To solve the above problems, the present invention adopts the following technical solution.

[0008] An asymmetric stacked valve-sealed packaging bag includes a bag body having a front side, a rear side, a left side, a right side, a top surface, and a bottom surface. The front side is formed by at least two layers of valve sheets stacked together, including an inner valve sheet located on the inner side and an outer valve sheet located on the outer side. The lateral width of the inner valve sheet is smaller than the total lateral width of the front side, and the inner valve sheet extends from the left edge of the bag body to the right, covering only a portion of the front side. The lateral width of the outer valve sheet is smaller than the total lateral width of the front side, and the outer valve sheet covers the outer side of the inner valve sheet and substantially covers the entire front side. The outer valve sheet... A ventilated structure is provided, which is set corresponding to the coverage area of ​​the inner valve plate, and is used to connect the inner cavity of the bag body with the interlayer space between the inner valve plate and the outer valve plate; the inner valve plate and the outer valve plate are each divided into an upper section and a lower section in the vertical direction; in the lower section, the lower section of the inner valve plate and the lower section of the outer valve plate are pressed together to form a sealed pressing part, and the sealed pressing part has at least one venting microchannel connecting the inner cavity of the bag body with the outside atmosphere; in the upper section, the upper section of the inner valve plate and the upper section of the outer valve plate are in a non-sealed free contact state, and the gap between them constitutes a lateral feed port.

[0009] Furthermore, the lateral coverage width of the inner valve plate is 1 / 4 to 1 / 3 of the total lateral width of the front side. This ratio range ensures that the lateral feed inlet has sufficient guiding space for the filling tube to be inserted, and also ensures that the inner valve plate provides sufficient passive contact area to achieve reliable sealing when the bag expands.

[0010] Furthermore, the venting microchannel is paperclip-shaped or labyrinth-shaped, and is defined by the unpressurized area within the sealing and pressing part. The tortuous channel shape effectively extends the gas discharge path, while utilizing the kinetic energy attenuation and natural accumulation effect of particulate material at the channel turning points to achieve venting and prevent material leakage.

[0011] Furthermore, the breathable structure comprises multiple breathable micropores formed on the outer valve plate and corresponding to the area covered by the inner valve plate. The breathable micropores penetrate the outer valve plate and are used to connect the inner cavity of the bag with the interlayer space between the inner and outer valve plates.

[0012] Furthermore, the width of the venting microchannel is between 0.1 mm and 2 mm. This size range allows air molecules to pass freely, while powdery or granular materials with a particle size greater than 0.05 mm are effectively blocked due to the abrupt change in the channel cross-section and the mutual compression between particles.

[0013] Furthermore, the bag body, inner valve plate, and outer valve plate are all made of moisture-proof material. The moisture-proof material can be polyethylene, polypropylene, composite plastic film, or food-grade or pharmaceutical-grade packaging material.

[0014] Furthermore, in the vertical direction, the length of the sealing and pressing portion accounts for 4 / 5 to 9 / 10 of the total vertical length of the overlapping portion of the inner and outer valve plates in the lower section region. This sealing ratio ensures the connection strength between the inner and outer valve plates while reserving sufficient free area in the upper section as a lateral feed port.

[0015] Furthermore, when the material is filled into the bag through the side feed port, the upper section of the inner valve plate and the upper section of the outer valve plate are passively bonded together under the pressure inside the bag, forming a check valve type seal.

[0016] 3. Beneficial effects: Compared with the prior art, the technical solution provided by this invention has the following advantages: (1) The present invention separates the valve structure from the M-type folding process of the bag body, and uses inner and outer valve plates of different widths to directly stack on the front side to form a side feed port. There is no need for a complicated valve folding process, the bag making equipment is simplified, the manufacturing cost is reduced, and the consistency and reliability of the valve are significantly improved. (2) The present invention utilizes the asymmetrical structure in which the inner valve plate only covers part of the front side, and the feeding channel is located in one side area of ​​the front side. The filling tube can be directly inserted from this area. The structure is simple and the operation is convenient. (3) The present invention integrates a venting microchannel in the lower sealing and pressing part, realizing the simultaneous completion of valve plate fixing and venting channel construction in one process, which is simple and low cost; (4) The venting microchannel adopts the shape of a paperclip or a labyrinth, combined with the venting micropores on the outer valve plate, to form a composite venting path of "venting micropores → interlayer space → tortuous microchannel", which can effectively vent the air in the bag, and can also use the particle repose angle and the flow channel turning effect to prevent material leakage, greatly improving the moisture-proof effect and stacking stability. (5) After filling, the inner valve plate and the outer valve plate are passively bonded together under the pressure of the material inside the bag to form a reliable check valve type automatic seal, which does not require manual or equipment secondary sealing and has high packaging efficiency.

[0017] It should be noted that the structures not described in this invention are not related to the design points and improvement directions of this invention, and are the same as or can be implemented using existing technologies, so they will not be elaborated here. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of an asymmetric stacked valve packaging bag provided in an embodiment of the present invention.

[0019] Figure 2 for Figure 1 The exploded view of the front side of the packaging bag shown illustrates the overlapping relationship between the inner and outer valve plates. Figure 3 for Figure 1 The perspective view of the front side of the packaging bag shown illustrates the overlapping relationship between the inner and outer valve plates. Figure 4 This is a schematic diagram of the structure of the asymmetric stacked valve packaging bag after sealing, as provided in an embodiment of the present invention.

[0020] Explanation of the labels in the diagram: 1. Bag body; 2. Inner valve plate; 21. Upper section of inner valve plate; 22. Lower section of inner valve plate; 3. Outer valve plate; 31. Upper section of outer valve plate; 32. Lower section of outer valve plate; 33. Breathable micropores; 4. Venting microchannel; 5. Side feed inlet. Detailed Implementation

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of protection of the present invention.

[0022] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "front", "rear", "inner", "outer", "lateral", "vertical", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Example 1

[0023] like Figures 1 to 4 As shown, this embodiment provides an asymmetric laminated valve packaging bag, including a bag body 1. The bag body 1 has a front side, a rear side, a left side, a right side, a top side, and a bottom side. The left side and right side of the bag body 1 can both have an M-shaped folding structure (not shown in the figure), so that the bag body 1 is flat when not in use, which is convenient for storage and transportation, and unfolds into a three-dimensional shape when filling.

[0024] The front side of the bag body 1 is composed of two overlapping valve plates: an inner valve plate 2 located on the inside (close to the inner cavity of the bag) and an outer valve plate 3 located on the outside (exposed to the outside). Both the inner valve plate 2 and the outer valve plate 3 are made of the same or compatible moisture-proof material as the bag body 1, such as polyethylene film, polypropylene film, or composite plastic film. Food-grade or pharmaceutical-grade materials can also be selected according to the requirements of the packaging materials.

[0025] Please see Figure 2 The lateral width W1 of the inner valve plate 2 is smaller than the total lateral width W of the front side. Specifically, W1 is approximately 1 / 3 of W. That is, the inner valve plate 2 extends from the left edge of the bag body 1 to the right, covering only about 1 / 3 of the left side of the front side. The remaining area of ​​the front side (middle and right side) is formed by the front membrane material of the bag body 1 itself as the base layer. The lateral width W2 of the outer valve plate 3 is close to and slightly smaller than the total lateral width W of the front side. The outer valve plate 3 extends from the right edge of the bag body 1 to the left, covering the outside of the inner valve plate 2 and essentially covering the entire front side. The left edge of the outer valve plate 3 is sealed with the left edge of the bag body 1, the right edge of the outer valve plate 3 is sealed with the right edge of the bag body 1, the upper edge of the outer valve plate 3 is sealed with the top surface, and the lower edge of the outer valve plate 3 is sealed with the bottom surface. Thus, the inner valve plate 2 is sandwiched between the base layer of the front side of the bag body 1 and the outer valve plate 3.

[0026] The inner valve plate 2 and the outer valve plate 3 are each divided into an upper section and a lower section in the vertical direction, namely, the upper section 21 of the inner valve plate, the lower section 22 of the inner valve plate, the upper section 31 of the outer valve plate, and the lower section 32 of the outer valve plate, as shown below. Figure 2 As shown.

[0027] In the overlapping area corresponding to the lower section 22 of the inner valve plate and the lower section 32 of the outer valve plate, the two are pressed together by hot pressing or ultrasonic welding to form a sealed pressing part. The sealed pressing part occupies approximately 4 / 5 of the total vertical length H of the overlapping area of ​​the inner valve plate 2 and the outer valve plate 3. Within the sealed pressing part, one or more unpressed areas are constructed through the shape design of the pressing mold. These unpressed areas form the venting microchannels 4 that connect the inner cavity of the bag to the outside atmosphere. Figure 1-3 As shown, the venting microchannel 4 is paperclip shaped (or labyrinth shaped) with at least two turning sections, thereby extending the gas discharge path and increasing the resistance to material passage. The cross-sectional width d of the venting microchannel 4 is approximately 0.5 mm, which ensures smooth gas discharge while effectively blocking leakage of common powdery materials (such as flour, cement, etc., with a particle size generally greater than 0.05 mm).

[0028] In the overlapping area corresponding to the upper section 21 of the inner valve plate and the upper section 31 of the outer valve plate, the two are not sealed but in free contact. The gap between them constitutes the lateral feed port 5 for inserting the filling tube. The lateral feed port 5 is located on the left side of the front side, corresponding to the coverage area of ​​the inner valve plate 2.

[0029] Furthermore, multiple air-permeable micropores 33 are formed on the outer valve plate 3, corresponding to the coverage area of ​​the inner valve plate 2. The air-permeable micropores 33 are oriented towards the inside of the bag, that is, they penetrate the outer valve plate 3, so that the inner cavity of the bag is connected to the interlayer space between the inner valve plate 2 and the outer valve plate 3. The pore size of the air-permeable micropores 33 is preferably 0.3 mm to 1 mm, which is smaller than the particle size of common materials.

[0030] In this embodiment, the packaging bag is made by simply placing the pre-cut narrow inner valve piece 2 and wide outer valve piece 3 on the front side of the bag body according to the above stacking relationship, and then sealing the perimeter and pressing the parts together. It does not require the use of complex M-type folding equipment and edge insertion mechanism to specially construct the valve structure, which significantly reduces the investment and debugging difficulty of bag making equipment.

[0031] Usage process and working principle Please see Figure 1 During filling, the filling tube of the automatic filling machine is inserted into the side feed port 5, passes through the gap between the upper section 21 of the inner valve plate and the upper section 31 of the outer valve plate, and enters the inner cavity of the bag body 1. The material (such as powder or granular material) is filled into the bag body 1 at high speed through the filling tube.

[0032] As material is continuously filled, bag 1 gradually expands. Under the filling pressure and material compression, the air inside bag 1 first enters the interlayer space between inner valve 2 and outer valve 3 through the venting micropores 33 on the outer valve plate 3, and then is discharged to the outside through the venting microchannel 4. Because the venting microchannel 4 is tortuous, the air can be discharged smoothly along the tortuous path. When the material particles move with the airflow to the vicinity of the inlet of the venting microchannel 4, the kinetic energy of the particles rapidly decreases and they are deposited on the outer edge of the channel due to the sudden narrowing of the channel cross-section and multiple changes in direction, forming a natural accumulation and blockage, thereby achieving the effect of "venting without leakage".

[0033] Please see Figure 4 Once the material has been filled to the predetermined capacity, the filling tube exits from the side inlet 5. At this point, the bag 1 is filled with material. The tension generated by the expansion of the bag 1 and the pressure of the material on the inner side of the front side cause the upper section 21 of the inner valve plate and the upper section 31 of the outer valve plate to be pressed tightly together, and the side inlet 5 is automatically closed. Since both the inner valve plate 2 and the outer valve plate 3 are flexible membrane materials, they are tightly bonded under internal pressure, forming a one-way closed structure similar to a check valve. The material inside the bag cannot flow out in reverse, achieving an automatic sealing function without the need for an additional sealing process.

[0034] After filling, the packaging bags are tightly packed and nearly vacuum-like because the internal air has been fully expelled through the venting microchannel 4. This not only significantly enhances the moisture-proof effect but also greatly improves the stability when stacking, saving storage and transportation space. Example 2

[0035] This embodiment is basically the same in structure as Embodiment 1, except that: the lateral coverage width of the inner valve plate 2 is 1 / 4 of the total lateral width of the front side; the sealing and pressing part occupies 9 / 10 of the total vertical length of the overlapping area; and the venting microchannel 4 is a labyrinth shape with multiple bends, with a cross-sectional width of 1.2 mm. This structure is suitable for materials with larger particle sizes (such as rice, white sugar, etc.), ensuring rapid venting while effectively preventing material leakage. Example 3

[0036] This embodiment is basically the same as the first embodiment in terms of structure, except that: the lateral coverage width of the inner valve plate 2 is 1 / 2 of the total lateral width of the front side; the sealing and pressing part occupies 5 / 6 of the total vertical length of the overlapping area; the venting microchannel 4 is two parallel spiral needle-shaped channels; the venting micropores 33 are opened in the entire coverage area of ​​the outer valve plate 3 and are arranged in a vertical downward multi-row array to guide the condensed water vapor to be discharged downward, further enhancing the moisture-proof effect.

[0037] The above description is merely a preferred embodiment of the present invention and does not limit the scope of the patent. Any equivalent structural modifications made based on the inventive concept of the present invention and the description and drawings, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. An asymmetric laminated valve packaging bag, comprising a bag body (1), said bag body (1) having a front side, a rear side, a left side, a right side, a top surface, and a bottom surface, characterized in that: The front side is composed of at least two layers of valve plates stacked together, including an inner valve plate (2) located on the inside and an outer valve plate (3) located on the outside. The lateral width of the inner valve plate (2) is smaller than the total lateral width of the front side. The inner valve plate (2) extends from the left edge of the bag body (1) to the right, covering only a part of the front side. The lateral width of the outer valve plate (3) is smaller than the total lateral width of the front side. The outer valve plate (3) covers the outside of the inner valve plate (2) and basically covers the entire front side. The outer valve plate (3) is provided with a breathable structure, which is provided in accordance with the coverage area of ​​the inner valve plate (2) and is used to connect the inner cavity of the bag body (1) with the interlayer space between the inner valve plate (2) and the outer valve plate (3). The inner valve plate (2) and the outer valve plate (3) are each divided into an upper section and a lower section in the vertical direction; In the lower section region, the lower section of the inner valve plate (22) and the lower section of the outer valve plate (32) are pressed together to form a sealing pressing part, and the sealing pressing part has at least one venting microchannel (4) that connects the inner cavity of the bag with the outside atmosphere. In the upper region, the upper section of the inner valve plate (21) and the upper section of the outer valve plate (31) are in a non-sealed free contact state, and the gap between them constitutes a lateral feed port (5).

2. The asymmetric laminated valve-mouth packaging bag according to claim 1, characterized in that, The lateral coverage width of the inner valve plate (2) is 1 / 4 to 1 / 3 of the total lateral width of the front side.

3. The asymmetric laminated valve-mouth packaging bag according to claim 1, characterized in that, The venting microchannel (4) is in the shape of a paperclip or a maze, and the venting microchannel (4) is defined by the unpressed area within the sealing and pressing part.

4. The asymmetric laminated valve-mouth packaging bag according to claim 1, characterized in that, The breathable structure consists of multiple breathable micropores (33) formed on the outer valve plate (3) and corresponding to the area covered by the inner valve plate (2). The breathable micropores (33) penetrate the outer valve plate (3) and are used to connect the inner cavity of the bag with the interlayer space between the inner valve plate (2) and the outer valve plate (3).

5. The asymmetric laminated valve-mouth packaging bag according to claim 1, characterized in that, The width of the venting microchannel (4) is 0.1 mm to 2 mm.

6. The asymmetric laminated valve-mouth packaging bag according to claim 1, characterized in that, The bag body (1), inner valve plate (2) and outer valve plate (3) are all made of moisture-proof material.

7. The asymmetric laminated valve-mouth packaging bag according to claim 1, characterized in that, In the vertical direction, the length of the sealing press portion accounts for 4 / 5 to 9 / 10 of the total vertical length of the overlapping portion of the inner valve plate (2) and the outer valve plate (3) in the lower section region.

8. The asymmetric laminated valve-mouth packaging bag according to any one of claims 1 to 7, characterized in that, When the material is filled into the bag body (1) through the side feed port (5), the upper section (21) of the inner valve plate and the upper section (31) of the outer valve plate are passively bonded together under the pressure inside the bag to form a check valve type seal.

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