Fresh-keeping bag

Abstract

The utility model discloses a freshness protection bag which comprises a bag body and a ventilation layer, ventilation holes are formed in the bag body, and the ventilation layer seals the ventilation holes and is fixedly connected with the bag body. The breathable layer comprises air channel cloth and a nuclear track membrane arranged on the air channel cloth, the area of the air channel cloth is larger than that of the nuclear track membrane, an outer welding area surrounding the nuclear track membrane is formed by an area gap between the air channel cloth and the nuclear track membrane, and the nuclear track membrane is arranged between the air channel cloth and the bag body and completely covers the air holes. The welding area of the air passage cloth is fixed to the bag body through ultrasonic welding, and the air passage cloth is made of hard non-woven fabric. The hard non-woven fabric and the freshness protection bag body are subjected to ultrasonic welding, the nuclear track film is not damaged, more material layers are not involved, the welding difficulty is low, the structure is more stable after welding, the welding strength is high, and as ultrasonic vibration can enable plastic film molecules to generate strong friction and fusion, the freshness protection bag is more stable in structure. The strength of the welded joint can generally reach or even exceed the strength of the plastic film itself.

Description

Technical Field

[0001] This utility model relates to the field of food packaging technology, and in particular to a food preservation bag. Background Technology

[0002] How to better preserve fruits and vegetables during storage and transportation has always been a key concern in the industry. After harvesting, fruits and vegetables continue to respire and undergo physiological metabolism. Commonly used preservation bags are made of PE material, which has very poor air permeability. If completely sealed, this leads to insufficient oxygen, forcing the fruits and vegetables to undergo anaerobic respiration, producing alcohol and unpleasant odors, and causing rapid cell death. Carbon dioxide accumulation, especially high concentrations, inhibits normal metabolism and accelerates tissue browning. Ethylene retention prevents the release of ethylene from the fruits and vegetables, accelerating the ripening and decay of both the produce and surrounding plants. Current methods involve perforating the preservation bags to allow for proper respiration and expel some harmful gases, but this still doesn't solve the problem of humidity imbalance. Water vapor produced by respiration condenses inside the bag, and the perforations also provide entry points for external bacteria. Combined with the high humidity environment, this accelerates mold growth, leading to the spoilage of the fruits and vegetables.

[0003] To address the problem of fruit and vegetable preservation, current research suggests applying nucleoporous membranes (NPMs) to the fruit and vegetable industry. Utilizing the permeability and microbial barrier properties of NPMs, these membranes are installed on the ventilation holes of preservation packaging products to achieve moisture removal, air permeability, and contamination resistance. However, NPMs themselves lack sufficient strength and rigidity; wrinkles can affect the perforation function and they are easily damaged. To ensure the open state of the NPM, additional functional layers are generally required to ensure its proper functioning. For example, Chinese Patent No. 2024202904832, entitled "Utility Model of a Preservation Bag," describes a breathable layer that is connected and fixed to the first and second layers of the bag body. The breathable layer includes a NPM and a polyester air duct fabric, and the connection and fixation methods include heat welding or adhesive bonding. Firstly, the bonding strength of adhesive bonding is not reliable enough, and there is a risk of the breathable layer falling off during the use of the food storage bag. Secondly, the hot welding method is difficult to operate, mainly because the breathable layer is located between the first and second layers of the bag body, forming a sandwich structure. Hot welding is better when the materials of the core pore membrane, airway cloth, first layer and second layer are the same. However, if the materials of the parties are different, coupled with the multi-layer structure, it is difficult to control the hot welding time and temperature. If the heating is uneven or the pressure is insufficient, it may lead to a decrease in welding strength, resulting in problems such as incomplete welding or missing welding. There may also be some defects after hot welding, such as heating marks, bubbles, deformation, etc. In severe cases, it may even damage the pore structure of the core pore membrane. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of existing technologies by proposing a food preservation bag.

[0005] To achieve the above objectives, a food preservation bag includes a bag body and a breathable layer, wherein the bag body is provided with breathable holes, and the breathable layer seals the breathable holes and is fixedly connected to the bag body.

[0006] The breathable layer includes an air duct fabric and a nucleopore membrane disposed on the air duct fabric. The area of ​​the air duct fabric is larger than that of the nucleopore membrane, and the area gap between the air duct fabric and the nucleopore membrane forms a welding area surrounding the nucleopore membrane. The nucleopore membrane is placed between the air duct fabric and the bag body and completely covers the air vents. An inner welding area surrounding the air vents is provided on the edge area of ​​the portion of the nucleopore membrane extending beyond the air vents. The welding area of ​​the air duct fabric is fixed to the bag body by ultrasonic welding, and the inner welding areas of the air duct fabric and the nucleopore membrane are fixed to the bag body by ultrasonic welding.

[0007] Preferably, the airway fabric is a rigid nonwoven fabric.

[0008] Preferably, the air duct fabric is fixed to the outer or inner surface of the bag.

[0009] Preferably, the bending stiffness of the rigid nonwoven fabric is 50-500 mN·m.

[0010] Preferably, the abrasion resistance of the rigid nonwoven fabric is greater than 10mg / 1000 cycles.

[0011] Preferably, the shape of the nuclear pore membrane is a circle, rectangle, polygon, or other irregular shape corresponding to the pores.

[0012] Preferably, the airway fabric is circular, rectangular, polygonal, or other irregular shapes.

[0013] Preferably, the pore size of the nuclear pore membrane is 300 nm-14 µm, and the thickness of the nuclear pore membrane is 8 µm-50 µm.

[0014] Preferably, the material of the nuclear pore membrane includes polycarbonate, polyester, polyimide, polyethylene, polypropylene, polytetrafluoroethylene, or polyethersulfone.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] The food preservation patch provided by this utility model provides protection for the nuclear pore membrane and meets the strength and hardness requirements through rigid non-woven fabric. The stable support of the rigid non-woven fabric effectively prevents poor air conduction caused by wrinkles in the nuclear pore membrane, facilitates production and processing, and helps control production costs. The high abrasion resistance of the rigid non-woven fabric can better protect the nuclear pore membrane and effectively prevent damage from external forces. At the same time, the air permeability of the rigid non-woven fabric does not affect the air permeability of the nuclear pore membrane.

[0017] The outer welding zone uses ultrasonic welding between rigid nonwoven fabric and the bag body to secure the nonwoven fabric, core-pore membrane, and bag body as a whole. This eliminates the risk of damaging the core-pore membrane. Direct welding between the rigid nonwoven fabric and the bag body avoids additional material layers, resulting in lower welding difficulty, a more stable structure, and higher weld strength. Because ultrasonic vibration causes strong friction and fusion between plastic film molecules, the weld joint strength can typically reach or even exceed the strength of the plastic film itself. The inner welding zone uses ultrasonic welding between the rigid nonwoven fabric, core-pore membrane, and bag body to ultrasonically weld the edge of the core-pore membrane to the bag body, providing a seal. Gas exchange within the bag can only occur through the core-pore membrane, preventing damage to the membrane covering the vents. Furthermore, ultrasonic welding offers stable weld quality, reducing the likelihood of incomplete or missed welds, and results in a better appearance with minimal heating marks or deformation. In addition, ultrasonic welding achieves excellent welding results without damaging the bag's structure and performance, increasing welding efficiency and effectively ensuring efficient production processes.

[0018] The preservation sticker provided by this utility model is attached to the ventilation holes of preservation packaging. Through a nucleoporous membrane, it effectively regulates the respiration of fruits and vegetables inside the packaging. The excellent permeability of the nucleoporous membrane effectively removes gases such as acetylene and carbon dioxide, as well as moisture, from the packaging. Furthermore, it prevents external microorganisms from entering the packaging, providing a favorable environment for the storage of fruits and vegetables. This achieves the effects of regulating the respiration of fruits and vegetables, reducing their physiological metabolism, and inhibiting microbial growth, thereby extending the lifespan of fruits and vegetables. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the accompanying drawings used in the embodiments will be briefly introduced below.

[0020] Figure 1 This is a bottom view of the breathable layer in embodiments 1-3 of this utility model.

[0021] Figure 2 This is a cross-sectional view of the breathable layer in Embodiments 1-3 of this utility model.

[0022] Figure 3 This is a schematic diagram of the structure of the food preservation bag in Embodiments 1-3 of this utility model. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.

[0024] Example 1

[0025] Provide a food storage bag 100, such as Figure 3 As shown in Figure b, the food storage bag 100 includes a bag body 101 and a breathable layer 102, as follows: Figure 3 As shown in Figure a, the bag body 101 is provided with a ventilation hole 103, and the ventilation layer 102 closes the ventilation hole 103 and is fixedly connected to the bag body 101, thereby enabling the fruits and vegetables in the bag body 101 to breathe through the ventilation layer 102.

[0026] like Figures 1-2 As shown, the breathable layer 102 includes an air duct fabric 104 and a core-pore membrane 105 disposed on the air duct fabric 104. The area of ​​the air duct fabric 104 is larger than that of the core-pore membrane 105, and the area gap between the air duct fabric 104 and the core-pore membrane 105 forms an outer welding area 106 surrounding the core-pore membrane 105. The core-pore membrane 105 is placed between the air duct fabric 104 and the bag body 101 and completely covers the air vents 103. The outer welding area 106 of the air duct fabric 104 is fixed to the bag body 101 by ultrasonic welding. The air duct fabric 104 is a rigid non-woven fabric. Ultrasonic welding between the rigid non-woven fabric and the bag body 101 does not involve the risk of damaging the core-pore membrane 105. Direct welding between the rigid non-woven fabric and the bag body 101 does not involve more material layers, the welding difficulty is low, and the structure after welding is more stable and the welding strength is high. Because ultrasonic vibration can generate strong friction and fusion between the molecules of the plastic film, the strength of the weld joint can usually reach or even exceed the strength of the plastic film itself. The edge region of the portion of the nuclear pore membrane 105 extending out of the vent 103 is provided with an inner welding area 107 surrounding the vent 103. The air duct cloth 104, the inner welding area 107 of the nuclear pore membrane 105 and the bag body 101 are fixed by ultrasonic welding, so that the nuclear pore membrane closes the vent and seals the area around the vent, and gas can only be exchanged through the vent through the nuclear pore membrane.

[0027] In one embodiment, the airway fabric 104 is fixed to the outer surface of the bag body 101. Correspondingly, depending on the usage requirements, the airway fabric 104 can also be fixed to the inner surface of the bag body 101.

[0028] The rigid nonwoven fabric has a bending stiffness of 50 mN·m. Through the support of the rigid nonwoven fabric, the nucleopore membrane 105 is not easily wrinkled or deformed, and exhibits good unfolding properties after welding. The rigid nonwoven fabric has an abrasion resistance of 10 mg / 1000 cycles, ensuring that the nucleopore membrane 105 is not easily worn during storage and transportation, effectively preventing damage or deformation caused by external forces. The nucleopore membrane 105 completely covers the vent 103. In one embodiment, the shape of the nucleopore membrane 105 corresponds to the shape of the vent 103, being circular. The pore size of the nucleopore membrane 105 is 300 nm, and its thickness is 8 µm. Gas and moisture can effectively pass through the nucleopore membrane 105, and the nucleopore membrane 105 has excellent blocking effect against microorganisms and liquid water. Correspondingly, the shape of the nucleopore membrane 105 can also be rectangular, polygonal, or other irregular shapes. The shape of the airway fabric 104 can also be circular, rectangular, polygonal or other irregular shapes, which can correspond to or not correspond to the shape of the nuclear pore membrane 105, but it is necessary to ensure that the airway fabric 104 has an outer welding area 106 surrounding the nuclear pore membrane 105.

[0029] Oxygen and carbon dioxide enter and exit the preservation bag 100 through the vent 103, and are then regulated by the nucleopore membrane 105. This effectively controls the concentration of oxygen and carbon dioxide within the preservation bag 100, reducing the respiration of fruits and vegetables. The regulation of oxygen prevents fruits and vegetables from being forced into anaerobic respiration, which produces alcohol and off-odors, and causes rapid cell necrosis. The regulation of carbon dioxide prevents high concentrations of carbon dioxide from inhibiting normal metabolism in fruits and vegetables and accelerating tissue browning.

[0030] The accumulation of ethylene released by the physiological metabolism of fruits and vegetables accelerates the ripening and decay of the fruits and vegetables themselves and surrounding fruits and vegetables. The permeability coefficient of the nuclear pore membrane 105 to ethylene reaches 2.1×10⁻ 6 Its capacity of cm³·cm / (cm²·s·Pa) is five times that of LDPE film. This property allows for the rapid removal of ethylene released by fruits and vegetables, slows down the decomposition rate of chlorophyll, and inhibits the activity of polyphenol oxidase, thereby slowing down the ripening and decay of fruits and vegetables.

[0031] Water vapor produced by the respiration of fruits and vegetables condenses when it encounters cold air inside the preservation bag 100, forming condensate. The high humidity environment will accelerate the growth of mold and cause the fruits and vegetables to rot. The core pore membrane 105 has a high permeability to water vapor and can effectively discharge water vapor inside the preservation packaging to avoid the formation of condensate.

[0032] The area of ​​the nucleopore membrane 105 is larger than the area of ​​the vent 103. After the air duct fabric 104 is welded to the bag body 101, the nucleopore membrane 105 must completely cover the vent 103. The outer welding area 106 fixes the whole structure, and the inner welding area 107 at the edge of the nucleopore membrane completely surrounds the vent 103 to form a closed structure. Microorganisms cannot enter the preservation bag 100 through the gaps outside the nucleopore membrane 105. The blocking effect of the nucleopore membrane 105 on microorganisms can effectively intercept external microorganisms from entering the preservation bag, reduce the amount of microorganisms in the preservation bag, and control the rate of microbial reproduction.

[0033] The nuclear pore membrane 105 is made of materials including polycarbonate, polyester, polyimide, polyethylene, polypropylene, polytetrafluoroethylene, or polyethersulfone. The airway fabric 104 and the nuclear pore membrane 105 can be fixed together in various ways to form an integrated structure. For example, the edge areas of the airway fabric 104 and the nuclear pore membrane 105 can be glued together, or the airway fabric 104 with a similar melting point can be heat-pressed together with the nuclear pore membrane 105. The pressing structure must not damage the pores of the nuclear pore membrane 105.

[0034] Example 2

[0035] like Figures 1-3 As shown, this embodiment provides a food preservation bag with a structure similar to that of Embodiment 1. The difference is that the rigid nonwoven fabric has a bending stiffness of 300 mN·m. Through the support of the rigid nonwoven fabric, the nucleopore membrane 105 is less prone to wrinkling and deformation, and exhibits good unfolding properties after welding. The rigid nonwoven fabric has an abrasion resistance of 30 mg / 1000 cycles, ensuring that the food preservation bag 100 is not easily worn during storage and transportation, effectively preventing damage or deformation of the nucleopore membrane 105 from external forces. The nucleopore membrane 105 is circular in shape, with a pore size of 2 µm and a thickness of 25 µm. Gas and moisture can effectively pass through the nucleopore membrane 105, and the nucleopore membrane 105 has excellent blocking properties against microorganisms and liquid water.

[0036] Example 3

[0037] like Figures 1-3As shown, this embodiment provides a food preservation bag with a structure similar to that of Embodiment 1. The difference is that the rigid nonwoven fabric has a bending stiffness of 500 mN·m. Through the support of the rigid nonwoven fabric, the nucleopore membrane 105 is less prone to wrinkling and deformation, and exhibits good unfolding properties after welding. The rigid nonwoven fabric has an abrasion resistance of 90 mg / 1000 cycles, ensuring that the food preservation bag 100 is not easily worn during storage and transportation, effectively preventing damage or deformation of the nucleopore membrane 105 from external forces. The nucleopore membrane 105 is circular in shape, with a pore size of 14 µm and a thickness of 50 µm. Gas and moisture can effectively pass through the nucleopore membrane 105, and the nucleopore membrane 105 has excellent blocking properties against microorganisms and liquid water.

[0038] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A food storage bag, characterized in that, It includes a bag body and a breathable layer, wherein the bag body is provided with breathable holes, and the breathable layer seals the breathable holes and is fixedly connected to the bag body; The breathable layer includes an air duct fabric and a core pore membrane disposed on the air duct fabric. The area of ​​the air duct fabric is larger than that of the core pore membrane, and the area gap between the air duct fabric and the core pore membrane forms an outer welding area surrounding the core pore membrane. The core pore membrane is placed between the air duct fabric and the bag body and completely covers the air pores. An inner welding area surrounding the air pores is provided on the edge area of ​​the core pore membrane extending out of the air pores. The outer welding area of ​​the air duct fabric is fixed to the bag body by ultrasonic welding. The air duct fabric is a rigid non-woven fabric. The inner welding areas of the air duct fabric and the core pore membrane are fixed to the bag body by ultrasonic welding.

2. A food preservation bag according to claim 1, characterized in that, The air duct fabric is fixed to the outer or inner surface of the bag.

3. A food preservation bag according to claim 1, characterized in that, The bending stiffness of the rigid nonwoven fabric is 50-500 mN·m.

4. A food preservation bag according to claim 1, characterized in that, The abrasion resistance of the rigid nonwoven fabric is greater than 10mg / 1000 cycles.

5. A food preservation bag according to claim 1, characterized in that, The shape of the nuclear pore membrane is a circle or a polygon corresponding to the venting pores.

6. A food preservation bag according to claim 1, characterized in that, The airway fabric is circular or polygonal in shape.

7. A food preservation bag according to claim 1, characterized in that, The pore size of the nuclear pore membrane is 300nm-14µm, and the thickness of the nuclear pore membrane is 8µm-50µm.

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