PLA packaging bag with indication function

Abstract

The utility model provides a PLA packaging bag with indicating function, it includes the bag body, the bag body contains first packaging film and second packaging film, forms storage cavity between first packaging film and second packaging film, and the upper end of bag body is equipped with the unsealing part, the unsealing part contains the first self -sealed strip of fixed in first packaging film inner side and the second self -sealed strip of fixed in second packaging film inner side, the inner wall of first packaging film has the indication area, the indication area is printed with the indication layer, and the inner wall of first packaging film is connected with the inner sealing film covering the indication area still, the edge of inner sealing film is fixedly connected with the inner wall of first packaging film, and the middle part between inner sealing film and first packaging film forms the air cavity, is provided with the air hole on inner sealing film. The utility model sets up the inner sealing film to cover the indication area to avoid the indication layer and food direct contact, prevents food pollution, is equipped with the air hole on inner sealing film, makes the indication layer can contact the gaseous environment in the bag.

Description

Technical Field

[0001] This utility model relates to the field of packaging bag technology, and specifically to a PLA packaging bag with an indicator function. Background Technology

[0002] Food safety is a major concern for society, especially for foods with short shelf lives, such as fresh meat, fish, shrimp, and dairy products. Freshness is greatly affected by storage conditions, and ordinary consumers often cannot accurately assess the condition of these foods. With increased investment and research in packaging, biodegradable food packaging films or bags, bio-based materials, and moisture-absorbing and mildew-proof materials have emerged. These packaging materials can improve the storage environment, extend shelf life, and reduce packaging contamination to some extent, but consumers still cannot directly assess the freshness of the food.

[0003] Patent application CN201910137063.4 discloses a packaging film material comprising, from bottom to top: a first substrate layer, a heat-insulating film layer, a first adhesive layer, a second substrate layer, an antibacterial film layer, a second adhesive layer, a third substrate layer, and a pH indicator film layer. The first, second, and third substrate layers are transparent, and the pH indicator film layer faces the side of the packaging film material that is exposed to the packaged food. When food spoils, it typically releases acidic or alkaline gases, which are absorbed by the pH indicator film layer, causing a color change. This allows for visual observation of whether the food inside the packaging film has spoiled without opening the package, facilitating the classification, management, and selection of food materials of different freshness levels. The above technical solution can intuitively show whether food has spoiled or rotten through the color change reaction of the pH indicator film. However, the indicator film needs to be exposed to the inner air of the packaging bag to come into contact with the characteristic gas. During storage, the food will come into contact with the indicator film, which may cause some safety hazards. In particular, when storing some foods with high moisture content, the indicator may dissolve in the liquid and contaminate the food, causing food contamination. Utility Model Content

[0004] To address the aforementioned issues, this invention provides a PLA packaging bag with an indicator function. This bag can detect changes in the concentration of characteristic gases inside the bag, visually displaying the freshness of the food, and is less likely to cause food contamination.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A PLA packaging bag with an indicator function includes a bag body, which comprises a first packaging film and a second packaging film connected by an edge, forming a storage cavity between the first packaging film and the second packaging film. The upper end of the bag body has an opening portion, which includes a first self-sealing strip fixed to the inner side of the first packaging film and a second self-sealing strip fixed to the inner side of the second packaging film. The inner wall of the first packaging film has an indicator area, on which an indicator layer is printed. An inner sealing film covering the indicator area is also connected to the inner wall of the first packaging film. The edge of the inner sealing film is fixedly connected to the inner wall of the first packaging film. An air cavity is formed between the middle of the inner sealing film and the first packaging film. A vent hole communicating between the air cavity and the storage cavity is provided on the inner sealing film.

[0007] This invention features an indicator area on the inside of the packaging bag. The indicator area has an indicator layer printed with ink containing an indicator agent. When the indicator layer comes into contact with a characteristic gas inside the bag, it changes color, displaying different shades of color depending on the concentration of the characteristic gas. The color of the indicator layer allows for assessment of the gas environment inside the bag, and consequently, the state of the food inside. Specifically, this invention also includes an inner sealing film covering the indicator area to prevent direct contact between the indicator layer and the food, thus avoiding food contamination. An air cavity is formed between the center of the inner sealing film and the first packaging film. The inner sealing film has vents connecting the air cavity to the storage cavity, allowing the indicator layer to come into contact with the gas environment inside the bag.

[0008] Furthermore, the first self-sealing strip is fixedly connected to the inner sealing film, and the vent hole is located on the lower side of the first self-sealing strip.

[0009] Furthermore, the upper end of the inner sealing film is integrally bent and connected to the upper end of the first packaging film.

[0010] Furthermore, the inner wall of the second packaging film has a second indicator area, on which a second indicator layer is printed. The inner wall of the second packaging film is also connected to a second inner sealing film that covers the second indicator area. The edge of the second inner sealing film is fixedly connected to the inner wall of the second packaging film. A second air cavity is formed between the middle part of the second inner sealing film and the second packaging film. A second vent hole is provided on the second inner sealing film that connects the second air cavity and the storage cavity.

[0011] Furthermore, the second self-sealing strip is fixedly connected to the second inner sealing film, and the second vent hole is located on the lower side of the second self-sealing strip.

[0012] Furthermore, the upper end of the second inner sealing film is integrally bent and connected to the upper end of the second packaging film.

[0013] Furthermore, a control area is provided on the outer wall of the first packaging film, and the control area is provided with a control printing layer.

[0014] Furthermore, the control area and the indicator area are staggered.

[0015] Furthermore, the first packaging film and the second packaging film are formed by multi-layer composite.

[0016] The following beneficial effects can be achieved by applying this utility model:

[0017] 1. This utility model provides an indicator area on the inside of the packaging bag. The indicator area has an indicator layer formed by printing ink containing an indicator. When the indicator layer comes into contact with the characteristic gas inside the bag, it will change color and show different degrees of color according to the concentration of the characteristic gas. The gas environment inside the bag can be judged according to the color of the indicator layer, and thus the state of the food inside the bag can be judged.

[0018] 2. This utility model is provided with an inner sealing film to cover the indicator area to avoid direct contact between the indicator layer and the food, thereby preventing food contamination. An air cavity is formed between the middle of the inner sealing film and the first packaging film. The inner sealing film is provided with a vent hole that connects the air cavity and the storage cavity, so that the indicator layer can come into contact with the gas environment inside the bag.

[0019] 3. In some embodiments of this utility model, the self-sealing strip is connected to the inner sealing film. When the self-sealing strip is opened, it will pull the inner sealing film, forcing the gas in the air chamber to circulate with the outside air, so as to ensure that the gas in the air chamber is reset and consistent with the environment inside the bag after each opening and resealing of the packaging bag, thus ensuring the accuracy of the indication effect. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a PLA packaging bag with an indicator function in the embodiment;

[0021] Figure 2 A partial cross-sectional view of a PLA packaging bag with indicator function;

[0022] Figure 3 A partial cross-sectional view of a PLA packaging bag with an indicator function in another embodiment;

[0023] In the figure, 1-first packaging film, 11-indicator layer, 2-second packaging film, 21-second indicator layer, 3-first self-sealing strip, 4-second self-sealing strip, 5-storage cavity, 6-inner sealing film, 61-air cavity, 62-vent hole, 7-second inner sealing film, 71-second air cavity, 72-second vent hole. Detailed Implementation

[0024] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model. Example

[0025] Reference Figure 1 and Figure 2 This embodiment provides a PLA packaging bag with an indicating function, comprising a PLA bag body, the bag body including a first packaging film 1 and a second packaging film 2 connected by an edge, a storage cavity 5 being formed between the first and second packaging films, and an opening portion being formed at the upper end of the bag body, the opening portion including a first self-sealing strip 3 adhered to the inner wall of the first packaging film and a second self-sealing strip 4 adhered to the inner wall of the second packaging film. The first self-sealing strip has a mating protrusion, and the second self-sealing strip has a mating groove. The first and second self-sealing strips can form a sealed connection and close the opening at the top of the bag. The first and second packaging films are rectangular structures. The left and right sides of the first packaging film are heat-sealed to the second packaging film. The lower side of the first packaging film is integrally connected to the second packaging film, and the upper side of the first packaging film is separate from the second packaging film. The inner wall of the first packaging film has an indicator area. The indicator area is provided with an indicator layer 11 formed by printing ink containing an indicator. The indicator layer will change color after contacting a specific gas, and the degree of color change is related to the concentration of the specific gas. The indicator area is covered by an inner sealing film 6. The edge of the inner sealing film is connected to the inner wall of the first packaging film. An air cavity 61 is formed between the middle of the inner sealing film and the first packaging film. The first inner sealing film is provided with a vent 62 that connects the air cavity 61 and the storage cavity 5.

[0026] The principle of this invention is as follows: When the indicator layer comes into contact with the characteristic gas inside the bag, it will change color, and different degrees of color will appear according to the concentration of the characteristic gas. The color of the indicator layer can be used to judge the gas environment inside the bag, and thus judge the state of the food inside the bag. The inner sealing film covers the indicator area to avoid direct contact between the indicator layer and the food, thus avoiding food contamination. An air cavity is formed between the middle of the inner sealing film and the first packaging film. The inner sealing film is provided with a vent hole that connects the air cavity and the storage cavity, so that the indicator layer can come into contact with the gas environment inside the bag.

[0027] In a preferred embodiment, the indicator area is located near the upper end of the first packaging film. The upper end of the inner sealing film 6 is integrally bent and connected to the upper end of the first packaging film. The first self-sealing strip 3 is fixedly connected to the inner sealing film 6. The vent 62 is located on the lower side of the first self-sealing strip. When the packaging bag is opened, the first self-sealing strip will pull the inner sealing film. After the inner sealing film is deformed, the gas in the air chamber 61 will be forced to circulate with the outside gas, thereby resetting the gas composition in the air chamber. When the packaging bag is closed again, the gas composition in the air chamber will be relatively consistent with the gas composition inside the bag again, ensuring the accuracy of the indicator effect.

[0028] In a preferred embodiment, a reference area is provided on the outer wall of the first packaging film. The reference area is printed with a reference layer. The reference layer can be compared with the indicator layer in color to facilitate customer differentiation. The reference layer should be set at a position that is offset from but close to the indicator layer to facilitate color comparison.

[0029] Reference Figure 3 In a further embodiment, the inner wall of the second packaging film 2 has a second indicator area, on which a second indicator layer 21 formed by printing with ink containing an indicator is provided. The second indicator layer changes color upon contact with a specific gas, and the degree of color change is related to the concentration of the specific gas. The second indicator area is covered by a second inner sealing film 7, the edge of which is connected to the inner wall of the second packaging film. A second air cavity 71 is formed between the middle of the second inner sealing film and the second packaging film. A second vent 72 is provided on the second inner sealing film, connecting the second air cavity 71 and the storage cavity 5. Preferably, the second self-sealing strip is fixedly connected to the second inner sealing film, the second vent is located on the lower side of the second self-sealing strip, and the upper end of the second inner sealing film is integrally bent and connected to the upper end of the second packaging film. The indicator contained in the second indicator layer 21 is different from that in the indicator layer 11. It can determine the freshness of food from different indicators. For example, when fruit is left to rot normally, it will consume oxygen and produce carbon dioxide due to respiration. The freshness of the fruit can be determined by detecting oxygen or carbon dioxide through the indicator layer 11. During the process of fruit spoilage, some characteristic gases will be produced. The fruit can be determined to be spoiled by detecting these characteristic gases through the second indicator layer 21.

[0030] In some other embodiments, the first and second packaging films may be formed by multilayer composites, each layer having different functions, such as antibacterial and UV-resistant properties, to improve the storage conditions of food.

[0031] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A PLA packaging bag with an indicator function, characterized in that: The bag includes a bag body comprising a first packaging film and a second packaging film connected by an edge, forming a storage cavity between the first and second packaging films. The upper end of the bag body has an opening portion, which includes a first self-sealing strip fixed to the inner side of the first packaging film and a second self-sealing strip fixed to the inner side of the second packaging film. The inner wall of the first packaging film has an indicator area printed with an indicator layer. An inner sealing film covering the indicator area is also connected to the inner wall of the first packaging film. The edge of the inner sealing film is fixedly connected to the inner wall of the first packaging film. An air cavity is formed between the middle of the inner sealing film and the first packaging film. A vent hole communicating between the air cavity and the storage cavity is provided on the inner sealing film.

2. A PLA packaging bag with an indicator function according to claim 1, characterized in that: The first self-sealing strip is fixedly connected to the inner sealing film, and the vent hole is located on the lower side of the first self-sealing strip.

3. A PLA packaging bag with an indicator function according to claim 2, characterized in that: The upper end of the inner sealing film is integrally bent and connected to the upper end of the first packaging film.

4. A PLA packaging bag with an indicator function according to claim 1, characterized in that: The inner wall of the second packaging film has a second indicator area, on which a second indicator layer is printed. The inner wall of the second packaging film is also connected to a second inner sealing film that covers the second indicator area. The edge of the second inner sealing film is fixedly connected to the inner wall of the second packaging film. A second air cavity is formed between the middle part of the second inner sealing film and the second packaging film. A second vent hole is provided on the second inner sealing film that connects the second air cavity and the storage cavity.

5. A PLA packaging bag with an indicator function according to claim 4, characterized in that: The second self-sealing strip is fixedly connected to the second inner sealing film, and the second vent hole is located on the lower side of the second self-sealing strip.

6. A PLA packaging bag with an indicator function according to claim 5, characterized in that: The upper end of the second inner sealing film is integrally bent and connected to the upper end of the second packaging film.

7. A PLA packaging bag with an indicator function according to claim 1, characterized in that: The outer wall of the first packaging film is provided with a reference area, and the reference area is provided with a reference printing layer.

8. A PLA packaging bag with an indicator function according to claim 7, characterized in that: The control area and the indicator area are staggered.

9. A PLA packaging bag with an indicator function according to claim 1, characterized in that: The first and second packaging films are formed by multi-layer composite.

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