Degradable single-layer bag capable of preventing seal from being torn

Abstract

A film layer of the degradable single-layer bag is sequentially provided with a PLA heat sealing layer, a PLA core layer and a PLA surface layer from outside to inside, and the PLA heat sealing layer, the PLA core layer and the PLA surface layer are all two-way stretching polylactic acid films. The hot cutting edge of the degradable single-layer bag is perpendicular to the MD direction, the end opening of the hot cutting edge of the degradable single-layer bag is provided with a crack stopping part, and the bag opening of the degradable single-layer bag is provided with an adhesive tape. The degradable single-layer bag capable of preventing the seal from being torn has good mechanical performance, printing performance and biodegradability, the seal position is not prone to being torn, and the degradable single-layer bag can be widely applied to the field of soft packages such as stationery, toys and clothes and has very wide application prospects.

Description

Technical Field

[0001] This utility model belongs to the field of flexible packaging materials technology, and specifically relates to a biodegradable single-layer bag that prevents the seal from tearing. Background Technology

[0002] Single-layer heat-sealed bags are a highly efficient and environmentally friendly packaging production process. They are sealed by heat, avoiding the use of glue or adhesives, thus reducing VOC (volatile organic compound) emissions and effectively minimizing environmental pollution. However, most single-layer heat-sealed bags currently use traditional resin films, such as BOPP (biaxially oriented polypropylene film), CPE (cast polyethylene film), or OPE (blown polyethylene film). While these traditional plastic films have excellent performance, they are difficult to degrade, leading to increasingly severe white pollution problems and placing enormous pressure on the environment. With increasing environmental awareness, the environmental problems caused by traditional plastics are receiving growing attention, and the development of biodegradable materials has become a global focus. Polylactic acid (PLA), as a bio-based biodegradable material, is gradually becoming an ideal alternative to traditional petroleum-based plastics due to its good biocompatibility and degradability. PLA can be decomposed into carbon dioxide and water by microorganisms in the natural environment, without causing long-term pollution. However, PLA has certain deficiencies in heat resistance and mechanical strength, limiting its widespread application in the packaging field. To overcome these shortcomings of PLA, biaxially oriented polylactic acid film (BOPLA) was developed. BOPLA uses biaxial stretching and heat setting processes to orient and crystallize PLA molecules, significantly improving its heat resistance and mechanical properties, enabling it to meet the needs of single-layer bag packaging. However, molecular orientation also brings new problems: the ends of the heat-cut PLA film are extremely prone to tearing, which seriously affects its effectiveness in actual packaging applications.

[0003] Therefore, there is a great need to develop a biodegradable single-layer bag that is resistant to sealing tear to provide a solution for the application of PLA film single-layer heat-sealing tape bags in packaging. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a biodegradable single-layer bag that is resistant to tearing at the seal. It has good mechanical properties, printability and biodegradability, and the seal is not easily torn. It can be widely used in the field of flexible packaging such as stationery, toys and clothing.

[0005] To achieve the above objectives, the technical solution adopted by this utility model to solve its technical problems is as follows: a biodegradable single-layer bag with anti-tear sealing, wherein the film layer is provided with a PLA heat-sealing layer, a PLA core layer and a PLA surface layer from the outside to the inside, wherein the PLA heat-sealing layer, PLA core layer and PLA surface layer are all biaxially oriented polylactic acid film; the heat-cut edge of the biodegradable single-layer bag is perpendicular to the MD direction, the port of the heat-cut edge of the biodegradable single-layer bag is provided with a tear-stopping part, and the bag opening of the biodegradable single-layer bag is provided with an adhesive strip.

[0006] The biodegradable single-layer bag is folded along the MD direction (the longitudinal stretching direction of the biaxially oriented film) and then heat-cut into a bag along the TD direction (the transverse stretching direction of the biaxially oriented film).

[0007] In a preferred embodiment of this utility model, the crack-stopping part is a circular or elliptical hole, and the circular or elliptical hole is tangent to the hot-cut edge at the port.

[0008] A tear-resistant part is set at the end of the heat-cut edge of the biodegradable single-layer bag. When the biodegradable single-layer bag is opened to package the contents, the tear-resistant part plays a role in stress transfer, solving the problem of easy tearing of the seal. An adhesive strip is set at the bag opening to facilitate folding and sealing after filling the contents.

[0009] In a preferred embodiment of this utility model, the thickness of the PLA heat-sealing layer is 1-5 μm.

[0010] In a preferred embodiment of this invention, the thickness of the PLA core layer is 10-40 μm.

[0011] In a preferred embodiment of this invention, the thickness of the PLA surface layer is 1-3 μm.

[0012] Compared with the prior art, this technical solution has the following advantages:

[0013] 1. The biodegradable single-layer bag with anti-tear sealing provided by this utility model adopts a new biodegradable PLA film single-layer heat-cutting bag technology, which combines the environmental advantages of PLA and the high efficiency of heat-cutting technology, and is an important direction for solving white packaging pollution;

[0014] 2. This utility model provides a tear-stopping part at the port of the heat-cut edge of the biodegradable single-layer bag that prevents the seal from tearing. When the biodegradable single-layer bag is opened to package the contents, the tear-stopping part plays a stress transfer role, which effectively solves the problem of easy tearing of the seal, improves the reliability of the packaging, and reduces the risk of leakage of contents or damage to the packaging due to tearing of the seal.

[0015] 3. This utility model has an adhesive strip at the bag opening, which can be folded and sealed after the contents are filled. This design makes the sealing operation simpler and faster, improves packaging efficiency, and also ensures the sealing performance, further enhancing the protective performance of the packaging. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a schematic diagram of a biodegradable single-layer bag film structure that prevents sealing tears, provided by this utility model.

[0018] Among them, 1-PLA heat-sealing layer, 2-PLA core layer, and 3-PLA surface layer;

[0019] Figure 2 This is a structural schematic diagram of a biodegradable single-layer bag that prevents sealing tears, provided by this utility model.

[0020] Among them, 4-hot-cut edge, 4-1-port, 5-bag opening, 6-tear-stopping part, 7-adhesive strip. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be further described below in conjunction with the accompanying drawings and embodiments. These embodiments may take different forms and should not be construed as limited to the description herein. Throughout the document, the same reference numerals always represent the same elements, and similar reference numerals represent similar elements.

[0022] It should be noted that the terms "inner" refer to the side in contact with the contents, and "outer" refer to the side away from the contents, and should not be construed as a limitation on this utility model.

[0023] like Figure 1 As shown, a biodegradable single-layer bag with tear-resistant seal has a film layer consisting of a PLA heat-sealing layer 1, a PLA core layer 2, and a PLA surface layer 3 arranged sequentially from the outside to the inside. The PLA heat-sealing layer 1, PLA core layer 2, and PLA surface layer 3 are all biaxially oriented polylactic acid (PLA) films. The thickness of the PLA heat-sealing layer 1 is 1-5 μm, the thickness of the PLA core layer 2 is 10-40 μm, and the thickness of the PLA surface layer is 1-3 μm.

[0024] The biodegradable single-layer bag is folded along the MD direction (the longitudinal stretching direction of the biaxially oriented film) and then heat-cut into a bag along the TD direction (the transverse stretching direction of the biaxially oriented film).

[0025] like Figure 2As shown, the heat-cut edge 4 of the biodegradable single-layer bag is perpendicular to the MD direction. A tear-prevention part 6 is provided at the port 4-1 position of the heat-cut edge 4 of the biodegradable single-layer bag, and an adhesive strip 7 is provided at the bag opening 5 of the biodegradable single-layer bag. The tear-prevention part 6 is a circular or elliptical hole, which is tangent to the heat-cut edge 4 at the port 4-1 position.

[0026] The biodegradable single-layer bag with anti-tear sealing produced by this invention has good mechanical properties, printability and biodegradability, and the sealing position is not easily torn. It can be widely used in the field of flexible packaging such as stationery, toys and clothing, and has a very broad application prospect.

[0027] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A degradable single layer bag resistant to seal tear, characterized by, The film layers of the bag are sequentially provided from outside to inside with a PLA heat-sealing layer, a PLA core layer and a PLA surface layer, wherein the PLA heat-sealing layer, the PLA core layer and the PLA surface layer are all biaxially oriented polylactic acid films; the heat-cut edge of the bag is perpendicular to the MD direction, and the port of the heat-cut edge is provided with a crack stopping part, and the bag opening is provided with an adhesive tape.

2. The tamper-evident degradable monolayer bag of claim 1, wherein, The crack stopping part is a circular or elliptical hole.

3. The tamper-evident degradable monolayer bag of claim 2, wherein, The circular or elliptical hole is tangent to the heat-cut edge at the port.

4. The tamper-evident degradable monolayer bag of claim 1, wherein, The thickness of the PLA heat-sealing layer is 1-5 μm.

5. The tamper-evident degradable monolayer bag of claim 1, wherein, The thickness of the PLA core layer is 10-40 μm.

6. The tamper-evident degradable monolayer bag of claim 1, wherein, The thickness of the PLA surface layer is 1-3 μm.

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