Composite film food packaging bag with easy-to-tear line

Abstract

The utility model discloses a composite film food packaging bag with an easy-to-tear line, which belongs to the technical field of food packaging and comprises a bag body and an easy-to-unseal structure formed by wavy pre-indentations at the top of the bag body, and a semicircular stress dispersion notch is arranged at the tail end of the bag body to control a tearing path. Embedded sealing mechanisms are arranged on the two sides of the top of the bag body and comprise trapezoidal concave-convex matched male and female sealing strips and limiting clamping grooves, and the surface of each embedded sealing mechanism is coated with a silica gel wear-resistant coating so as to improve durability; the intelligent pressure relief function during vacuumizing sealing and microwave heating is achieved; the bag body is of a five-layer composite structure which sequentially comprises an anti-abrasion layer, an aluminum foil barrier layer, an anti-puncture layer, an EVOH high barrier layer and a heat sealing layer, and the bag body has the anti-abrasion performance, the oxygen barrier performance and the anti-puncture performance. Through structure optimization and function integration, the easy-to-open performance, the sealing reliability, the compression resistance, the explosion resistance and the anti-counterfeiting capability of the packaging bag are remarkably improved, and the packaging bag is suitable for high-requirement food packaging scenes.

Description

Technical Field

[0001] This utility model relates to the field of food packaging technology, specifically to a composite film food packaging bag with an easy-open structure, multiple sealing and pressure regulation functions, which is particularly suitable for food packaging scenarios that require multiple opening and closing, moisture prevention and oxygen barrier and microwave heating. Background Technology

[0002] With the rapid development of food packaging technology, consumers' demands for the convenience, safety, and functionality of packaging bags are increasing. Traditional food packaging bags often employ a straight pre-indentation design for ease of opening, but this type of structure is prone to problems such as tear direction deviation and uneven opening when torn. Furthermore, stress concentration during tearing can easily lead to film separation in unintended areas. In addition, the sealing structure of existing packaging bags generally uses ordinary zippers or heat-sealing strips, which have poor repeated opening and closing performance and are prone to seal failure after long-term use, leading to moisture absorption or oxidation and deterioration of the contents.

[0003] In terms of packaging protection, conventional composite films mostly use a three-layer structure (such as PET / AL / CPP). While they provide basic barrier properties, their puncture resistance and abrasion resistance are insufficient, making them unsuitable for transporting sharp ingredients or over long distances. Furthermore, existing packaging bags are prone to bursting or deformation under microwave heating or high-altitude environments due to the inability to effectively regulate internal and external pressure differences. Regarding hanging designs, ordinary hanging holes lack reinforcement and are prone to edge tearing under load, limiting their application in large-capacity packaging. In addition, existing anti-counterfeiting labels are easily counterfeited, failing to meet brand protection requirements.

[0004] Therefore, there is an urgent need for a composite film food packaging bag that combines easy opening, high sealing reliability, excellent protective performance, and intelligent pressure regulation function to solve the many technical bottlenecks existing in the current technology. Utility Model Content

[0005] 1. Technical problem to be solved:

[0006] In view of the problems existing in the prior art, the purpose of this utility model is to provide a composite film food packaging bag that is easy to tear, has reliable sealing, supports dynamic pressure adjustment, and has anti-counterfeiting function.

[0007] 2. Technical Solution:

[0008] To solve the above problems, the present invention adopts the following technical solution.

[0009] A composite film food packaging bag with an easy-tear line includes a bag body, wherein a wave-shaped pre-indentation is provided on one side of the top of the bag body for easy opening, and a semi-circular stress dispersion notch is provided at the end of the easy-opening structure.

[0010] The top two sides of the bag body are equipped with a mating sealing mechanism, which includes mating male and female sealing strips and limiting grooves, and is located 5-8mm below the easy-open structure;

[0011] The top of the bag extends to form a suspension wing, which has suspension holes covered with a tear-resistant coating;

[0012] The front surface of the bag is provided with a laser anti-counterfeiting mark area, and a pressure balancing device is embedded on the side.

[0013] The bag body has a five-layer composite structure, which includes, in sequence, an abrasion-resistant layer, a barrier layer, a puncture-resistant layer, a high-barrier layer, and a heat-sealing layer.

[0014] A further improvement is that the pressure balancing device includes a valve body base and an elastic limiting sleeve disposed in the valve cavity. The elastic limiting sleeve is provided with an array of vent holes in its circumference, and a one-way flow guide component is connected to its front end. The flow guide component is provided with an umbrella-shaped check diaphragm made of polytetrafluoroethylene. The valve body base is connected to an air inlet pipe.

[0015] A further improvement is that, in the five-layer composite structure, the wear-resistant layer is a biaxially oriented polyester film, the barrier layer is a 9-12μm aluminum foil layer, the puncture-resistant layer is a biaxially oriented nylon film, the high-barrier layer is an ethylene-vinyl alcohol copolymer layer, and the heat-sealing layer is a modified polyethylene material.

[0016] A further improvement is that the male and female sealing strips of the interlocking sealing mechanism have a trapezoidal concave-convex fit structure, the depth of the limiting groove is 1.2-1.5 times the height of the sealing strip, and the surface of the sealing strip is provided with a silicone wear-resistant coating.

[0017] Further improvements include: a reinforcing rib structure at the connection between the suspension wing and the bag body; an aramid fiber reinforcing membrane surrounding the suspension hole; and a tear-resistant coating with a thickness of 80-120 μm.

[0018] Further improvements include: the opening pressure of the umbrella-shaped check diaphragm is 0.5-1.2 kPa; a stainless steel helical spring is provided between the elastic limiting sleeve and the valve body base; and the diameter of the array-type vent holes is 0.3-0.5 mm and they are distributed at a 45° oblique angle.

[0019] 3. Beneficial effects:

[0020] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0021] (1) Improved ease of opening and tear resistance

[0022] The wavy pre-indentation structure reduces the tearing force to 2.8N (measured value) through waveform stress dispersion, resulting in a straight and controllable tear.

[0023] The semi-circular stress-dispersing notch effectively prevents tearing and extension, while the laser-sealed edge of the notch further prevents delamination.

[0024] (2) High reliability of sealing and durability

[0025] The trapezoidal concave-convex interlocking sealing mechanism, combined with the limiting slot design, achieves precise alignment and prevents excessive compression. The silicone wear-resistant coating allows the sealing strip to be repeatedly opened and closed more than 250 times, with a leakage rate of less than 0.1 mL / min.

[0026] The distance between the sealing strip and the easy-tear line is optimized to 5-8mm to avoid stress interference in the heat-sealing area.

[0027] (3) Synergistic protection of multi-layer composite membranes

[0028] The five-layer composite structure (abrasion-resistant layer / aluminum foil layer / puncture-resistant layer / EVOH layer / heat-sealing layer) achieves multiple functions such as abrasion resistance, high oxygen barrier (oxygen permeability <5cm³ / m²·24h·atm), puncture resistance (puncture resistance ≥30N) and low-temperature heat sealing.

[0029] (4) Intelligent pressure balancing and explosion-proof design

[0030] The pressure balancing device uses an umbrella-shaped check valve (opening pressure 0.5-1.2 kPa) and an elastic limiting sleeve to achieve vacuuming (oxygen content ≤0.3%) and automatic pressure relief during microwave heating (pressure stabilized below 1.2 kPa), significantly reducing the risk of bag bursting.

[0031] (5) High-strength suspension and anti-counterfeiting guarantee

[0032] The suspension holes are reinforced with a composite aramid fiber membrane and coated with a tear-resistant coating, enabling them to withstand a tensile force of 15kg, which is 200% higher than ordinary designs.

[0033] Laser anti-counterfeiting labels combined with QR code encryption technology enhance brand protection capabilities.

[0034] It should be noted that the structures not described in this utility model are the same as or can be implemented using existing technology, and will not be elaborated here, as they do not involve the design points and improvement directions of this utility model. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0036] Figure 2 This is a schematic diagram of the structure of the five-layer composite film of the bag body of this utility model;

[0037] Figure 3 This is a schematic diagram of the pressure balancing device of this utility model.

[0038] Explanation of the labels in the diagram:

[0039] 1. Bag body; 11. Abrasion-resistant layer; 12. Barrier layer; 13. Puncture-resistant layer; 14. High-barrier layer; 15. Heat-sealing layer;

[0040] 2. Easy-opening structure;

[0041] 3. Fitting sealing mechanism;

[0042] 4. Suspension flaps; 5. Suspension holes;

[0043] 6. Pressure balancing device; 61. Valve body base; 62. Air inlet pipe; 63. Elastic limiting sleeve; 64. Array-type vent holes; 65. One-way flow guide assembly; 66. Umbrella-shaped check diaphragm;

[0044] 7. Laser anti-counterfeiting label area. Detailed Implementation

[0045] To facilitate understanding of this utility model, a more comprehensive description of the utility model will be given below with reference to the accompanying drawings, which show several embodiments of the utility model. However, the utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the utility model will be more thorough and complete.

[0046] The purpose of this utility model is to provide a composite film food packaging bag that is easy to tear, has reliable sealing, supports dynamic pressure adjustment, and has anti-counterfeiting function.

[0047] 1. Composite film preparation and bag forming

[0048] Step 1.1: Co-extrusion molding of five-layer composite film

[0049] Stacked in sequence:

[0050] (1) Abrasion-resistant layer 11: biaxially oriented polyester film (thickness 12μm), surface corona treatment (dyne value ≥50);

[0051] (2) Barrier layer 12: Aluminum foil layer (thickness 10μm), which is bonded to the wear-resistant layer by a dry composite process, and the adhesive is polyurethane (coating amount 3.5g / m²).

[0052] (3) Puncture-resistant layer 13: Biaxially oriented nylon film (thickness 15μm), interlayer bonding strength ≥4N / 15mm;

[0053] (4) High barrier layer 14: EVOH layer (ethylene content 44%, thickness 8μm), hot-melt composite with puncture-resistant layer;

[0054] (5) Heat-sealing layer 15: Modified polyethylene (melting point 110℃, thickness 20μm).

[0055] Composite process parameters: curing temperature 50℃×48h, composite roller pressure 0.8MPa, linear speed 15m / min.

[0056] Step 1.2: Processing of the easy-open structure 2

[0057] (1) Use a molding roller (temperature 80℃, pressure 3MPa) to press a wavy pre-indentation on the top of the bag (wavelength 2mm, crest height 0.12mm).

[0058] (2) Punch a semi-circular stress dispersion notch (5mm in diameter) at the end of the pre-indentation, and laser seal the edge of the notch to prevent delamination.

[0059] When in use, its wavy structure reduces the tearing force to 2.8N (measured value), and the stress gap prevents the tear from extending to non-target areas.

[0060] 2. Installation of the interlocking sealing mechanism 3

[0061] Step 2.1: Injection molding of male and female sealing strips

[0062] Materials: The male strip is made of modified PP (hardness Shore D65), and the female strip is made of TPE (hardness Shore A70).

[0063] Structure: The cross-section is trapezoidal with concave and convex fit (convex height 1.2mm, groove depth 1.5mm), and the surface is coated with a silicone wear-resistant coating (thickness 50μm).

[0064] Step 2.2: Hot melt welding of sealing strip

[0065] (1) Weld the male and female sealing strips to the top two sides of the bag body respectively (6mm away from the tear line).

[0066] (2) Welding parameters: temperature 150℃, pressure 0.5MPa, holding time 3 seconds;

[0067] (3) Synchronous molding limiting slot (depth 1.8mm), with a silicone buffer pad (thickness 0.3mm) pre-placed inside the slot.

[0068] Operation process:

[0069] (1) When the user presses the male and female strips, the trapezoidal structure guides the precise fitting, and the limiting groove prevents excessive squeezing and deformation;

[0070] (2) The silicone coating reduces friction loss and can maintain its sealing performance after being opened and closed 250 times (leakage rate <0.1mL / min).

[0071] 3. Pressure balancing device 6 assembly

[0072] Step 3.1: Pre-assembly of valve body assembly

[0073] (1) Valve body base 61: Injection molded PP material (temperature resistant 130℃), base outer diameter 10mm, with internal threaded interface;

[0074] (2) Elastic limiting sleeve 63: made of silicone, with 45° beveled vent holes in the circumference (hole diameter 0.4mm, hole spacing 1.2mm).

[0075] (3) Umbrella-shaped check membrane 66: PTFE membrane (thickness 0.05mm), fixed to the front end of the flow guide assembly by laser welding.

[0076] Step 3.2: Device Integration

[0077] (1) Make a hole (8mm in diameter) on the side of the bag body and fix the valve body base 61 by ultrasonic welding (frequency 20kHz, amplitude 40μm, welding time 0.5 seconds).

[0078] (2) Install the stainless steel spiral spring, elastic limit sleeve 63 and flow guide assembly 65 in sequence, and finally tighten the air inlet pipe 62.

[0079] Operation process and effects

[0080] (1) Vacuuming mode: An external vacuum pump pipe is connected, and one end of the pipe is inserted into the inside of the umbrella-shaped check membrane 66. The umbrella-shaped check membrane 66 expands inward under the pressure of the pipe and opens. Air is drawn out through the air inlet pipe 62, and the oxygen content in the bag drops to 0.3% (actual value). When the vacuum pump pipe is removed, the umbrella-shaped check membrane 66 closes again to achieve a seal.

[0081] (2) Microwave heating mode: When the steam pressure inside the bag is ≥0.8kPa, the elastic limiting sleeve 63 is automatically pushed out under pressure. At this time, the stainless steel spiral spring is stretched and deformed. Then the steam pressure inside the bag is released through the vent hole 64 on the side of the elastic limiting sleeve 63 to prevent the bag from bursting (the pressure is stable below 1.2kPa). When the steam pressure decreases to below the threshold, the stainless steel spiral spring drives the elastic limiting sleeve 63 to reset and retract to the valve body base 61.

[0082] (3) Daily sealing: The spring provides a 0.5N preload force, so that the elastic limit sleeve 63 is tightly fitted and stored inside the valve body base 61 under normal conditions, and the vent hole 64 cannot release other things to the outside. At the same time, the umbrella-shaped check membrane 66 is closed when subjected to resistance, blocking external oxygen penetration (oxygen permeability < 5cm³ / m²·24h·atm).

[0083] 4. Reinforcement treatment of suspension winglets 4

[0084] Step 4.1: Wing Forming

[0085] The top extension of the bag body is die-cut into a wing (25mm wide), and the connection is reinforced with a heat-pressed reinforcing rib (3mm wide, 0.5mm high).

[0086] After the suspension hole 5 is punched, a polyurethane tear-resistant coating (100μm thick) is applied around it, and an aramid fiber reinforced film (20g / m²) is laminated on it.

[0087] When in use, the suspension hole 5 can withstand a pulling force of 15kg (actual value), which is 200% higher than the ordinary design, making it suitable for the hanging needs of large-capacity packaging.

[0088] 5. Overall bag sealing and inspection

[0089] Step 5.1: Three-sided heat sealing

[0090] (1) The bottom edge and both sides of the bag are pulse heat sealed (temperature 180℃, pressure 0.6MPa, sealing time 2 seconds), and the sealing width is 8mm;

[0091] (2) After sealing, pressurize and test (pressure 0.1MPa). If there is no leakage after holding the pressure for 10 minutes, it is considered qualified.

[0092] Step 5.2: Anti-counterfeiting label processing

[0093] Laser hot stamping (energy density 15J / cm²) is performed on a reserved area on the front surface of the bag to form a laser anti-counterfeiting label area containing a QR code.

[0094] The above-described embodiments are merely illustrative of certain implementations of this utility model, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A composite film food packaging bag with an easy-tear line, comprising a bag body (1), characterized in that: The top side of the bag (1) is provided with an easy-opening structure (2) consisting of a wavy pre-indentation, and the end of the easy-opening structure (2) is provided with a semi-circular stress dispersion notch. The top two sides of the bag body (1) are equipped with a fitting sealing mechanism (3), which includes interlocking male and female sealing strips and a limiting groove, and is located 5-8mm below the easy-opening structure (2). The top of the bag body (1) extends to form a suspension wing (4), which has a suspension hole (5) covered with a tear-resistant coating. The front surface of the bag (1) is provided with a laser anti-counterfeiting mark area (7), and a pressure balancing device (6) is embedded on the side. The bag body (1) has a five-layer composite structure, which includes an anti-wear layer (11), a barrier layer (12), an anti-puncture layer (13), a high barrier layer (14), and a heat-sealing layer (15) in sequence.

2. The composite film food packaging bag with a tear line according to claim 1, characterized in that: The pressure balancing device (6) includes a valve body base (61) and an elastic limiting sleeve (63) disposed in the valve cavity. The elastic limiting sleeve (63) is provided with an array of vent holes (64) in the circumferential direction, and its front end is connected to a one-way flow guide assembly (65). The one-way flow guide assembly is provided with an umbrella-shaped check membrane (66) made of polytetrafluoroethylene. The valve body base (61) is connected to an air inlet pipe (62).

3. A composite film food packaging bag with an easy-tear line according to claim 1, characterized in that: In the five-layer composite structure, the wear-resistant layer (11) is a biaxially oriented polyester film, the barrier layer (12) is a 9-12μm aluminum foil layer, the puncture-resistant layer (13) is a biaxially oriented nylon film, the high barrier layer (14) is an ethylene-vinyl alcohol copolymer layer, and the heat-sealing layer (15) is a modified polyethylene material.

4. The composite film food packaging bag with a tear line according to claim 1, characterized in that: The male and female sealing strips of the interlocking sealing mechanism (3) have a trapezoidal concave-convex fit structure, the depth of the limiting groove is 1.2-1.5 times the height of the sealing strip, and the surface of the sealing strip is provided with a silicone wear-resistant coating.

5. The composite film food packaging bag with a tear line according to claim 1, characterized in that: The connection between the suspension wing (4) and the bag body (1) is provided with a reinforcing rib structure, the suspension hole (5) is surrounded by an aramid fiber reinforced membrane, and the thickness of the tear-resistant coating is 80-120μm.

6. A composite film food packaging bag with a tear line according to claim 2, characterized in that: The opening pressure of the umbrella-shaped check diaphragm (66) is 0.5-1.2 kPa. A stainless steel spiral spring is provided between the elastic limiting sleeve (63) and the valve body base (61). The diameter of the array-type vent holes (64) is 0.3-0.5 mm and they are distributed at a 45° oblique angle.

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