Tear-resistant vacuum compression bag

Abstract

The utility model relates to a tear-resistant vacuum compression bag which comprises a front piece, a rear piece and a bottom piece. Wherein after being folded inwards, the rectangular bottom piece is provided with an upwards arched central fold line, a forward half piece and a backward half piece, more than one arc opening is cut at the corresponding positions of the two side edges of the forward half piece and the backward half piece, and the front piece and the rear piece are directly contacted through the surfaces of the arc openings after being folded in place; the forward half piece and the backward half piece of the bottom piece are correspondingly welded with the two lower corners of the front piece and the rear piece in an arc mode to form an arc welding section, and solid welding blocks with arcs facing the interior of the bag are welded to the arc welding section at the starting points of the two side edges; the front piece and the rear piece are welded together in a hot melting mode at least through the arc openings on the circular arc welding sections of the bottom piece. The tear resistance of the vacuum compression bag is improved through arc welding of the four corners of the bottom piece and solid welding blocks at the intersections of the two layers and the four layers.

Description

Technical Field:

[0001] The utility model belongs to the technical field of bag making, and particularly relates to an anti-tearing vacuum compression bag, especially an improvement of a stand-up bag. Background Art:

[0002] In real life, the storage of items such as quilts and clothes requires a large amount of storage space. Vacuum compression bags can effectively reduce the volume occupied by items during storage, save a large amount of space, and at the same time can classify and store items in an orderly manner. At present, most of the vacuum compression bag products on the market are made of PA / / PE, PET / / PE or multi-layer co-extruded films of PA and PE. Due to the limitations of material properties, problems such as breakage, air leakage, and poor sealing often occur during the use of the products, affecting the secondary use of the products.

[0003] How to strengthen it structurally has become the object of research of the present invention. Summary of the Invention:

[0004] The purpose of the utility model is to design an anti-tearing vacuum compression bag in which the front and rear pieces of the bag body and the bottom piece are arc-welded.

[0005] The technical solution of the utility model is realized as follows: an anti-tearing vacuum compression bag, including a front piece, a rear piece and a bottom piece cut into a rectangle; the upper parts of the two sides of the front piece and the rear piece are mutually heat-sealed and welded to form an upper welding section, and the top forms a bag mouth, and mutually matching sealing zippers are compounded on the inner surfaces of the front piece and the rear piece at the bag mouth; its characteristics are: after the rectangular bottom piece is folded inwards, it has a central fold line that arches upwards, a front half piece and a rear half piece. One or more arc-shaped openings are cut at the corresponding positions on the two sides of the front half piece and the rear half piece. Before folding in place, the front piece and the rear piece directly contact through the surface of the arc-shaped opening; the front half piece and the rear half piece of the bottom piece are correspondingly arc-welded with the two lower corners of the front piece and the rear piece to form an arc welding section. At the starting points of the two sides of the arc welding section, solid welding blocks with arcs facing the inside of the bag are welded; the front piece and the rear piece are at least heat-sealed and welded together through the arc-shaped opening at the arc welding section with the bottom piece.

[0006] The arc welding section between the front piece, the rear piece and the bottom piece starts from the central fold line of the bottom piece, and a solid welding block is welded here.

[0007] The solid welding block has a square head end and a round head end, and the round head end faces inwards and protrudes into the bag body.

[0008] The arc-shaped openings cut on the front half piece and the rear half piece of the bottom piece are not larger than semi-circular openings.

[0009] The front piece, the rear piece and the bottom piece are all composed of a composite of a PA film and a PE film, and the PE film faces the inside of the bag.

[0010] The PA film is a BOPA film produced by a step-by-step mechanical stretching method; the PE film is a three-layer co-extruded film, and the three layers from the inside to the outside are the corona layer, the reinforcing layer, and the heat-sealing layer respectively.

[0011] The PA film and the PE film are dry-compounded and coated with a polyurethane adhesive, and the amount of glue applied is 2.0 - 2.5 g / ㎡.

[0012] The arc welding segments formed by arc welding at the four corners of the negative film of the present utility model can effectively disperse the stress at local positions and avoid the problem of breakage during use; and at the starting point of the arc welding segments, solid welding blocks are added to solve the problem of incomplete heat sealing at the intersection of two layers and four layers of films, and improve the tear resistance of the vacuum compression bag. Description of the drawings:

[0013] The present invention will be further described below with specific illustrations:

[0014] Figure 1 It is a schematic diagram of a tear-resistant vacuum compression bag

[0015] Figure 2 It is a schematic diagram of the decomposition of the sheet material of the tear-resistant vacuum compression bag

[0016] Figure 3 It is a schematic diagram of the cross-section of the sheet material

[0017] Among them

[0018] 1 - front piece; 11 - upper welding segment;

[0019] 2 - rear piece;

[0020] 3 - negative film; 31 - front half piece; 32 - rear half piece; 33 - center fold line; 34 - arc opening;

[0021] 35 - arc welding segment;

[0022] 4 - bag mouth; 5 - sealing zip; 6 - air inlet / outlet;

[0023] 7 - solid welding block; 71 - square head end; 72 - round head end;

[0024] 8 - PA film; 81 - polyurethane adhesive;

[0025] 9 - PE film; 91 - corona layer; 92 - reinforcing layer; 93 - heat-sealing layer; Specific embodiments:

[0026] Referring to Figure 1 and Figure 2 In the figure, the dotted line is the inner edge along the hot melt welding.

[0027] Tear-resistant vacuum compression bag, comprising a front piece 1, a rear piece 2 and a bottom piece 3 which are cut into a rectangle; the upper parts of both sides of the front piece 1 and the rear piece 2 are heat-sealed and welded to form an upper welded section 11, and the top forms a bag opening 4. On the inner surfaces of the front piece and the rear piece at the bag opening 4, there are mutually cooperating sealing zippers 5, and an air inlet / outlet 6 is provided on the front piece 1. This is also the existing conventional design and composition.

[0028] Among them: after the rectangular bottom piece 3 is folded inwards, it has a centrally folded line 33 that arches upwards, a front half piece 31 and a rear half piece 32. One or more arc openings 34 are cut at corresponding positions on both sides of the front half piece 31 and the rear half piece 32. In the figure, there are two arc openings; before folding in place, the front piece 1 and the rear piece 2 are in direct contact through the surface of the arc openings, which can not only ensure the contact of the heat-sealing surface, but also only have two layers of heat-sealing and welding composite; the front half piece 31 and the rear half piece 32 of the bottom piece 3 are arc-welded to the two lower corners of the front piece 1 and the rear piece 2 to form an arc welded section 35. At the starting points of both sides of the arc welded section 35, there are solid welded blocks 7 with the arcs facing the inside of the bag, ensuring that the gaps at the intersection of the two layers and the four layers of the film are completely heat-sealed; the front piece 1 and the rear piece 2 are heat-sealed and welded together at least through the arc openings 34 with the arc welded section 35 of the bottom piece 3; that is, within the range of the arc welded section 35, the front piece 1 and the rear piece 2 are only spot-welded together according to the arc openings 34, and the gap remains soft and convenient for folding when standing. In addition, the arc openings 34 cut out from the front half piece 31 and the rear half piece 32 of the bottom piece are not larger than semi-circular openings.

[0029] Further, the arc welded section 35 between the front piece 1 and the rear piece 2 and the bottom piece 3 starts from the centrally folded line 33 of the bottom piece, and a solid welded block 7 is welded here. At the intersection of the upper welded section 11, the arc welded section 35 and the centrally folded line 33, adding a solid welded block 7 can not only eliminate the gap formed by the drop of the multi-layer intersection, but also restrain the bottom piece 3 and improve the integrity, especially the load-bearing capacity of the bottom piece.

[0030] More specifically, the solid welded block 7 has a square head end 71 and a round head end 72. The round head end 72 faces inwards and protrudes into the bag body, which is beneficial to the smooth distribution of stress at the intersection point and effectively avoids tearing at the intersection point.

[0031] The above structural settings have the following functions:

[0032] First, the four corners of the bottom piece 3 are welded in a circular arc. When filling the items and squeezing forcefully towards the inside, it will generate a large shear stress on the heat-sealed edge at the bottom. The circular arc welded bottom can effectively disperse the stress at the local position and avoid the problem of damage during use;

[0033] II. Solid welding block 7, which is the intersection point of two layers and four layers of thin films. During normal production, due to the height difference between the thick and thin films, the heat-sealing knife cannot completely compact the two layers of thin films during hot pressing (very small gaps, near the four-layer film). Therefore, it may lead to poor sealing of the seal, and there may be a slow air leakage phenomenon during use. Using a small-area solid welding block can increase the pressure at the hot-pressing position and ensure that the gaps that are not completely heat-sealed are completely heat-sealed. At the same time, the arc-shaped welding block avoids the stress concentration problem at the intersection point and effectively avoids the tearing problem at the intersection point during use.

[0034] III. Arc-shaped opening 34 can heat-seal the thin films on both the front and back sides of the bag. Moreover, it is distributed in a spaced manner, enabling the bottom to stand in the form of an accordion.

[0035] Furthermore, the following selections are made for the thin film material and processing method of the bag body:

[0036] Refer to Figure 3 , the front piece 1, the back piece 2, and the bottom piece 3 are all composed of a composite of PA film 8 and PE film 9, and the PE film 9 faces the inside of the bag. Among them, the PA film 8 is a BOPA film produced by the step-by-step mechanical stretching method; the PE film 9 is a three-layer co-extruded film, and the three layers from the inside to the outside are the corona layer 91, the reinforcement layer 92, and the heat-sealing layer 93 respectively.

[0037] The PA film 8 and the PE film 9 are compounded by the dry method and coated with polyurethane adhesive 81, and the amount of glue applied is 2.0 - 2.5 g / ㎡. The selection of materials and processes has the following beneficial effects:

[0038] (1) The PA film selects a BOPA film produced by the step-by-step mechanical stretching method. The film produced by this process is mainly reflected in that compared with the BOPA film produced by the synchronous stretching method, it has higher tensile strength and puncture strength, providing better protection for the surface layer of the product; if there is a printed pattern, it can be on the inner surface of the PA film, between the polyurethane adhesives 81.

[0039] (2) The inner-layer PE film selects a three-layer co-extruded PE film with ultra-low temperature and high softness. Through the design of the formula, the film is divided into three-layer structures, namely the corona layer, the reinforcement layer, and the heat-sealing layer; among them:

[0040] Corona layer: This layer is in direct contact with the glue and the PA film. Through the design of the formula, it is ensured that the melting point of the material of this layer is about 130 °C, avoiding heat-sealing defects (shearing phenomenon) due to the material not being temperature-resistant during heat-sealing;

[0041] Reinforcement layer: This layer mainly adds high-strength metallocene materials and some inorganic fillers to improve the overall tensile strength and puncture resistance of the entire PE film. At the same time, it has a certain heat resistance to ensure that the melting temperature of the material is between 120 - 125 °C, avoiding heat-sealing defects (shearing phenomenon) due to the material's lack of heat resistance during heat sealing.

[0042] Heat-sealing layer: This layer mainly ensures that the product has excellent sealing performance and an ultra-low heat-sealing temperature. By introducing SEBS / POE thermoplastic elastomers, it ensures that the PE film has a soft characteristic, while effectively reducing the heat-sealing temperature of the film. It ensures that the melting point of this layer of film is between 95 - 100 °C, effectively protecting the other two layers from heat-sealing defects during heat sealing. At the same time, the introduction of thermoplastic elastomer materials can improve the sealing performance of the product. Due to the relatively high melt strength and strong thermal viscosity of this material, it can effectively avoid the problem of sealing shear during heat sealing.

[0043] In terms of process, since the material structure is a PA / / PE structure, the required composite process plays a decisive role in the quality of the entire product itself.

[0044] (1) Composite process: The dry composite process is selected for production. Since the dry composite process quickly passes through a high-temperature hot press roller for lamination after coating the glue, it can effectively increase the activation energy of the polyurethane adhesive and improve the composite strength between product layers.

[0045] (2) Selection of adhesive: The dry composite polyurethane adhesive is selected. Since there are more -OH (alcohol hydroxyl) groups in the macromolecular groups of the adhesive for dry composite, for high-molecular adhesives, it can improve the softness of the adhesive layer after curing, which is of great help in improving the overall softness of the product.

[0046] In addition, the polyurethane adhesive for dry composite has a relatively large molecular weight and forms a high-strength cross-linked network structure after curing, effectively improving the composite strength of the product.

[0047] (3) The amount of glue applied is controlled at 2.0 - 2.5 g / ㎡. A lower amount of glue applied can make the adhesive layer thinner, avoiding the influence of an overly thick adhesive layer structure on the final softness of the product.

Claims

1. An anti-tear vacuum compression bag, comprising a front piece, a rear piece and a bottom piece which are cut into a rectangle; an upper welding section is formed by thermally fusing and welding a section of the upper parts of the two side edges of the front piece and the rear piece, a bag opening is formed at the top, and mutually cooperating sealing zippers are compounded on the inner surfaces of the front piece and the rear piece at the bag opening; characterized in that: After the rectangular negative film is folded inwards, it has a central fold line that arches upwards, a front half piece and a rear half piece. One or more arc-shaped openings are cut at corresponding positions on both sides of the front half piece and the rear half piece. Before folding in place, the front piece and the rear piece are in direct contact through the surface of the arc-shaped openings; the front half piece and the rear half piece of the negative film are arc-welded to the lower corners of the front piece and the rear piece to form arc-welded segments. At the starting points of the two sides of the arc-welded segments, solid solder blocks with arcs facing into the bag are welded; the front piece and the rear piece are heat-sealed together at least through the arc-shaped openings with the arc-welded segments of the negative film.

2. The anti-tear vacuum compression bag according to claim 1, wherein: The arc-welded segments between the front piece, the rear piece and the negative film start from the central fold line of the negative film, and solid solder blocks are welded here.

3. The anti-tear vacuum compression bag according to claim 1 or 2, characterized in that: The solid solder block has a square head end and a round head end, and the round head end faces inwards and protrudes into the bag body.

4. The anti-tear vacuum compression bag according to claim 1 or 2, wherein: The arc-shaped openings cut in the front half piece and the rear half piece of the negative film are not larger than semi-circular openings.

5. The anti-tear vacuum compression bag according to claim 1 or 2, characterized in that: The front piece, the rear piece and the negative film are all composed of a composite of PA film and PE film, and the PE film faces into the bag.

6. The anti-tearing vacuum compression bag according to claim 5, characterized in that: The PA film is a BOPA film produced by a step-by-step mechanical stretching method; the PE film is a three-layer co-extruded film, and the three layers from the inside to the outside are a corona layer, a reinforcement layer and a heat-sealing layer respectively.

7. The anti-tear vacuum compression bag according to claim 6, wherein: The PA film and the PE film are compounded by a dry method and coated with a polyurethane adhesive, and the amount of glue applied is 2.0 - 2.5 g / ㎡.

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