Composite film and packaging bag

Abstract

The utility model discloses a composite film and a packaging bag. The composite film comprises a base film and at least two first film covering sections. The base film is strip-shaped, the length of the base film is arranged along a first direction, and the width of the base film is arranged along a second direction; the at least two first film covering sections are arranged on one side of the base film and arranged in the first direction, the first film covering sections are rectangular, the tensile strength of the base film in the first direction is larger than that of the first film covering sections in the first direction, and the tensile strength of the base film in the second direction is smaller than that of the first film covering sections in the second direction. In the production process, one strip-shaped film material is cut into a plurality of rectangular first film covering sections in the width direction, the first film covering sections are rotated by 90 degrees and then are arranged and attached to one side of the base film, two strip-shaped composite films with high tensile strength in the orthogonal direction are formed, waste edges cannot be generated in the production process of the composite films, and the production efficiency of the composite films is improved. Therefore, material waste during production can be reduced, the material utilization rate is improved, and production procedures are simplified.

Description

Technical Field

[0001] The utility model relates to the field of stretch films, in particular to a composite film and a packaging bag. Background Art

[0002] Stretch film is often used in packaging items to cover and protect items and fix the position of items. Stretch film can be produced by the blown film method, which is to extrude the molten plastic through an extruder and blow it to form a cylindrical original film. The original film is then stretched twice through a stretching process to form a stretch film, which is then wound into a tube film roll, and then cut and rolled into two strip-shaped tube film rolls. According to the different stretching directions, stretch film is divided into longitudinal stretch film and transverse stretch film. Compared with the original film, the tensile strength of the longitudinal stretch film along its length direction is increased while the tensile strength along its width direction is decreased, while the tensile strength of the transverse stretch film along its width direction is increased while the tensile strength along its length direction is decreased.

[0003] Generally, the production cost of longitudinal stretch film is much lower than that of transverse stretch film. In order to produce a film material with low cost and high tensile strength in both directions, there is a composite film made by stacking stretch films. The film roll of the longitudinal stretch film is cut in a spiral manner to form a plurality of parallelogram-shaped film sheets. Two film sheets are selected and one of them is turned over. The two film sheets are then stacked and connected together to form a composite film with high tensile strength in two orthogonal directions. However, during the production process of this composite film, the edges of the two film sheets are not completely overlapped, and there are a small amount of waste edge areas on each of the two film sheets. The waste edge areas need to be cut off during production, resulting in material waste. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a composite film that can reduce material waste during production.

[0005] The utility model also provides a packaging bag having the above-mentioned packaging bag.

[0006] According to the composite film of the first embodiment of the utility model, the composite film comprises a base film and at least two first film sections. The base film is strip-shaped and its length is arranged along the first direction, and the width of the base film is arranged along the second direction; at least two first film sections are arranged on one side of the base film and arranged along the first direction, the first film section is rectangular, the tensile strength of the base film along the first direction is greater than the tensile strength of the first film section along the first direction, and the tensile strength of the base film along the second direction is less than the tensile strength of the first film section along the second direction.

[0007] The composite film according to the embodiment of the first aspect of the utility model has at least the following beneficial effects: during production, one of the strip-shaped film materials is cut along the width direction to form a plurality of rectangular first coating sections, and the first coating sections are rotated 90 degrees and arranged and coated on one side of the base film to form a strip-shaped composite film with high tensile strength in two orthogonal directions. No waste edges will be generated during the production of such a composite film, thereby reducing material waste during production, improving material utilization and simplifying the production process, and can improve the tensile strength of the base film in the second direction, so that the tensile strength of the composite film in the first direction and the second direction are relatively high, so that the composite film can withstand greater impact and puncture external forces.

[0008] According to some embodiments of the utility model, the base film and the first coating segment are both longitudinally stretched films and their stretching directions are perpendicular to each other; the first coating segment is formed by cutting an auxiliary film, and the auxiliary film and the base film are formed by cutting the same type of tubular film roll.

[0009] According to some embodiments of the present invention, the base film is a longitudinally stretched film, and the first coating section is an original film that has not been stretched for a second time.

[0010] According to some embodiments of the present invention, edges of two adjacent first coating sections are aligned, or two adjacent first coating sections partially overlap.

[0011] According to some embodiments of the present invention, the base film and the first coating segment are made of polyethylene.

[0012] According to some embodiments of the present invention, the width of the base film is A, and the dimension of the first coating section along the first direction is B, satisfying A=B.

[0013] According to some embodiments of the utility model, it also includes a second coating, which is in a strip shape and its length is set along the first direction, the width of the second coating is set along the second direction, all the first coating segments are set on one side of the second coating, the first coating segment is located between the base film and the second coating, and the base film and the second coating are both longitudinally stretched films and the stretching directions of the two are parallel.

[0014] According to some embodiments of the present invention, the thickness of the base film is C, the thickness of the first coating section is D, and the thickness of the second coating section is E, satisfying C+E=D.

[0015] According to some embodiments of the present invention, the thickness of the base film is C, the thickness of the first coating section is D, and the thickness of the second coating section is E, satisfying C=D=E.

[0016] The packaging bag according to the embodiment of the second aspect of the utility model adopts the above-mentioned composite film.

[0017] The packaging bag according to the embodiment of the second aspect of the utility model has at least the following beneficial effects: due to the use of the above-mentioned composite film, the packaging bag reduces material waste during production, improves material utilization and simplifies the production process, can withstand greater impact and puncture external forces, and has a stronger storage capacity.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 It is a top view schematic diagram of a double-layer composite membrane of the first embodiment of the utility model;

[0021] Figure 2 It is a schematic front view of a double-layer composite membrane according to the first embodiment of the utility model;

[0022] Figure 3 A schematic top view of a three-layer composite membrane according to a second embodiment of the present invention;

[0023] Figure 4 It is a front view schematic diagram of a three-layer composite membrane of the second embodiment of the utility model.

[0024] Reference numerals:

[0025] Basement membrane 100;

[0026] A first coating section 200;

[0027] A second coating 300;

[0028] The stretching direction of the base film is 400;

[0029] The stretching direction 500 of the first coating section;

[0030] The stretching direction 600 of the second coating. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In the description of the present invention, it should be understood that the descriptions involving orientation, such as the orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] In the description of the present utility model, "a plurality" means more than two. If there is a description of "first" or "second", it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0035] During the stretching process, the stretch film will be strengthened by drawing, that is, the molecular chains will be preferentially oriented, so it will be oriented in a certain direction during the processing. Therefore, the tensile strength in a certain direction is very high, and the tensile strength in the direction perpendicular to it is very low. At present, the film material stretched along the length direction is called longitudinal stretch film, and the film material stretched along the width direction is called transverse stretch film. The production cost and processing difficulty of longitudinal stretch film are much lower than those of transverse stretch film, so longitudinal stretch film is widely used in the market.

[0036] There is another composite film on the market, which is a composite film formed by directly overlapping and connecting a longitudinally stretched film and a transversely stretched film to form a composite film with good tensile strength in two orthogonal directions. However, due to the high production cost of the transversely stretched film, the overall manufacturing cost of this composite film is high.

[0037] Reference Figure 1 to Figure 2 , is a composite film of an embodiment of the utility model, comprising a base film 100 and at least two first film sections 200. The base film 100 is in a strip shape and its length is arranged along the first direction, and the width of the base film 100 is arranged along the second direction; at least two first film sections 200 are arranged on one side of the base film 100 and arranged along the first direction, the first film section 200 is rectangular, the tensile strength of the base film 100 along the first direction is greater than the tensile strength of the first film section 200 along the first direction, and the tensile strength of the base film 100 along the second direction is less than the tensile strength of the first film section 200 along the second direction.

[0038] During production, one of the strip-shaped film materials is cut along the width direction to form a plurality of rectangular first film sections 200, and the first film sections 200 are rotated 90 degrees and arranged to be attached to one side of the base film 100, forming two strip-shaped composite films with high tensile strength in orthogonal directions. No waste edges are generated during the production of such composite films, thereby reducing material waste during production, improving material utilization and simplifying the production process. Moreover, the composite film can be formed into a film roll, which is convenient for cutting and selecting the length of use as needed. In addition, the tensile strength of the base film 100 in the second direction is improved by the first film section 200, so that the tensile strength of the composite film in the first direction and the second direction is relatively high, so that the composite film can withstand greater impact and puncture external forces.

[0039] Specifically, two, three, four or more first coating segments 200 can be arranged along the first direction on one side of the base film 100. The first coating segment 200 should fully cover one side of the base film 100. Those skilled in the art can make specific configurations according to actual needs.

[0040] In some embodiments, the base film 100 and the first film covering section 200 are both longitudinally stretched films and the stretching directions of the two are perpendicular to each other. Since the longitudinally stretched film has a high tensile strength in the longitudinal direction, the first film covering section 200 is rotated 90° and overlapped and connected to the base film 100, so that the tensile strength of the composite film in the length direction and the width direction is high, and since the base film 100 and the first film covering section 200 are both longitudinally stretched films, the production cost of the composite film is low.

[0041] In other embodiments, the base film 100 is a longitudinally stretched film, and the first film covering section 200 is an original film that has not been stretched twice. When the base film 100 is a longitudinally stretched film and the first film covering section 200 is an original film that has not been stretched twice, after the base film 100 and the first film covering section 200 are superimposed, since the tensile strength of the original film along the second direction is greater than the tensile strength of the base film 100 along the second direction, the formed composite film also has the effect of improving the tensile strength of the base film 100 along the second direction, thereby improving the tensile strength of the composite film in two orthogonal directions.

[0042] In other embodiments, the base film 100 may be an original film that has not been stretched for the second time, and the first coating section 200 uses a longitudinally stretched film rotated 90 degrees. After the base film 100 and the first coating section 200 are superimposed, the formed composite film also has the effect of improving the tensile strength of the base film 100 along the second direction, thereby improving the tensile strength of the composite film in two orthogonal directions.

[0043] In the embodiment, the edges of two adjacent first film sections 200 are aligned, or the two adjacent first film sections 200 partially overlap. When the edges of two adjacent first film sections 200 are aligned, or the two adjacent first film sections 200 partially overlap, the second direction tensile strength improvement effect of the composite film can be spread over the entire base film 100, and the second direction tensile strength improvement effect is relatively balanced.

[0044] In the embodiment, the base film 100 and the first film segment 200 are made of polyethylene, which is light in weight, has good flexibility, is chemically stable, and has low material cost. It is conceivable that the base film 100 and the first film segment 200 can also be made of other materials, such as polyvinyl chloride, polypropylene, or polyolefin, and those skilled in the art can make specific configurations according to actual needs.

[0045] In the embodiment, the width of the base film 100 is A, and the dimension of the first film section 200 along the first direction is B, satisfying A = B. The above structure enables the first film section 200 to be produced by cutting another roll film material of the same type as the base film 100, and the two roll film materials are made into a composite film, which simplifies the production process and material types, making the procurement of raw materials easier.

[0046] Specifically, in this embodiment, since the width of the base film 100 is basically fixed, another roll of longitudinally stretched film can be cut into multiple first film segments 200, and when the first film segments 200 are rotated 90 degrees and attached to the base film 100, the size of each first film segment 200 along the first direction is also basically fixed. The size of each first film segment 200 along the second direction is determined according to the width of the base film 100.

[0047] In some embodiments, the first film segment 200 is formed by cutting the auxiliary film, and the auxiliary film and the base film 100 are formed by cutting the same roll film. The base film 100 and the plurality of first film segments 200 are formed by cutting the same roll film material, which makes raw material procurement more convenient and improves production convenience.

[0048] Reference Figure 3 to Figure 4In some embodiments, the second coating 300 is further included. The second coating 300 is in a strip shape and its length is arranged along the first direction. The width of the second coating 300 is arranged along the second direction. All the first coating segments 200 are arranged on one side of the second coating 300. The first coating segment 200 is located between the base film 100 and the second coating 300. The base film 100 and the second coating 300 are both longitudinally stretched films and their stretching directions are parallel. The first coating segment 200 is sandwiched between the base film 100 and the second coating 300, and the second coating 300 and the base film 100 are both longitudinally stretched films, so that the composite film has a higher longitudinal tensile strength, and the first coating segment 200 is not easy to fall off relative to the base film 100 and the second coating 300, so that the use effect of the composite film is more stable and reliable.

[0049] In some embodiments, the thickness of the base film 100 is C, the thickness of the first coating segment 200 is D, and the thickness of the second coating segment 300 is E, satisfying C+E=D, so that the first coating segment 200 can further improve the tensile strength of the composite film in the second direction, and cooperate with the base film 100 and the second coating segment 300 to improve the tensile strength of the composite film in the first direction, so that the tensile strength of the composite film along the first direction and the second direction is relatively high, and the tensile strength in the two directions is relatively balanced, and the structure is relatively simple.

[0050] In other embodiments, the thickness of the base film 100 is C, the thickness of the first coating segment 200 is D, and the thickness of the second coating 300 is E, satisfying C=D=E, which facilitates the base film 100, the first coating segment 200 and the second coating 300 to be made of the same longitudinal stretch film, thereby simplifying the production difficulty and material selection requirements of the composite film.

[0051] It is conceivable that, in other embodiments, the thickness C of the base film 100 may not be equal to the thickness E of the second coating 300, and those skilled in the art may configure it according to actual needs; the thickness specification and material of the base film 100 may also be different from the thickness specification and material of the second coating 300, and those skilled in the art may configure it according to actual needs.

[0052] Specifically, the base film 100 and the first coating layer may be connected by an adhesive, or by hot pressing and laminating. The first coating segment 200 and the second coating 300 may be connected by an adhesive, or by hot pressing and laminating. Those skilled in the art may configure the connection according to actual needs.

[0053] The utility model also discloses a packaging bag, which adopts the above-mentioned composite film. Due to the use of the above-mentioned composite film, the packaging bag reduces material waste during production, improves material utilization and simplifies the production process, so that when the packaging bag contains articles, it can withstand greater impact and puncture external force and has a stronger accommodating capacity.

[0054] Specifically, the edges of the two composite films are aligned and connected and sealed together to form the above-mentioned packaging bag. When the packaging bag has an opening, the edges of the two composite films close to the opening are separated, and the remaining edges are connected and sealed. When the packaging bag is fully sealed, the peripheries of the two composite films are aligned and connected and sealed together to form a fully sealed packaging bag.

[0055] Specifically, the base film 100 and the second covering film 300 may both have a heat-sealing effect, so that the edges of the two composite films can be sealed and connected by heat pressing to form a packaging bag.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0057] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A composite film, characterized in that include: The base film (100) is in a strip shape and its length is arranged along a first direction, and the width of the base film (100) is arranged along a second direction; At least two first coating sections (200) are arranged on one side of the base film (100) and arranged along the first direction, the first coating section (200) is rectangular and two opposite sides are aligned with the two long sides of the base film (100), the tensile strength of the base film (100) along the first direction is greater than the tensile strength of the first coating section (200) along the first direction, and the tensile strength of the base film (100) along the second direction is less than the tensile strength of the first coating section (200) along the second direction.

2. The composite membrane according to claim 1, characterized in that: The base film (100) and the first coating section (200) are both longitudinally stretched films, and the stretching directions of the two are perpendicular to each other; the first coating section (200) is formed by cutting an auxiliary film, and the auxiliary film and the base film (100) are formed by cutting the same type of tubular film roll.

3. The composite membrane according to claim 1, characterized in that: The base film (100) is a longitudinally stretched film, and the first coating section (200) is an original film that has not been stretched for a second time.

4. The composite membrane according to claim 1, characterized in that: The edges of two adjacent first coating sections (200) are aligned, or the edges of two adjacent first coating sections (200) are partially overlapped.

5. The composite membrane according to claim 1, characterized in that: The base film (100) and the first coating section (200) are made of polyethylene.

6. The composite membrane according to claim 1, characterized in that: The width of the base film (100) is A, and the dimension of the first coating section (200) along the first direction is B, satisfying A=B.

7. The composite membrane according to claim 1, characterized in that: The invention also comprises a second coating (300), wherein the second coating (300) is in a strip shape and its length is arranged along the first direction, the width of the second coating (300) is arranged along the second direction, all the first coating sections (200) are arranged on one side of the second coating (300), the first coating section (200) is located between the base film (100) and the second coating (300), and the base film (100) and the second coating (300) are both longitudinally stretched films and the stretching directions of the two are parallel.

8. The composite membrane according to claim 7, characterized in that: The thickness of the base film (100) is C, the thickness of the first coating section (200) is D, and the thickness of the second coating (300) is E, satisfying C+E=D.

9. The composite membrane according to claim 7, characterized in that: The thickness of the base film (100) is C, the thickness of the first coating section (200) is D, and the thickness of the second coating (300) is E, satisfying C=D=E.

10. A packaging bag, characterized in that: The composite film comprises the composite film according to any one of claims 1 to 9.

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