One-way check valve, valve membrane of one-way check valve and inflatable bag

Abstract

The invention provides a one-way check valve, a valve membrane thereof and an inflatable bag, the valve membrane comprises a first membrane layer, a second membrane layer, a third membrane layer, a fourth membrane layer and a fifth membrane layer which are sequentially stacked, the first membrane layer is an LDPE layer, the second membrane layer is an adhesive resin layer, the third membrane layer is an EVOH layer or a PA layer, the fourth membrane layer is an adhesive resin layer, and the fifth membrane layer is an adhesive resin layer. The fifth film layer is a ULDPE (Ultra Low Density Polyethylene) layer.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging materials, and particularly to a one-way check valve, its valve film, and an inflatable bag. Background Art

[0002] With the development of modern logistics industry, the requirements for protecting items during transportation are getting higher and higher. During transportation, items are often damaged due to dropping or vibration, resulting in unnecessary losses. An inflatable bag is a new packaging system filled with natural air and widely used in product packaging and transportation. The inflatable bag has excellent characteristics such as being inflated once, being fully filled, having independent air columns, and only the corresponding air column failing when damaged, while the other air columns are not affected.

[0003] As Figure 1 is an inflatable bag of the prior art. The inflatable bag includes a bag body film and an inflation valve disposed between the bag body films. Gas is inflated into the bag body film through the inflation valve, and the inflated gas is stored between the two layers of bag body films. Since the pressure of the gas in the bag will close the inflation valve, the gas in the bag will not leak out from the bag body film. Ideally, such an inflatable bag will not leak or will have very little leakage. However, the gas in the inflatable bag of the prior art penetrates through the film layer of the inflation valve. Due to the poor barrier property of the valve film of the inflation valve itself and too large oxygen permeability coefficient, the result is that the gas leaks out from area A shown in the figure; or the gas leaks into the space between the two layers of valve films from area B, destroying the fitting and sealing degree of the two layers, and then causing the gas in the container (air column) cavity to escape; or the gas leaking out from area B will also escape from the cavity.

[0004] Chinese Patent Invention No. 201310154050.0 discloses a polar film material with adsorbability, a one-way check valve, and an inflatable bag. The polar film material includes a PE film substrate, and an adhesive layer is compounded on one side of the PE substrate. The adhesive layer is a PE grafted with maleic anhydride added to EVA; wherein the amount of EVA accounts for 2 - 3% of the total mass of the entire polar film material, and the PE grafted with maleic anhydride accounts for 0.5 - 1% of the total mass of the entire polar film material. However, the oxygen permeability of such a polar film material in the prior art is too large, and the gas leakage during long-term storage is relatively large. Summary of the Invention

[0005] A main advantage of the present invention is to provide a one-way check valve, its valve film, and an inflatable bag, wherein the valve film does not need to add elastomers (EVA), etc., and has good economic heat resistance and high strength.

[0006] Another advantage of the present invention lies in providing a one-way check valve, its valve film, and an inflatable bag. The film material forming the one-way check valve is adhered in a manner where the surface with a large coefficient of friction (ULDPE surface) faces each other. Due to its high viscosity (ULDPE surface) itself, after the two valve films are adhered, relative movement is very difficult, so as to achieve the self-adhesive and locking functions.

[0007] Another advantage of the present invention lies in providing a one-way check valve, its valve film, and an inflatable bag, wherein the gas retention effect of the valve film is good, improving the sealing effect of the inflatable bag.

[0008] According to one aspect of the present invention, a valve film of the present invention capable of achieving the foregoing objects and other objects and advantages includes:

[0009] A first film layer, a second film layer, a third film layer, a fourth film layer, and a fifth film layer stacked in sequence, wherein the first film layer is an LDPE layer, the second film layer is an adhesive resin layer, the third film layer is an EVOH layer or a PA layer, the fourth film layer is an adhesive resin layer, and the fifth film layer is a ULDPE layer.

[0010] According to an embodiment of the present invention, the mass fraction of the third film layer is 2 - 5%.

[0011] According to an embodiment of the present invention, the third film layer is an EVOH layer with a mass fraction of 4%.

[0012] According to an embodiment of the present invention, the third film layer is a PA layer with a mass fraction of 5%.

[0013] According to another aspect of the present application, the present application further provides a one-way check valve, including:

[0014] A first valve film and a second valve film, wherein the first valve film and the second valve film form an inflatable channel, and the fifth film layer of the first valve film and the fifth film layer of the second valve film face each other in the positive direction.

[0015] According to another aspect of the present application, the present application further provides an inflatable bag, including:

[0016] A first bag body film and a second bag body film; and

[0017] At least one one-way check valve as described above, wherein the first bag body film and the second bag body film are sealed to form a gas storage chamber, and the inflatable channel of the at least one one-way check valve communicates with the external environment and the gas storage chamber.

[0018] According to an embodiment of the present invention, the one-way check valve further includes an air inlet end and an air outlet end integrally extending from the air inlet end, wherein the air inlet end is disposed at the ends of the first bag body film and the second bag body film, and an air inlet is formed by the first valve film and the second valve film at the air inlet end, the air outlet end is disposed between the first bag body film and the second bag body film, and an air outlet is formed between the first valve film and the second valve film at the air outlet end.

[0019] According to an embodiment of the present invention, the first valve film located at the air inlet end is adhered to the inner side of the film layer of the first bag body film, and the second valve film is adhered to the inner side of the film layer of the second bag body film.

[0020] According to an embodiment of the present invention, the air outlet end of the one-way check valve is adhered to the inner side of the first bag body film or the second bag body film.

[0021] According to an embodiment of the present invention, the first valve film and the second valve film located at the air outlet end are fixed to the first bag body film or the second bag body film by means of heat-sealing points.

[0022] Through the understanding of the subsequent description and the drawings, further objects and advantages of the present invention will be fully embodied.

[0023] These and other objects, features and advantages of the present invention are fully embodied by the following detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural view of an inflatable bag according to a first preferred embodiment of the present invention.

[0025] Figure 2 is a schematic plan view of the inflatable bag according to the above first preferred embodiment of the present invention.

[0026] Figure 3 is a schematic structural view of the valve film of the inflatable bag according to the above first preferred embodiment of the present invention. Figure 4 is a schematic structural view of the multi-layer composite material of the valve film of the inflatable bag according to the above first preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description can be applied to other embodiments, variations, improvements, equivalent schemes, and other technical schemes that do not depart from the spirit and scope of the present invention.

[0028] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationship indicated by terms such as "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is 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. Therefore, the above terms should not be construed as limiting the present invention.

[0029] It can be understood that the term "a" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of the element can be multiple. The term "a" should not be construed as limiting the quantity.

[0030] Referring to the Figures 1 to 4 drawings of the specification of the present application, a one-way check valve, its valve film, and an inflatable bag according to the first preferred embodiment of the present application are illustrated in the following description. The inflatable bag includes a first bag body film 10, a second bag body film 20, and a one-way check valve 30 disposed between the first bag body film 10 and the second bag body film 20. The first bag body film 10 and the second bag body film 20 are sealed to form an air chamber 102 with a gas storage function. The one-way check valve 30 communicates the air chamber 102 with the external environment and allows gas to be filled into the air chamber 102 from the external environment. After gas is filled into the air chamber 102, the gas in the air chamber 102 squeezes the valve film of the one-way check valve 30, causing the passage of the one-way check valve 30 to close, thereby preventing gas from leaking out.

[0031] The one-way check valve 30 further includes at least two valve films, hereinafter referred to as the first valve film 31 and the second valve film 32 for the convenience of description. The first valve film 31 and the second valve film 32 face each other directly, and an inflation passage 301 is formed between the first valve film 31 and the second valve film 32. During inflation, the inflation passage 301 between the first valve film 31 and the second valve film 32 is propped up by gas, that is, the inflation passage 301 is opened, and gas can enter the air chamber 102 along the inflation passage 301 between the first valve film 31 and the second valve film 32. After inflation, the gas in the air chamber 102 squeezes the first valve film 31 and / or the second valve film 32 on the outer side of the valve film, causing the first valve film 31 and the second valve film 32 to fit together. At this time, the inflation passage 301 between the first valve film 31 and the second valve film 32 is closed, and gas cannot leak out from the inflation passage 301.

[0032] The valve membrane of the one-way check valve 30 is a multi-layer composite material formed by stacking multiple film layers in sequence, wherein the valve membrane includes a first film layer 310, a second film layer 320, a third film layer 330, a fourth film layer 340 and a fifth film layer 350, wherein the first film layer 310, the second film layer 320, the third film layer 330, the fourth film layer 340 and the fifth film layer 350 are stacked in sequence in the thickness direction. The first film layer 310 and the fifth film layer 350 are the outermost film layers on both sides of the valve membrane, and the second film layer 320, the third film layer 330 and the fourth film layer 340 are film layer materials arranged between the first film layer 310 and the fifth film layer 350.

[0033] In this preferred embodiment of the present application, the first film layer 310 is an LDPE layer (low-density polyethylene (LDPE)), the second film layer 320 is an adhesive resin layer, the third film layer 330 is an EVOH layer (Ethylene Vinyl Silane, ethylene-vinyl alcohol copolymer) or a PA layer (Polyamide, polyamide material), the fourth film layer 340 is an adhesive resin layer, and the fifth film layer 350 is a ULDPE layer (ultra-low density polyethylene film).

[0034] It is worth mentioning that when the first valve membrane 31 and the second valve membrane 32 of the one-way check valve 30 are not opened before inflation, during the inflation process, since gas rushes into the inflation channel 301 between the first valve membrane 31 and the second valve membrane 32, under the action of air pressure, the first valve membrane 31 and the second valve membrane 32 are stretched open by the gas, that is, the inflation channel 301 is opened, and the gas enters the air chamber from the inflation channel 301. When the air chamber 102 is inflated, the gas filled in the air chamber 102 squeezes the first valve membrane 31 and the second valve membrane 32, and in fact, the inflation channel 301 between the first valve membrane 31 and the second valve membrane 32 is closed, and the first valve membrane 31 and the second valve membrane 32 are self-adhered together, that is, the inflation channel is closed.

[0035] The "self-adhesive" mentioned in this application is a popular expression for the friction coefficient. Since the inherent viscosity of the ULDPE material (friction coefficient ≥ 0.4) meets the viscosity requirement of the air valve, there is no need to add elastomers (EVA) or the like.

[0036] In the unidirectional check valve disclosed in the Chinese invention with the application number 201310154050.0, the valve film is based on a PE film substrate. Starting from the side compounded with the self-adhesive layer, it is successively an LDPE layer, an HDPE layer or an MLDPE layer, and an LDPE layer, forming a multi-layer composite film. And the dosage of HDPE or MLDPE is 0.2-0.5% of the total mass of the entire polar film material. The "TNPP" described in this application is a heat-resistant antioxidant and anti-aging agent, and this material does not need to be used in this preferred embodiment of this application. The first film layer 310 of the valve film in this preferred embodiment of this application is an LDPE layer, which does not affect the heat resistance and antioxidant functions.

[0037] It should be noted that in this preferred embodiment of this application, the film materials of the first valve film 31 and the second valve film 32 are adhered face to face in a positive direction with the fifth film layer 350 (i.e., the ULDPE surface) with a large coefficient of friction facing each other. Since the viscosity of the fifth film layer 350 (i.e., the ULDPE surface) is large (the coefficient of friction is large, ≥0.4). When the first valve film 31 and the second valve film 32 are adhered to each other, it is very difficult to move relative to each other to achieve the self-adhesive and locking functions.

[0038] It should be noted that during the inflation process, the first film layer 31 and the second film layer 32 need to be peeled off so that gas can enter the air chamber 102 through the inflation channel. At this time, it is necessary to ensure that when the gas enters the air chamber 102, the deformation (tensile) of the first film layer 31 and the second film layer 32 on both sides of the inflation channel 301 can quickly return to flatness to achieve fitting and sealing at the end of inflation. Therefore, the valve film requires appropriate tensile strength and yield strength. For this reason, in this preferred embodiment of this application, adding 3-5% of PA can improve this strength. That is to say, in this preferred embodiment of this application, when the third film layer 330 is PA, the PA material can improve the tensile strength and yield strength of the valve film, so that after inflation, the first valve film 31 and the second valve film 32 of the unidirectional check valve 30 can quickly return to flatness, that is, self-adhere together.

[0039] During inflation until the end of inflation, the air pressure in the air chamber 102 will continue to rise, and then the air pressure in the air chamber 102 will press the first valve film 31 and / or the second valve film 32 of the unidirectional check valve 30, so that the first valve film 31 and the second valve film 32 are adhered to each other. It is worth mentioning that at this time, the so-called self-adhesive adsorption force can be ignored, and what is important is the friction force between the two layers. That is to say, at the end of inflation, the state (flatness, fitting, coefficient of friction, etc.) of the unidirectional check valve 30 should return to the preset state value.

[0040] After inflation, air retention becomes the most important. As mentioned above, the main defect of the existing check valve membrane lies in its own air permeability. In this preferred embodiment of the present application, the dosage of the third film layer 330 accounts for 2-5% of the total weight of the entire film layer.

[0041] As shown in Table 1 below, the comparison of the oxygen permeability of valve membranes with different material compositions at the same thickness.

[0042] Table 1

[0043]

[0044] As shown in Table 1, the oxygen permeability value of this valve membrane material in the prior art is between 4500 and 5000, while the oxygen permeability value of the valve membrane material provided in this preferred and better embodiment of the present application is much lower than that of the valve membrane material in the prior art. For example, when the third film layer 330 is EVOH with a mass fraction of 4%, the oxygen permeability value of the valve membrane material is only 5; when the third film layer 330 is PA with a mass fraction of 4%, the oxygen permeability value of the valve membrane material is only 550.

[0045] In order to comprehensively consider the requirements for the check valve membrane in each link; such as: the stretching and recovery of the material during inflation, the heat resistance temperature during production, the peel strength between material layers, the appropriate matching of oxygen permeability, etc., the third film layer 330 is PA666 (2-5%). It should be noted that the valve membrane material provided in the present application not only has good economy, excellent heat resistance but also high strength, meeting the requirements for the valve membrane at each stage of inflation.

[0046] The one-way check valve 30 further includes an air inlet end 33 and an air outlet end 34 integrally extending from the air inlet end 33, wherein the air inlet end 33 is arranged at the ends of the first bag body film 10 and the second bag body film 20, and an air inlet is formed by the first valve film 31 and the second valve film 32 at the air inlet end 33. The air outlet end is arranged between the first bag body film 10 and the second bag body film 20, and an air outlet is formed between the first valve film 31 and the second valve film 32 at the air outlet end 34.

[0047] In this preferred embodiment of the present application, the first valve film 31 located at the air inlet end 33 is adhered to the inner side of the film layer of the first bag body film 10, and the second valve film 32 is adhered to the inner side of the film layer of the second bag body film 20. Preferably, in this preferred embodiment of the present application, the air inlet end of the one-way check valve 30 adheres the first valve film 31 to the inner side of the film layer of the first bag body film 10 by heat sealing, and the second valve film 32 is adhered to the inner side of the film layer of the second bag body film 20.

[0048] The air outlet end of the one-way check valve 30 is adhered to the inner side of the first bag body film 10 or the second bag body film 20, that is, the first valve film 31 and the second valve film 32 are adhered to the inner side of the bag body film on the same side. In this way, when inflated, the gas in the air chamber 102 can squeeze the first valve film 31 or the second valve film 32 to prevent the separation between the first valve film 31 and the second valve film 32.

[0049] As an example, in this preferred embodiment of the present application, the first valve film 31 and the second valve film 32 at the air outlet end are fixed to the first bag body film 10 or the second bag body film 20 by means of heat-sealing points.

[0050] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the drawings are only examples and do not limit the present invention. The object of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been shown and described in the embodiments, and the embodiments of the present invention can have any deformation or modification without departing from the principle.

Claims

1. A valve membrane, characterized in that: include: The first film layer, the second film layer, the third film layer, the fourth film layer and the fifth film layer are stacked in sequence, wherein the first film layer is an LDPE layer, the second film layer is an adhesive resin layer, the third film layer is an EVOH layer or a PA layer, the fourth film layer is an adhesive resin layer, and the fifth film layer is a ULDPE layer. 2 . The valve membrane according to claim 1 , wherein the mass fraction of the third membrane layer is 2-5%. The valve film according to claim 1 , wherein the third film layer is an EVOH layer with a mass fraction of 4%. The valve membrane according to claim 1 , wherein the third membrane layer is a PA layer with a mass fraction of 5%.

5. A one-way check valve formed by the valve film according to any one of claims 1 to 4, characterized in that: include: A first valve membrane and a second valve membrane, wherein the first valve membrane and the second valve membrane form an inflatable inflation channel, wherein the fifth membrane layer of the first valve membrane and the fifth membrane layer of the second valve membrane are facing each other.

6. An inflatable bag, characterized in that: include: a first bag body film and a second bag body film; as well as At least one one-way check valve as described in claim 5, wherein the first bag film and the second bag film are sealed to form an air chamber capable of storing air, and the inflation channel of the at least one one-way check valve connects the external environment with the air chamber.

7. The inflatable bag according to claim 6, wherein the one-way check valve further includes an air inlet end and an air outlet end extending integrally from the air inlet end, wherein the air inlet end is arranged at the end of the first bag body film and the second bag body film, and an air inlet is formed by the first valve film and the second valve film at the air inlet end, and the air outlet end is arranged between the first bag body film and the second bag body film, and an air outlet is formed between the first valve film and the second valve film at the air outlet end.

8. The inflatable bag according to claim 7, wherein the first valve film located at the air inlet end is adhered to the inner side of the film layer of the first bag body film, and the second valve film is adhered to the inner side of the film layer of the second bag body film. 9 . The inflatable bag according to claim 8 , wherein the air outlet end of the one-way check valve is adhered to the inner side of the first bag body film or the second bag body film.

10. The inflatable bag according to claim 8, wherein the first valve film and the second valve film located at the air outlet end are fixed to the first bag body film or the second bag body film by heat sealing points.

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