CN112477344A

CN112477344A - Recyclable high-barrier membrane material and preparation method and processing system thereof

Info

Publication number: CN112477344A
Application number: CN202011120068.5A
Authority: CN
Inventors: 汤亮; 胡翔宇
Original assignee: Guangdong Furijie New Material Co ltd
Current assignee: Guangdong Furijie New Material Co ltd
Priority date: 2020-10-19
Filing date: 2020-10-19
Publication date: 2021-03-12

Abstract

The invention discloses a recyclable high-barrier membrane material, which comprises a first, dimer olefin type functional layer, an ethylene-vinyl alcohol copolymer type intermediate barrier layer, a first, dimer olefin type functional layer, and an intermediate barrier layer The adhesive resin layers are closely bonded to form a whole, and the peeling strength test of conventional composite film materials cannot be effectively peeled between the layers; the preparation method includes feeding, heating and melting, co-extrusion, film blowing and cooling There are multiple steps of setting, drawing, and winding. The blown film cooling and setting stage is a one-time blowing film forming to obtain all the film layers, and a thick film stretching operation is added during the drawing process. The corresponding processing system includes a hopper, a film blowing machine, an extruder, a conveying device, a thick film stretching mechanism, a slitting device and a winding device. The product of the invention can better maintain the high barrier property of the film material, realize all-plastic composite, can be recycled, and has high strength, stiffness, water and oxygen resistance.

Description

Recyclable high-barrier membrane material and preparation method and processing system thereof

Technical Field

The invention relates to an organic packaging film material, a preparation method and a processing system thereof, belonging to the technical field of high polymer materials.

Background

Most of the existing toothpaste tubes, shoe polish bags, medicines and other paste packaging bags are formed by compounding aluminum, lead, tin and other metals and plastics, the film layer structure of most of the existing aluminum-plastic composite film materials is schematically shown in figure 1 and is divided into 3 layers, the middle layer of pure aluminum is arranged between the two layers of low-density polyethylene (LDPE), the inner layer and the outer layer of the low-density polyethylene (LDPE) are adhered by glue (polyurethane adhesive) and ethyl ester solvent is added between the 3 layers of materials, and harmful gas is easily volatilized. Fig. 2 is a film electron microscope photograph of a commercially available aluminum-plastic composite film, and the product generally adopts a process route of 'film blowing, film spraying, slitting, offset printing, tube rolling, shoulder injection and finished product'. Because the usage amount of the film material packaging bag is very large, not only is a great deal of metal material wasted and the product packaging cost is obviously improved, but also the wide application of the metals such as aluminum, lead, tin and the like in the packaging material processing and the secondary processing can cause serious pollution to the production environment. In addition, as shown in fig. 8, the processing process of the packaging material containing metal objects is complex, the processing cost is high, and the composite application of multiple materials brings great difficulty to the recycling of the subsequent packaging material; and a large amount of packaging waste with extremely low recycling value is discarded in the environment, which causes secondary pollution and secondary waste of resources.

In 2016, a policy for VOCs remediation was issued, wherein it was pointed out that the emission of VOCs from the industry (packaging and printing industry) accounts for over 50% and over 2000 million tons per year, which is the focus of current VOCs remediation. VOCs treatment is to calculate charge according to the total discharge amount of VOCs, and if the treatment cost of 1 ton of VOCs is 1 ten thousand yuan, if an enterprise does not treat and settle, 1.5 ten thousand yuan to 2 ten thousand yuan is charged, and even the most serious VOCs stops production and settle, which means that the industries such as packaging, printing ink, adhesive and the like are bound to accelerate the discharge reduction of VOCs. Based on the above-mentioned defects of the metal-plastic composite packaging material, it is a technical problem to be solved by those skilled in the art to develop a product that not only achieves the same performance as the aluminum-plastic composite packaging material, but also reduces the emission of VOCs. The market needs a functional film with environmental protection, high barrier and high strength to replace the traditional aluminum-plastic composite film with high pollution and high waste, and the production and processing of the all-plastic composite sheet (without metal materials) become the development trend of composite packaging materials.

Nowadays, all-plastic composite packaging materials are applied less in the industry mainly because the preparation process is relatively complex and the cost is high. The plastic composite packing material is produced through extrusion filming process, and the main technological process includes tube drawing, silk screen printing, shoulder injecting and finishing, and the obtained product has the structure as shown in figure 3 and has the demerits of low production efficiency, low yield, high cost and high total cost. At present, a small amount of all-plastic composite packaging materials adopt a more advanced blow molding EVOH (ethylene-vinyl alcohol copolymer) coextrusion film technical route. The process flows in the technical route mainly comprise the following two processes.

One is to adopt the film blowing-laminating composite technology, namely the inner polyethylene film and the outer polyethylene film are laminated and compounded through laminating PE to prepare the full-plastic composite sheet shown in figure 4, and the process flow comprises film blowing, laminating, slitting, flexo printing, pipe coiling, shoulder injecting and finished product. Taking a microscopic electron microscope image of a conventional all-plastic composite packaging sheet material object shown in fig. 6 as an example, the all-plastic composite packaging sheet material object is prepared by a laminating lamination technology, and from the composition of a film layer, the all-plastic composite packaging sheet material object can be roughly divided into a five-layer structure (namely, L2, L3, L4, L5 and L6 shown in fig. 6), wherein L2 is an EVOH three-layer co-extruded film (containing two TIE layers of bonding resin), L3 and L4 are extrusion laminating layers, L3 and L4 are used as bonding transition layers to bond L5 and L6 with L2 respectively, and L5 and L6 are three-layer PE inner films or three-layer PE outer films formed by film blowing respectively. However, the loss of the composite packaging material in the production process is large (2-3% of waste products in the film blowing process and 4-6% of waste products in the film spraying process), and the EVOH co-extruded film needs to be blown separately and then bonded with the PE layers on the inner side and the outer side through the film spraying layer, so that the process flow is complex, the efficiency is low, and the processing cost is high.

The other is a barrier composite all-plastic sheet formed by direct film blowing lamination, as shown in fig. 5, the barrier composite all-plastic sheet generally comprises at least two EVOH material layers, the process flow comprises 'film blowing-laminating-slitting-offset printing-pipe rolling-shoulder injecting-finished product', in the film blowing production, ethylene vinyl acetate copolymer (EVA) is used as a heat sealing layer to be placed in the inner layer of the film blowing, and the two layers of the film bubble are extruded and heat sealed through a drawing roller to form a thickened sheet. Taking a microscopic electron microscope image of an all-plastic composite packaging sheet material object shown in fig. 7 as an example, the all-plastic composite packaging sheet material object is prepared by adopting a film blowing lamination compounding technology, and in view of the composition of a film layer, the all-plastic composite packaging sheet material at least comprises eight layers, wherein L1 and L2 are both EVOH layers, L3+ L4 are laminated EVA layers serving as bonding transition layers, and the outer sides of L5, L6 and EVOH layers are PE inner films or outer films. The cost of the barrier composite full-plastic sheet is 30-60% higher than that of the aluminum-plastic composite hose, and the pipe body of the processed pipe is softer, which is not beneficial to market popularization.

In addition, due to the limitation of the existing production equipment of the all-plastic composite packaging material, the composite film material with high thickness, high barrier property and high interlayer peel strength is generally difficult to process, and the application of the all-plastic composite film material in other fields is greatly limited.

Disclosure of Invention

The invention aims to overcome the technical problems in the prior art and provides a recyclable high-barrier film.

The technical scheme provided by the invention is that the recyclable high-barrier film comprises a first polyolefin functional layer, an ethylene-vinyl alcohol copolymer intermediate barrier layer and a second polyolefin functional layer, wherein two sides of the ethylene-vinyl alcohol copolymer intermediate barrier layer are respectively combined with the first polyethylene functional layer and the second polyethylene functional layer through adhesive resin layers, the first polyolefin functional layer, the ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer are tightly adhered into a whole through the adhesive resin layers, and the first polyolefin functional layer, the ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer cannot be effectively peeled off when a conventional composite film material peeling strength test is adopted. In the existing various blow-molding co-extrusion all-plastic composite film products, due to the limitation of processing equipment and processing technology, when the composite film material is to be very thick (for example, more than 200 micrometers), a first polyolefin functional layer, an ethylene-vinyl alcohol copolymer intermediate barrier layer and a second polyolefin functional layer are often compounded into a whole in a film spraying, laminating or other secondary bonding modes, the processing equipment of the product is simple and mature, but the whole thickness of the formed composite film product is thin, the interlayer compounding fastness is poor, the layers are difficult to be tightly adhered into a whole, and when the product is tested by using a conventional method (for example, known conventional testing methods such as GB/T8808-. However, the invention breaks through the conventional thinking and improves the existing processing design scheme, so that each layer of material can be directly subjected to one-time blow molding in a film blowing machine, functional layers of the prepared composite film material are tightly adhered into a whole through an adhesive resin layer, and each layer is not easy to peel off and firmly adhered, so that the high barrier property of the film material can be better maintained, and the full-plastic compounding is realized and the recyclable composite film material can be recycled.

In the recyclable high barrier film, the first polyolefin-based functional layer and the ethylene-vinyl alcohol copolymer-based intermediate barrier layer, and the ethylene-vinyl alcohol copolymer-based intermediate barrier layer and the second polyolefin-based functional layer preferably have a composite fastness of 15N/15mm or higher. The high-barrier film material is obtained by one-time blow molding of each film layer, so that the compounding fastness between the layers can reach very high and is obviously higher than that of the existing full-plastic composite film material.

In the recyclable high barrier film, the total thickness of the high barrier film is preferably 150 to 400 micrometers, and preferably 250 to 350 micrometers. Because in the high-barrier film material with large thickness, the advantages of the product and the process of the invention are more obvious and sufficient, and the invention is beneficial to the later application in various large-thickness packaging tubes such as toothpaste, shoe polish and the like.

Preferably, in a multi-layer structure of the high barrier film shown under a microscopic electron microscope, the peelable adhesive transition layer formed by extruding a laminated film composite layer, laminating an adhesive layer or other secondary adhesion modes is not included between the first polyolefin functional layer and the intermediate barrier layer of the ethylene-vinyl alcohol copolymer and between the intermediate barrier layer of the ethylene-vinyl alcohol copolymer and the second polyolefin functional layer. Based on the one-time blow molding process, the product does not contain a conventional laminating composite layer, a laminating bonding layer or other bonding transition layers in a multi-film layer structure displayed under a microscopic electron microscope, and can be obviously distinguished from the existing all-plastic composite film.

In the recyclable high barrier film, the film layers included in the high barrier film are preferably formed by one-time coextrusion through a film blowing process. Due to the limitations of the existing blow molding process and film blowing machine, the ordinary skilled in the art can hardly think that the high-barrier film material of the present invention is prepared by adopting a one-time film blowing forming method, when the existing film blowing machine is used for preparing a co-extruded film product containing EVOH, the co-extruded composite film with the thickness of less than 100 microns can be obtained by film blowing forming, and based on the property difference between the middle barrier layer of EVOH and the polyolefin functional layers on both sides, the one-time film blowing forming of multi-film layers and large thickness is difficult to perform, the multi-film layer structure which is barely blown out is often poor in composite fastness, easy to wrinkle and unsmooth, difficult to cut, and poor in film forming quality. The invention improves the film forming process and system, so that each film layer contained in the high-resistance film material can be obtained by one-time co-extrusion molding through the film blowing process, thereby greatly improving the microstructure and the connection relation of the high-resistance film material and remarkably improving the quality of the film material.

Preferably, the recyclable high-barrier film comprises only one intermediate barrier layer of ethylene-vinyl alcohol copolymer in the film structure shown under a microscopic electron microscope. When the total thickness of the high-barrier film material is 150-400 micrometers, the layer thickness ratio of the ethylene-vinyl alcohol copolymer intermediate barrier layer in the high-barrier film material is less than 5%, preferably less than 4% shown under a microscopic electron microscope. The layer thickness ratio described herein is substantially equivalent to the volume ratio thereof, because the volume ratio is expressed in the thickness ratio when the areas of the respective film layers are the same. Under the condition that the total thickness of the film layer is kept to be 150-400 micrometers, the volume proportion of the ethylene-vinyl alcohol copolymer intermediate barrier layer is obviously smaller than that of the intermediate barrier layer in the existing product. In the existing products, based on the limitations of process conditions and product requirements, the volume content of the intermediate barrier layer of ethylene-vinyl alcohol copolymer is generally controlled to be more than 15% or at least more than 10% so as to improve the barrier property of the intermediate barrier layer as much as possible and prevent the loss of substances such as internal fragrance and the like, but the volume content of the intermediate barrier layer of ethylene-vinyl alcohol copolymer is not more than 10% by comprehensively controlling the structure and components of the film layer, which is a breakthrough of the conventional operation. In addition, in the occasion with higher environmental protection requirement, the EVOH layer is made as low as possible, so that the environmental protection grade standard of the product can be improved, and the method has very important significance for subsequent recycling of the product and expansion of foreign markets. More preferably, if the total thickness of the high-barrier film material is 250-350 microns, the product performance is further improved so as to be applied to more severe condition occasions. In addition, the material proportion of the EVOH is reduced to a greater extent, and the content of the EVOH is reduced, so that the cost can be reduced, and the process can be simplified.

In the above recyclable high-barrier film, the adhesive resin layer (TIE) is preferably a maleic anhydride grafted linear polyethylene or a blend of a maleic anhydride grafted linear polyethylene and a linear polyethylene. More preferably, the volume content of the single-layer adhesive resin layer in the high-barrier film material is 3-10% as shown under a microscopic electron microscope.

Preferably, the ethylene content of the ethylene-vinyl alcohol copolymer is 30 wt% to 44 wt%. The oxygen barrier properties are more excellent at lower ethylene contents.

In the recyclable high-barrier film, the first polyolefin functional layer and the second polyolefin functional layer are preferably at least one selected from polyethylene, polypropylene and polyethylene-polypropylene copolymer. More preferablyThe first polyolefin functional layer and the second polyolefin functional layer are respectively a first polyethylene functional layer and a second polyethylene functional layer. The first polyethylene functional layer and/or the second polyethylene functional layer comprise an outer side PE layer and an inner side PE layer close to the bonding resin layer, the outer side PE layer is made of Medium Density Polyethylene (MDPE) and/or Low Density Polyethylene (LDPE), and the inner side PE layer is made of High Density Polyethylene (HDPE). More preferably, the low density polyethylene has a density of 0.910 to 0.93kg/cm³The density of the medium density polyethylene is 0.930-0.940kg/cm³The density of the high-density polyethylene is 0.940kg/cm³The above (preferably 0.940 to 0.970).

In the recyclable high barrier film material, the inner HDPE layer is preferably composed of HDPE single layers or a plurality of HDPE single layers which are compounded and superposed under a microscopic electron microscope, particularly preferably composed of 1-3 HDPE single layers, and further can form a high barrier film material layer structure with 7 layers, 9 layers and 11 layers, and does not contain other functional layers.

Specifically, the film layer structure of the high-barrier film material displayed under a microscopic electron microscope is seven, nine or eleven layer structure below, and does not contain other functional layers, but functional additives can be added into each film layer structure.

The seven-layer structure comprises the following components from outside to inside in sequence: a first outer PE layer + a first HDPE monolayer + a first adhesive resin layer + an ethylene-vinyl alcohol copolymer intermediate barrier layer + a second adhesive resin layer + a second HDPE monolayer + a second outer PE layer;

the nine-layer structure comprises the following components from outside to inside in sequence: a first outer PE layer + a first HDPE monolayer + a third HDPE monolayer + a first adhesive resin layer + an ethylene-vinyl alcohol copolymer intermediate barrier layer + a second adhesive resin layer + a fourth HDPE monolayer + a second outer PE layer;

the eleven-layer structure comprises the following components in sequence from outside to inside: the first outer PE layer + the first HDPE monolayer + the third HDPE monolayer + the fifth HDPE monolayer + the first adhesive resin layer + the ethylene-vinyl alcohol copolymer intermediate barrier layer + the second adhesive resin layer + the sixth HDPE monolayer + the fourth HDPE monolayer + the second outer PE layer.

Preferably, under a microscopic electron microscope, the volume ratio of the outer PE layers positioned at two sides of the middle barrier layer of the ethylene-vinyl alcohol copolymer in the high barrier film material is 10-30%; the volume ratio of each bonding resin layer in the high-barrier film material is 3-10%, and the rest is occupied by the inner PE layer. More preferably, under a microscopic electron microscope, the total volume of the inner PE layer included in the high barrier film is 40% to 70%. Compared with the film material in the prior art, the content of EVOH is reduced, the content of the HDPE layer on the inner side is obviously increased, so that the sheet material is stiffer and higher in stiffness, and the total cost of the high-barrier film material can be saved. Furthermore, under a microscopic electron microscope, the volume ratio of the inner PE layer positioned on one side of the middle barrier layer of the ethylene-vinyl alcohol copolymer in the high barrier film material is controlled to be 15-35%. By controlling the thickness of the inner PE layers on two sides of the middle barrier layer of the ethylene-vinyl alcohol copolymer in a nearly equal way, the EVOH layer can be better ensured to play a role and prevented from contacting moisture in the air.

The recyclable high barrier film may be further compounded with a PE printed film on the outermost layer (i.e., the outer side of the first polyolefin functional layer) of the high barrier film.

As a general technical concept, the invention further provides a preparation method of the recyclable high-barrier film material, the preparation method comprises the steps of feeding, heating and melting, co-extrusion, film blowing, cooling and shaping, drawing and rolling, wherein in the film blowing, cooling and shaping stage, all film layers are obtained by one-time film blowing and shaping, and a thick film stretching and extending operation is additionally carried out in the drawing process. Under the condition that the total thickness of the film is thicker, the sheet is formed by one-time film blowing, the cost can be greatly reduced, the efficiency is improved, and the forming quality of the film product is improved. More preferably, the film body after the blown film cooling is stereotyped draws after a chinese character style of calligraphy splint presss from both sides, and draws the operation of the tensile extension of thick film through the tensile extension mechanism of a thick film in the process of drawing, be equipped with film body heating device and film body cooling device in the tensile extension mechanism of thick film, draw the extension through cold and hot alternative thick film that carries on repeatedly.

In the preparation method of the recyclable high-barrier film material, preferably, the film body subjected to the thick film stretching and stretching operation is subjected to primary secondary cooling and shaping operation in the conveying process, the secondary cooling and shaping operation is applied to the film body through an air ring cooling device, the temperature of the film body subjected to secondary cooling and shaping is controlled to be 30-50 ℃, and the secondary cooling and shaping operation is preferably arranged at the position near the upstream or downstream of the slitting operation.

Preferably, in the feeding process, the raw material particles are directly added into a hopper of the extruder according to the proportion in the set formula in an automatic weighing system, and the proportion of the materials is completed in the conveying process.

Preferably, in the step of film blowing and forming, the film body is cooled and shaped through an air ring, the blow-up ratio of the film body is 1-3, and the traction ratio of the film body is 4-6.

In the preparation method of the recyclable high-barrier film material, preferably, the film body subjected to secondary cooling and shaping is pulled by a pulling roll and finally conveyed to a winding roll for winding, a heating roll group for continuously heating the film material subjected to secondary cooling and shaping or a cooling roll group for continuously cooling can be further arranged in a roller behind the pulling roll, and the film material is repeatedly heated and cooled to correct the defects before final winding.

Preferably, in the preparation method of the recyclable high-barrier film material, the two layers of films are separately processed in the secondary cooling, shaping and rolling steps.

As a general technical concept, the invention also provides a processing system for preparing recyclable high-resistance membrane material, which comprises a hopper, a membrane blowing machine, an extruder, a conveying device, a thick film stretching and extending mechanism, a slitting device and a winding device, wherein the hopper is connected with the extruder, and a plurality of extruders are connected to the bottom of the membrane blowing machine. The thick film stretching and extending mechanism is internally provided with a conveying channel of a conveying device, and the conveying channel is internally provided with a film body heating device and a film body cooling device which repeatedly perform cold and hot alternation on a film body. In the existing processing system of the film blowing machine, a thick film stretching and extending mechanism is not adopted, and the configuration of the device is based on the requirement of processing a thick film by one-time film blowing, so that the intermediate product formed by cooling and forming the film blowing is ensured to be subjected to further extending treatment, the defect of the thick film product generated in the one-time film blowing process is prevented from entering the subsequent step, and the quality of the thick film product is ensured.

Preferably, the processing system is characterized in that a cold-hot alternating film stretching and extending mechanism is additionally arranged at the downstream of the top of the film blowing machine, so that the processing system is convenient to integrate into the existing processing system, is low in cost and is convenient to control the quality of a film.

In the processing system, more preferably, the film material output by the thick film stretching and stretching mechanism is connected by the conveying device, passes through the secondary cooling and shaping device, and is finally connected to the winding device; the secondary cooling and shaping device is arranged near the upstream or downstream of the splitting device. The secondary cooling and shaping device comprises an air ring cooling device applied to the film material. The secondary cooling and shaping device further comprises a heating roller set and a cooling roller set which are arranged in front of the air ring cooling device and are alternately subjected to cold and heat treatment, and the heating roller set and the cooling roller set are arranged in a horizontal rolling mode on the film material. If the situation that the quality of the film body does not reach the standard before secondary cooling and shaping is considered, the primary cold and hot alternate roller heating can be compensated before shaping, so that the cost is low, the operation is convenient, and the stability of the film material can be further improved.

In the processing system, the number of the extruders is preferably consistent with the number of layers of the high-barrier film to be prepared. The configuration of the number of runners in the die head of the film blowing machine is consistent with the layer number of the high-resistance film material to be prepared. More preferably, the width of the single flow channel within the die is greater than the opening size of the single flow channel at the air ring cooling discharge. The width of the flow channel is designed to be larger than the size of the opening, so that the extrusion force for discharging near the opening can be increased, and the medium in the die head flows and the discharging is smoother.

In the processing system, the cutter of the cutting device is preferably driven by a vibration mechanism. More preferably, the vibration mechanism includes a transverse vibration mechanism for driving the cutter to vibrate in the horizontal direction and a vertical vibration mechanism for driving the cutter to vibrate in the vertical direction. In consideration of the inconvenience of the thick film product in slitting, a vibration driving mechanism is additionally arranged in the slitting device, and the composite vibration mode is more beneficial to the convenience and the high efficiency of slitting.

Compared with the prior art, the invention has the beneficial effects that:

1. compared with the existing aluminum-plastic composite film material, the recyclable high-barrier film material provided by the invention is a high-performance film formed by co-extruding high-barrier material EVOH (ethylene-vinyl alcohol copolymer), polyethylene and other related adhesive materials, and can achieve the functions of high strength, high barrier, puncture resistance and the like which can be achieved only by compounding traditional Al and PE films without compounding metal materials.

2. The process operation of the invention further controls the dosage of the middle barrier layer and optimizes the design of other layers, thus further reducing the cost and simultaneously achieving better high barrier property, higher air retention property and aroma retention property.

3. The number of the middle barrier layers is further controlled through the process operation of the invention, and the design of other layers is optimized, so that the process steps and the product thickness can be further simplified, and the cost is further reduced.

4. Through the structural design of the film layer, particularly the content and the number of the HDPE layers, the glossiness, the mechanical strength, the stiffness and the puncture resistance of the film material can be further improved.

5. The film material of the invention has good printing adaptability through the structural design of the film layer, particularly the arrangement position of each layer and the position distribution of the PE printing film.

6. Through the selection of the film material, the design of the film structure and the parameter control, the film material has good environmental stress crack resistance, flexibility and heat sealing performance, and meets the requirement of high-frequency sealing of the hose.

7. The product of the invention is environment-friendly and pollution-free, and the packaging film material can be recycled by 100 percent, thereby being beneficial to saving resources and protecting the environment.

8. The packaging pipe prepared by the high barrier film material has uniform thickness, smooth pipe body and stiff finished pipe, and can greatly reduce the processing cost of the packaging pipe.

Drawings

Fig. 1 is a schematic diagram of a film structure of a conventional aluminum-plastic composite film.

Fig. 2 is an electron microscope photograph of a conventional aluminum-plastic composite film, wherein the thickness parameters (unit: micrometer) of L1, L2, L3, L4, L5 and L6 are 263.87, 124.63, 29.13, 13.56, 34.54 and 61.87, respectively.

FIG. 3 is a schematic view of the film structure of the all-plastic composite packaging material prepared by the existing extrusion film-forming process, wherein PE is a polyethylene layer, TIE is a bonding resin layer, and EVOH is an ethylene-vinyl alcohol copolymer layer.

Fig. 4 is a schematic structural diagram of a film layer of an all-plastic composite packaging material prepared by a conventional laminating and compounding process.

Fig. 5 is a schematic structural diagram of a film layer of an all-plastic composite packaging material prepared by a conventional film blowing lamination compounding process, wherein PE is a polyethylene layer, and EVA is an ethylene vinyl acetate copolymer layer.

FIG. 6 is an electron microscope photograph of the film layers of the prior all-plastic composite packaging sheet laminated by laminating the laminated films, wherein the thickness parameters (unit: micron) of L1, L2, L3, L4, L5 and L6 are 318.94, 75.00, 29.08, 33.89, 110.27 and 72.16 respectively.

FIG. 7 is an electron micrograph of the film layers of the all-plastic composite packaging sheet laminated by the prior art blown film, wherein the thickness parameters (unit: micron) of L1, L2, L3, L4, L5, L6 and L7 are respectively 10.44, 11.32, 29.88, 24.72, 37.35, 35.70 and 151.61.

Fig. 8 is a simplified diagram of a conventional aluminum-plastic composite process.

Fig. 9 is an electron micrograph of the high barrier film of example 2 of the present invention, wherein the thickness parameters of each layer are shown in table 2.

Fig. 10 is an electron micrograph of the high barrier film of example 3 of the present invention, wherein the thickness parameters of each layer are shown in table 3.

Fig. 11 is an electron micrograph of the high barrier film of example 4 of the present invention, wherein the thickness parameters of each layer are shown in table 4.

Fig. 12 is a schematic process diagram of the method for preparing the recyclable high-barrier film of the invention.

Fig. 13 is a schematic structural diagram of a recyclable high barrier film processing system according to the present invention.

FIG. 14 is a schematic diagram of the die of the film blowing machine in the recyclable high barrier film processing system according to the present invention.

Fig. 15 is a schematic view of a film structure of the high barrier film of the present invention.

FIG. 16 is a photograph of a product of the present invention when tested for peel strength.

Fig. 17 is a partially enlarged view of the thick film stretching mechanism of the high barrier film processing system in the embodiment of the present invention.

Fig. 18 is a partially enlarged view of the slitting device and the winding device of the high barrier film processing system in the embodiment of the invention.

Illustration of the drawings:

1. a hopper; 2. a film blowing machine; 21. a die head; 22. a flow channel; 23. a flow passage opening; 3. an extruder; 4. a conveying device; 5. A thick film stretching and extending mechanism; 51. a film body heating device; 52. a film body cooling device; 6. a slitting device; 61. a transverse vibration mechanism; 62. a vertical vibration mechanism; 7. a winding device; 8. and (5) secondary cooling and shaping device.

Detailed Description

In order to facilitate an understanding of the invention, the invention is described more fully and in detail below, but the scope of the invention is not limited to the following specific examples.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

Example 1 (theoretical design example):

the recyclable high-barrier film comprises a first polyethylene functional layer (in the embodiment, a first outer PE layer and a first HDPE single layer are adopted), an ethylene-vinyl alcohol copolymer intermediate barrier layer (in the embodiment, an EVOH layer is selected) and a second polyethylene functional layer (in the embodiment, a second HDPE single layer and a second outer PE layer are adopted), wherein two sides of the ethylene-vinyl alcohol copolymer intermediate barrier layer are respectively combined with the first polyethylene functional layer and the second polyethylene functional layer through adhesive resin layers, the first polyolefin functional layer, the ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer are tightly adhered into a whole through the adhesive resin layers, and the first polyolefin functional layer, the second polyolefin functional layer and the first polyolefin functional layer cannot be subjected to repeated stress relaxation test (for example, GB 880/T8-, The ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer are effectively stripped, and the compounding fastness between the first polyolefin functional layer and the ethylene-vinyl alcohol copolymer intermediate barrier layer and between the ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer is larger than 15N/15 mm.

The structure of the high-barrier film of the present embodiment is specifically shown in fig. 15, and includes a seven-layer structure of PE/HDPE/TIE/EVOH/TIE/HDPE/PE; the seven-layer structure comprises the following components from outside to inside in sequence: first outer PE layer (relative density 0.935) + first HDPE monolayer (relative density 0.961) + first tie resin layer + intermediate barrier layer of ethylene-vinyl alcohol copolymer + second tie resin layer + second HDPE monolayer + second outer PE layer. In the multi-film structure shown under a microscopic electron microscope, each layer of the high-barrier film material of this embodiment does not contain a peelable adhesive transition layer formed by an extrusion lamination composite layer, a lamination adhesive layer, or other secondary adhesion means, and each film layer included in the high-barrier film material is obtained by one-time coextrusion molding through a film blowing process (see the preparation process below in detail). The high-barrier film material comprises only one layer of ethylene-vinyl alcohol copolymer intermediate barrier layer in a film structure shown under a microscopic electron microscope, and the ethylene content of the ethylene-vinyl alcohol copolymer intermediate barrier layer is 38 wt%. The composition design and layer thickness ratio parameters of each layer are shown in the following table 1, and the total thickness of the high-barrier film material is 250 micrometers.

Table 1: example 1 design table of parameters of high barrier film

As shown in fig. 12, the preparation method of the high-barrier film material of this embodiment includes multiple steps of feeding, heating and melting, co-extrusion, film blowing, cooling and shaping, drawing, and rolling, and specifically includes the following operations:

s1: conveying raw material particles of the first outer PE layer, the first HDPE single layer, the first adhesive resin layer, the ethylene-vinyl alcohol copolymer intermediate barrier layer, the second adhesive resin layer, the second HDPE single layer and the second outer PE layer to hoppers of the extruders from respective storage tanks; in the conveying process, raw material particles pass through the automatic weighing system, the raw material particles are added into the hoppers of the extruders in the automatic weighing system according to the proportion in the formula, the proportion of materials is completed in the conveying process, the metering accuracy is realized, and the weighing process in the processing process is reduced.

S2: in the embodiment, seven hoppers are respectively used for storing the raw material particles of each layer, in other embodiments, 9-11 hoppers can be arranged according to the difference of film layer structures, and part of the hoppers can be additionally arranged for storing functional additives; the raw material particles are respectively stored in different hoppers, so that the conveying is convenient, the proportion of each component is also convenient to adjust, the processing device is suitable for the conditions of different material proportions, and the whole processing device is more flexible; after the material is fed by a hopper, the raw material particles are heated, melted, distributed, co-extruded and cooled and shaped by an air ring in an extruder to obtain a film body formed in one step.

S3: when the film body is cooled and shaped through the air ring, the blow-up ratio of the film body is generally 1-3, and the traction ratio of the film body is 4-6, so that the film material reaches the preset thickness.

S4: the film body after the air ring cooling is finalized the design is through drawing formation two-layer film after the herringbone splint presss from both sides flat, together gets into a tensile extension mechanism of thick film and carries out the tensile extension operation of thick film, is equipped with film body heating device and film body cooling device in the tensile extension mechanism of thick film, carries out the tensile extension of thick film through cold and hot alternation repeatedly.

S5: the film body after the thick film stretching and extending operation can be subjected to secondary cooling and shaping operation (but the operation is not necessary) in the conveying process, the secondary cooling and shaping operation can be applied to the film body through an air ring cooling device, and the film body can be more flat and more uniform in performance through a plurality of groups of horizontally arranged heating roller sets and cooling roller sets; and the temperature of the film body after secondary cooling and shaping is controlled to be 30-50 ℃. The film material moves in the roller to enable the material to be smoother and more uniform in performance, and the physical function of each component is exerted to the utmost extent.

S6: and (4) the film body after secondary cooling and shaping is subjected to traction by a traction roller, post-processing treatment and cooling, and is conveyed to a winding roller for winding. Specifically, a heating roller set and a cooling roller set can be arranged in the roller behind the traction roller according to requirements, and are alternately arranged to repeatedly heat and cool the film material, so that the roller can continuously heat or cool the film material subjected to secondary cooling and shaping, the hardness of the material is improved, and the extensibility is better; the post-processing treatment comprises corona and edge cutting, and after the post-processing treatment, the two layers of films are respectively cooled, shaped and rolled.

The preparation method of the embodiment realizes one-time direct molding of the high-barrier membrane material, can be used for manufacturing the packing tubes such as toothpaste tubes and the like, and has the advantages of simplified process and reduced cost. The characteristics of the high-strength material process enable the material to have the advantages of uniform pipe thickness, smooth pipe body, good barrier property, high processing efficiency, low material cost, higher stiffness and the like in the field of pipe manufacturing.

Example 2:

a recyclable high barrier film as shown in FIG. 9 comprises a first polyethylene functional layer (in this embodiment, a first outer PE layer + a first HDPE single layer), an intermediate barrier layer of ethylene-vinyl alcohol copolymer (in this embodiment, an EVOH layer is selected), and a second polyethylene functional layer (in this embodiment, a second HDPE single layer + a second outer PE layer), wherein two sides of the intermediate barrier layer of ethylene-vinyl alcohol copolymer are respectively bonded to the first polyethylene functional layer and the second polyethylene functional layer through adhesive resin layers, the first polyolefin functional layer, the intermediate barrier layer of ethylene-vinyl alcohol copolymer and the second polyolefin functional layer are tightly bonded into a whole through the adhesive resin layers, and the polyolefin functional layer cannot be peeled off in the first functional layer in the conventional composite film material peeling strength test (for example, GB/T8808: "Soft composite Plastic Material peeling test method", etc.), The ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer are effectively stripped, and the compounding fastness between the first polyolefin functional layer and the ethylene-vinyl alcohol copolymer intermediate barrier layer and between the ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer is larger than 15N/15 mm.

The structure of the high-barrier film of the present embodiment is specifically shown in fig. 15, and includes a seven-layer structure of PE/HDPE/TIE/EVOH/TIE/HDPE/PE; the seven-layer structure comprises the following components from outside to inside in sequence: the first outer PE layer (relative density 0.935) + the first HDPE monolayer (relative density 0.960) + the first tie resin layer + the ethylene vinyl alcohol copolymer-based intermediate barrier layer + the second tie resin layer + the second HDPE monolayer + the second outer PE layer. As shown in fig. 9, in the multi-layer structure of the high barrier film shown under a microscopic electron microscope, each layer does not include a peelable adhesive transition layer formed by an extrusion lamination composite layer, a lamination adhesive layer, or other secondary adhesion methods, and each layer included in the high barrier film is obtained by one-step co-extrusion molding through a blown film process (see the preparation process of example 1). The high-barrier film material comprises only one layer of ethylene-vinyl alcohol copolymer intermediate barrier layer in a film structure shown under a microscopic electron microscope, and the ethylene content of the ethylene-vinyl alcohol copolymer intermediate barrier layer is 38 wt%. The composition design and layer thickness ratio parameters of each layer are shown in table 2 below, and the total thickness of the high-barrier film is 232.6 micrometers (because the measured positions of each layer are slightly different, the total thickness of 232.53 micrometers of the film product shown in the figure is slightly different from the calculated value).

Table 2: example 2 design table of parameters of high barrier film

The preparation process of the high-barrier film material of the embodiment can be as shown in embodiment 1.

Example 3:

as shown in FIG. 10, the recyclable white high-barrier film of the present invention comprises a first polyethylene functional layer (in this embodiment, a first outer PE layer + a first HDPE single layer), an intermediate barrier layer of ethylene-vinyl alcohol copolymer (in this embodiment, an EVOH layer is selected), and a second polyethylene functional layer (in this embodiment, a second HDPE single layer + a second outer PE layer), wherein two sides of the intermediate barrier layer of ethylene-vinyl alcohol copolymer are respectively bonded to the first polyethylene functional layer and the second polyethylene functional layer through adhesive resin layers, the intermediate barrier layer of first polyolefin functional layer and ethylene-vinyl alcohol copolymer and the second polyolefin functional layer are tightly bonded together through the adhesive resin layers, and the peel strength test of conventional composite film materials is adopted (for example, GB/T8808. 1988. Peel test methods for Soft composite Plastic materials), see fig. 16), the effective peeling-off between the first polyolefin-based functional layer, the intermediate barrier layer of ethylene-vinyl alcohol copolymer, and the second polyolefin-based functional layer cannot be performed, and the composite fastness between the first polyolefin-based functional layer and the intermediate barrier layer of ethylene-vinyl alcohol copolymer, and between the intermediate barrier layer of ethylene-vinyl alcohol copolymer and the second polyolefin-based functional layer are both greater than 15N/15 mm. As shown in FIG. 16, the conventional peel strength test requires manual work, the sample is cut to have a width of 15mm and a length of 20mm, then manually peeled from each other, and then put on a tensile tester to be subjected to a peel force test, but the product of the invention is difficult to manually peel because the layers are firmly adhered, so that the composite fastness is obviously higher than 15N/15 mm.

Compared with the high-barrier film materials of examples 1 and 2, the recyclable high-barrier film material of the present embodiment is mainly characterized in that a white masterbatch is added to the first HDPE monolayer. As shown in fig. 10, a seven-layer structure comprising PE/HDPE (white master)/TIE/EVOH/TIE/HDPE/PE; the seven-layer structure comprises the following components from outside to inside in sequence: the first outer PE layer (relative density 0.935) + the first HDPE monolayer (relative density 0.960) + the first tie resin layer + the intermediate barrier layer of ethylene vinyl alcohol copolymer + the second tie resin layer + the second HDPE monolayer (relative density 0.960) + the second outer PE layer (relative density 0.935). In the multi-layer structure shown under a microscopic electron microscope, each layer of the high barrier film of this embodiment does not contain a peelable adhesive transition layer formed by an extrusion lamination composite layer, a lamination adhesive layer, or other secondary adhesion means, and each layer of the high barrier film is obtained by one-time coextrusion molding through a film blowing process (see the preparation process of example 1). The high-barrier film material comprises only one layer of ethylene-vinyl alcohol copolymer intermediate barrier layer in a film structure shown under a microscopic electron microscope, and the ethylene content of the ethylene-vinyl alcohol copolymer intermediate barrier layer is 38 wt%. The composition design and layer thickness ratio parameters of each layer are shown in table 3 below, and the total thickness of the high-barrier film material is 238.05 microns.

Table 3: example 3 design table for parameters of high barrier film

The preparation method of this example is essentially the same as example 1, except that a certain amount of white masterbatch is added to the hopper of the first HDPE monolayer, and the measured thickness values and layer thickness ratios of the layers are fine-tuned.

Example 4:

as shown in FIG. 11, the recyclable nine-layer white high-barrier film comprises a first polyethylene functional layer (in this embodiment, a first outer PE layer + a first HDPE monolayer (white master) + a third HDPE monolayer (white master)), an intermediate barrier layer (in this embodiment, an EVOH layer is selected) of an ethylene-vinyl alcohol copolymer, and a second polyethylene functional layer (in this embodiment, a fourth HDPE monolayer + a second outer PE layer), wherein two sides of the intermediate barrier layer of the ethylene-vinyl alcohol copolymer are respectively bonded to the first polyethylene functional layer and the second polyethylene functional layer through adhesive resin layers, the first polyolefin functional layer, the intermediate barrier layer of the ethylene-vinyl alcohol copolymer, and the second polyolefin functional layer are tightly bonded into a whole through the adhesive resin layers, and a peeling strength test of a conventional composite film material is adopted (for example, GB/T8808- Test methods), the effective stripping cannot be carried out among the first polyolefin functional layer, the ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer, and the composite fastness between the first polyolefin functional layer and the ethylene-vinyl alcohol copolymer intermediate barrier layer and between the ethylene-vinyl alcohol copolymer intermediate barrier layer and the second polyolefin functional layer is more than 15N/15 mm.

Compared with the high-barrier film materials of

embodiments

1 and 2, the recyclable high-barrier film material of the embodiment is mainly characterized in that two HDPE layers are added, and white masterbatch is added into the first HDPE layer and the third HDPE layer. As shown in fig. 11, a nine-layer structure of PE/HDPE + white masterbatch/TIE/EVOH/TIE/HDPE/PE; the nine-layer structure comprises the following components from outside to inside in sequence: the first outer PE layer + the first HDPE monolayer (white master) + the third HDPE monolayer (white master) + the first adhesive resin layer + the ethylene-vinyl alcohol copolymer-based intermediate barrier layer + the second adhesive resin layer + the fourth HDPE monolayer + the second outer PE layer. In the multi-layer structure shown under a microscopic electron microscope, each layer of the high barrier film of this embodiment does not contain a peelable adhesive transition layer formed by an extrusion lamination composite layer, a lamination adhesive layer, or other secondary adhesion means, and each layer of the high barrier film is obtained by one-time coextrusion molding through a film blowing process (see the preparation process of example 1). The high-barrier film material comprises only one layer of ethylene-vinyl alcohol copolymer intermediate barrier layer in a film structure shown under a microscopic electron microscope, and the ethylene content of the ethylene-vinyl alcohol copolymer intermediate barrier layer is 38 wt%. The composition design and layer thickness ratio parameters of each layer are shown in table 4 below, and the total thickness of the high-barrier film is 320.67 microns.

Table 4: example 4 design table of parameters of high barrier film

The preparation method of this example is substantially the same as that of example 1, and the only difference is that two HDPE layers are added, and white masterbatch is added to the first and third HDPE monolayers, two extruders are correspondingly required to be added, and in addition, the actually measured thickness value and layer thickness ratio of each layer are finely adjusted.

The comparative performance test data for the high barrier films of examples 2, 3, 4 above are shown in table 5 below:

table 5: comparison experiment table for performance parameters of high-barrier film in each embodiment

Example 5:

the utility model provides a system for processing for preparing high resistant barrier film material that can cyclic utilization as shown in fig. 12, 13, including hopper 1, inflation film manufacturing machine 2, a plurality of extruders 3, conveyor 4, the tensile extension mechanism 5 of thick film, cut device 6 and coiling mechanism 7, extruder 3 is connected to hopper 1, a plurality of extruders 3 are connected in the bottom of inflation film manufacturing machine 2, the quantity of a plurality of extruders 3 corresponds unanimously with the number of piles of the high resistant barrier film material of preparation, the film material of the output of inflation film manufacturing machine 2 top passes through conveyor 4 and connects through the tensile extension mechanism 5 of thick film, the film material of the tensile extension mechanism 5 output of thick film is finally connected to cutting device 6 and coiling mechanism 7.

Fig. 17 is a partial enlarged view of the thick film stretching and spreading mechanism 5 of the present invention, and as can be seen from fig. 17, a conveying channel for accommodating the conveying device 4 is arranged in the thick film stretching and spreading mechanism 5, and a film body heating device 51 and a film body cooling device 52 for alternately heating and cooling the film body are arranged in the conveying channel. The thick film drawing and stretching mechanism 5 is disposed near the discharge of the film blowing machine 2 (on the top of the film blowing machine 2 in the present embodiment), and the film body heating device 51 and the film body cooling device 52 are alternately provided with a plurality of sets.

As shown in fig. 12 and 13, the film material outputted by the thick film stretching mechanism 5 is further selectively connected by the conveying device 4 and passes through a secondary cooling and shaping device 8, and the secondary cooling and shaping device 8 is connected with the slitting device 6 and the winding device 7. The secondary cooling and shaping device comprises an air ring cooling device applied to the film material, and further comprises a heating roller set and a cooling roller set which are arranged in front of the air ring cooling device and are alternately subjected to cold and heat treatment, wherein the heating roller set and the cooling roller set are arranged in a horizontal rolling mode (see fig. 12) for the film material.

As shown in fig. 14, the number of the runners 22 in the die head 21 of the film blowing machine 2 is configured in accordance with the number of layers of the high barrier film to be produced, and the width of the single runner 22 located in the die head 21 is larger than the size of the runner opening 23 of the single runner 22 at the air ring cooling discharge.

As shown in fig. 18, the cutter of the slitting device 6 in the processing system of this embodiment is driven by a vibrating mechanism. The vibrating mechanism includes a transverse vibrating mechanism 61 that drives the cutter to vibrate in the horizontal direction and a vertical vibrating mechanism 62 that drives the cutter to vibrate in the vertical direction.

Claims

1. A recyclable high-barrier film, comprising a first polyolefin-based functional layer, a second polyolefin-based functional layer, and an ethylene-vinyl alcohol copolymer-based intermediate barrier layer, the ethylene-vinyl alcohol copolymer-based The two sides of the intermediate barrier layer are respectively combined with the first polyethylene functional layer and the second polyethylene functional layer through the adhesive resin layer. The barrier layer and the second polyolefin-based functional layer are tightly bonded into a whole through the adhesive resin layer, and the first polyolefin-based functional layer, ethylene-vinyl alcohol copolymer-based Effective peeling is performed between the intermediate barrier layer and the second polyolefin-based functional layer.

2 . The recyclable high-barrier film according to claim 1 , wherein, between the first polyolefin-based functional layer and the ethylene-vinyl alcohol copolymer-based intermediate barrier layer, and the ethylene- The composite fastness between the vinyl alcohol copolymer-based intermediate barrier layer and the second polyolefin-based functional layer is both above 15N/15mm.

3 . The recyclable high-barrier film according to claim 1 , wherein in the multi-layer structure of the high-barrier film displayed under an electron microscope, the first polyolefin-based functional layer Between the ethylene-vinyl alcohol copolymer-type intermediate barrier layer, and between the ethylene-vinyl alcohol copolymer-type intermediate barrier layer and the second polyolefin-based functional layer, there is no composite layer by extrusion coating, Laminate tie layer or other peelable adhesive transition layer formed by secondary bonding.

4 . The recyclable high-barrier film according to claim 1 , wherein each film layer included in the high-barrier film is obtained by one-time co-extrusion molding through a blown film process. 5 .

5 . The recyclable high-barrier film according to claim 1 , wherein the total thickness of the high-barrier film is 150-400 μm, preferably 250-350 μm. 6 .

6. The recyclable high-barrier film according to any one of claims 1 to 4, wherein the film structure of the high-barrier film displayed under an electron microscope contains one and only one Layer ethylene-vinyl alcohol copolymer type intermediate barrier layer.

7. The recyclable high-barrier film according to any one of claims 1 to 4, wherein the ethylene-vinyl alcohol copolymer-based intermediate barrier layer displayed under an electron microscope is in a high-barrier The layer thickness ratio in the film material is 5% or less, preferably 4.2% or less.

8 . The recyclable high-barrier membrane according to claim 1 , wherein the adhesive resin layer is maleic anhydride grafted linear polyethylene, or maleic anhydride grafted linear polyethylene. 9 . The linear polyethylene and linear polyethylene blends show that the layer thickness ratio of the single-layer adhesive resin layer in the high-barrier film under the electron microscope is 3% to 10%.

9 . The recyclable high-barrier film according to claim 1 , wherein the first polyolefin-based functional layer and the second polyolefin-based functional layer are selected from polyethylene, At least one of polypropylene and polyethylene-polypropylene copolymer.

10 . The recyclable high-barrier film according to claim 9 , wherein the first polyolefin-based functional layer and the second polyolefin-based functional layer are respectively a first polyethylene functional layer and a second polyolefin functional layer. 11 . A polyethylene functional layer, the first polyethylene functional layer and/or the second polyethylene functional layer include an outer PE layer and an inner PE layer close to the adhesive resin layer, and the outer PE layer is selected from medium density polyethylene (MDPE) and/or low density polyethylene (LDPE), the inner PE layer is selected from high density polyethylene (HDPE).

11. The recyclable high-barrier membrane material according to claim 10, wherein the density of the low density polyethylene is 0.910-0.93kg/cm ³ , and the density of the medium density polyethylene is 0.930-0.930- 0.940kg/cm ³ , the density of the high-density polyethylene is above 0.940kg/cm ³ (preferably 0.940-0.970).

12. The recyclable high-barrier membrane material according to claim 10, wherein the inner HDPE layer is shown under a microscope to be composed of a single layer of HDPE or composed of multiple layers of HDPE monolayers. to make.

13 . The recyclable high-barrier film according to claim 12 , wherein the film structure of the high-barrier film under an electron microscope is the following seven layers, nine layers or eleven layers. 14 . structure without other functional layers:

The seven-layer structure from outside to inside is: the first outer PE layer + the first HDPE single layer + the first adhesive resin layer + the ethylene-vinyl alcohol copolymer intermediate barrier layer + the second adhesive resin layer + the first adhesive resin layer. Two HDPE single layer + second outer PE layer;

The nine-layer structure from outside to inside is: first outer PE layer + first HDPE single layer + third HDPE single layer + first adhesive resin layer + ethylene-vinyl alcohol copolymer intermediate barrier layer + second Adhesive resin layer + fourth HDPE single layer + second HDPE single layer + second outer PE layer;

The eleven-layer structure from outside to inside is: first outer PE layer + first HDPE single layer + third HDPE single layer + fifth HDPE single layer + first adhesive resin layer + ethylene-vinyl alcohol copolymer Similar to the middle barrier layer + the second adhesive resin layer + the sixth HDPE single layer + the fourth HDPE single layer + the second HDPE single layer + the second outer PE layer.

14. The recyclable high-barrier membrane material according to claim 10, characterized in that, under an electron microscope, the outer PE layers on both sides of the ethylene-vinyl alcohol copolymer-based intermediate barrier layer are in the high-barrier layer. The layer thickness ratio in the film is 10% to 30%; the layer thickness ratio of each adhesive resin layer in the high barrier film is 3% to 10%, and the rest is occupied by the inner PE layer. .

15 . The recyclable high-barrier film according to claim 14 , wherein, under an electron microscope, the total thickness of the inner PE layer contained in the high-barrier film accounts for 40% to 70% of the total thickness. 16 . %.

16. The recyclable high-barrier membrane material according to claim 15, characterized in that, under an electron microscope, the inner PE layer on one side of the ethylene-vinyl alcohol copolymer-based intermediate barrier layer is in the high-barrier layer. The layer thickness ratio in the film is controlled at 15% to 35%.

17. A method for preparing a recyclable high-barrier membrane, the preparation method comprising the steps of feeding, heating and melting, co-extrusion, blown film cooling and shaping, drawing, and winding, wherein the In the cooling and setting stage of the blown film, all the film layers are obtained by blowing the film at one time, and a thick film stretching operation is added during the drawing process.

18 . The method for preparing a recyclable high-barrier film according to claim 17 , wherein the film body after cooling and shaping of the blown film is flattened by a splint and then pulled, and during the pulling process. 19 . The thick film stretching operation is performed by a thick film stretching mechanism, wherein the thick film stretching mechanism is provided with a film body heating device and a film body cooling device, and the thick film stretching and stretching is performed by repeated alternating cold and heat.

19 . The method for preparing a recyclable high-barrier film material according to claim 18 , wherein the film body that has undergone the thick film stretching operation is subjected to a secondary cooling and shaping operation during the conveying process, and the The secondary cooling and shaping operation is applied to the film body through an air ring cooling device, and the temperature of the film body after the secondary cooling and shaping is controlled at 30°C to 50°C.

20. The method for preparing a recyclable high-barrier membrane according to any one of claims 17 to 19, wherein in the feeding process, the raw material particles are in an automatic weighing system according to a set formula The proportion of the blown film is directly added to the hopper of the extruder, and the material proportion is completed during the conveying process; Through the cooling and shaping of the air ring, the inflation ratio of the film body is 1-3, and the traction ratio of the film body is 4-6.

21. A processing system for preparing a recyclable high-barrier film, comprising a hopper, a film blowing machine, an extruder, a conveying device, a thick film stretching mechanism, a slitting device and a winding device, said The hopper is connected to the extruder, and a plurality of the extruders are connected to the bottom of the film blowing machine. It is characterized in that the film material output from the top of the film blowing machine is connected by a conveying device and passes through a thick film stretching mechanism , the film material output by the thick film stretching mechanism is finally connected to the slitting device and the winding device; the thick film stretching mechanism is provided with a conveying channel for the conveying device, and the conveying channel is provided with A film heating device and a film cooling device with repeated cooling and heating.

22. The processing system according to claim 21, characterized in that, the film material outputted through the thick film stretching mechanism is connected through a conveying device, passed through a secondary cooling and setting device, and finally connected to a winding device; The secondary cooling and shaping device is arranged near the upstream or downstream of the slitting device; the secondary cooling and shaping device includes an air ring cooling device applied on the film material.

23 . The processing system according to claim 22 , wherein the secondary cooling and sizing device further comprises a heating roller group and a cooling roller group that are arranged in front of the air ring cooling device to perform alternate cooling and heat treatment, and the heating rollers are 23 . The group and the cooling roll group are arranged in a horizontal rolling mode for the film material.

24. The processing system according to any one of claims 21 to 23, wherein the number of the extruders corresponds to the number of layers of the high-barrier film to be prepared; The configuration of the number of flow channels in the head is consistent with the number of layers of the high-barrier membrane to be prepared, and the width of a single flow channel in the die head is larger than the opening size of the single flow channel at the cooling outlet of the air ring.

25. The processing system according to any one of claims 21 to 23, wherein the cutter of the slitting device is driven by a vibrating mechanism, and the vibrating mechanism comprises a transverse direction that drives the cutter to vibrate in a horizontal direction. The vibration mechanism and the vertical vibration mechanism that drives the cutter to vibrate in the vertical direction.