CN216708596U

CN216708596U - Biodegradable aluminized composite film material structure with waterproof surface

Info

Publication number: CN216708596U
Application number: CN202122938457.5U
Authority: CN
Inventors: 辜伟悦
Original assignee: Zhuhai Hengqin Huizefeng Packaging Technology Co ltd
Current assignee: Zhuhai Hengqin Huizefeng Packaging Technology Co ltd
Priority date: 2021-11-27
Filing date: 2021-11-27
Publication date: 2022-06-10
Anticipated expiration: 2031-11-27

Abstract

The utility model provides a surface waterproof biodegradable aluminized composite film material structure, which comprises a PLA film layer, a cellulose aluminized layer, a PBAT film layer, a first adhesive layer clamped between the PLA film layer and the cellulose aluminized layer and a second adhesive layer clamped between the cellulose aluminized layer and the PBAT film layer from the surface layer to the inner layer in sequence, wherein the PLA film layer, the first adhesive layer, the cellulose aluminized layer, the second adhesive layer and the PBAT film layer are combined together through a composite film forming technology. The utility model compounds the PLA film layer with printing adaptability, but poor extensibility and heat sealing property with the cellulose aluminized layer with high barrier property, then compounds the PLA film layer with heat sealing property and extensibility with the PBAT film layer with heat sealing property and extensibility, the performances are complementary, and the composite film material with surface water resistance, heat sealing property and the performance requirements of low-temperature freezing, high barrier condition and the like is prepared; except the cellulose aluminum-plated layer, the degradable part can be completely degraded, and the degradable rate of the degradable part is more than 90%.

Description

Biodegradable aluminized composite film material structure with waterproof surface

Technical Field

The utility model relates to the technical field of degradable composite film materials, in particular to a biodegradable aluminized composite film material structure with a waterproof surface.

Background

At present, under the push of environmental protection concept and plastic limitation, biodegradable packaging films are popular packaging materials in the market and gradually replace non-degradable plastic films. At present, most of degradable compostable film materials have poor water resistance due to molecular structures and the like, cannot meet more functional requirements, and the surfaces of the degradable compostable film materials are easily affected by moisture to influence use.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art, solve the defect of barrier property of a degradable material in the moisture permeability aspect, provide a method for solving the problem of environmental pollution caused by non-degradable plastics, meet the structure of a degradable aluminized composite film material for functional packaging application and expand the application range of the degradable aluminized composite film material.

In order to achieve the purpose, the technical scheme provided by the utility model is as follows: the utility model provides a but surface waterproof's biodegradable aluminizes composite film material structure, composite film material includes PLA thin layer, cellulose aluminizing layer, PBAT thin layer and centre gripping from top layer toward the nexine in proper order and is in first adhesive layer, centre gripping between PLA thin layer and the cellulose aluminizing layer are in second adhesive layer between cellulose aluminizing layer and the PBAT thin layer, PLA thin layer, first adhesive layer, cellulose aluminizing layer, second adhesive layer and PBAT thin layer combine together through compound filming technique.

Preferably, a printing layer is further arranged between the PLA film layer and the first adhesive layer, and the printing layer is arranged on the inner surface of the PLA film layer.

Preferably, the PLA film layer may be replaced by a cellulose layer, outside of which a PVDC coating is provided.

Preferably, the PLA film layer may be replaced by a kraft paper layer, outside which a PVDC coating is provided.

According to the scheme, the PLA film layer with printing adaptability but poor extensibility and heat sealability and the cellulose aluminized layer with high barrier property are compounded together through the first adhesive layer, and then compounded together with the PBAT film layer with heat sealability and extensibility and then the second adhesive layer, so that the performances are complementary, and the composite film material with surface water resistance, heat sealability and the performance requirements of low-temperature freezing, high barrier condition and the like can be prepared; the material layer except the cellulose aluminum-plated layer is completely derived from degradable raw materials, the degradable rate of the degradable part is more than 90%, and the material is energy-saving and environment-friendly.

Description of the drawings:

FIG. 1 is a first schematic structural diagram of a composite film material according to the present invention;

FIG. 2 is a schematic structural diagram of a composite film material according to the present invention;

FIG. 3 is a schematic view of a preparation process of the present invention;

FIG. 4 is a simplified schematic view of the process flow of the dry compounding method of the present invention;

FIG. 5 is a simplified schematic diagram of the process flow of the solventless compounding method of the present invention.

Detailed Description

The utility model will be further illustrated with reference to specific examples:

example 1:

as shown in fig. 1, the structure of the waterproof biodegradable aluminized composite film material 1 of the present embodiment includes a PLA film layer 2, a cellulose aluminized layer 3, a PBAT film layer 4, a first adhesive layer 5 sandwiched between the PLA film layer 2 and the cellulose aluminized layer 3, and a second adhesive layer 6 sandwiched between the cellulose aluminized layer 3 and the PBAT film layer 4, wherein the PLA film layer 2, the first adhesive layer 5, the cellulose aluminized layer 3, the second adhesive layer 6, and the PBAT film layer 4 are combined together by a composite film-forming technique.

The main component of the PLA film layer 2 is a transparent film product prepared by polylactic acid extracted and synthesized from corn, sugarcane and cassava through a biaxial stretching process or a blow molding process, the PLA film layer 2 is high in tensile strength, good in stiffness, good in flatness, good in surface printing performance and waterproof in surface, and the thickness of the PLA film layer 2 is 12UM-100 UM.

The cellulose aluminum coating 3 is processed by adopting a natural cellulose film through a vacuum aluminum plating process, has higher water vapor and oxygen barrier property, and has the general thickness of 10UM-50UM if the cellulose aluminum coating 3 is used in a flexible package.

Cellulose is commonly known as cellophane, the english name cellophane (cellophane) has good printability. The cellophane is degradable: tests of Zhejiang industry and commerce university show that 'when the film product is buried in soil for 45 days, the film is extremely seriously disintegrated and is cracked together with the soil during digging, and the weight loss rate of the film for degradation cannot be measured'; secondly, the coating is nontoxic and tasteless, and the film product has no dense smoke and stink when burning; good insulativity (surface resistance is 8.2 multiplied by 107 omega), no static electricity, dust resistance and good printing adaptability; fourthly, the air permeability is good: the average oxygen permeability is 67.018 cc/square meter day, and the film is made of cellulose, has pores and is suitable for fresh-keeping storage of fruits, vegetables and the like. High temperature resistance: the oven is kept at 200 ℃ for 24 hours without deformation.

The PBAT film layer 4 is a degradable material with good comprehensive performance, and can be a degradable film material produced by the mixture ratio of starch, PBAT, PBS, PBSA, PCL, inorganic powder, PHA, PLA polylactic acid, PPC, PGA and the like or a single material. Wherein PLA is derived from corn, sugarcane or cassava to extract glucose and synthesize polylactic acid as a biological organic material; PBAT belongs to thermoplastic biodegradable plastic, is a copolymer of butanediol adipate and butanediol terephthalate, has the characteristics of PBA and PBT, and has better ductility and elongation at break as well as better heat resistance and impact property; in addition, the biodegradable plastic has excellent biodegradability, and is one of the particularly good degradable materials which are very active in the research of the current biodegradable plastics and are applied in the market. PBAT, PBS, PBSA, PCL, PPC and PGA are derived from petroleum-based materials extracted from nature or refined from petroleum, and the film materials of the PBAT, the PBSA, the PCL, the PPC and the PGA have good heat sealing property and are used as heat sealing layers in the utility model, and the thickness of the film materials of the PBAT, the PBSA, the PCL, the PPC and the PGA is between 10UM and 200 UM.

The first adhesive layer 5 and the second adhesive layer 6 are polyurethane adhesive or other environment-friendly adhesive, and the PLA film layer 2, the cellulose aluminum-plated layer 3 and the PBAT film layer 4 can be bonded into a whole through traditional dry compounding or solvent-free compounding. The binder for the composition may be: 1. dibasic acid polyester polyol type glue; 2. a polyurethane glue; 3. the acrylic acid ester adhesive can also be an aqueous environment-friendly acrylic acid ester adhesive used for the electronic protective film adhesive. The oil-based pressure-sensitive adhesive overcomes the problems that the traditional oil-based pressure-sensitive adhesive is difficult to degrade after being used and causes pollution to the environment, and can be rapidly degraded under the action of external factors such as sunlight, temperature, water, microorganisms and the like, and finally decomposed into carbon dioxide and water. When functional packaging is carried out, the adhesive needs to have barrier property and cold resistance, can bear the requirement on blocking moisture evaporation after film making and bag making, and can also bear the environmental requirement of low-temperature refrigeration or freezing storage (has lower embrittlement temperature); the adhesive is nontoxic, odorless, good in flowability and leveling property, and good in adhesion between the composite film materials 1 so as to bear the corrosion of various media in contents and an external environment.

As shown in table 1, the PLA film layer 2 had printing suitability, good flatness, but poor extensibility; the PBAT film layer 4 has poor temperature resistance, but has heat sealability and extensibility: the cellulose aluminized layer 3 has high barrier property. The three material layers except the cellulose aluminized layer 3 are degradable materials derived from biological raw materials, are bonded into a whole through an adhesive, have complementary properties, meet the requirements of temperature-resistant heat-sealing, low-temperature freezing and high-barrier packaging materials after preparation and forming, can be printed according to the requirements, and improve the added value of products.

The thickness of the prepared composite film material 1 is between 30UM and 350UM, the finished product has good barrier property and tensile resistance, and the like, and achieves the packaging functionality of common plastic films.

The prepared composite film material 1 can be prepared into food packaging bags (the composite strength is more than or equal to 1N), vacuum-pumping packaging bags (the heat sealing strength is more than or equal to 10N), freezing bags (below 15 ℃) or commodity packaging bags, in particular to moisture-proof packaging application and degradable film materials applied in various industries.

TABLE 1 comparison of Single layer product with composite film product Properties

As shown in fig. 2, a printing layer 7 is further disposed between the PLA film layer 2 and the first adhesive layer 5, and the printing layer 7 is disposed on an inner surface of the PLA film layer 2, i.e., fixed to the first adhesive layer 5.

The composite film material 1 can be used for printing characters and patterns on the PLA film layer 2 by adopting a surface printing or inner printing process, so that the added value of products is improved. The composite film material 1 is compounded with other material layers after being printed by adopting an inner printing mode, and because the printing ink is clamped between the film layers, the printing ink layer is prevented from being polluted and damaged by direct friction, scratches and various corrosive substances, so that the problems of color bleeding and color fading in degradable film printing can be reduced, the influence of the printing ink on the sanitation and safety of food and medicines is avoided, and the environment-friendly and safe requirements of the food and the medicines can be met.

If the printing layer and the PBAT film layer 4 have requirements on corona strength, the surfaces of the PLA film layer 2 and the PBAT film layer 4 can be subjected to corona treatment in addition, so that the adhesive force between the printing layer ink or the first adhesive and the second adhesive layer 6 is enhanced.

The PLA film layer 2 has the same waterproof performance as the plastic film, and can prevent water from permeating from the surface to influence the performance of the cellulose aluminized layer 3 in the material combination of the utility model under the high-humidity environment. The PLA film layer 2 of the composite film material 1 may also be replaced by a cellulose layer or kraft paper, but it is advisable to provide a water-repellent coating to reduce or modify the moisture absorption of the material, for example a PVDC coating.

Kraft paper is a tough, water-resistant packaging paper, is brownish yellow, has a wide range of uses, and is commonly used for making paper bags, envelopes, workbooks, album covers, files, sandpaper and the like. The quantitative range is 40UM to 120UM, and there are differences in web and sheet, and also single-sided light, double-sided light and striped. The main quality requirements are that the cable is flexible and firm, has high bursting strength, and can bear large tensile force and pressure without cracking. The kraft paper has high tension, and has single light, double light, stripes, no stripes and the like. The paper is mainly used for packing paper, envelopes, paper bags and the like and cylinder linings of printing machines.

Table 2: comparison of Properties of different Material combinations

As shown in table 2, the combination of the PLA film layer 2, the cellulose aluminized layer 3, and the PBAT film layer 4 according to the present invention has the effect of surface waterproofing and moistureproof, compared to the groups 1 to 7.

PBAT, PLA, PGA, PBSA, cellulose and environment-friendly adhesive which meet the degradation requirement are selected, and the following international authoritative degradation certification is met but not limited:

germany DIN EN13432

USA BPI ASTM D6400

Australian Australia ABAM.

The performance of the adhesive used in the composite should meet, but is not limited to, the following health and safety regulations:

chinese food packaging material additive regulation GB9685-2008

American Food and Drug Administration (FDA)21CFR175.300

Directive restriction of hazardous substances by ROHS of European Union

As shown in fig. 3, the composite method suitable for the composite film material 1 has two processes: dry compounding and solvent-free compounding.

The dry-type compounding method comprises the steps of firstly coating a layer of solvent-based adhesive on a film by using a gravure screen line roller, drying the film in a drying channel of compounding equipment, and then laminating a first film PLA film layer 2 and a second cellulose aluminized layer 3 in a hot-pressing state; the composite film with the 2-layer structure is coated and dried for the second time through the same coating process again, is compounded with the third PBAT film layer 4, and is rolled and molded.

The dry lamination method is suitable for lamination of various films, has excellent chemical corrosion resistance, and is widely applied to packaging of harsh conditions of contents, such as foods containing basic, acidic, spicy, and grease components, cosmetics containing essence, emulsifier components, and chemicals containing corrosive solvents, pesticides, and the like.

The dry compounding method has the following characteristics: the method has the advantages of good stability and strength, suitability for producing common composite films and functional composite films for freezing, fresh-keeping or high-temperature sterilization, and the like, is the most widely applied film compounding method at present, and is flexible to operate and stable in output.

The dry compounding method comprises the following steps: as shown in fig. 4, a dry composite preparation method of a surface-waterproof biodegradable aluminized composite film material structure is provided, the first substrate passes through a coating mechanism composed of a rubber disc 8, a scraper, a gravure roller 9 and a rubber press roller i 10, the first substrate is generally the PLA film layer 2, the surface of the first substrate is coated with the solvent-based first adhesive layer 5, the first substrate enters a drying tunnel 11, the solvent-based first adhesive layer 5 is dried to remove the solvent and is solidified, the temperature of the drying tunnel 11 is between 60 and 85 ℃, the first substrate enters a hot press mechanism composed of a heating steel roller 13 and a rubber press roller ii 12, the second substrate is hot-pressed on the solvent-based first adhesive layer 5, the PLA film layer 2, the first adhesive layer 5 and the cellulose aluminized layer 3 are pressed together, the temperature of the heating steel roller 13 is between 70 and 90 ℃, the composite pressure of the hot-pressing mechanism can be properly increased to enhance the composite strength under the condition of not damaging the film, and finally the composite film I16 is obtained through a cooling roller 14; and compounding the semi-finished product two-layer film prepared by the composite film I16 as a third base material with the fourth base material PBAT thin film layer 4 by the above procedures.

The solvent-free compounding method comprises the steps of firstly coating a solvent-free polyurethane adhesive on a first base material by using a coating roller, wherein the viscosity of the solvent-free polyurethane adhesive is higher at normal temperature, the viscosity is sharply reduced along with the temperature rise, the solvent-free polyurethane adhesive has good coating performance, the moisture of air can be used as a curing agent, the adhesive strength is good, then the viscosity of the solvent-free polyurethane adhesive is reduced under the hot pressing state, the solvent-free polyurethane adhesive is coated on the first base material (the gluing amount is 0.8-4 g/square meter), finally, a second layer of film, a first layer of film and the adhesive are compounded together, and the like, one layer is coated. The first substrate and the second substrate on the gluing surface can be replaced for gluing without influencing the effect.

The adhesive prepared by the solvent-free compounding method does not contain an organic solvent, and a drying device is not needed.

The solvent-free compounding method comprises the following steps: as shown in fig. 5, a method for preparing a surface-waterproof biodegradable aluminized composite film material structure includes that a first substrate passes through a coating mechanism composed of a rubber disc 8, a scraper, a coating roller 13 and a rubber pressing roller i 10, the first adhesive layer coated on the surface of the first substrate is sent to a hot-pressing mechanism composed of a heating steel roller 13 and a rubber pressing roller ii 12 under the belt of a guide roller, a second substrate is hot-rolled on the first adhesive layer 5, the PLA film layer 2, the first adhesive layer 5 and the cellulose aluminized layer 3 are pressed together, the heating steel roller 13 is at a temperature of 65-90 ℃, the composite pressure of the hot-pressing mechanism is required to be increased as much as possible under the condition that the film is not damaged, and finally, a composite film ii 17 is obtained through a cooling roller 14; and (3) obtaining a composite film material 111 by using the composite film II 17. The obtained semi-finished product is a third base material and then is cured after the three-layer compounding is finished with the fourth base material according to the process operation, and the product is prepared.

First adhesive layer 5 and second adhesive layer 6 can be in the same place in PLA thin layer 2, cellulose aluminized layer 3 and PBAT thin layer 4 bonding respectively, because when first adhesive layer 5 and second adhesive layer 6 respectively with PLA thin layer 2, cellulose aluminized layer 3 and PBAT thin layer 4 bonding, generate adhesive force in the in-process of drying solidification or heating solidification, promptly at the composite process, first adhesive layer 5 and second adhesive layer 6 get into PLA thin layer 2 under the pressurized condition, form adhesive force each other in cellulose aluminized layer 3 and the PBAT thin layer 4, the adhesion effect can receive factors influences such as speed in the composite process, the scraper distance, the solvent formula, pressure distribution.

The composite film I16 and the composite film II 17 obtained by the dry-type composite method and the solvent-free composite method both need to be subjected to a curing process, the curing process can be carried out in a constant temperature room at 45-60 ℃ for more than 12 hours, and the chemical reaction speed can be accelerated by increasing the temperature.

The curing reaction is beneficial to the curing of the first adhesive layer 5 and the second adhesive layer 6, and is beneficial to accelerating the mutual reaction of-NCO groups in the first adhesive layer 5 and the second adhesive layer 6 and active hydrogen groups on the surfaces of the PLA film layer 2, the cellulose aluminum-plated layer 3 and the PBAT film layer 4. The first adhesive layer 5 and the second adhesive layer 6 can be softened by heating, so that the wetting of the surfaces of the PLA film layer 2, the cellulose aluminum-plated layer 3 and the PBAT film layer 4 is increased, the molecular movement is facilitated, the bonding force is improved, the product can be rapidly subjected to normal subsequent processing, the production period is shortened, the peel strength of the composite film I16 and the peel strength of the composite film II 17 are changed all the time before the curing reaction is completed, and the process is a process presenting increase-attenuation-stability.

The curing reaction process can be continued for more than 48 hours in a natural environment at 25 ℃ to achieve the purpose of curing.

The peel strength of the cured composite film material 1 can reach more than 1N-2N.

The compounding process can be changed into a laminating compounding method for compounding, and the utility model has qualified effect after corresponding experiments, but has low production speed.

A surface waterproof biodegradable aluminized composite film material 1 structure is made into a packaging bag, the packaging bag is formed by cutting two pieces of the composite film material 1 with the same size by a bag making machine, overlapping the two pieces of the composite film material 1, using the heat sealing and edge cutting technology at the temperature of 130-300 degrees on multiple edges, and forming an N +1 edge packaging bag with an opening.

The composite strength of the prepared packaging bag is more than or equal to 1.5N, and the heat sealing strength is more than or equal to 10N.

And packaging the product by the manufactured packaging bag, and then performing the packaging for the second side to achieve the purpose of product packaging.

Meanwhile, the composite film material 1 can be made into a roll film for product packaging application of a horizontal or vertical automatic packaging machine; or functional degradation materials for industrial use.

Claims

1. The utility model provides a surface waterproof's biodegradable aluminizes composite film material structure which characterized in that: the composite film material sequentially comprises a PLA thin film layer, a cellulose aluminum-plated layer, a PBAT thin film layer and a clamping layer from the surface layer to the inner layer, wherein a first adhesive layer and a clamping layer between the PLA thin film layer and the cellulose aluminum-plated layer are in a second adhesive layer between the cellulose aluminum-plated layer and the PBAT thin film layer, and the PLA thin film layer, the first adhesive layer, the cellulose aluminum-plated layer, the second adhesive layer and the PBAT thin film layer are combined together through a composite film forming technology.

2. The biodegradable aluminum-plated composite film material structure with waterproof surface according to claim 1, characterized in that: a printing layer is further arranged between the PLA film layer and the first adhesive layer, and the printing layer is arranged on the inner surface of the PLA film layer.

3. The biodegradable aluminum-plated composite film material structure with waterproof surface according to claim 1, characterized in that: the PLA film layer may be replaced by a cellulose layer, outside of which a PVDC coating is provided.

4. The biodegradable aluminum-plated composite film material structure with waterproof surface according to claim 1, characterized in that: the PLA film layer may be replaced by a kraft paper layer, outside which a PVDC coating is provided.