CN219360531U

CN219360531U - Recoverable biodegradable transparent composite film material structure

Info

Publication number: CN219360531U
Application number: CN202121538249.XU
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: 2021-07-07
Filing date: 2021-07-07
Publication date: 2023-07-18
Anticipated expiration: 2031-07-07

Abstract

The utility model provides a recoverable biodegradable transparent composite film material structure, which comprises a modified PLA film layer, a BOPLA film layer and an adhesive layer clamped between the modified PLA film layer and the BOPLA film layer, wherein the modified PLA film layer, the adhesive layer and the BOPLA film layer are combined together through a composite film forming technology. According to the utility model, the BOPLA film layer which is relatively resistant to temperature, has printing adaptability and high tensile resistance, but has poor extensibility and high hardness and the modified PLA film layer which is relatively good in heat sealability and extensibility are compounded together through the adhesive, and the properties of the two film layers are complementary, so that the transparent composite film material which is good in surface wetting Zhang Liliang, has the surface heat sealability, can be printed as required, can be recycled and is biodegradable can be prepared; the main raw material is completely derived from biological raw materials, can be degraded completely and is a carbon-neutralized product, and is energy-saving and environment-friendly.

Description

Recoverable biodegradable transparent composite film material structure

Technical Field

The utility model relates to the technical field of degradable film materials, in particular to a recoverable biodegradable transparent composite film material structure.

Background

At present, under the promotion of the environmental protection concept and the plastic restriction, the degradable packaging film is a hot packaging material on the market and gradually replaces the plastic film. The degradable film material is mainly single-layer film application at present, the single-layer application cannot meet more functional requirements, and the fully degradable film raw material is mainly derived from natural substances, has performance defects, and cannot meet diversified packaging application.

Disclosure of Invention

The utility model aims to overcome the defects of the prior art, provides a biodegradable composite film material which solves the environmental pollution problem of non-degradable plastics and simultaneously meets the requirement of functional packaging application, and the material can be recycled in a homologous way and can be decomposed into water and carbon dioxide by biological composting, so that the material is a preferred material for carbon neutralization.

In order to achieve the above purpose, the technical scheme provided by the utility model is as follows: the utility model provides a recoverable biodegradable's transparent composite film material structure, composite film material includes modified PLA thin film layer, BOPLA thin film layer and centre gripping between modified PLA thin film layer and BOPLA thin film layer, combine together through composite film forming technique between modified PLA thin film layer, gluing agent layer and the BOPLA thin film layer.

Preferably, a printing layer is further arranged between the BOPLA film layer and the adhesive layer.

Preferably, an alumina coating may be added to the outside of the modified PLA film layer and BOPLA film layer.

Preferably, a PVDC coating may be added over the modified PLA film layer and the BOPLA film layer.

According to the scheme, the BOPLA film layer which is relatively resistant to temperature, has printing adaptability and high tensile resistance, but has poor extensibility and high hardness and the modified PLA film layer which is relatively good in heat sealability and extensibility are compounded together through the adhesive, and the properties of the modified PLA film layer and the modified PLA film layer are complementary with each other, so that the transparent composite film material which is good in surface wetting Zhang Liliang, has the surface heat sealability, can be printed as required, can be recycled and is biodegradable can be prepared; the main raw material is completely derived from biological raw materials, can be degraded completely and is a carbon-neutralized product, and is energy-saving and environment-friendly.

Description of the drawings:

FIG. 1 is a schematic view of a composite film material according to the present utility model;

FIG. 2 is a schematic view of a composite film material according to the present utility model;

FIG. 3 is a schematic illustration of the preparation process of the present utility model;

FIG. 4 is a simplified schematic diagram of the process flow of the dry composite method of the present utility model;

fig. 5 is a simplified schematic diagram of the process flow of the solvent-free compounding method of the present utility model.

Detailed Description

The utility model is further illustrated by the following examples:

example 1:

as shown in fig. 1, in the structure of the recoverable biodegradable transparent composite film material according to this embodiment, the composite film material 1 includes a modified PLA film layer 2, a bopa film layer 3, and an adhesive layer 4 sandwiched between the modified PLA film layer 2 and the bopa film layer 3, where the modified PLA film layer 2, the adhesive layer 4, and the bopa film layer 3 are combined together by a dry composite or solvent-free composite film forming technique.

The modified PLA film layer 2 is a degradable material with good comprehensive performance, and can be a film material produced by the proportion of starch, PBAT, PPC, PBS and PLA polylactic acid or a single material. The high-transparency waterproof toughened fully-degradable environment-friendly film comprises a high-transparency waterproof toughened fully-degradable environment-friendly film, a preparation method, a degradable environment-friendly material with high transparency, a preparation method and application of ZL2021103796747, wherein the modified PLA material is prepared by a mixing modification method, and the prepared modified PLA material has high transparency and strength. The PLA is derived from polylactic acid synthesized by extracting corn/sugarcane/cassava, the transparent or semitransparent degradable film material is prepared by taking natural substances as raw materials through modification and film blowing or casting processes, the thickness of the modified PLA film layer 2 is between 15UM and 200UM, and the modified PLA film layer has good heat sealing property and is mainly used as a heat sealing layer in the application.

The main component of the BOPLA film layer 3 is a transparent film product prepared from polylactic acid extracted and synthesized by corn/sugarcane/cassava through a biaxial stretching process, the BOPLA film layer 3 has high tensile strength, good stiffness, good flatness, good surface printing performance and better surface temperature resistance compared with the modified PLA film layer 2. The thickness of the BOPLA film layer 3 is 12UM-100UM.

The adhesive layer 4 is a polyurethane adhesive, and the BOPLA layer and the modified PLA film layer 2 films can be adhered into a whole through traditional dry type compounding or solvent-free compounding. The polyurethane adhesive has heat resistance and cold resistance, can bear the temperature requirements of bag restraint, boiling and steaming, and also can bear the temperature requirements of low-temperature refrigeration or freezing preservation (lower embrittlement temperature); the composite material can bear the corrosion of various media in the content and the environment, has no toxicity, no peculiar smell, good fluidity and leveling property, and has good adhesive force to the used composite material.

The BOPLA film layer 3 is biaxially oriented polylactic acid, and has good printing adaptability and tensile property, but poor extensibility; the modified PLA film layer 2 has poor temperature resistance and tensile strength, but has heat sealability and extensibility. 2, completely deriving from the degradable film of biological raw materials, laminating into a whole through an adhesive, and preparing into a heat-resistant, heat-sealable, recyclable and biodegradable transparent composite film material with complementary performances; in addition, the printing can be carried out according to the requirements, materials such as packaging bags or packaging films with high comprehensive performance are processed according to the composite technology, the main raw materials are completely sourced from biological raw materials, and the degradable material is a carbon-neutralized product, so that the energy is saved and the environment is protected.

As shown in Table 1, the comparison of single modified PLA film material, BOPLA film material and composite BOPLA+PBAT, cellulose+PBAT and modified PLA+BOPLA shows that the modified PLA+BOPLA composite material has higher transparency, higher tensile property, good heat sealability, recoverable degradation, improved surface temperature resistance, tensile resistance and other properties of the finished product, and achieves the performance of a common plastic film and is not easy to crack.

The thickness of the prepared composite film material 1 is between 25UM and 250UM, and the prepared composite film material 1 can be prepared into food packaging bags (the composite strength is more than or equal to 1.5N), vacuumizing packaging bags (the heat sealing strength is more than or equal to 10N), freezing bags (-10 ℃) and industrial packaging bags, industrial degradable film materials for various industries and the like.

TABLE 1 comparison of Single film Material products and composite film Material Performance

A printing layer is further arranged between the BOPLA film layer 3 and the adhesive layer 4, and the printing layer is arranged on the inner surface of the BOPLA film layer 3, namely, the inner surface of the BOPLA film layer 3 is printed. The composite film material 1 can be printed with characters and patterns, and can meet the environmental protection requirements of foods and medicines by adopting the inner printing on the inner surface of the BOPLA film layer 3. After being printed, the composite film material 1 is compounded, and as the ink is clamped in the middle of the film layer, the ink layer is prevented from being directly rubbed, scratched and damaged by various corrosive substances, so that the problems of bleeding and fading in the degradable film printing are well solved, and the problems of safety and sanitation caused by the fact that the ink is directly contacted with food and medicines are also avoided.

If the printing layer has a requirement on corona intensity, the surfaces of the BOPLA film layer 3 and the modified PLA film layer 2 can be subjected to corona treatment, so that the adhesive force of printing ink or adhesive of the printing layer is enhanced.

When the high-barrier-property coating is carried out on the base material, an aluminum oxide coating or a PVDC coating can be added outside the modified PLA film layer 2 and the BOPLA film layer 3, so that the application requirement of the high-barrier-property can be met.

Selecting a PLA modified film layer and a BOPLA film layer 3 which meet degradation requirements, and meeting but not being limited to the following international authoritative degradation certification:

● Germany DIN EN13432

● U.S. USA BPI ASTM D6400

● Belgium Belgium OK COMPOSTABLE

● Australia ABAM.

The polyurethane adhesive used in the composite adhesive should have properties that meet, but are not limited to, the following health and safety regulations:

● Additive regulations for Chinese food packaging materials GB9685-2008

● U.S. Food and Drug Administration (FDA) 21CFR175.300

● Restriction of harmful substances by European Union ROHS

In the composite film making process, the modified PLA film layer 2 or the BOPLA film layer 3 can be arbitrarily set as a rubberizing surface, namely a first base material, and is attached to another material after being coated with the adhesive layer 4.

As shown in fig. 3, there are two processes suitable for the compounding process of the present composite film material 1: dry compounding and solvent-free compounding.

The dry compounding method includes coating a solvent type adhesive on a first film by using a gravure wire roll, drying the solvent type adhesive to remove the solvent in the drying process, and compounding a second film, the first film and the adhesive together in a hot-pressing state by hot-pressing, and so on.

The dry compounding method is suitable for compounding various composite films, has excellent chemical corrosion resistance, and is widely applied to packages with harsh content conditions, such as foods containing alkaline, acidic, spicy, oil and other components, cosmetics containing components such as essence, emulsifying agent and other components, chemicals containing corrosive solvents, pesticides and other components, and the like.

The dry type compounding method has the following characteristics: the high-strength high-transparency high-stability composite film has the advantages of good stability, high strength and high transparency, can be used for producing composite films, can be used for producing composite molds for freezing, preserving or sterilizing at high temperature, and is flexible and convenient to use and simple to manufacture.

The dry compounding method comprises the following steps: as shown in fig. 4, a method for preparing a recoverable biodegradable transparent composite film material structure by dry compounding, wherein a first substrate is generally a BOPLA film layer 3 through a coating mechanism composed of a rubber disc 6, a scraper, a gravure roll 7 and a rubber press roll i 8, the first substrate is coated with the solvent-type adhesive layer 4, then enters a drying tunnel 9 to dry and remove solvent from the solvent-type adhesive layer 4, the temperature of the drying tunnel 9 is between 40 and 60 ℃, then enters a hot pressing mechanism composed of a heating steel roll 11 and a rubber press roll ii 10, a second substrate is hot-pressed on the solvent-type adhesive layer 4, so that the PLA-modified film layer 2, the adhesive layer 4 and the BOPLA film layer 3 are pressed together, the temperature of the heating steel roll 11 is between 40 and 60 ℃, the compound pressure of the hot pressing mechanism should be increased as much as possible under the condition of not damaging the film, and finally, the composite film i 14 is obtained through a cooling roll 12; and curing the composite film I14 to obtain the composite film material 1.

The solvent-free compounding method comprises the steps of firstly coating a solvent-free polyurethane adhesive on a first substrate by using a coating roller, wherein the solvent-free polyurethane adhesive has higher viscosity at normal temperature, has good coating performance when the viscosity is rapidly reduced along with the temperature rise, can take air moisture as a curing agent and has good bonding strength, then coating the solvent-free polyurethane adhesive on the first substrate in a hot-pressing state (the sizing amount is 1-4 g/square meter), finally compounding a second film, the first film and the adhesive together by hot-pressing, and the like.

The adhesive of the solvent-free compounding method does not contain an organic solvent and does not need a drying device.

Solvent-free compounding method: as shown in fig. 5, a preparation method of a recoverable biodegradable transparent composite film material structure is disclosed, wherein after passing through a coating mechanism composed of a rubber disc 6, a scraper, a coating roller 13 and a rubber press roller i 8, under the belt of a guide roller, the surface of a first substrate is coated with an adhesive layer 4, and then the first substrate is sent to a hot-pressing mechanism composed of a heating steel roller 11 and a rubber press roller ii 10, a second substrate is hot-pressed on the adhesive layer 4, so that the PLA modified film layer 2, the adhesive layer 4 and the BOPLA film layer 3 are pressed together, the temperature of the heating steel roller 11 is between 40 ℃ and 60 ℃, the composite pressure of the hot-pressing mechanism should be increased as much as possible under the condition that the film is not damaged, and finally the composite film ii 15 is obtained through a cooling roller 11; and curing the composite film II 15 to obtain the composite film material 1.

The adhesive layer 4 can be adhered to the PLA modified film layer and the bopa film layer 3 respectively, because when the adhesive layer 4 is adhered to the modified PLA film layer 2 and the bopa film layer 3 respectively, adhesion is generated during drying curing (solvent-free polyurethane adhesive) or heating curing (solvent-free polyurethane adhesive), that is, during compounding, the adhesive layer 4 enters the modified PLA film layer 2 and the bopa film layer 3 under compression to form adhesion therebetween, and the adhesion effect is affected by factors such as speed, scraper distance, solvent formula, pressure distribution and the like during compounding.

The composite film I14 and the composite film II 15 of the products obtained by the dry composite method and the solvent-free composite method are subjected to a curing process, the curing process can be placed in a constant temperature chamber at 35-50 ℃ for more than 6 hours, and the chemical reaction speed can be accelerated by increasing the temperature.

The curing reaction is beneficial to the curing of the adhesive layer 4 itself and to the acceleration of the interaction of the-NCO groups in the adhesive layer 4 with the active hydrogen groups on the surfaces of the modified PLA film layer 2 and BOPLA film layer 3. The adhesive layer 4 can be softened by heating, so that the surface wetting of the modified PLA film layer 2 and the BOPLA film layer 3 is increased, the molecular movement is facilitated, the adhesion is improved, the product can be rapidly processed normally and subsequently, the peeling strength of the composite film I and the composite film II is changed all the time before the curing reaction is completed, and the process of increasing-attenuating-stabilizing is presented.

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

The peeling strength of the cured composite film material 1 can reach more than 1.5N-2N.

Claims

1. A recyclable biodegradable transparent composite film material structure, characterized in that: the composite film material comprises a modified PLA film layer, a BOPLA film layer and an adhesive layer clamped between the modified PLA film layer and the BOPLA film layer, wherein the modified PLA film layer, the adhesive layer and the BOPLA film layer are combined together through a composite film forming technology.

2. A recyclable biodegradable transparent composite film material structure according to claim 1, characterized in that: and a printing layer is further arranged between the BOPLA film layer and the adhesive layer.

3. A recyclable biodegradable transparent composite film material structure according to claim 1 or 2, characterized in that: an aluminum oxide coating can be added outside the modified PLA film layer and the BOPLA film layer.

4. A recyclable biodegradable transparent composite film material structure according to claim 1 or 2, characterized in that: PVDC coating can be added outside the modified PLA film layer and the BOPLA film layer.