阅读说明：本技术 一种气体阻隔性良好的氟树脂多层共挤薄膜生产工艺 (Production process of fluororesin multilayer co-extrusion film with good gas barrier property ) 是由 不公告发明人 于 2021-06-02 设计创作，主要内容包括：本发明公开了一种气体阻隔性良好的氟树脂多层共挤薄膜生产工艺,具体涉及临近空间浮空器技术领域,包括以下步骤：S1、计量：将聚乙烯树脂等原辅材料,人工倒入料斗中,按照一定比例自动计量称重；S2、螺杆挤出塑化：采用定制的多层挤出设备将氟树脂与其他树脂相结合,制备出多层共挤薄膜。本发明通过采用定制的多层挤出设备将氟树脂与其他树脂相结合,再通过平挤上吹设备,制备出高性能多层复合氟膜；最外层氟树脂耐高低温、耐紫外老化、耐摩擦、耐腐蚀、阻隔水；粘结层链接氟树脂与阻气层,起到良好粘结性能；阻气层采用高性能未改性(或改性)的阻隔材料；三者有机统一制备的多层复合薄膜,填补了国内对多层共挤氟树脂薄膜吹塑拉伸工艺的空白。(The invention discloses a fluororesin multilayer co-extrusion film production process with good gas barrier property, and particularly relates to the technical field of near space aerostats, which comprises the following steps: s1, metering: manually pouring raw and auxiliary materials such as polyethylene resin and the like into a hopper, and automatically metering and weighing according to a certain proportion; s2, screw extrusion plasticizing: and combining the fluororesin with other resin by adopting customized multilayer extrusion equipment to prepare the multilayer co-extruded film. According to the invention, the fluororesin and other resins are combined by adopting customized multilayer extrusion equipment, and then the high-performance multilayer composite fluorine film is prepared by flat extrusion and upward blowing equipment; the outermost fluororesin is resistant to high and low temperature, ultraviolet aging, friction, corrosion and water; the bonding layer is linked with the fluororesin and the gas barrier layer, so that good bonding performance is achieved; the gas barrier layer adopts a high-performance unmodified (or modified) barrier material; the three components are organically and uniformly prepared into the multilayer composite film, and the domestic blank of the blow molding and stretching process of the multilayer co-extrusion fluororesin film is filled.)

1. A fluororesin multilayer co-extrusion film production process with good gas barrier property is characterized in that: the method comprises the following steps:

s1, metering: the raw and auxiliary materials such as polyethylene resin and the like are manually poured into a hopper, and are automatically metered and weighed according to a certain proportion.

S2, screw extrusion plasticizing: and combining the fluororesin with other resin by adopting customized multilayer extrusion equipment to prepare the multilayer co-extruded film.

S3, shaping: the melted resin is longitudinally stretched under the action of mechanical force of extrusion blow molding in an extruder, and is transversely stretched by compressed air blowing at the same time or later, so that the multilayer composite film is blown into a film, and then the film is co-extruded by a plurality of extruders in the multilayer film extruder and is extruded by the same machine head; and cooling, mechanically and automatically drawing, stretching, shaping and rolling the multilayer film in the cooling line by matching a fan arranged on the extruder with a cooling ring arranged on the machine head to prepare the multilayer film.

S4, cutting, flattening and rolling: the film after shaping is rolled by a multi-roller shaft of the multilayer film extruder, the shaped film is trimmed by edge trimming equipment of the multilayer film extruder, and the trimmed film is flattened and rolled by a flattening machine.

S5, checking: and cutting a plurality of samples with the length of about 5m before and after rolling the multilayer composite film, and inspecting.

S6, packaging and warehousing: sticking the multilayer composite film which meets the relevant requirements and does not meet the relevant requirements after inspection to a sample, packaging the film which meets the relevant requirements, and entering a finished product raw material area; and sticking labels on the films which do not meet the relevant requirements, and putting the films into a finished product raw material area for independent storage.

2. The process for producing a fluororesin multilayer coextruded film having good gas barrier properties according to claim 1, characterized in that: the raw and auxiliary materials put into the hopper in the step S1 include nylon, polyethylene, acid-modified polyolefin composition, and fluororesin, which are all in the form of particles, have a large particle size, and do not contain dust particles.

3. The process for producing a fluororesin multilayer coextruded film having good gas barrier properties according to claim 1, characterized in that: the resin particles metered in the step S2 are sheared and plasticized into a fluid under the heating of a screw extruder of the multi-layer film extrusion equipment specially designed and customized, so that the fluid reaches a molten state, and the temperature of the screw extruder is controlled to be 240-350 ℃.

4. The process for producing a fluororesin multilayer coextruded film having good gas barrier properties according to claim 1, characterized in that: in the step S2, the resin particles are fluororesin, binder, barrier layer, adhesive layer, and fluororesin in order from outside to inside.

5. The process for producing a fluororesin multilayer coextruded film having good gas barrier properties according to claim 1, characterized in that: in the step S5, a film is taken from a plurality of samples and subjected to temperature resistance test in a high-low temperature environment box, mechanical test and detection are performed on the film by an electronic tensile testing machine according to standard sample preparation, and gas permeability of a film is measured from a plurality of samples by a gas permeameter.

6. The process for producing a fluororesin multilayer coextruded film having good gas barrier properties according to claim 1, characterized in that: in the step S5, a film is taken from a plurality of samples to be subjected to an ultraviolet aging test, the aged sample is tested for the mechanical properties of the aged film by an electronic tensile testing machine, and finally the gas permeability of the aged film is tested by a gas permeameter.

7. The process for producing a fluororesin multilayer coextruded film having good gas barrier properties according to claim 1, characterized in that: in the step S5, a piece of film is taken from the sample and tested by a laminating machine for experiments, and the adhesive property of the film is tested; a film is taken from a sample, and is subjected to heat sealing by a film heat sealing tester to test the heat sealing performance of the film, (the cut film is folded in half, and the folded double-layer film is directly subjected to heat sealing, wherein the pressure of the film heat sealing tester is not lower than 0.1MPa, the time is not lower than 1s during the heat sealing, and no waste is generated in the process).

Technical Field

The invention relates to the technical field of near space aerostats, in particular to a production process of a fluororesin multilayer co-extrusion film with good gas barrier property.

Background

The near space environment has low atmospheric density, small heat convection, strong solar radiation and high ozone concentration, and the working environment of the capsule of the near space aerostat is very harsh, so that the capsule material is one of the key technologies of the near space airship; the capsule material has extremely high specific strength, and the capsule with the same volume can generate larger effective buoyancy only if the surface density is small enough, and the control of the volume of the boat capsule is a basic requirement for ensuring the engineering feasibility and the economic feasibility of the near space aerostat; the strength of the bag body material is required to be large enough to resist the pressure difference load inside and outside the bag body caused by the temperature difference between day and night in the running process of the airship, so that the safety of the airship in the running process is ensured; helium is generally adopted by modern aerostats such as airships, so the capsule material has good sealing performance, and a helium sealing layer with good environmental adaptability must be integrated in the capsule material with limited surface density, so that aerostats such as airships are ensured not to leak air and the buoyancy is not reduced in the long-time flying process; the capsule body material needs to contain an anti-aging layer with excellent performance to resist the comprehensive aging effect brought by ultraviolet rays and ozone in the adjacent space, and a light-isolating layer is needed to prevent the damage of solar radiation to the inner layer material; all functional layers in the capsule material need to work in a low-temperature environment below-80 ℃ and can resist day and night temperature change close to 100 ℃, and therefore the optional range of the high polymer material is greatly limited.

Because the surface area of the capsule body is huge, the processing difficulty is very high, and very high requirements are put forward on the processability, the damage resistance, the maintainability and the like of the capsule body material; thus, multilayer composite films of LLDPE; the special PET and other materials become the preferred materials for manufacturing the aerostat capsule; LLDPE is linear low density polyethylene, the toughness of the material is better, but the mechanical strength is low, the force action among the molecules is small, which causes the heat sealing, gas barrier and other properties of the material to be poor, and the difference of the processing technique can also cause the property difference of the material, the film casting and film blowing are common technique, the blown film has the advantage of one-step forming compared with the cast film, the transverse and longitudinal molecular chains or crystal arrangement of the film is relatively regular, and the mechanical property, gas barrier property and heat sealing property of the film are improved; while the domestic multilayer coextrusion fluororesin film blow molding stretching process is in a blank stage.

Disclosure of Invention

In order to overcome the defects in the prior art, the embodiment of the invention provides a fluororesin multilayer co-extruded film production process with good gas barrier property, wherein a customized multilayer extrusion device is adopted to combine fluororesin with other resins to prepare a multilayer co-extruded film, and then a flat extrusion upward blowing device is adopted to prepare a high-performance multilayer composite fluorine film, so that the blank of the blow molding and stretching process of the multilayer co-extruded fluororesin film in China is filled, and the problems in the background art are solved.

In order to achieve the purpose, the invention provides the following technical scheme: a production process of a fluorine resin multilayer co-extrusion film with good gas barrier property comprises the following steps:

s1, metering: the raw and auxiliary materials such as polyethylene resin and the like are manually poured into a hopper, and are automatically metered and weighed according to a certain proportion.

S2, screw extrusion plasticizing: and (3) combining the fluororesin with other resin by adopting customized multilayer extrusion equipment to prepare the multilayer co-extruded film.

S3, shaping: the melted resin is longitudinally stretched under the action of mechanical force of extrusion blow molding in an extruder, and is transversely stretched by compressed air blowing at the same time or later, so that the multilayer composite film is blown into a film, and then the film is co-extruded by a plurality of extruders in the multilayer film extruder and is extruded by the same head; the multilayer film in the cooling line is cooled, mechanically and automatically drawn, stretched, shaped and rolled by a fan arranged on the extruder and a cooling ring arranged on the machine head, so that the multilayer film is prepared.

S4, cutting, flattening and rolling: and rolling the shaped film by a multi-roller shaft of the multilayer film extruder, cutting the edge of the shaped film by edge cutting equipment of the multilayer film extruder, and flattening and rolling the cut edge of the film by a flattening machine.

S5, checking: before and after the multilayer composite film is rolled, a plurality of samples with the length of about 5m are respectively cut and inspected.

S6, packaging and warehousing: sticking the multilayer composite film which meets the relevant requirements and does not meet the relevant requirements after inspection to a sample, packaging the film which meets the relevant requirements, and entering a finished product raw material area; and sticking labels on the films which do not meet the relevant requirements, and putting the films into a finished product raw material area for independent storage.

In a preferred embodiment, the raw and auxiliary materials put into the hopper in step S1 include nylon, polyethylene, acid-modified polyolefin composition, and fluorine resin, which are all in granular form and have a large particle size and no dust particles.

In a preferred embodiment, the resin particles metered in step S2 are shear-plasticized into a fluid by heating in a screw extruder of a specially designed and customized multilayer film extrusion device, and the temperature of the screw extruder is controlled to be 240-350 ℃.

In a preferred embodiment, the resin particles in step S2 are fluororesin, adhesive, barrier layer, adhesive layer, fluororesin in order from the outside to the inside.

In a preferred embodiment, in step S5, a film in several samples is tested for temperature resistance by a high and low temperature environment box, and is tested for mechanical test by an electronic tensile testing machine according to a standard sample, and a film in several samples is tested for gas permeability by a gas permeameter.

In a preferred embodiment, in step S5, a film is taken from several samples to be subjected to an ultraviolet aging test, the aged sample is tested for mechanical properties of the aged film by an electronic tensile testing machine, and finally the gas permeability of the aged film is tested by a gas permeameter.

In a preferred embodiment, a piece of film is taken from the sample in step S5 and tested by an experimental laminating machine to check the adhesion performance; a film is taken from a sample, and is subjected to heat sealing by a film heat sealing tester to test the heat sealing performance of the film, (the cut film is folded in half, and the folded double-layer film is directly subjected to heat sealing, wherein the pressure of the film heat sealing tester is not lower than 0.1MPa, the time is not lower than 1s during the heat sealing, and no waste is generated in the process).

The invention has the technical effects and advantages that:

1. according to the invention, a customized multilayer extrusion device is adopted to combine fluororesin with other resins to prepare a multilayer co-extruded film, and then a flat extrusion up-blowing device is adopted to prepare a high-performance multilayer composite fluorine film; the multilayer composite fluorine film utilizes the advantages of a multilayer structure, and the outermost layer of fluororesin is resistant to high and low temperature, ultraviolet aging, friction, corrosion and water; the bonding layer is linked with the fluororesin and the gas barrier layer, so that good bonding performance is achieved; the gas barrier layer adopts a high-performance unmodified (or modified) barrier material; the multilayer composite film prepared by the three components organically and uniformly fills the domestic blank of the blow molding and stretching process of the multilayer co-extrusion fluororesin film, and simultaneously leads macromolecules in the fluororesin film to be orderly arranged in the transverse direction and the longitudinal direction; further improves the transverse and longitudinal mechanical properties (tensile strength, tensile modulus, breaking strength and breaking elongation) of the fluororesin film.

2. The invention combines the fluororesin with other resins by adopting the customized multilayer extrusion equipment to prepare the multilayer co-extruded film, and then prepares the high-performance multilayer composite fluorine film by using the flat extrusion upward blowing equipment.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Example 1

A production process of a fluororesin multilayer co-extrusion film with good gas barrier property comprises the following steps:

s1, metering: the raw and auxiliary materials such as polyethylene resin and the like are manually poured into a hopper, and are automatically metered and weighed according to a certain proportion.

S2, screw extrusion plasticizing: and (3) combining the fluororesin with other resin by adopting customized multilayer extrusion equipment to prepare the multilayer co-extruded film.

S3, screw extrusion plasticizing: and (3) combining the fluororesin with other resin by adopting customized multilayer extrusion equipment to prepare the multilayer co-extruded film.

S4, cutting, flattening and rolling: and rolling the shaped film by a multi-roller shaft of the multilayer film extruder, cutting the edge of the shaped film by edge cutting equipment of the multilayer film extruder, and flattening and rolling the cut edge of the film by a flattening machine.

S5, checking: before and after the multilayer composite film is rolled, a plurality of samples with the length of about 5m are respectively cut and inspected.

S6, packaging and warehousing: sticking the multilayer composite film which meets the relevant requirements and does not meet the relevant requirements after inspection to a sample, packaging the film which meets the relevant requirements, and entering a finished product raw material area; and sticking labels on the films which do not meet the relevant requirements, and putting the films into a finished product raw material area for independent storage.

The raw and auxiliary materials put into the hopper in the step S1 include nylon, polyethylene, acid-modified polyolefin composition, and fluororesin, which are all in the form of particles, have a large particle size, and do not contain dust particles.

The resin particles metered in the step S2 are sheared and plasticized into a fluid under the heating of a screw extruder of the multi-layer film extrusion equipment specially designed and customized, so that the fluid reaches a molten state, and the temperature of the screw extruder is controlled to be 240-350 ℃.

The resin particles in step S2 are fluororesin, binder, barrier layer, adhesive layer, fluororesin in that order from outside to inside.

In the step S5, a film is taken from a plurality of samples and subjected to temperature resistance test by a high-low temperature environment box, mechanical test and detection are performed on the film by an electronic tensile tester according to standard sample preparation, and gas permeability of a film is taken from a plurality of samples and tested by a gas permeameter.

In the step S5, a film is taken from a plurality of samples to be subjected to an ultraviolet aging test, the aged sample is tested for the mechanical properties of the aged film by an electronic tensile testing machine, and finally the aged film is tested for the gas permeability by a gas permeameter.

In the step S5, a piece of film is taken from the sample and tested by a film laminating machine for experiment, and the bonding performance is tested; a film is taken from a sample, and is subjected to heat sealing by a film heat sealing tester to test the heat sealing performance of the film, (the cut film is folded in half, and the folded double-layer film is directly subjected to heat sealing, wherein the pressure of the film heat sealing tester is not lower than 0.1MPa, the time is not lower than 1s during the heat sealing, and no waste is generated in the process).

Example 2

The method adopts the domestic existing fluororesin film production process flow, namely, a casting-grade single-phase film is firstly made, then biaxial stretching equipment is subsequently added to make BO fluororesin, and the process flow for preparing the fluororesin biaxial stretching film is divided into two steps.

Comparative example: the multilayer co-extruded film is prepared by the process flows of the embodiment 1 and the embodiment 2 respectively, three rolls of film rolls with the same size are prepared each time, after the preparation is completed each time, the waste material amount and the raw material amount are compared and recorded, and the quality of the finished film product is checked, wherein three groups of comparison data are as follows:

amount of waste material	Example 1	Example 2
			First batch	Is less	Much more
Second batch	Is less	Much more
			Third batch	Is less	Much more

Raw material dosage	Example 1	Example 2
			First batch	Much more	Is less
Second batch	Much more	Is less
			Third batch	Much more	Is less

Film quality inspection	Example 1	Example 2
			First batch	Is excellent in	Good wine
Second batch	Is excellent in	Good wine
			Third batch	Is excellent in	Good wine

In conclusion, the fluororesin multilayer co-extruded film is prepared by completely using the fluororesin multilayer co-extruded film production process provided by the invention, so that the consumption of raw materials can be reduced, and the mechanical property of the film can be improved; edge cutting is not needed, and the generation of waste materials is reduced.

The points to be finally explained are: first, in the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may be a mechanical connection or an electrical connection, or a communication between two elements, and may be a direct connection, and "upper," "lower," "left," and "right" are only used to indicate a relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship may be changed;

and finally: the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.