1. A production process of a multilayer co-extruded film based on fluororesin with good stability is characterized by comprising the following steps:

(1) metering: raw and auxiliary materials such as polyethylene resin and the like are manually poured into a hopper, and composite particles dispersed in the fluororesin are automatically weighed according to a certain proportion, wherein the raw and auxiliary materials comprise (nylon, polyethylene, acid modified polyolefin compound and fluororesin) which are all granular and have larger grain diameter, so that dust particles are not generated.

(2) Screw extrusion plasticizing: the measured raw materials such as the fluororesin are in a resin particle shape, and then a screw extruder arranged on a multilayer film extrusion device is used for heating, so that the raw materials are sheared and plasticized into fluid in the heating process to be in a molten state, and the temperature can be controlled within the range of 210-350 ℃.

(3) Shaping: after the fluorine resin is used for producing fluid under the high-temperature melting, longitudinal stretching is carried out by utilizing the mechanical force effect of extrusion blow molding in an extruder, and meanwhile or later transverse stretching is carried out by compressed air blowing, so that the multilayer composite film is blown into a film; after extrusion, the multilayer film is cooled by a fan in the extruder and a cooling ring of a head, and then drawn, stretched, set, and wound by a machine to form a multilayer film, and the fluororesin film composite particles have a multilayer film structure of fluororesin, binder, barrier layer, adhesive layer, fluororesin, and the like, which comprises titanium oxide-containing particles, a first coating layer comprising silica or a composite oxide of silica and alumina, a second coating layer comprising cerium oxide, and a third coating layer comprising silica in this order from the inside.

(4) Splitting, flattening and rolling: after fluororesin multilayer film is stereotyped and is extruded, utilize the multiple roll axle in the extruder to roll up, with its rolling to the side cut equipment in, utilize the side cut equipment to carry out the cutting edge to it, make it can equal amount cut edge, after accomplishing multilayer film side cut, utilize the flattening machine to carry out the exhibition flat rolling to the good film in cutting edge.

(5) And (4) checking: cutting a part of film sample with the sample length ranging from 4m to 5m after the fluororesin multilayer film is shaped and rolled, carrying out inspection, cutting the sample into multiple equal parts, and respectively inspecting each part of sample, wherein the inspection steps are as follows; firstly, a film is taken and put in a high-temperature and low-temperature environment box for inspection, so that the temperature resistance condition of the film is observed; secondly, taking a film and testing the gas permeability of the film by a gas permeameter; thirdly, taking a film to carry out an ultraviolet aging test, testing the mechanical property of the aged film by an electronic tensile testing machine, and testing the gas permeability of the aged film by a gas permeameter; fourthly, performing mechanical test detection on the film through an electronic tensile testing machine according to standard sample preparation; fifthly, taking a piece of film to test by a film laminating machine for testing, and inspecting the adhesive property of the film; and sixthly, taking a film, carrying out heat sealing through a film heat sealing tester, and testing the heat sealing performance of the film.

(8) Packaging and warehousing: the inspected films are classified and packaged, the films with the quality meeting the requirements and the films with the quality not meeting the requirements are respectively stuck with sample labels, and then the films meeting the relevant requirements are packaged and enter a finished product raw material area; the film which does not meet the relevant requirements is labeled and is placed in a finished product raw material area for independent storage, waste packaging materials can be generated in the raw material unpacking and packing processes, and the packaging wastes are subjected to centralized and harmless treatment.

2. The process for producing a multilayer co-extruded film based on fluororesin with good stability according to claim 1, wherein the process comprises the following steps: the raw and auxiliary materials fed into the hopper comprise: nylon, polyethylene, acid modified polyolefin composition and ethylene tetrafluoroethylene polymer are all granular, and no dust particles are generated.

3. The process for producing a multilayer co-extruded film based on fluororesin with good stability according to claim 1, wherein the process comprises the following steps: the fluororesin and the barrier layer resin are subjected to a multilayer coextrusion process to prepare the multilayer coextrusion high-performance barrier film containing the fluororesin.

4. The process for producing a multilayer co-extruded film based on fluororesin with good stability according to claim 1, wherein the process comprises the following steps: preparing a multi-layer co-extrusion film containing fluorine resin by adopting a multi-layer co-extrusion process for fluororesin and barrier layer resin, so that the molecular structures in the multi-layer composite film are orderly arranged in the transverse direction and the longitudinal direction; the transverse and longitudinal mechanical properties (tensile strength, tensile modulus, breaking strength and breaking elongation) of the composite film are further improved; further improving the gas barrier property of the composite film.

5. The process for producing a multilayer co-extruded film based on fluororesin with good stability according to claim 1, wherein the process comprises the following steps: and reserving one part of each film generated by the back-end research and development, carrying out secondary inspection, comparing the film meeting the requirements with the film not meeting the requirements, and improving.

Background

The existing fluororesin multilayer co-extruded film is a high-transparency film with moisture resistance in plastics, is suitable for barrier application, has light permeability in the range of ultraviolet rays-visible light, and cannot be changed under the long-term corrosion of acid, alkali and organic solvents.

In the prior art, fluororesin and other composite films and other raw and auxiliary materials are mainly used for preparation, and the composite films are as follows: the materials are processed and prepared to enable the materials to be capable of being used as barrier films and are mainly applied to key parts such as barrier layers of high-altitude balloons and the like.

However, in the actual production, there still exist some disadvantages, such as: the film material is easy to generate dust particles, the number of layers of the film is small, the barrier property is poor, the wear-resisting strength is low, the film is not suitable for high-temperature and low-temperature environments, and the aging degree is high under the ultraviolet environment, so that the production stability is poor.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a production process of a multilayer co-extrusion film based on fluororesin with good stability, which solves the problems that the existing material film material is easy to generate dust particles, the number of film layers is small, the barrier property is poor, the wear-resisting strength is low, the film is not suitable for high and low temperature environments, and the aging degree is fast in an ultraviolet environment.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a production process of a multilayer co-extruded film based on fluororesin with good stability comprises the following steps:

(1) metering: raw and auxiliary materials such as polyethylene resin and the like are manually poured into a hopper, and composite particles dispersed in the fluororesin are automatically weighed according to a certain proportion, wherein the raw and auxiliary materials comprise (nylon, polyethylene, acid modified polyolefin compound and fluororesin) which are all granular and have larger grain diameter, so that dust particles are not generated.

(2) Screw extrusion plasticizing: the measured raw materials such as the fluororesin are in a resin particle shape, and then a screw extruder arranged on a multilayer film extrusion device is used for heating, so that the raw materials are sheared and plasticized into fluid in the heating process to be in a molten state, and the temperature can be controlled within the range of 210-350 ℃.

(3) Shaping: after the fluorine resin is used for producing fluid under the high-temperature melting, longitudinal stretching is carried out by utilizing the mechanical force effect of extrusion blow molding in an extruder, and meanwhile or later transverse stretching is carried out by compressed air blowing, so that the multilayer composite film is blown into a film; after extrusion, the multilayer film is cooled by a fan in the extruder and a cooling ring of a head, and then drawn, stretched, set, and wound by a machine to form a multilayer film, and the fluororesin film composite particles have a multilayer film structure of fluororesin, binder, barrier layer, adhesive layer, fluororesin, and the like, which comprises titanium oxide-containing particles, a first coating layer comprising silica or a composite oxide of silica and alumina, a second coating layer comprising cerium oxide, and a third coating layer comprising silica in this order from the inside.

(4) Splitting, flattening and rolling: after fluororesin multilayer film is stereotyped and is extruded, utilize the multiple roll axle in the extruder to roll up, with its rolling to the side cut equipment in, utilize the side cut equipment to carry out the cutting edge to it, make it can equal amount cut edge, after accomplishing multilayer film side cut, utilize the flattening machine to carry out the exhibition flat rolling to the good film in cutting edge.

(5) And (4) checking: cutting a part of film sample with the sample length ranging from 4m to 5m after the fluororesin multilayer film is shaped and rolled, carrying out inspection, cutting the sample into multiple equal parts, and respectively inspecting each part of sample, wherein the inspection steps are as follows; firstly, a film is taken and put in a high-temperature and low-temperature environment box for inspection, so that the temperature resistance condition of the film is observed; secondly, taking a film and testing the gas permeability of the film by a gas permeameter; thirdly, taking a film to carry out an ultraviolet aging test, testing the mechanical property of the aged film by an electronic tensile testing machine, and testing the gas permeability of the aged film by a gas permeameter; fourthly, performing mechanical test detection on the film through an electronic tensile testing machine according to standard sample preparation; fifthly, taking a piece of film to test by a film laminating machine for testing, and inspecting the adhesive property of the film; and sixthly, taking a film, carrying out heat sealing through a film heat sealing tester, and testing the heat sealing performance of the film.

(8) Packaging and warehousing: the inspected films are classified and packaged, the films with the quality meeting the requirements and the films with the quality not meeting the requirements are respectively stuck with sample labels, and then the films meeting the relevant requirements are packaged and enter a finished product raw material area; the film which does not meet the relevant requirements is labeled and is placed in a finished product raw material area for independent storage, waste packaging materials can be generated in the raw material unpacking and packing processes, and the packaging wastes are subjected to centralized and harmless treatment.

Preferably, the raw and auxiliary materials entering the hopper of the project comprise: nylon, polyethylene, acid modified polyolefin composition and ethylene tetrafluoroethylene polymer are all granular, and no dust particles are generated.

Preferably, the adhesion performance test: after the multilayer composite fluorine film is subjected to corona, PUR glue is adopted, after the multilayer composite fluorine film is melted at 80 ℃, the layer is coated on the film by using a scraper, and continuous lamination is carried out by using a film laminating machine, wherein the temperature of a heat sealing machine is 90 ℃, and the speed of the heat sealing machine is 3-6 m/min; the process does not produce any waste.

Preferably, the heat sealing performance test: folding the cut film in half, and directly heat-sealing the folded double-layer film; when in heat sealing, the pressure of the utilization equipment is not lower than 0.1MPa, and the time is not lower than 1 s; the process does not produce any waste.

Preferably, one part of each film generated by the back-end development is reserved, secondary inspection is carried out, and films meeting the requirements are compared with films not meeting the requirements, so that improvement is carried out.

(III) advantageous effects

The invention provides a production process of a multilayer co-extrusion film based on fluororesin with good stability, which has the following beneficial effects:

according to the invention, the fluororesin and other resins are combined by adopting customized multilayer extrusion equipment to prepare a multilayer co-extruded film, and various equipment in an extruder is utilized for combined processing, such as screw extrusion plasticization, film shaping, extrusion blow molding, cooling and shaping by a fan and a cooling ring, and then flattening and rolling are carried out, so that the high-performance multilayer composite fluorine film is prepared, and has higher stability during production; the advantages of the multilayer film structure are utilized, the fluororesin on the outermost layer is utilized for blocking ultraviolet rays, rapid aging is prevented, meanwhile, the multilayer structure can prevent high and low temperature immersion, the balance of internal temperature is kept, the multilayer film has friction resistance and corrosion resistance, the multilayer film can prevent water from permeating, the waterproof performance of the multilayer film is improved, and the bonding layer is connected with the fluororesin and the gas barrier layer and has good bonding performance; the fluororesin multilayer co-extrusion film with good stability is prepared by metering and feeding fluororesin, a binder, a barrier layer, a bonding layer and the like, then adopting a multilayer co-extrusion process, longitudinally stretching the multiple layers, transversely stretching the multiple layers by blowing compressed air at the same time or later, and blowing the multilayer composite film into a film, so that the multilayer co-extrusion is further carried out, and the number of layers, the barrier property, the wear-resistant strength and the stability of the multilayer composite film are improved.

Detailed Description

All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The invention provides a technical scheme that: a production process of a multilayer co-extruded film based on fluororesin with good stability comprises the following steps:

(1) metering: raw and auxiliary materials such as polyethylene resin and the like are manually poured into a hopper, and composite particles dispersed in the fluororesin are automatically weighed according to a certain proportion, wherein the raw and auxiliary materials comprise (nylon, polyethylene, acid modified polyolefin compound and fluororesin) which are all granular and have larger grain diameter, so that dust particles are not generated.

(2) Screw extrusion plasticizing: the measured raw materials such as the fluororesin are in a resin particle shape, and then a screw extruder arranged on a multilayer film extrusion device is used for heating, so that the raw materials are sheared and plasticized into fluid in the heating process to be in a molten state, and the temperature can be controlled within the range of 210-350 ℃.

(3) Shaping: after the fluorine resin is used for producing fluid under the high-temperature melting, longitudinal stretching is carried out by utilizing the mechanical force effect of extrusion blow molding in an extruder, and meanwhile or later transverse stretching is carried out by compressed air blowing, so that the multilayer composite film is blown into a film; after extrusion, the multilayer film is cooled by a fan in the extruder and a cooling ring of a head, and then drawn, stretched, set, and wound by a machine to form a multilayer film, and the fluororesin film composite particles have a multilayer film structure of fluororesin, binder, barrier layer, adhesive layer, fluororesin, and the like, which comprises titanium oxide-containing particles, a first coating layer comprising silica or a composite oxide of silica and alumina, a second coating layer comprising cerium oxide, and a third coating layer comprising silica in this order from the inside.

(4) Splitting, flattening and rolling: after fluororesin multilayer film is stereotyped and is extruded, utilize the multiple roll axle in the extruder to roll up, with its rolling to the side cut equipment in, utilize the side cut equipment to carry out the cutting edge to it, make it can equal amount cut edge, after accomplishing multilayer film side cut, utilize the flattening machine to carry out the exhibition flat rolling to the good film in cutting edge.

(5) And (4) checking: cutting a part of film sample with the sample length ranging from 4m to 5m after the fluororesin multilayer film is shaped and rolled, carrying out inspection, cutting the sample into multiple equal parts, and respectively inspecting each part of sample, wherein the inspection steps are as follows; firstly, a film is taken and put in a high-temperature and low-temperature environment box for inspection, so that the temperature resistance condition of the film is observed; secondly, taking a film and testing the gas permeability of the film by a gas permeameter; thirdly, taking a film to carry out an ultraviolet aging test, testing the mechanical property of the aged film by an electronic tensile testing machine, and testing the gas permeability of the aged film by a gas permeameter; fourthly, performing mechanical test detection on the film through an electronic tensile testing machine according to standard sample preparation; fifthly, taking a piece of film to test by a film laminating machine for testing, and inspecting the adhesive property of the film; and sixthly, taking a film, carrying out heat sealing through a film heat sealing tester, and testing the heat sealing performance of the film.

(8) Packaging and warehousing: the inspected films are classified and packaged, the films with the quality meeting the requirements and the films with the quality not meeting the requirements are respectively stuck with sample labels, and then the films meeting the relevant requirements are packaged and enter a finished product raw material area; the film which does not meet the relevant requirements is labeled and is placed in a finished product raw material area for independent storage, waste packaging materials can be generated in the raw material unpacking and packing processes, and the packaging wastes are subjected to centralized and harmless treatment.

(9) Back-end research and development: firstly, heating a hot melt adhesive into a fluid by a multilayer composite film machine, bonding a film meeting related requirements with a fiber fabric together, wherein the hot melt adhesive cannot be reused, and the heating temperature of the hot melt adhesive is 75-85 ℃;

secondly, cutting the material compounded by the film and the multiple layers according to requirements by using a vibrating knife cutting machine, and storing all cut raw materials;

thirdly, heat-sealing the cut film by using a strip sticking machine, and carrying out heat sealing on the film and the balloon together at the temperature of 90 ℃, the pressure of not less than 0.1MPa and the time of not less than 2 s;

and fourthly, connecting the cut multilayer composite materials by using a special fabric sewing machine, and then thermally sealing the sewing thread part by using a strip sticking machine.

Wherein, the raw and auxiliary materials that drop into the hopper include: nylon, polyethylene, acid modified polyolefin composition, ethylene tetrafluoroethylene polymer, each material is granular, will not produce the dust particulate matter, the adhesion property test: melting PUR glue at 80 ℃, coating the melted PUR glue on a film by using a scraper, and continuously laminating by using a laminating machine, wherein the temperature of a heat-sealing machine is 90 ℃, and the PUR glue is moved forward at the speed of 3-6 m/min; the process does not generate any waste, the cut film is folded in half, and the folded double-layer film is directly heat-sealed; when in heat sealing, the pressure of the utilization equipment is not lower than 0.1MPa, and the time is not lower than 1 s; the process does not generate any waste, one part of each film generated by the back-end research and development is reserved, secondary inspection is carried out, and the film meeting the requirements is compared with the film not meeting the requirements to be improved.

Example 2

The difference from the embodiment 1 is that: in the back end development step, the film comparison was retained by quality inspection of the fluororesin multilayer film.

10 parts of the raw material was produced according to the procedure of example 1, and a silica raw material containing titanium oxide particles was added during the charging to produce a multilayer film, which was used for comparative examination with the multilayer film of example 1.

Acid solubility (%) (amount of titanium oxide in sulfuric acid (g)/0.2(g)) × 100

The smaller the acid solubility, the denser the silica coating layer, and the more excellent weather resistance can be obtained, preferably 20 to 50%, more preferably 20 to 30%, specifically referring to the following table:

container number	Silica raw material	Acid solubility	Weather resistance strength
				1	0.2g～0.3g	20％～30％	High strength
2	0.4g～0.5g	40％～50％	Medium and high grade
				3	0.6g～0.7g	60％～70％	Weak (weak)

In conclusion, the multilayer film with low acid solubility can achieve the best performance and make the weather resistance strong.

The multilayer co-extrusion film production process based on the good stability of the fluororesin is characterized in that the multi-equipment in an extruder is used for combined processing, such as screw extrusion plasticization, film shaping, extrusion blow molding, cooling and shaping by a fan and a cooling ring, and then flattening and rolling are carried out, so that the high-performance multilayer composite fluororesin film is prepared and has higher stability during production; utilize multilayer film structure's advantage, utilize its outermost fluororesin to carry out the separation of ultraviolet ray, prevent quick ageing, utilize multilayer structure can prevent high microthermal immersion simultaneously, keep the balance of inside temperature, and still have antifriction, corrosion resisting property, and multilayer film can prevent the infiltration of water, improves its waterproof performance, and the tie coat links fluororesin and choke layer, plays good adhesive property.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.