CN111331770A - Carbon material modification-based foaming injection molding preparation of thermoplastic elastomer flexible foam product, preparation method and molding system - Google Patents
Carbon material modification-based foaming injection molding preparation of thermoplastic elastomer flexible foam product, preparation method and molding system Download PDFInfo
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Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/02—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/34—Auxiliary operations
- B29C44/36—Feeding the material to be shaped
- B29C44/38—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length
- B29C44/42—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length using pressure difference, e.g. by injection or by vacuum
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16S—CONSTRUCTIONAL ELEMENTS IN GENERAL; STRUCTURES BUILT-UP FROM SUCH ELEMENTS, IN GENERAL
- F16S5/00—Other constructional members not restricted to an application fully provided for in a single class
Abstract
The invention relates to a method for preparing a thermoplastic elastomer flexible foam product based on carbon material modification by foaming injection molding, and a preparation method and a molding system thereof, wherein the method comprises the following steps: mixing a thermoplastic elastomer and a carbon material, and forming a molten state substance under the action of heat and mechanical shearing; injecting supercritical fluid into the molten substance, and forming a homogeneous melt under the action of mechanical force; and filling the homogeneous melt into a mold cavity, maintaining the pressure for a certain time, supplementing the homogeneous melt into the mold cavity, continuously maintaining the pressure, decompressing and foaming, cooling and opening the mold after foaming is finished, and forming the thermoplastic elastomer foam product. The invention has the advantages that: the foam product has excellent heat insulating performance and electromagnetic shielding performance, and the forming process has the features of high efficiency, flexible and stable process, less waste, low cost, etc.
Description
Technical Field
The invention relates to the technical field of preparation of polymer foam products, in particular to a thermoplastic elastomer flexible foam product prepared by foaming injection molding based on carbon material modification, a preparation method and a forming system.
Background
The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.
The thermoplastic elastomer foam product has the characteristics of light weight, high elasticity, shock absorption, heat insulation, toughness and the like, and can be widely applied to the fields of sports clothes, sports equipment, plastic tracks, packaging, buildings, transportation, safety protection and the like. Currently, thermoplastic elastomer-based foam articles are mainly prepared by three routes. The first approach is: firstly preparing thermoplastic elastomer bead foam through kettle pressure foaming or extrusion foaming, and then processing the thermoplastic elastomer bead foam into a thermoplastic elastomer foam product with a certain geometric shape through a steam molding technology; the second approach is: firstly, processing the thermoplastic elastomer solid granules into sheets through injection molding or extrusion molding, then processing the solid sheets into foam sheets through mould pressing foaming, and finally processing the foam sheets into foam products through methods such as machining, hot mould pressing and the like; the third approach is: the thermoplastic elastomer foam product is directly prepared by foaming injection molding by using a chemical foaming agent or a physical foaming agent. The first two processing modes have the main problems of long processing flow, low efficiency, high rejection rate and high cost, and the third processing mode has the advantages of short flow, high flexibility, high efficiency and the like, but the density of the thermoplastic elastomer foam products processed and prepared by the mode is higher.
The carbon material has excellent electromagnetic function characteristics, and the carbon material and the thermoplastic elastomer resin are compounded and foamed to prepare the light flexible thermoplastic elastomer/carbon material composite foam material or product with excellent electromagnetic function characteristics, so that the carbon material can be widely applied to the fields of electromagnetic protection, wearable electronic devices, new energy sources and the like. At present, the preparation method of the lightweight flexible thermoplastic elastomer/carbon material composite foam material or product is disclosed and reported to be mainly based on batch processing processes such as freeze drying, chemical corrosion and the like, but the inventor finds that: the methods have the problems of complex process flow, low preparation efficiency, high cost and the like, and the processes usually need to use a large amount of toxic chemical reagents or medicines, so that potential health and environmental hazards exist.
The patent literature discloses a process for preparing a conductive particle foam based on thermoplastic polyurethane by coating foam particles with an emulsion of a conductive substance in a plasticizer, and also discloses a process for preparing a particle foam article by thermally joining the foam particles by means of high-frequency electromagnetic radiation. The preparation process comprises the following steps: selecting bulk density of 30-250 kg/m3Of the range of (a) or (b), coating the foam beads with an emulsion of graphite in 1,2, 3-glycerol triacetate, and then thermally joining the coated foam beads together by using high-frequency electromagnetic radiation, to finally obtain a foam bead having a volume resistivity of less than 106Ω·mm2Block foam product of/m.
The patent literature discloses a preparation method of a multi-component graphene/polyurethane elastomer composite material. The method comprises the steps of firstly growing three-dimensional graphene on a growth substrate, and then etching to obtain a three-dimensional graphene network framework; preparing a polyurethane elastomer solution with a certain concentration, adding graphene nanoplatelets, and preparing a uniformly dispersed graphene/polyurethane elastomer composite solution; and finally, injecting the uniform graphene microchip/polyurethane elastomer composite solution into the three-dimensional graphene network framework to enable the graphene microchip/polyurethane elastomer composite solution to be fully soaked and completely permeate the three-dimensional graphene network framework, so as to obtain the force-sensitive flexible composite material of the multi-component graphene/polyurethane elastomer, which is formed by combining the graphene microchip with a porous continuous structure and the three-dimensional graphene network framework with multiple conductive network ducts.
The patent literature discloses a method for making a polymeric microcellular foam conductive gasket. The method is to make a precipitate having impact and vibration absorbing properties and conductivity by perforating an elastomer itself or an elastomer laminated with a conductive fabric or a metal film to form pores, and then applying a conductive material thereon by dipping and coating to reduce surface resistivity and volume resistivity.
Disclosure of Invention
In order to overcome the problems, the invention provides a method for preparing a thermoplastic elastomer flexible foam product based on foaming injection molding modified by a carbon material. The method can be used for directly forming and preparing the low-density TPU foam structural part, has the outstanding advantages of stable and reliable process, high production efficiency, low cost and the like, and simultaneously the density and the conductivity of the foam product can be accurately regulated and controlled in a large range.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
the invention provides a first aspect of the invention, which provides a thermoplastic elastomer flexible foam product prepared by foaming injection molding based on carbon material modification, wherein the flexible foam product is in a sandwich structure in the thickness direction, a foam layer with a porous structure is arranged in the center, two skin layers are compact layers, and the density of the foam product is 0.15-1.2 g/cm3Preferably 0.15 to 0.6g/cm3。
The invention adopts a foaming injection molding mode to prepare the thermoplastic elastomer flexible foam product modified by the carbon material, and the product can be prepared in a large range (0.15-1.2 g/cm)3) The density of the foam product is accurately regulated and controlled, so that the foam product has excellent electromagnetic shielding performance, and meanwhile, the preparation method has the advantages of stable and reliable process, high production efficiency, low cost and the like.
In a second aspect of the present invention, there is provided a method for preparing a thermoplastic elastomer flexible foam product based on foaming injection molding modified by carbon material, comprising:
mixing a thermoplastic elastomer and a carbon material, and forming a molten state substance under the action of heat and mechanical shearing;
injecting supercritical fluid into the molten substance, and forming a homogeneous melt under the action of mechanical force;
and filling the homogeneous melt into a mold cavity, maintaining the pressure for a certain time, supplementing the homogeneous melt into the mold cavity, continuously maintaining the pressure, decompressing and foaming, cooling and opening the mold after foaming is finished, and forming the thermoplastic elastomer foam product.
The method has the advantages of simple process flow, low preparation efficiency, low cost, no need of toxic chemical reagents or medicines, small harm to health and environment, adjustable product density and excellent electromagnetic shielding performance.
In a third aspect of the present invention, there is provided a molding system for preparing a thermoplastic elastomer flexible foam product based on foaming injection molding modified by a carbon material, comprising: the injection molding machine is characterized in that one end of the injection molding machine charging barrel (6) is provided with a hopper (8), the outer wall of the injection molding machine charging barrel (6) is also provided with a heating element (3), a screw (10) is arranged in the injection molding machine charging barrel (6), the injection molding machine charging barrel (6) is also provided with a feed valve (4), and the feed valve is sequentially connected with a metering device (9) and a storage tank (1); the front end of the charging barrel (6) of the injection molding machine is provided with a nozzle (5), and the front end of the nozzle (5) is communicated with a cavity of the mold (2).
The forming system can be well matched with a foaming injection molding process, and can directly form thermoplastic elastomer foam products with three-dimensional complex structures.
The invention has the beneficial effects that:
(1) the invention can directly form the thermoplastic elastomer foam product with a three-dimensional complex structure, and the density of the foam product can be in a large range (0.15-1.2 g/cm)3) The internal precise regulation and control are realized, the foam product has excellent electromagnetic shielding performance, and meanwhile, the preparation method has the outstanding technical advantages of stable and reliable process, high production efficiency, low cost and the like.
(2) The operation method is simple, low in cost, universal and easy for large-scale production.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.
FIG. 1 is a schematic view of a molding apparatus for preparing a foamed article based on a carbon material-modified thermoplastic elastomer by injection foaming according to the present invention.
FIG. 2 is a photograph of a cross-section of the foamed article prepared in example 2.
FIG. 3 is the internal cell structure of the foamed article prepared in example 2.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
A method for preparing a thermoplastic elastomer flexible foam product based on foaming injection molding of carbon material modification comprises the following steps: (1) blending the thermoplastic elastomer and the carbon material according to a certain proportion to obtain a thermoplastic elastomer/carbon material compound; (2) adding the thermoplastic elastomer/carbon material composite into a hopper of a microporous foaming injection molding machine, and gradually plasticizing and melting the thermoplastic elastomer/carbon material under the dual actions of shearing of a screw of the injection molding machine and heating of a charging barrel; (3) after the thermoplastic elastomer/carbon material is gradually plasticized and melted, injecting a supercritical fluid foaming agent into the melt of the thermoplastic elastomer/carbon material through a gas injection port on a charging barrel of an injection molding machine; under the stirring action of a screw of an injection molding machine, the supercritical fluid is quickly diffused to form a homogeneous melt with the thermoplastic elastomer/carbon material melt; (4) injecting the homogeneous melt into a mold cavity until the homogeneous melt fills the entire mold cavity; (5) after the homogeneous melt is filled in the mold cavity, the homogeneous melt is continuously supplemented into the mold cavity by pressure maintaining; (6) after maintaining the pressure for a certain time, quickly opening the mold for a certain distance, and quickly reducing the system pressure so as to induce the homogeneous melt to foam; (7) after foaming the homogeneous melt, cooling for a period of time to completely shape the foam; (8) the mold is fully opened and the thermoplastic elastomer/carbon material flexible foam article is removed.
Further, in the step (1) of the preparation method, the thermoplastic elastomer is one material or a mixture of two or more materials selected from Thermoplastic Polyurethane (TPU), polyether block Polyamide (PEBA), polyolefin thermoplastic elastomer (TPO) or thermoplastic polyester elastomer (TPEE), and the hardness of the thermoplastic elastomer is 50A-98A, and the preferable hardness range is 75A-95A.
Further, in the step (1) of the preparation method, the carbon material is one or a mixture of two or more of carbon fiber, carbon nanotube, graphene, graphite flake or graphite powder, and the addition amount thereof is 0 to 25% by mass (based on the total mass of the raw material), preferably 0.1 to 10% by mass (based on the total mass of the raw material).
In the present invention, the mass fraction is based on the total mass of the raw materials unless otherwise specified.
Further, in the step (2) of the preparation method, the temperature of the plasticized and melted TPU-based composite melt is 160-250 ℃, preferably 170-230 ℃; the pressure of the TPU-based composite melt in the plasticizing and melting process is maintained at 5-25 MPa, preferably 10-20 MPa.
Further, in the step (3) of the preparation method, the supercritical fluid is one or a mixture of two of supercritical carbon dioxide and supercritical nitrogen; the addition amount of the supercritical carbon dioxide is 0-10% by mass, preferably 3-8% by mass; the addition amount of the supercritical nitrogen is 0-1% by mass, preferably 0.25-0.8% by mass.
Further, the air conditioner is provided with a fan,in the step (4) of the preparation method, the injection speed of the homogeneous melt is 1-500 cm3Preferably 25 to 200 cm/s3/s。
Further, in the step (4) of the preparation method, the temperature of the die cavity is 0-200 ℃, and preferably 25-120 ℃.
Further, in the step (5) of the preparation method, the pressure maintaining pressure is 5-100 MPa, preferably 10-50 MPa; the dwell time is 0 to 300s, preferably 10 to 60 s.
Further, in the step (6) of the preparation method, the opening speed of the die is 10-100 mm/s, preferably 25-60 mm/s.
Further, the cooling time of the die in the step (7) of the preparation method is 5-500 s, preferably 15-150 s.
Further, the foam product prepared in the step (8) of the preparation method has a typical sandwich structure in the thickness direction, the center is a foam layer with a porous structure, the two skin layers are compact layers containing only a few cells or no cells at all, and the density of the foam product is 0.15-1.2 g/cm3Preferably 0.15 to 0.6g/cm3。
The present invention is described in further detail below with reference to specific examples, which are intended to be illustrative of the invention and not limiting.
Example 1
Referring to the attached figure 1, the typical processing procedure for preparing the thermoplastic elastomer flexible foam product based on the carbon material modified foaming injection molding of the invention is as follows: 1) solid particle materials 7 such as thermoplastic elastomer particles, carbon materials and the like are added into a charging barrel 6 of an injection molding machine from a hopper 8; 2) the heat generated by the heating element 3 is transferred to the solid particle material 7 through the charging barrel 6, and simultaneously, under the rotary shearing action of the screw 10 of the injection molding machine, the solid particle material 7 is gradually plasticized and melted to become a molten state material; 3) the rotating screw 10 continuously conveys the molten state substance to the front end, and meanwhile, the gas in the storage tank 1 is pressurized to a supercritical fluid state through the supercritical fluid generation metering device 9, then is injected into the cylinder through the valve 4, and under the stirring, mixing and shearing actions of the screw 10, the supercritical fluid injected into the cylinder rapidly diffuses and forms a homogeneous melt with the molten state substance; 4) after enough homogeneous melt is reserved at the front end of the screw 10, the homogeneous melt is injected into a cavity of the mold 2 through a nozzle 5 by using the screw 10 of the injection molding machine; 5) after the mold cavity is filled, maintaining the pressure for a period of time by using the screw 10 to supplement homogeneous melt into the mold cavity, so as to crush bubbles formed in the injection filling process, and redissolving the gas subjected to phase separation into polymer melt; 6) after the pressure maintaining is finished, the mould 2 is quickly opened for a certain distance to reduce the pressure of homogeneous phase melt in the mould cavity, so as to induce foaming; 7) after the foaming is finished and the product is cooled for a certain time, the mould is opened, and the final thermoplastic elastomer foam product is taken out.
Specifically, the material used in this example was a polyether TPU having a hardness of 75A and a density of 1.20g/cm3(@23 ℃); the carbon material is chopped carbon fiber with average diameter of 6.5 μm, length of 3-5mm, and addition amount of 12 wt%; the foaming agent used was supercritical carbon dioxide with a purity of 99.9%, and the amount added was 8.0% by weight.
The injection molding machine is a sea-sky constant-flying sub-electric injection molding machine, the maximum mold locking force is 900kN, the diameter of a screw is 32mm, and the length-diameter ratio is 22: 1; the supercritical fluid injection molding equipment matched with the injection molding machine is a T-100 series supercritical fluid conveying system produced by the United states of America high-grade (Trexel) company; the thickness of an initial cavity of the injection mold is 2.0 mm; the temperature of a charging barrel of the injection molding machine is sequentially set to be 60-140-170 ℃ from a hopper to a nozzle; the screw back pressure is 10MPa during plasticizing and melting; melt injection rate of 25cm3S; the pressure maintaining pressure is 10MPa, and the pressure maintaining time is 10 s; the temperature of the die is 20 ℃; the mold opening rate is 10mm/s, and the mold opening distance is 2.0 mm; the mold cooling time was 15 s.
Using the above equipment and process conditions, a TPU foam article was prepared having a density of 0.6g/cm3The average cell diameter was 32.5 μm, and the electromagnetic shielding effectiveness was 25 dB.
Example 2
The raw material is PEBA with the hardness of 85A and the density of 1.05g/cm3(@23 ℃); the carbon material is a multi-wall carbon nano tube, the average diameter of the carbon material is 12nm, the average length of the carbon material is 50 mu m, and the addition amount of the carbon material is 0.25 percent by weight; the foaming agent used was supercritical nitrogen with a purity of 99.9%, and the amount added was 0.25% by weight.
The injection molding machine is a sea-sky constant-flying sub-electric injection molding machine, the maximum mold locking force is 900kN, the diameter of a screw is 32mm, and the length-diameter ratio is 22: 1; the supercritical fluid injection molding equipment matched with the injection molding machine is a T-100 series supercritical fluid conveying system produced by the United states of America high-grade (Trexel) company; the thickness of an initial cavity of the injection mold is 3.0 mm; the temperature of a charging barrel of the injection molding machine is set to be 60-160-220-230-220 ℃ from a hopper to a nozzle in sequence; the back pressure of the screw is 20MPa during plasticizing and melting; melt injection rate of 200cm3S; the pressure maintaining pressure is 50MPa, and the pressure maintaining time is 80 s; the temperature of the die is 100 ℃; the mold opening rate is 80mm/s, and the mold opening distance is 6.0 mm; the mold cooling time was 150 s.
Using the above equipment and process conditions, a PEBA foam article was prepared having a density of 0.31g/cm3The average cell diameter was 52.8 μm, and the electromagnetic shielding effectiveness was 34.5 dB.
Example 3
TPEE is used as raw material, the hardness of the TPEE is 90A, and the density of the TPEE is 1.2g/cm3(@23 ℃); the carbon material is graphene, the average thickness of the carbon material is 6.5nm, and the addition amount of the carbon material is 0.5% by weight; the foaming agent used was supercritical nitrogen with a purity of 99.9%, and the amount added was 0.65% by weight.
The injection molding machine is a sea-sky constant-flying sub-electric injection molding machine, the maximum mold locking force is 900kN, the diameter of a screw is 32mm, and the length-diameter ratio is 22: 1; the supercritical fluid injection molding equipment matched with the injection molding machine is a T-100 series supercritical fluid conveying system produced by the United states of America high-grade (Trexel) company; the thickness of an initial cavity of the injection mold is 4.0 mm; the temperature of a charging barrel of the injection molding machine is set to be 60-160-220-210 ℃ from a hopper to a nozzle in sequence; the screw back pressure is 15MPa during plasticizing and melting; the melt injection rate was 150cm3S; the pressure maintaining pressure is 35MPa, and the pressure maintaining time is 40 s; the temperature of the die is 55 ℃; the mold opening rate was 50mm/s and the mold opening distance was16.0 mm; the mold cooling time was 120 s.
Using the above equipment and process conditions, a PEBA foam article was prepared having a density of 0.25g/cm3The average cell diameter was 68.7 μm, and the electromagnetic shielding effectiveness was 21.6 dB.
Example 4
The raw material is polyester TPU with the hardness of 95A and the density of 1.20g/cm3(@23 ℃); the carbon material is 5000-mesh graphite flake, the average thickness is 92nm, and the addition amount is 8% by weight; the foaming agent used was supercritical carbon dioxide with a purity of 99.9%, and the amount added was 3.0% by weight.
The injection molding machine is a sea-sky constant-flying sub-electric injection molding machine, the maximum mold locking force is 900kN, the diameter of a screw is 32mm, and the length-diameter ratio is 22: 1; the supercritical fluid injection molding equipment matched with the injection molding machine is a T-100 series supercritical fluid conveying system produced by the United states of America high-grade (Trexel) company; the thickness of an initial cavity of the injection mold is 1.0 mm; the temperature of a charging barrel of the injection molding machine is set to 60 ℃, 160 ℃, 200 ℃, 210 ℃ and 200 ℃ from a hopper to a nozzle in sequence; the back pressure of the screw is 17.5MPa during plasticizing and melting; melt injection rate of 60cm3S; the pressure maintaining pressure is 12MPa, and the pressure maintaining time is 25 s; the temperature of the die is 70 ℃; the mold opening rate was 45mm/s and the mold opening distance was 7 mm; the mold cooling time was 100 s.
Using the above equipment and process conditions, a TPU foam article was prepared having a density of 0.14g/cm3The average cell diameter was 98.7 μm, and the electromagnetic shielding effectiveness was 15.8 dB.
It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and the present invention is not limited thereto, and although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and equivalents can be made in the technical solutions described in the foregoing embodiments, or equivalents thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. Although the present invention has been described with reference to the specific embodiments, it should be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.
Claims (10)
1. The carbon material modification-based foaming injection molding preparation thermoplastic elastomer flexible foam product is characterized in that the flexible foam product is of a sandwich structure in the thickness direction, the center of the flexible foam product is a foam layer with a porous structure, two skins of the flexible foam product are dense layers, and the density of the foam product is 0.15-1.2 g/cm3Preferably 0.15 to 0.6g/cm3。
2. A method for preparing a thermoplastic elastomer flexible foam product based on foaming injection molding of carbon material modification is characterized by comprising the following steps:
mixing a thermoplastic elastomer and a carbon material, and forming a molten state substance under the action of heat and mechanical shearing;
injecting supercritical fluid into the molten substance, and forming a homogeneous melt under the action of mechanical force;
and filling the homogeneous melt into a mold cavity, maintaining the pressure for a certain time, supplementing the homogeneous melt into the mold cavity, continuously maintaining the pressure, decompressing and foaming, cooling and opening the mold after foaming is finished, and forming the thermoplastic elastomer foam product.
3. The method for preparing the thermoplastic elastomer flexible foam product based on the carbon material modified foaming injection molding according to claim 2, wherein the thermoplastic elastomer is at least one of thermoplastic polyurethane, polyether block polyamide, polyolefin thermoplastic elastomer or thermoplastic polyester elastomer;
or the thermoplastic elastomer has a hardness of 50A to 98A, and a preferable hardness range is 75A to 95A.
4. The method for preparing the thermoplastic elastomer flexible foam product based on the carbon material modified foaming injection molding according to claim 2, wherein the carbon material is at least one of carbon fiber, carbon nanotube, graphene, graphite flake or graphite powder;
or the addition amount of the carbon material is 0 to 25% by mass, preferably 0.25 to 10% by mass.
5. The method for preparing the thermoplastic elastomer flexible foam product based on the carbon material modified foaming injection molding according to claim 2, wherein the temperature of the molten substance is 160-250 ℃, preferably 170-230 ℃;
or the pressure of the molten substance is maintained at 5-25 MPa, preferably 10-20 MPa in the melting process.
6. The method for preparing the thermoplastic elastomer flexible foam product based on the carbon material modified foaming injection molding according to claim 2, wherein the supercritical fluid is one or a mixture of two of supercritical carbon dioxide and supercritical nitrogen;
or the addition amount of the supercritical carbon dioxide is 0-10% by mass fraction, preferably 3-8% by mass fraction;
or the addition amount of the supercritical nitrogen is 0-1% by mass fraction, preferably 0.25-0.8% by mass fraction.
7. The method for preparing the thermoplastic elastomer flexible foam product based on the carbon material modified foaming injection molding according to claim 2, wherein the injection speed is 1-500 cm during the process of filling the mold cavity3Preferably 25 to 200 cm/s3/s；
Or the temperature of the mold cavity is 0-200 ℃, preferably 25-120 ℃.
8. The method for preparing the thermoplastic elastomer flexible foam product based on the carbon material modified foaming injection molding according to claim 2, wherein the pressure holding pressure is 5 to 100MPa, preferably 10 to 50 MPa;
or the pressure maintaining time is 0 to 300s, preferably 10 to 60 s.
9. The method for preparing the thermoplastic elastomer flexible foam product based on the carbon material modified foaming injection molding according to claim 2, wherein the decompression is realized by opening the mold for a certain distance, and the opening speed is 10-100 mm/s, preferably 25-60 mm/s;
or the cooling time is 5 to 500s, preferably 15 to 150 s.
10. A molding system for preparing a thermoplastic elastomer flexible foam product based on foaming injection molding of carbon material modification is characterized by comprising: the injection molding machine is characterized in that one end of the injection molding machine charging barrel (6) is provided with a hopper (8), the outer wall of the injection molding machine charging barrel (6) is also provided with a heating element (3), a screw (10) is arranged in the injection molding machine charging barrel (6), the injection molding machine charging barrel (6) is also provided with a feed valve (4), and the feed valve is sequentially connected with a metering device (9) and a storage tank (1); the front end of the charging barrel (6) of the injection molding machine is provided with a nozzle (5), and the front end of the nozzle (5) is communicated with a cavity of the mold (2).
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