A multi-interface electromagnetic shielding composite material and a preparation method thereof

Abstract

The application discloses a multi-interface electromagnetic protection composite material and a preparation method thereof. The composite material is prepared by using polyester cloth or non-woven cloth containing metal compound microparticles or containing nano-carbon material micropowder or containing both, silver-plated or nickel-plated non-woven cloth, metal mesh cloth and polytetrafluoroethylene / nano-carbon three-dimensional microporous membrane multi-layer material, and bonding the materials into the composite material by using a bonding liquid containing metal compound microparticles, nano-carbon material micropowder or both. The material can shield or absorb electromagnetic interference from the outside world in all directions and from multiple interfaces in terms of blocking or absorbing electromagnetic waves, thereby effectively protecting human health and military equipment safety. The product has the functions of high-efficiency electromagnetic wave reflection and dielectric loss, and excellent heat conduction performance.

Description

Technical Field

[0001] This invention belongs to the field of protective materials and relates to a multi-interface electromagnetic protection composite material and its preparation method. This protective material is suitable for both military and civilian use. Background Technology

[0002] With the continuous growth of wireless communication technology, the rapid development of mobile devices, and the emergence of electronic and information-based means in modern combat systems, wide-frequency, high-megahertz electromagnetic waves have become widely distributed. Electronic shielding has become a pressing issue for prevention and research in daily life and military fields such as aviation, electronics, communications, and medical equipment.

[0003] In existing technologies, using traditional metal materials as shielding materials to block electromagnetic radiation and electronic interference is one of the effective ways to avoid the hazards of electromagnetic radiation. Replacing traditional metal materials with new materials such as conductive and thermally conductive polymer composite materials is also a current research and exploration direction in this field. Among them, using protective materials to absorb and block electromagnetic waves has become the top priority in the research of new electromagnetic shielding materials for large outdoor electronic equipment and military equipment in modern warfare. Summary of the Invention

[0004] This invention addresses existing technologies by providing a multi-interface electromagnetic protection composite material that also has thermal conductivity.

[0005] This composite material has multiple protective interfaces, thus effectively establishing a unique "absorption-reflection-absorption" electromagnetic wave loss mechanism, achieving high thermal conductivity, high electromagnetic protection efficiency, and a longer service life.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned composite material.

[0007] The objective of this invention is achieved through the following means:

[0008] The multi-interface electromagnetic protection composite material of the present invention comprises polyester fabric or nonwoven fabric containing metal compound particles or nano-carbon material powder or a combination of both materials, silver-plated or nickel-plated nonwoven fabric, metal mesh fabric, and polytetrafluoroethylene / nano-carbon three-dimensional microporous membrane multilayer material, which are bonded together by an adhesive liquid containing metal compound particles, nano-carbon material powder or a combination of both nanomaterials.

[0009] The aforementioned protective materials enable multi-layered protective materials to not only shield electromagnetic waves but also further enhance the shielding effect by absorbing electromagnetic waves. Simultaneously, they contribute to improved thermal conductivity and enhanced mechanical properties, offering multiple benefits. Another significant feature of this invention is the provision of a process technology for preparing polymer polyester fibers and nonwoven fabrics, comprising metal microparticle masterbatches and nano-carbon-containing material micropowder masterbatches.

[0010] The preparation method of the multi-interface electromagnetic protection composite material of the present invention includes:

[0011] 1) Preparation of polyester fabrics or nonwoven fabrics containing metal compound particles, nano-carbon material powders, or both materials;

[0012] 2) Preparation of multilayer materials of silver- or nickel-plated nonwoven fabrics, metal mesh fabrics, and polytetrafluoroethylene / nanocarbon three-dimensional microporous membranes;

[0013] 3) Preparation of adhesive liquids containing metal compound particles, or containing nano-carbon material powder, or containing both types of nanomaterials;

[0014] 4) Preparation of multi-interface electromagnetic protection composite materials.

[0015] Preferably, the preparation of the polyester fabric or nonwoven fabric containing metal compound particles, nano-carbon material powder, or both materials is as follows:

[0016] Single metal or metal compound microparticles, or 2-3 kinds of metal or metal compound microparticles, are mixed and stirred evenly with polyethylene terephthalate resin powder in a certain proportion. After drying, the mixture is injected into a screw extruder and melt-extruded into cylindrical strips with a diameter of 2-3 mm. After cooling, the strips are cut into masterbatches with a length of 4-6 mm. The metal microparticles can be iron, nickel, copper, aluminum, or other metal compounds, with a particle diameter of 0.05-0.15 μm. The content of metal microparticles can be 8-12% of the mass of the polyester resin.

[0017] The preparation process of nano-carbon material micro powder masterbatch is the same as that of metal microparticle masterbatch. The type of nano-carbon material can be one or more of the following: nano-carbon black, carbon nanotubes, graphene, graphene oxide, reduced graphene oxide, and their derivatives. The micro powder diameter is 0.02-0.05μm, the specific surface area is 80-90%, and the content is 2-5% of the mass of polyethylene terephthalate resin powder.

[0018] Metal microparticle masterbatch or nano-carbon material micropowder masterbatch is mixed with polyester chips in a certain proportion, stirred, dried, and then injected into a screw extruder. After melting and extrusion, the filaments are spun out through a spinneret, cooled in air, and wound into polymer polyester fibers. The fineness of the polymer polyester fibers is 75-550 dtex. Alternatively, the molten filaments spun out through the spinneret are placed randomly on a running conveyor belt and hot-pressed into spunbond nonwoven fabric. Or, the spun filaments are cut into short fibers, then laid into a web and reinforced to form a polymer nonwoven fabric with a weight of 40-120 g / m². 2 Metal microparticle masterbatch and nano-carbon material masterbatch account for 3-5% and 0.5-1.5% of the polyester chips by mass, respectively.

[0019] Preferably, the preparation of the silver- or nickel-plated nonwoven fabric, metal mesh fabric, and polytetrafluoroethylene / nanocarbon three-dimensional microporous membrane multilayer material includes 2-4 layers of several materials such as a polymer polyester fiber fabric containing metal compound particles or containing nanocarbon materials, or containing both metal compound particles and nanocarbon material powder, a nonwoven fabric containing the same particles and powders, silver-plated nonwoven fabric, metal mesh fabric, and three-dimensional nanocarbon microporous membrane.

[0020] Metallic microparticles, such as compounds of copper, silver, iron, and cobalt, have electrical conductivity at different wavelengths, which can reflect and absorb electromagnetic waves. Nanomaterials, such as carbon fibers, carbon black nanoparticles, carbon nanotubes, graphene nanoparticles, or one or more of their derivatives, such as graphene oxide and reduced graphene oxide, not only have the function of absorbing and shielding electromagnetic waves, but also help to improve thermal conductivity and enhance the mechanical properties of multilayer materials and composite materials.

[0021] Preferably, the polyester fabric or nonwoven fabric containing metal compound particles, nano-carbon material powder, or both materials is prepared by weaving the polyester fibers spun above using machine or knitting methods. The polymer polyester fiber fabric has a warp and weft density of 2-4 threads / cm x 3-5 threads / cm and a mass of 60-200g / m³. 2 Polymer polyester spunbond nonwoven fabrics and polymer polyester nonwoven fabrics made from short fibers through web laying, needle punching, or composite processes have a weight of 40-120 g / m². 2 .

[0022] Preferably, the silver- or nickel-plated nonwoven fabric is prepared by using a pre-prepared polymer polyester spunbond nonwoven fabric, coating its surface with a chemical precipitation method or by incorporating silver or nickel micropowder into an adhesive. The Ag or Ni content accounts for 3-8% of the nonwoven fabric weight.

[0023] Preferably, stainless steel fibers, copper fibers, nickel fibers, or other metal fibers with a fiber diameter of 0.2-0.5 mm are used to weave a fabric with a warp and weft density of 2-4 fibers / cm and a weight of 50-100 g / m. 2 Metal mesh fabric.

[0024] Preferably, the polytetrafluoroethylene / nanocarbon three-dimensional microporous membrane is prepared by the following method:

[0025] The process involves incorporating one or two of the following into polytetrafluoroethylene (PTFE) nanopowder: carbon nanotubes, nano-carbon black, and nano-graphite. Multiple auxiliary materials are added, and the mixture is mechanically stirred to achieve uniform dispersion. A lubricant is used to prepare a paste, which is then formed into strips, calendered into sheets, and finally subjected to a three-dimensional stretching process. The amount of any one or two of the following—carbon nanotubes, nano-carbon black, and nano-graphite—added is 5-30% of the mass of the PTFE nanopowder. The multiple auxiliary materials are a dispersant, stabilizer, and nonionic surfactant in a mass ratio of 5:3:2, and the amount added is 1-2.5% of the mass of the PTFE nanopowder.

[0026] Dispersants include PD-85, cyclohexanol, and dimethyl sulfoxide, with cyclohexanol being preferred. Stabilizers include octyltin mercaptan and dioxane, with octyltin mercaptan being preferred. Surfactants include MPEG750 and sodium dodecyl sulfonate, with MPEG750 being preferred. Membrane mass is 30-60 g / m³. 2 The micropore diameter is 0.1-5μm, the membrane thickness is 10-30μm, and the porosity is >80%. The strength of the polytetrafluoroethylene / nanocarbon three-dimensional microporous membrane is about 1.5 times higher than that of the traditional biaxially oriented membrane.

[0027] Preferably, the preparation of the adhesive liquid containing metal compound particles, or containing nano-carbon material powder, or containing both types of nanomaterials:

[0028] Acrylic ester emulsion or polydimethylsiloxane resin is selected as the binder, and 3-6% of metal compound microparticles or 0.5-1% of nano-carbon material powder is added and thoroughly mixed. Alternatively, both metal compound microparticles and nano-carbon material powder can be mixed and stirred simultaneously. To obtain a lightweight composite material, the prepared adhesive liquid is passed through a foam generator during lamination to form foams of varying sizes for foam bonding.

[0029] Foam adhesive formulation: 35-45% polyacrylate emulsion or polydimethylsiloxane resin; 3-6% metal compound microparticles or 0.5-1.5% nano-carbon material powder; 5-12% titanium dioxide; 5-12% kaolin; 1-2% thickener; 1-2% crosslinking agent; 2-6% surface affinity agent; 1-2% ammonia; 0.1-1% thermosetting adhesive; the remainder is water.

[0030] Preferably, the preparation of the multi-interface electromagnetic protection composite material is as follows:

[0031] Based on the varying electromagnetic frequencies and wavelengths radiated by electronic devices, different types, numbers, arrangements, types of metal micropowders, and nano-carbon materials from the four pre-fabricated materials in step 2 are selected, along with varying amounts of these multilayer materials. These are then combined with adhesive layers of different materials between the two layers to form a polymer protective composite material. The inner layer of the composite material is a polyester fabric layer containing metal microparticles and nano-carbon material powder, while the surface layer is a three-dimensional nano-carbon microporous membrane layer.

[0032] Multi-interface electromagnetic protection composite materials are prepared on a laminating machine. This laminating machine can simultaneously use different types of composite layers, completing the lamination of two or more material layers in one operation. The structure of the multi-functional laminating machine is shown in the attached figure. Figure 2 As shown.

[0033] The specific lamination steps are as follows: the adhesive is placed in the adhesive tank of the laminating machine, the pre-made multi-layer materials are placed on multiple roll rollers of the laminating machine, the fabric path is selected so that the adhesive in the adhesive tank is applied to the reverse side of the material in the form of foam, and the material is laminated with another layer of material under the action of the rolling mill. The multi-layer materials complete the lamination process in one go. The polymer composite material is wound into a shaft on the finished roll roller of the multi-functional laminating machine.

[0034] Lamination process conditions: Laminating machine speed 15-30m / min, adhesive application rate 15-30g / m 2 It has a solid content of 40-60%, a foam diameter of 0.2-5mm, and a foam density of 45-60g / l.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows: The electromagnetic protection material with multiple interfaces prepared by the present invention can shield or absorb electromagnetic interference from the outside world from two aspects: blocking or absorbing electromagnetic waves. It effectively protects human health and the safety of military equipment. The product has the function of efficiently reflecting electromagnetic waves and dielectric loss, and also has excellent thermal conductivity. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a multi-interface electromagnetic protection composite material;

[0037] In the figure: 1. Polyester fabric or nonwoven fabric layer containing metal compound particles, nano-carbon material powder, or a combination of both materials; 2. Adhesive layer containing metal compound particles, nano-carbon material powder, or a combination of both nanomaterials; 3. Silver- or nickel-plated nonwoven fabric layer; 4. Adhesive layer containing metal compound particles, nano-carbon material powder, or a combination of both nanomaterials; 5. Metal mesh fabric layer; 6. Adhesive layer containing metal compound particles, nano-carbon material powder, or a combination of both nanomaterials; 7. Polytetrafluoroethylene / nano-carbon three-dimensional microporous membrane.

[0038] Figure 2 This is a schematic diagram of the multi-functional composite machine structure used in the embodiment.

[0039] Figure 3 This is an enlarged structural diagram of the heating box of the composite machine. Detailed Implementation

[0040] The present invention will be further explained and illustrated below through specific embodiments.

[0041] Example 1:

[0042] 1. Preparation of fibers containing Fe2O3 microparticle masterbatch and nano-carbon black micropowder masterbatch:

[0043] Ferric oxide compound microparticles with a particle size of 0.07 μm and polyethylene terephthalate resin powder were mixed in a weight ratio of 9:91, stirred evenly, dried, and then injected into a screw extruder. The mixture was melt-extruded into cylindrical strips with a diameter of 2.5 mm, and then air-cooled and cut into masterbatches with a length of 4.5 mm.

[0044] The preparation process of the masterbatch containing nano-carbon black powder is the same as above. The nano-carbon black powder has a particle size of 0.05 μm, and the nano-carbon black powder and polyethylene terephthalate resin powder are mixed in a ratio of 2:98.

[0045] Ferric oxide microparticle masterbatch and nano carbon black micropowder masterbatch are mixed with polyester chips at ratios of 3:97 and 1:99, respectively. After drying, they are injected into a screw extruder separately or mixed. After melting and extrusion, they are spun through a spinneret, cooled, and wound into polymer polyester fibers with a fineness of 450 dtex. Alternatively, the molten filaments spun from the spinneret are placed randomly on a running conveyor belt and hot-pressed into fibers with a mass of 80 g / m³. 2 Spunbond nonwoven fabric, or spun filaments cut into 45mm short fibers, then web-laid and reinforced to 80g / m². 2 Polymer nonwoven fabric.

[0046] 2. The 450 dtex polymer filaments melt-spun in step 1 are woven into 3 strands / cm x 4 strands / cm lengths using a rapier loom, with a mass of 120 g / m. 2 Polymer polyester fabric; Step 1: Melt-spun to form a material with a mass of 80 g / m 2 The spunbond nonwoven fabric is woven with copper wires of 0.3 mm in diameter, with a warp and weft density of 3 threads / cm x 3 threads / cm and a weight of 85 g / m. 2 Copper wire mesh; using nano-carbon black powder with a mass of 80g / m 2 Using polyester nonwoven fabric as the base fabric, metallic silver is deposited on the surface of the nonwoven fabric layers using a chemical precipitation process, resulting in a product with a mass of 95 g / m². 2Silver-plated nonwoven fabric; made from polytetrafluoroethylene resin micro powder (produced by Sichuan Zhonghao Chenguang Research Institute Co., Ltd.), mixed with 10% by weight of nano-carbon black micro powder, stirred at 50 rpm for 5 minutes, then 1.5% by weight of excipients (cyclohexanol, octyltin mercaptan, and MPEG750) were added and stirred at 50 rpm for 5 minutes. The three components were stirred in a mass ratio of 50:30:20. The above mixture was then mixed with 19% by weight of aviation kerosene to form a paste, which was then formed into strips, pressed into sheets, and prepared using a three-dimensional stretching process to achieve a mass of 55 g / m³. 2 A corrosion-resistant three-dimensional polytetrafluoroethylene nanofiber carbon black microporous membrane, with a thickness of 20 μm and a mass of 60 g / m³. 2 The micropores have a diameter of 0.3-2.5 μm and a porosity of 90%.

[0047] 3. Polyacrylate emulsion was selected as the adhesive. When preparing the adhesive liquid for the second and fourth layers, ferric oxide particles with a diameter of 0.07 μm were incorporated. When preparing the adhesive liquid for the sixth layer, nano-graphene powder was incorporated. The formulation of the foam adhesive liquid for the second and fourth layers is as follows: (1) 40% polyacrylate emulsion, 3.5% ferric oxide particles, 8.5% titanium dioxide, 6.5% kaolin, 1.5% thickener, 1.5% crosslinking agent, 3% surface affinity agent, 1.5% ammonia, 1.0% thermosetting adhesive, and the remainder is water. The formulation of the foam adhesive liquid for the sixth layer is as follows: (2) 45% polyacrylate emulsion, 0.8% nano-graphene powder, 10% titanium dioxide, 6.5% kaolin, 1.5% thickener, 1.2% crosslinking agent, 3% surface affinity agent, 1.5% ammonia, 1.0% thermosetting adhesive, and 31.5% water.

[0048] 4. Preparation of polymer protective composite material: The adhesive liquid prepared according to formula (1) in step 3 is placed into the first and second adhesive tanks of the multi-functional composite machine, and the adhesive liquid prepared according to formula (2) is placed into the third adhesive tank. The pre-made Fe2O3-containing polyester fabric layer, silver-plated nonwoven fabric layer, metal fabric layer and three-dimensional nano-carbon microporous membrane layer rolls are placed on the first roll roller 8, the second roll roller 9, the third roll roller 10 and the fifth roll roller 12 of the composite machine, respectively. The polyester fabric layer and the silver-plated nonwoven fabric layer enter the first adhesive tank 13. After passing through the first liquid supply roller 14, the foam adhesive liquid in the adhesive tank is applied to the reverse side of the polyester fabric layer. The two fabric layers are bonded together by the rollers, and an adhesive layer 2 is formed between the two fabric layers. The two-layer fabric composite and the metal mesh layer on the third roll roller 10 enter the second adhesive tank 16. After passing through the third liquid supply roller 17, the foam adhesive liquid in the adhesive tank is applied to the reverse side of the two fabric layers. The three fabric layers are then bonded together by rollers to form adhesive layer 4. Similarly, the three-layer fabric composite is led to the third adhesive tank 19 on the second floor. After passing through the fifth liquid supply roller 20, the foam adhesive liquid in the adhesive tank is applied to the reverse side of the three fabric layers. It is then bonded to the three-dimensional nano-carbon microporous membrane led out from the fifth roll roller 12 to form a polymer protective composite material and adhesive layer 6. The polymer protective composite material passes through the first two-roll mill 32, the second two-roll mill 33 and the third two-roll mill 34, and enters the heating box 25. After the moisture is removed by the first heating roller 26, the second heating roller 27, the third heating roller 28, the fourth heating roller 29 and the fifth heating roller 30, it passes through the fourth two-roll mill 35 and enters the cooling system 31, where it is wound into a shaft on the finished fabric roll roller 36.

[0049] Composite processing conditions: Adhesive application rate 20g / m 2 It has a solid content of 50%, a foam diameter of 0.2-0.4 mm, a foam density of 55 g / L, and a multi-functional composite machine speed of 25 m / min.

[0050] Polymer protective material mass 420g / m 2 The composition includes 15.4g of Fe2O3 and nano-graphene. Key properties: thermal conductivity >70.6w / mk, electromagnetic shielding efficiency >70dB, wave absorption rate >93%, bandwidth 22GHz, and composite material strength 950N / 5×20cm.

[0051] Example 2:

[0052] 1. Preparation of CuO and Al2O3 microparticle masterbatches, nano-reduced graphene oxide micropowder masterbatches, and fibers:

[0053] CuO and Al2O3 particles with a particle size of 0.07μm were mixed in a 1:1 ratio and polyethylene terephthalate resin powder was mixed in a 9:91 ratio. After stirring evenly and drying, the mixture was injected into a screw extruder, heated and melted, and extruded into cylindrical strips with a diameter of 2.5mm. After air cooling, the strips were cut into masterbatches with a length of 4.5mm.

[0054] The preparation process for the masterbatch containing nano-reduced graphene oxide powder is the same as above. The powder particle size is 0.05 μm, and the nano-reduced graphene oxide powder and polyethylene terephthalate resin powder are mixed in a ratio of 2:98.

[0055] CuO and Al2O3 microparticle masterbatch and nano-reduced graphene oxide micropowder masterbatch were mixed with polyester chips at ratios of 3:97 and 1:99, respectively. After stirring and drying, the mixtures were injected into a screw extruder, heated and melted, extruded, and then spun through a spinneret. After cooling, the molten filaments were wound into 360 dtex polymer polyester fibers. The molten filaments extruded from the spinneret were randomly placed on a running conveyor belt and hot-pressed into fibers with a mass of 80 g / m³. 2 Spunbond nonwoven fabric.

[0056] 2. The 360dtex polymer filament melt-spun in step 1 is woven into a 100g / m² length using a domestic warp knitting machine. 2 Polymer polyester fabric. Made with nano-reduced graphene oxide micropowder, 60 g / m³. 2 Using polyester spunbond nonwoven fabric as the base fabric, metallic silver is deposited on the surface of the nonwoven fabric layers using a chemical precipitation process, resulting in a product with a mass of 75 g / m². 2 Silver-plated nonwoven fabric; made from polytetrafluoroethylene resin micro powder (produced by Sichuan Zhonghao Chenguang Research Institute Co., Ltd.), mixed with 8% by weight of nano carbon black micro powder, and 1.2% by weight of excipients (by weight of polytetrafluoroethylene micro powder), stirred at 50 rpm for 5 minutes. The excipients are cyclohexanol, octyltin mercaptan, and MPEG750, with a mass ratio of 50:30:20. The above mixture is then mixed with 19% by weight of aviation kerosene (by weight of polytetrafluoroethylene micro powder) to form a paste, which is then formed into strips, compressed into sheets, and prepared using a three-dimensional stretching process to achieve a thickness of 55 g / m³. 2 A corrosion-resistant three-dimensional polytetrafluoroethylene nanofiber carbon black microporous membrane, with a thickness of 30 μm and a mass of 50 g / m³. 2 The micropores have a diameter of 0.3-2.5 μm and a porosity of 90%.

[0057] 3. Using polyacrylate emulsion as the binder, 5.5% CuO and Al2O3 particles and 0.8% nano-reduced graphene oxide powder are added when preparing the foam adhesive liquid, and mixed evenly. The mass ratio of CuO to Al2O3 is 1:1. Foam adhesive liquid formula: 40% polyacrylate emulsion, 5.5% mixture of copper oxide and aluminum oxide particles, 0.8% nano-reduced graphene oxide powder, 8.5% titanium dioxide, 6.5% kaolin, 1.5% thickener, 1.5% crosslinking agent, 3% surface affinity agent, 1.5% ammonia, 1.0% thermosetting adhesive, and the remainder is water.

[0058] 4. Preparation of Polymer Protective Composite Material: The adhesive liquid prepared in step 3 is placed into the first and third adhesive tanks of the multi-functional laminating machine. Three fabric rolls—the polyester warp-knitted layer, the silver-plated nonwoven fabric layer, and the three-dimensional nano-carbon microporous membrane layer—are placed on the first fabric roll shaft 8, the second fabric roll shaft 9, and the fifth fabric roll shaft 12 of the multi-functional laminating machine, respectively. The polyester warp-knitted layer and the silver-plated nonwoven fabric layer enter the first adhesive tank 13. After passing through the first liquid supply roller 14, the foam adhesive liquid in the adhesive tank is applied to the reverse side of the polyester warp-knitted layer. The two fabric layers are then bonded together by rollers, forming an adhesive layer 2 between them. The bonded two fabric layers are then led to… The third viscous tank 19 on the second floor, after passing through the fifth liquid supply roller 20, applies the foam adhesive liquid in the viscous tank to the reverse side of the two-layer fabric, and bonds it with the three-dimensional nano-carbon microporous membrane drawn from the fifth roll fabric shaft 12 to form a polymer protective composite material, forming an adhesive layer 4. The polymer protective composite material passes through the first two-roll rolling mill 32, the second two-roll rolling mill 33 and the third two-roll rolling mill 34, and enters the heating box 25. Under the action of the first heating roller 26, the second heating roller 27, the third heating roller 28, the fourth heating roller 29 and the fifth heating roller 30, the moisture is removed, and then it enters the cooling system 31. After cooling, it is wound into a shaft on the finished roll fabric roller 36.

[0059] Composite processing conditions: Adhesive application rate 15g / m 2 It has a solid content of 50%, a foam diameter of 0.2-0.4 mm, a foam density of 55 g / L, and a multi-functional composite machine speed of 25 m / min.

[0060] Polymer protective material mass 260g / m 2 The metal microparticles and nano-carbon materials comprise 6.3g of the product. Key performance characteristics: thermal conductivity >69.4w / mk, electromagnetic shielding efficiency >71dB, wave absorption rate >93%, bandwidth 21GHz, composite material strength 840N / 5×20cm.

[0061] Example 3

[0062] The composite machine structure used in the embodiment is as follows: Figure 2 As shown, it includes:

[0063] The front section has a two-layer composite structure. On the ground layer, along the axial direction of the multi-functional composite machine, a first fabric roll shaft 8, a second fabric roll shaft 9, a third fabric roll shaft 10, and a fourth fabric roll shaft 11 are arranged. On the second layer, a fifth fabric roll shaft 12 is placed. A first viscous trough 13 is placed between the first fabric roll shaft 8 and the second fabric roll shaft 9, and a first liquid feeding roller 14 and a second liquid feeding roller 15 are arranged above the first viscous trough 13. A second viscous trough 16 is placed between the second fabric roll shaft 9 and the third fabric roll shaft 10, and a third liquid feeding roller 17 and a fourth liquid feeding roller 18 are arranged above the second viscous trough 16. A third viscous trough 19 is arranged on one side of the feeding direction of the fifth fabric roll shaft 12, and a fifth liquid feeding roller 20 and a sixth liquid feeding roller 21 are arranged above the third viscous trough 19.

[0064] The body section is a box structure, which includes a heating box 25 and five internal heating rollers, namely the first heating roller 26, the second heating roller 27, the third heating roller 28, the fourth heating roller 29 and the fifth heating roller 30. The discharge end of the car head section is connected to the feed end of the body section.

[0065] At the rear of the vehicle, the feeding end is connected to the discharge end of the vehicle body. The rear of the vehicle includes multiple cooling rollers, which form a cooling system 31. The discharge end of the rear of the vehicle is connected to the finished fabric roll roller 36.

[0066] The first two-roller rolling mill 32 is placed in the gap between the two layers of fabric rolling rollers, the second two-roller rolling mill 33 and the third two-roller rolling mill 34 are placed at the feeding end of the body part, and the fourth two-roller rolling mill 35 is placed at the discharge end of the body part.

[0067] In this embodiment, the movable foam baffles on both sides of the fifth liquid supply roller 13 and the sixth liquid supply roller 14 are arranged in an inverted octagon shape.

[0068] The viscous transport structure includes a foam generator 24, the outlet of which is connected to a third viscous tank 19.

[0069] The first liquid supply roller 14 and the second liquid supply roller 15 are a rubber roller and a steel roller, respectively, with the outer surface of the steel roller being uneven. The liquid supply roller above each viscous trough can be configured with the same structure as the first liquid supply roller 14 and the second liquid supply roller 15.

[0070] In this embodiment, an operating console portion and a transmission portion are also included, which are arranged opposite to each other.

[0071] In this embodiment, the walls of the first slime tank 13, the second slime tank 16, and the third slime tank 19 are all sandwich structures, made of stainless steel, and a heating tube is installed inside the jacket.

[0072] In this embodiment, the side wall of the body box is a double-layer metal plate with a heat insulation layer filling between the metal plates.

[0073] All heating rollers rotate in the same direction, while all cooling rollers rotate in different directions.

[0074] In summary, this multi-functional laminating machine for multi-layer fabric composite processing is approximately 21m long, with the front, body, and rear sections measuring 8m, 8m, and 5m respectively. The working width is 3.5m, and the effective processing width is 2.5m. The ground floor height of the front section is 2.5m, and the second floor height is also 2.5m. Both floor slabs are made of patterned steel plates. The steel frame, heating box 25, and cooling box of the front section are all made of channel steel. The heating box 25 has a thin insulated steel plate body, and an aerogel insulation layer is filled between the two steel plates. When the first viscous liquid tank 13 uses a full-coating process, the fabric layer to be laminated, upon contact with the first liquid-feeding roller 14, adheres the adhesive liquid adhering to the surface of the first liquid-feeding roller 14 in the first viscous liquid tank 13 to the back of the fabric layer, thus laminating it with another fabric layer entering in the same direction simultaneously.

Claims

1. A multi-interface electromagnetic shielding composite material, characterized by The composite material is made by bonding a multilayer material of polytetrafluoroethylene / nanocarbon three-dimensional microporous membrane with a binder containing metal compound particles, nano-carbon material powder, or both of the two materials into a composite material. The metal is one or more of copper, aluminum, or iron; the nano-carbon material is one or more of carbon fiber, nano-carbon black, carbon nanotubes, nano-graphene, or their derivatives; the metal compound particles, nano-carbon material powder, or polyester fabric or nonwoven fabric containing both materials are prepared by the following method: Polyester fiber as raw material, woven or knitted method is woven into, quality is 60-200g / m 2 ; The nonwoven fabric is a polyester spunbond nonwoven fabric and a nonwoven fabric made by a short fiber web-laying, needle punching or composite process, and has a mass of 40-120 g / m 2 The silver or nickel plated nonwoven fabric is prepared by the following method: Silver- or nickel-plated nonwoven fabrics are produced by chemical precipitation or by coating the surface of polymer polyester spunbond nonwoven fabrics or needle-punched nonwoven fabrics with silver or nickel micropowder mixed with adhesive. The silver or nickel content accounts for 3-8% of the nonwoven fabric weight. The metal mesh cloth is made of stainless steel fiber or metal fiber with fiber diameter of 0.2-0.5mm, and the warp and weft density is 2-4 root / cm, and the weight is 50-100g / m 2 ​ The polytetrafluoroethylene / nanocarbon three-dimensional microporous membrane is prepared by the following method: The process involves incorporating one or two of the following into polytetrafluoroethylene (PTFE) nanopowder: carbon nanotubes, nano-carbon black, and nano-graphite. Multiple auxiliary materials are added, and the mixture is mechanically stirred to achieve uniform dispersion. A lubricant is used to prepare a paste, which is then formed into strips, calendered into sheets, and finally stretched using a three-dimensional stretching process. The amount of any one or two of the following—carbon nanotubes, nano-carbon black, and nano-graphite—added is 5-30% of the mass of the PTFE nanopowder. The multiple auxiliary materials are a dispersant, stabilizer, and nonionic surfactant in a mass ratio of 5:3:2, and the amount added is 1-2.5% of the mass of the PTFE nanopowder.

2. The multi-interface electromagnetic shielding composite material according to claim 1, characterized in that The adhesive liquid containing metal compound particles, or containing nano-carbon material powder, or containing both nanomaterials, is prepared by the following method: using acrylate emulsion or polydimethylsiloxane resin as the adhesive, incorporating 3-6% of metal compound particles or 0.5-1% of nano-carbon material powder as the adhesive and mixing thoroughly, or simultaneously mixing both metal compound particles and nano-carbon material powder to obtain the adhesive liquid; during the lamination process, the prepared adhesive liquid is passed through a foam generator to form foams of varying sizes for foam bonding.

3. The multi-interface electromagnetic shielding composite material according to claim 2, characterized in that The adhesive formulation is as follows: 35-45% polyacrylate emulsion or polydimethylsiloxane resin; 3-6% metal compound microparticles or 0.5-1.5% nano-carbon material powder; 5-12% titanium dioxide; 5-12% kaolin; 1-2% thickener; 1-2% crosslinking agent; 2-6% surface affinity agent; 1-2% ammonia; 0.1-1% thermosetting adhesive; and the remainder is water.

4. A method for preparing the multi-interface electromagnetic protection composite material according to claim 1 includes the following steps: 1) Preparation of polyester fabrics or nonwoven fabrics containing metal compound particles, nano-carbon material powders, or both materials; 2) Preparation of multilayer materials of silver- or nickel-plated nonwoven fabrics, metal mesh fabrics, and polytetrafluoroethylene / nanocarbon three-dimensional microporous membranes; 3) preparation of adhesive liquid containing metal compound microparticles, or containing nano-carbon material micropowder, or containing both nano-materials; 4) preparation of multi-interface electromagnetic protection composite material.

5. The method of claim 4, wherein The preparation of the multi-interface electromagnetic protection composite material in step 4) comprises the following steps: The adhesive liquid is put into the adhesive liquid tank of the compounding machine, the pre-prepared multi-layer materials are respectively placed on the multiple cloth roller shafts of the compounding machine, the cloth passing route is selected so that the adhesive liquid of the adhesive liquid tank is in the form of foam or is coated to the opposite side of the material, and the multi-layer materials are compounded under the action of the calender and another layer of material, and the multi-layer materials complete the compounding process at one time, and the polymer composite material is wound into a shaft on the finished product cloth roller shaft of the multifunctional compounding machine.

Images