391results about How to "High electromagnetic shielding" patented technology

The invention provides an electromagnetic shielding conformal optical window with a longitude and latitude-shaped mesh structure, which belongs to the technical field of electromagnetic shielding of optical transparent pieces. The electromagnetic shielding conformal optical window comprises a conformal optical window and is characterized in that: (1) a longitude and latitude-shaped metal mesh is manufactured on the inner side surface of the conformal optical window shell; and the longitude and latitude-shaped metal mesh covers the whole inner side surface of the conformal optical window shell; or (2) a longitude and latitude-shaped metal mesh and a conformal optical window inner shell are manufactured on the inner surface of the conformal optical window shell from outside to inside in turn; the longitude and latitude-shaped metal mesh covers the whole inner surface of the conformal optical window shell and outer surface of the conformal optical window inner shell; the latitude-shaped metal mesh consists of metal longitudes and metal latitudes; the metal latitudes are uniformly arranged in an equivalent centre angle along a circumferential direction; the metal longitudes are arranged at equal intervals according to a metal mesh cycle along a generatrix direction; and the metal longitudes and the metal latitudes are electrically connected with one another. The electromagnetic shielding conformal optical window with the longitude and latitude-shaped mesh structure is suitable for electromagnetic shielding technology of military or civil conformal optical windows for remote measuring and sensing, medical diagnosis, secret communication, aerospace equipment and the like.

The invention discloses a multi-element structure composite conductive filling material. A surface of lightweight inorganic powder (hollow glass beads, mica, carbon fibers, flake graphite and the like) is plated with a layer of wave absorbing magnetic material (Ni, Fe, Co, Ni-P, Co-P, Ni-Co-P, Co-W-P, barium ferrite, ferriferrous oxide, carbonyl iron and the like), and then is plated with a layer of conductive material (such as metal of silver, nickel, copper and the like or inorganic oxides of doped tin oxide, doped indium oxide, doped zinc oxide, titanium dioxide and the like), and a novel multi-element structure composite conductive filling material-inorganic powder core/magnetic material coating layer/conductive material coating layer is prepared. The electromagnetic shielding performance of the composite conductive filling materials can be raised further by utilization of wave absorbing performances of the wave absorbing material to electromagnetic waves and the reflection performances of the conductive material to electromagnetic waves. The composite conductive filling material has advantages of light weight, low cost, wide shield frequency band, good shielding properties and the like, and has great application values in the electromagnetic shielding composite material field.

The invention provides a natural rubber composite with an electromagnetic shielding property. The composite comprises natural rubber, a short carbon fiber and a compounding agent, wherein the diameter of the short carbon fiber is 3-10 mu m, the length of the short carbon fiber is 1-5 mm, and the weight ratio of the natural rubber to the short carbon fiber at room temperature is 100:(0.5-11). Because the physical and mechanical properties of the natural rubber and the short carbon fiber are fully used for preparing the composite with the electromagnetic shielding property, the composite has the good electromagnetic wave absorption property of the short carbon fiber and the good physical and mechanical properties of the rubber material, and can be adaptive to the requirement on various environments. The composite has the advantages that the electromagnetic shielding property is high, the preparation method is simple, the preparation cost is low, and the energy consumption is reduced.

The invention relates to a preparation method of a Co3O4/PANI/MXene/PI electromagnetic shielding fabric. The preparation method comprises the steps: pretreating a PI fabric, and then carrying out plasma treatment; spraying MXene solution to the surface of the treated PI fabric for reaction; spraying Co3O4/PANI nanowire solution on the obtained MXene/PI composite for reaction; treating the obtainedCo3O4/PANI/MXene/PI composite in a PDMS (polydimethylsiloxane) solution. The preparation method is simple and has mild conditions, and the obtained electromagnetic shielding fabric has excellent conductivity and electromagnetic shielding performance.

The invention discloses a polymer/graphene foamed material with electromagnetic shielding performance, and a preparation method and an application thereof. The method is characterized in that a thermoplastic polymer/graphene micro-foamed film is produced mainly by using a solution blending and phase separation technology, and the thermoplastic polymer/graphene micro-foamed film and a wave transmitting material are bonded by glue to form the integral material with a sandwich structure. The polymer/graphene foamed material has good application prospect in the electromagnetic shielding field.

The invention provides a rubber composite material with good electromagnetic shielding performance and a preparation method thereof. The material has characteristics of low cost and high electromagnetic shielding performance. The composite material has magnesium alloy particles and ferrite composite particles coated with a polyaniline layers which are evenly distributed in a rubber matrix; the ferrite composite particles and the magnesium alloy particles have a volumetric ratio of 1-4:1 and volume percentage of 20-60% in the composite material; the ferrite composite particles are composed of an organic outer layer which is polyaniline and an inner core which is ferrite; the organic outer layer is 2-10mum thick, the ferrite is 2-5mm and is a mixture of ferric oxide and strontian ferrite at a volumetric ratio of 1:9-2:8; the magnesium alloy particles are made from the following compositions: 2-12% of Al, 1-5% of Zn, 0.05-0.5% of Cu, 0.01-0.05% of Sn, and Mg; and the magnesium alloy particles are 2-5mm.

The invention relates to a flexible circuit board, which comprises an insulation layer, a conduction pattern, a covering layer and a continuous metal sputtering plating layer, wherein the conduction pattern is formed on the insulation layer, the covering layer is covered on the conduction pattern, the conduction pattern comprises a grounding wire and a signal transmission wire, the covering layer is provided with a through hole used for exposing at least a part of grounding wire, and the metal sputtering plating layer is formed on the surface of the covering layer far away from the conduction pattern, the hole wall of the through hole and the surface of the grounding wire exposed out of the through hole through sputtering plating, so the metal sputtering plating layer is electrically connected with the grounding wire. The technical scheme also provides a manufacture method of the flexible circuit board. The flexible circuit board has good electromagnetic shielding performance.

The invention provides a simple and effective multi-parameter optimization algorithm without interval limitation, in particular to an optimization design algorithm of a superconducting magnet external magnetism shielding coil, which is used for the design of the superconducting magnet external magnetism shielding coil. The invention changes all parameters related to the design of the superconducting magnet external magnetism shielding coil one by one according to the optimization results on the basis of an initial value, in addition, constraint conditions are taken into consideration during the result evaluation, and the coefficients are regulated and changed according to the condition whether the results are optimized or not, so the optimization of the design parameters is realized.

The invention discloses a method of copper and iron alloy materials for novel motor rotors, and belongs to the technical field of nonferrous metal material manufacturing. The method mainly comprises the steps of (1) burdening, (2) vacuum induction smelting, (3) mechanical centrifugal atomization, (4) discharge plasma sintering and (5) aging. Cu and Fe raw materials with higher purity are selected,fed silver is excellent in electric conductivity, and meanwhile, iron, silicon and copper are lower in solid solubility, so that the influence on electricity and heat conductivity of copper rods is lower, the solid solubility cannot be changed along with the temperature change, and alloys formed by Cu and Fe achieve higher electric conductivity; and through the mechanical centrifugal atomizationmode, Cu-Fe alloys are atomized as drops, and the drops are quickly condensed through low-temperature and high-purity argon, so that the cooling speed of the alloy drops can be accelerated, the macroscopic segregation of the alloys is overcome, and the electromagnetic shielding performance of the alloys is further improved.

The invention discloses a composite electromagnetic shielding film and a preparation method thereof. The composite electromagnetic shielding thin film comprises bacterial cellulose film layers and MXene film layers, wherein the bacterial cellulose film layers and the MXene film layers are alternately arranged, and the bacterial cellulose film layers are arranged on the two outer surfaces of the composite electromagnetic shielding film. In the composite electromagnetic shielding film provided by the invention, intermolecular acting force mainly involving hydrogen bonds exists between the bacterial cellulose film layers and the MXene film layers, so the tensile stress of the MXene film layers can be transmitted to the bacterial cellulose film layers when the composite film bears the tensile stress due to the interaction force, and thus, the mechanical enhancement effect of bacterial cellulose is exerted; and in the structure that the bacterial cellulose film layers and the MXene film layers are alternately arranged, electromagnetic waves can generate an internal multiple reflection effect among the multiple MXene film layers, so the stroke of the electromagnetic waves in the composite film is increased, more electromagnetic wave radiation energy is absorbed by MXene, and therefore, the overall electromagnetic shielding performance of the composite film is improved.

The invention provides a flexible stretchable electromagnetic shielding fabric and a preparation method thereof. The method for preparing the flexible stretchable electromagnetic shielding fabric comprises the following steps: selecting a spandex stretch fabric as an elastic adhesion matrix, applying a certain tension to two ends of the fabric, stretching the fabric to a certain elongation and fixing, and coating a layer of liquid elastic adhesives on the surface of the elastic adhesion matrix; performing pressure dipping on a flexible nano electromagnetic shielding composite film on the liquid elastic adhesives, coating a layer of liquid elastic adhesives on the upper side of the flexible nano electromagnetic shielding composite film, allowing the composite film to be adhered to another spandex stretch fabric, and curing the adhesives under a certain conditions; releasing the tension applied to the elastic adhesion matrix so as to drive the flexible nano electromagnetic shielding composite film to retract, thereby obtaining the flexible stretchable electromagnetic shielding fabric. The flexible stretchable electromagnetic shielding fabric disclosed by the invention has the characteristics of high elasticity, high elongation, excellent electromagnetic shield property and the like.

The invention provides a flexible stretchable electromagnetic shielding film and a preparation method thereof. The preparation method of the flexible stretchable electromagnetic shielding film comprises the following steps: selecting an elastic membrane as an elastic adhesion matrix, stretching the elastic membrane to a certain elongation, then fixing the elastic membrane, and coating a liquid elastic adhesive layer on the surface of the elastic membrane; crushing a flexible nano electromagnetic shielding complex film on the liquid elastic adhesive layer, coating resin with protective effect at the upper side of the flexible nano electromagnetic shielding complex film to form a resin layer, and curing the liquid elastic adhesive and the resin under certain conditions; and releasing a tensile force applied onto the elastic adhesion matrix, so as to drive the flexible nano electromagnetic shielding complex film to retract, namely the flexible stretchable electromagnetic shielding film is obtained. The prepared flexible stretchable electromagnetic shielding film has good elasticity, high elongation (20-50%) and excellent electromagnetic shielding property (electromagnetic wave absorptivity is more than or equal to 99% at the frequency of 1-5GHz) and can bear certain bending and compression deformation.

The invention discloses a preparation method for an electromagnetic shielding PP thin film. The preparation method for the electromagnetic shielding PP thin film comprises the following steps in sequence that 1, PP raw materials are made to a PP melt-blown nonwoven fabric by a melt-blown spinning technology; 2, a PP composite conductive fiber net modified by carboxylic multi-walled carbon nanotubes (c-MWCNTs) is prepared; and 3, the electromagnetic shielding PP thin film is prepared. The preparation method for the electromagnetic shielding PP thin film uses the carboxylic multi-walled carbon nanotubes (c-MWCNTs) to modify the PP melt-blown nonwoven fabric so as to prepare and obtain the PP composite conductive fiber net, and the PP composite conductive fiber net and a PP film are subjectedto hot pressing combination to prepare the high-performance PP electromagnetic shielding thin film; and the PP composite film is high in shielding effectiveness, and is suitable for being applied tothe field of thin films.

The invention discloses a preparation method of an electromagnetic shielding TPU (thermoplastic polyurethane) film. The method comprises steps as follows: S1, TPU melt-blown non-woven fabric is prepared from the raw material, namely, TPU with a melt-blowing spinning technology; S2, a c-MWCNTs (carboxylic multi-walled carbon nanotubes)/TPU conductive composite fiber net is prepared; S3, the electromagnetic shielding TPU film is prepared. The melt-blown TPU fiber net is modified with c-MWCNTs, the TPU conductive composite fiber net and a TPU film are subjected to hot pressing, and the electromagnetic shielding TPU composite film is prepared, has excellent electromagnetic shielding performance and is applicable to films, clothes and other fields.

The invention belongs to the field of electronic materials, and provides a preparation method of a high-light transmission electromagnetic shielding film. The preparation method comprises the steps ofmixing a one-dimensional nanometer conductive material and resin to obtain uniform conductive ink, coating a washed clean transparent substrate with the conductive ink, and baking to form a grid transparent conductive film; soaking the material in an electrochemical film-plating solution for electroplating, adding voltage to enable electroplated metal to grow along the surface of the grid transparent conductive film so as to improve the conductivity and the electromagnetic shielding performance and form a conductive layer; then coating a high-molecular conductive polymer, enabling the conductive layer to form a complete conductive surface layer so as to further improve the electromagnetic shielding, and finally forming a transparent protective layer through coating thermal curing or photocuring hardened resin so as to complete the preparation of the film with high light transmission and good electromagnetic shielding performance. The thin prepared according to the invention has high light transmission and electromagnetic shielding performance, and is low in cost, simple in preparation and conducive to large-scale industrial production.

The invention discloses a graphene oxide-ferroferric oxide magnetic liquid-cement based composite material and a preparation method thereof. The graphene oxide is doped into the graphene oxide-Fe3O4 magnetic liquid-cement based composite material, so holes in a cement stone are reduced, the hole structure of the cement stone is improved and gel in the cement is more uniform and compact. Meanwhile,due to doping of the graphene oxide, the generation of needle-shaped ettringite can be reduced and the structure of the cement stone is more compact. In addition, the magnetic material, namely the Fe3O4 magnetic liquid, is added, and the magnetic conductance of the composite material is increased, so that the electromagnetic shielding performance of the cement based composite material is improved. Meanwhile, the invention innovatively provides a ball-milling mode to replace stirring, so that the difficulty that the ferroferric oxide magnetic liquid is difficult to distribute on the cement based material uniformly is overcome. Therefore, the composite material provided by the invention has wide application prospect.

The invention belongs to the technical field of electromagnetic shielding, and particularly relates to a modified carbon fiber, and a preparation method and an application thereof. The preparation method of the modified carbon fiber comprises the following steps: a) dipping a dopamine modified carbon fiber into a solution containing a substance A to obtain a substance A-dopamine modified carbon fiber; b) mixing and reacting the substance A-dopamine modified carbon fiber and a dopamine modified filler in a liquid phase under an alkaline condition to obtain a filler modified carbon fiber; and c)carbonizing the filler modified carbon fiber to obtain the modified carbon fiber. The problems of poor dispersibility and easy agglomeration of a small-scale filler in a modified material are solved,and the filler in the provided modified carbon fiber is uniformly dispersed and has excellent electromagnetic shielding performance; and a resin composite material prepared from the modified carbon fiber has good electromagnetic shielding performance and mechanical strength.

The invention relates to a high stability conductive elastomer for electromagnetic shielding. The high stability conductive elastomer comprises the following components: 100 parts by mass of siliconerubber, 100-400 parts by mass of conductive filler, 0-10 parts by mass of silicone oil, 0-10 parts by mass of graphene, 1-5 parts by mass of a silane coupling agent, 0.5-5 parts by mass of an internalreleasing agent, and 0.5-10 parts by mass of a crosslinking agent. The conductive elastomer prepared from the components has the advantages of high tensile strength, high elongation at break, low compressive deformation, low product cost and good shielding effectiveness, the tensile strength and elongation at break enable difficult pull-apart of the product in the assembly process and reusabilityof the product during reworking, the compressive deformation is low, and relative to pure electrically conductive silicone products, the product provided by the invention has low compressive deformation amount, so that the whole installation shell has good sealing performance and good shielding effectiveness, and the product cost is low. In addition, the invention also provides a preparation method of the high stability conductive elastomer for electromagnetic shielding.