42 results about "Ptfe composite" patented technology

The invention discloses a fluorine-containing emulsion constant-pressure feeding device and a polyimide composite film production system.The fluorine-containing emulsion constant-pressure feeding device comprises a liquid supplementing tank and an emulsion tank, and a liquid supplementing pipe used for conveying emulsion to the emulsion tank through the pressure difference between the liquid supplementing tank and the emulsion tank is arranged between the liquid supplementing tank and the emulsion tank; the emulsion tank is provided with a compressed gas inlet pipe and a compressed gas exhaust pipe, and the constant-pressure feeding device for the fluorine-containing emulsion further comprises a controller which is used for controlling the pressure in the emulsion tank to be basically constant by controlling the compressed gas flow of the compressed gas inlet pipe and the compressed gas flow of the compressed gas exhaust pipe. And the outlet of the emulsion tank is also provided with a feeding pipe for conveying the emulsion to the emulsion coating device through the pressure difference between the emulsion tank and the emulsion coating device. The invention further discloses a polyimide composite film production system provided with the fluorine-containing emulsion constant-pressure feeding device. The method is suitable for preparing the high-performance PI / PTFE composite film.

This invention discloses a method for producing PTFE filter fabric. It involves feeding PVC-U and PTFE filaments without drafting onto a ring spinning machine equipped with a yarn guiding device including a mounting frame, an arc-shaped connecting piece, and a spiral yarn guide hook. This allows for positional adjustment of the yarn guide hook and yarn tube during operation, maintaining concentricity and achieving efficient plying. High-temperature setting removes PVC-U, effectively preserving the crimp formed by the twisting of the PTFE filaments, resulting in PTFE twisted filaments with improved cohesion. By using PTFE, PPS, and aramid filaments as core yarns and the other two as outer layers, three types of PTFE composite yarns are produced. The PTFE twisted filaments are used as weft yarns, and the three types of PTFE composite yarns combined with the PTFE twisted filaments are used as warp yarns, achieving the processing of a PTFE filter fabric with both excellent strength and breathability.

This invention discloses a method for preparing a low-loss ultrathin PTFE microwave dielectric substrate. The method includes the following steps: 1. Preparation of PTFE composite adhesive; 2. Impregnation with glass fiber cloth; 3. Lamination of sheet substrates. The PTFE microwave dielectric substrate prepared by this method has fine filler particles and a high filling rate, improving the uniformity of the ultrathin substrate thickness and dielectric constant. The substrate thickness is 0.065mm ± 0.008mm, and the dielectric constant at 10GHz is 2.95 ± 0.03. It also reduces the loss factor at high frequencies, with a loss factor ≤ 0.0011 at 10GHz. The preparation process is simple, easy to scale up for continuous production, and the microwave substrate exhibits excellent performance, meeting the stringent performance requirements of multilayer circuit boards in high-frequency communication applications.

The application discloses a kind of polyimide composite film drying device and production system, polyimide composite film drying device includes for the polyimide substrate film surface coating emulsion formed by polyimide composite film passing and carrying out microwave heating drying microwave heating area and for the polyimide composite film after microwave heating drying passing and carrying out infrared heating drying infrared heating area, the microwave heating area and infrared heating area are sequentially arranged and mutually communicated, and polyimide composite film sequentially passes the microwave heating area and infrared heating area along vertical direction.The application further discloses a kind of production system with above-mentioned polyimide composite film drying device.The application can be used to dry PI / PTFE composite film, and drying efficiency is high, drying effect is good, can guarantee the quality of final composite film product.

This utility model relates to the field of heat exchanger technology and discloses a PTFE-graphene composite membrane heat exchanger, including a heat recovery core. The heat recovery core comprises several honeycomb flow channel cores spliced ​​together, each of which adopts a graphene-PTFE composite membrane structure. The honeycomb flow channel core is set at a 15° inclination angle relative to the primary air inlet. The graphene-PTFE composite membrane structure, from the inside out, includes a graphene inner coating, a PTFE microporous base membrane layer, and a SiO2 nano-hydrophobic layer fixed together. The hexagonal honeycomb flow channel core of the graphene-PTFE composite membrane structure and the 15° inclination improve heat exchange efficiency and gas handling capacity. The turbulence control strategy further enhances the system performance, improves sensible heat efficiency, avoids water accumulation and frost formation, and makes the system more stable and efficient.

The present application relates to the technical field of high polymer materials, and particularly relates to a preparation method of wear-resistant / low-dielectric PTFE composite material based on interface functionalization. Ammonia / hydrogen mixed gas is used to perform low-temperature plasma treatment on PTFE powder; then the activated PTFE powder is dispersed in an aqueous solution containing ammonium perfluorooctanoate and 4-dimethylamino pyridine; then an organic phase of pyromellitic acid dichloride and an aqueous phase of 4,4'-diamino diphenyl ether are synchronously added dropwise to implement in-situ interface polymerization on the surface of PTFE particles to generate a polyamide acid ammonium salt coating layer; finally, through programmed temperature rising, the coating layer is converted into polyimide, and under the action of hot pressing, a composite material with PTFE as a matrix and a three-dimensional network of polyimide nanofibers penetrating through the inside is formed. The interface bonding force between the reinforcing phase and the PTFE matrix is significantly enhanced, so that the composite material simultaneously has excellent wear resistance, low dielectric constant, high mechanical strength and thermal stability.

The application provides a silane coupling agent modified PTFE and modified fluorine rubber, the silane coupling agent surface modification of PTFE is used for FKM, and FKM / PTFE composite materials are prepared, so that the limitation of fluorine rubber in the aspect of mechanical properties is improved.The application explores the grafting behavior of the silane coupling agent on the surface of PTFE, the modification process has the advantages of environmental protection and low cost, the tensile strength and temperature resistance of the PTFE / FKM composite material can be significantly improved, the production cost is reduced, and the environmental pollution caused by the traditional chemical modification process is reduced.The application explores a new interface modification mechanism of synergistic enhancement of multifunctional groups through ultraviolet irradiation, realizes the grafting of the coupling agent on PTFE, is used for the modification of FKM, improves the performance, and can realize the application of fluorine rubber composite materials in new energy industry, aerospace and other sealing occasions, and has certain application value.

The invention relates to the field of high polymer materials, in particular to a high-dispersity hollow glass bead reinforced PTFE composite material and a preparation method thereof.The high-dispersity hollow glass bead reinforced PTFE composite material is prepared from, by weight, 50-80 parts of PTFE powder, 10-20 parts of PI powder, 10-30 parts of modified hollow glass beads and 5-15 parts of lubricant; the modified hollow glass beads are KH-550 modified hollow glass beads. PTFE and PI are blended to serve as a matrix, the compressive strength of the material can be remarkably improved through addition of PI, then KH-550 modified hollow glass beads are added, the hollow glass beads can be evenly dispersed in the matrix, and the composite material has the light weight effect on the basis of ideal mechanical strength; therefore, the high-dispersity hollow glass bead reinforced PTFE composite material with excellent performance is prepared.

The application discloses a method for electroplating a Ni-P-Fe2O3-PTFE composite lubricating layer on the surface of an aluminum nitride base material, which comprises the following steps: performing composite acid liquid micro-etching and roughening treatment on the base material; preparing a gradient transition layer with gradually changed phosphorus content; performing electroplating in a plating solution containing modified Fe2O3 particles and PTFE by adopting a periodic reverse current and intermittent ultrasonic coupling process; and finally performing two-stage heat treatment. By constructing a unique structure of a PTFE lubricating network and Fe2O3 interface pinning, the application synchronously realizes strong combination (Lc2> 50 N) of the plating layer and the base material, high hardness (HV> 400), low friction (μ< 0.12) and excellent wear resistance, effectively solves the problem of the contradiction between poor combination of the metal lubricating layer on the surface of the aluminum nitride and performance, and the process is stable and controllable and suitable for complex-shaped parts.

This invention discloses a method for manufacturing a PTFE composite rubber diaphragm with a metal insert, comprising the following steps: 1) fabricating a mold for the PTFE composite rubber diaphragm with a metal insert; 2) roughening the contact surface of the mold for contact with the PTFE membrane; 3) applying adhesive backing to the contact surfaces of the PTFE membrane and the rubber matrix, respectively; 4) sequentially placing the metal insert, the rubber matrix, and the PTFE membrane into the mold; 5) using a hot-press vulcanization device to hot-press and vulcanize the metal insert, the rubber matrix, and the PTFE membrane into a single unit to form the diaphragm; 6) removing any excess PTFE membrane material from the diaphragm. By roughening the contact surface of the mold for contact with the PTFE membrane, the surface roughness of the mold increases, the friction between the mold and the PTFE membrane increases, the resistance increases, and the fluidity of the rubber makes it difficult to stretch the PTFE, preventing the PTFE membrane from being stretched thinner and deformed, thus ensuring the service life of the diaphragm.

The application discloses a method for preparing PTFE composite material by using graphite exfoliated graphene nanosheets, which comprises the following steps: S1, adding raw materials into a container, wherein the raw materials comprise graphite and a first oil-water exfoliating solution; S2, sealing the container with the mixed raw materials, and vibrating and shaking the container for 5 minutes at room temperature to obtain exfoliated graphene nanosheets. The method for exfoliating graphene nanosheets is used to prepare graphene PTFE nanocomposite material, and the specific steps comprise the following: A1, adding composite material preparation materials into a container, wherein the composite material preparation materials comprise graphite, PTFE powder and a second oil-water exfoliating solution; A2, sealing the container with the mixed composite material preparation materials, and vibrating and shaking the container for 5 minutes. The graphite is used to realize the exfoliation of graphite to obtain graphene nanosheets by adding the first oil-water exfoliating solution, the whole process is simple in procedure and low in material cost, and the macroscopic 'climbing' process of the graphite in situ unfolding into graphene nanosheets can be clearly observed.

The invention discloses a PTFE composite emulsion, a PTFE prepreg, a copper-clad plate and a preparation method of the PTFE composite emulsion, the PTFE prepreg and the copper-clad plate, the PTFE composite emulsion is a composite emulsion obtained from a PTFE resin matrix and modified fluorine-containing elastomer micro powder, and the modified fluorine-containing elastomer micro powder contains carboxyl or / and hydroxyl active groups. The inherent defects that PTFE is extremely low in heat conductivity coefficient, poor in bonding performance with the copper foil and poor in processing fluidity are overcome, and the limitation that the comprehensive performance cannot be balanced through an existing modification technology is overcome.

The invention discloses a method for electroplating a Ni-P-Fe2O3-PTFE composite lubricating layer on the surface of an aluminum nitride base material. The method comprises the following steps: carrying out composite acid liquor micro-etching-roughening treatment on the base material; preparing a gradient transition layer with gradually changed phosphorus content; electroplating in a plating solution containing the modified Fe2O3 particles and PTFE (Polytetrafluoroethylene) by adopting a periodic commutation current and intermittent ultrasonic coupling process; and finally carrying out two-stage heat treatment. By constructing a unique structure of a PTFE lubricating network and Fe2O3 interface pinning, strong bonding (Lc2 > 50N), high hardness (HV > 400), low friction (mu < 0.12) and excellent wear resistance of a coating and a matrix are synchronously realized, the problem of poor bonding force and performance contradiction of an aluminum nitride surface metal lubricating layer is effectively solved, the process is stable and controllable, and the method is suitable for parts in complex shapes.

This invention relates to a connection device and construction method for the negative bending moment zone of a steel-concrete composite structure. The connection device is installed between the steel beam and the bridge deck. The device includes a rubber-PTFE composite plate disposed in the negative bending moment zone of the steel beam. The rubber-PTFE composite plate comprises two layers of rubber sheets (upper and lower) and two layers of PTFE sheets (between the rubber and PTFE sheets). The lower rubber sheet is connected to the upper surface of the steel beam, and the upper rubber sheet is connected to the bridge deck. Relative sliding and friction are allowed between the two PTFE sheets. After concrete pouring, relative sliding between the two PTFE sheets is permitted. This invention uses relative sliding between the two PTFE sheets instead of relative sliding between the steel beam and the concrete bridge deck, significantly increasing the prestress within the bridge deck, effectively controlling cracking in the negative bending moment zone of the steel-concrete composite structure, and simplifying the construction process for applying prestress.

This invention discloses a composition for preparing flexible composite films and its application, relating to the field of engineering plastic materials technology. The composition comprises the following raw materials by weight: 40-60 parts of lyotropic liquid crystal polymer, 20-40 parts of polytetrafluoroethylene powder, and 10-30 parts of modified Mg3B2O6 ceramic powder; the modified Mg3B2O6 ceramic powder is obtained by grinding Mg3B2O6 ceramic powder in an organic solvent with a surface modifier, followed by drying. The surface modifier is 1-3 wt% of the Mg3B2O6 ceramic powder and is selected from at least one of stearic acid and silane coupling agent KH550. This invention uses a surface modifier to modify the surface of Mg3B2O6 ceramic powder, which acts as a functional bridge between inorganic ceramic particles and LLCP / PTFE composite membrane, improves the interfacial compatibility between Mg3B2O6 ceramic powder and organic matter, promotes the uniform dispersion of Mg3B2O6 ceramic powder in organic matter, reduces the porosity of composite material, and is beneficial to reducing the thermal expansion coefficient and dielectric loss of composite membrane, thus giving the composite membrane better performance.

The invention provides a breathable waterproof composite fabric and a preparation method thereof, and belongs to the technical field of textiles, the preparation method of the fabric comprises the following preparation steps: mixing PTFE emulsion, polyoxyethylene, absolute ethyl alcohol, PNIPAM (at) PSF core-shell capsules and deionized water, defoaming, spinning and sintering to obtain a nanofiber membrane; putting the alkalized PET fiber cloth into the HFBA / HEA steeping liquor, heating, dehydrating and baking to obtain outer-layer base cloth; mixing polyurethane resin, DMF (Dimethyl Formamide), propylene glycol monomethyl ether, a defoaming agent and deionized water to prepare a PU coating solution; laminating the outer-layer base cloth and the nanofiber membrane, and performing hot pressing to obtain a PET / PTFE composite material; one side of the nanofiber membrane of the PET / PTFE composite material is coated with the PU coating liquid, an inner layer membrane is prepared through heating, and the breathable waterproof composite fabric is prepared through cooling and standing. The fabric prepared through the method has good mechanical strength, breathability and waterproof performance.

This invention discloses an integrated molding process for conductive bearings that are non-conductive and self-lubricating, belonging to the field of sliding bearing manufacturing technology. The invention uses a composite strip with a conductive metal mesh as the metal base and PTFE composite material as the lubricating layer as the substrate. Integrated molding is achieved through a six-station progressive die. First, 2-3 protrusions are stamped on the strip. Then, the stamping pressure drives a 30°-45° wedge mechanism to scrape the lubricating layer from the protrusion surface at a fixed depth. The finished product is obtained through slicing, rolling, extrusion shaping, and stamping flanging. A detachable scraper and pore design optimize the processing flow. This invention achieves automated one-step molding of conductive bearings from strip to finished product, significantly improving production efficiency. The manufactured bearings have low contact resistance and a stable coefficient of friction. After electrophoretic coating, the salt spray test duration exceeds 96 hours, and the product consistency and structural stability are significantly better than traditional processes.

The utility model relates to the technical field of alcohol recovery equipment, in particular to an alcohol recovery device which comprises a heating tank and a recovery tank arranged on the left side of the heating tank, a liquid inlet valve port and a controller are fixedly installed on the rear side of the heating tank respectively, a condenser is arranged on the top of the heating tank, a return pipe is arranged on the outer side of the condenser, and a liquid outlet valve port is arranged on the return pipe. A heating mechanism is arranged in the heating tank, a liquid outlet valve port and a nitrogen inlet are fixedly formed in the left end of the recycling tank, a pressure sensor is arranged on the rear side of the recycling tank, a lining layer is arranged in the recycling tank, and a PTFE composite layer, an aluminum foil layer and a polyvinyl alcohol composite layer are arranged in the lining layer. According to the alcohol recovery device, the structural design in the heating mechanism is utilized, and under the combination of the electric heating pipe and the heat conduction layer, generated heat can be uniformly conducted to the inner side of the heating tank, so that the heating time is effectively shortened, and the energy consumption of the device is prevented from being increased.

This invention relates to the field of polytetrafluoroethylene (PTFE) preparation technology, specifically to a nanofiller-modified PTFE composite material and its preparation method. By weight, the composite material comprises 80-120 parts PTFE resin, 1-10 parts nano-layered lubricating filler, 10-20 parts composite fiber filler, 0.5-3 parts coupling agent, and 0.5-2 parts dispersant. The composite fiber filler is a composite reinforcement of micron-sized fibers chemically loaded with nano-hard fillers and nano-rare earth oxides. Through surface activation of the fibers and silane coupling agent bridging, the nano-hard fillers and rare earth oxides are chemically loaded onto the surface of the micron-sized fibers, and then synergistically with the layered lubricating filler, ensuring uniform dispersion of the filler in the PTFE matrix. The transfer film exhibits high coverage, uniformity, and continuity, with a friction coefficient as low as 0.038 and a volumetric wear rate as low as 1.9 × 10⁻⁶. ‑5 mm 3 / N·m.

The invention discloses a preparation method of a high-efficiency bearing self-lubricating material. The preparation method comprises the following steps: S1, preparing a PTFE (Polytetrafluoroethylene) self-lubricating composite material; s2, preparation of a bearing: manufacturing the bearing by taking the PTFE self-lubricating composite material as a raw material, and preparing the bearing to a required size; s3, pretreatment of the liner; and S4, mounting the PTFE / aramid fiber composite woven liner. According to the efficient bearing self-lubricating preparation method, the friction and abrasion performance of the bearing can be effectively improved through the installed gasket, the friction factor and the abrasion loss of the bearing can be reduced along with the increase of swing comments, and the treated PTFE / aramid fiber composite woven gasket has the advantages of being low in cost, high in practicability and the like. The PTFE composite material has the advantages of low friction coefficient, low limit damage and low environmental pollution, and the bearing prepared from the PTFE composite material has the characteristics of low friction coefficient, wear resistance, good impact resistance and high limit PV value, and can work at high temperature.

The invention relates to the technical field of micro-nano manufacturing, in particular to a thermally induced deformation transfer device and method based on a graphene PTFE composite material, the thermally induced deformation transfer device based on the graphene PTFE composite material comprises a base, a first precision displacement table, a heat sink, a TEC module, a sample table, a second precision displacement table and a clamp; the top of the sample table is provided with a circular boss; one two-dimensional material sample is fixed on the circular boss through vacuum adsorption, another two-dimensional material sample needing to be transferred is clamped on the clamp through the heat release adhesive PDMS, the TEC module is controlled to be heated to the target temperature according to the calculated temperature rise rate, the sample table and the circular boss generate displacement in the vertical direction, and the two-dimensional material sample needs to be transferred. The two-dimensional material samples are attached without vibration, and the problem that in the prior art, when the two-dimensional material samples are attached, tiny vibration or impact or pressure concentration is introduced at the contact moment, and consequently the interface quality of the two-dimensional material is reduced is solved.

The application belongs to the technical field of catalytic membrane, and particularly relates to a Co-MoS2@PTFE ozone catalytic membrane, a preparation method thereof and application thereof in removal of pollutants in water. The surface of a PTFE hollow fiber membrane is treated by plasma to obtain a functionalized carrier p-PTFE; then MoS2 nanosheets are grown in situ on the surface of the p-PTFE to form a MoS2@PTFE composite membrane; finally, the Co-MoS2@PTFE ozone catalytic membrane is prepared by hydrothermal reaction in a cobalt source and a reducing agent to realize Co atom doping. A stable interface is constructed on the substrate by plasma treatment, so that the MoS2 nanosheets are firmly grown on the surface and the pores of the PTFE; the Co doping forms a heterojunction catalyst to enhance the catalytic activity. The catalytic membrane can synergize with ozone to efficiently degrade organic pollutants in water, realize efficient synergy of membrane separation and catalytic oxidation, and solve the problem that the active components of the traditional catalytic membrane are prone to fall off.

The application relates to an antistatic enhanced PTFE composite film material and a preparation method thereof, which comprises the following components in mass fractions: 80-100 parts of a PTFE resin, 6-8 parts of glass fiber, 3-5 parts of a metal oxide, and 12-22 parts of inorganic fillers, wherein the inorganic fillers comprise a carbon nanotube composite system and a composite powder, and the composite powder is a core-shell structure powder of tin dioxide coated calcium carbonate. The application has the effects of improving the antistatic property and strength of the PTFE composite film material.

The application discloses a composite coating structure on an aluminum alloy part of a vacuum pump and the vacuum pump, and the composite coating structure comprises an aluminum alloy base body, an anodic oxidation film layer and a NiP-PTFE composite plating layer which are prepared on the aluminum alloy base body from inside to outside in sequence. The composite coating structure can effectively improve the corrosion resistance of the aluminum alloy part.

The utility model relates to a copper sulfate wastewater treatment system, which comprises three stages of reaction kettles, the three stages of reaction kettles comprise at least three stages of gradient reaction kettles, the first gradient reaction kettle is a spiral guide plate, the second gradient reaction kettle is provided with a PH value detection module, and the PH value detection module is used for adjusting the injection rate of a catalyst according to the real-time PH value; the third gradient reaction kettle is provided with a PTFE (Polytetrafluoroethylene) composite membrane with gradient change aperture, and the first gradient reaction kettle, the second gradient reaction kettle and the third gradient reaction kettle are sequentially arranged from top to bottom along the reaction kettle; the double-pressure distillation tower is connected with the third-stage reaction kettle, the double-pressure distillation tower comprises a first pressure area and a second pressure area which are communicated with each other, and the pressure of the first pressure area is greater than that of the second pressure area; the centrifugal unit is connected with the double-pressure distillation tower, a diversion trench is arranged at an outlet of the centrifugal unit, and an electro-adsorption module is arranged in the diversion trench and used for adsorbing residual cationic polyacrylamide.

The invention provides a stainless steel band material with a self-lubricating characteristic, and relates to the technical field of stainless steel band materials. The stainless steel band material with the self-lubricating characteristic sequentially comprises a stainless steel base plate, a sintered bronze layer, a porous reservoir layer and a PTFE composite surface layer from inside to outside, a self-repairing repairing agent is stored in the porous reservoir layer, and the self-repairing repairing agent can slightly seep to the PTFE composite surface layer when the material is extruded or rubbed. Through collaborative design of the porous reservoir and the self-repairing repairing agent, dynamic repairing of the PTFE composite surface layer is achieved, the stable low friction coefficient is still maintained in the abrasion state, performance mutation is avoided, the integrated sintering and hot-pressing composite technology is adopted between layers, combination is firm, the structure is stable, and heavy loads, high-frequency vibration and impact loads can be tolerated. 316L stainless steel and other corrosion-resistant materials are selected, corrosion working conditions are adapted, addition of lubricants is reduced through a self-repairing mechanism, and the requirement for environmental protection is met.

The invention relates to the technical field of railway inspection, and provides a multifunctional grabbing mechanical arm for rail inspection equipment and a using method of the multifunctional grabbing mechanical arm for the rail inspection equipment. A self-adaptive flexible clamping jaw and a vacuum suction cup are installed on the device through two independent swing connecting rod mechanisms respectively, operation tools can be automatically switched according to the types of foreign matter, the self-adaptive flexible clamping jaw adopts a flexible finger claw with a silica gel and PTFE composite coating, a plurality of pressure sensors are embedded in the self-adaptive flexible clamping jaw, and the pressure sensors are connected with the vacuum suction cup. And the air cylinder drives the connecting rod assembly to achieve synchronous opening and closing of the finger claws and closed-loop self-adaptive adjustment of the grabbing force, foreign matter or rails are prevented from being damaged, the mechanical arm body is of a five-degree-of-freedom structure, and a visual camera is further arranged at the tail end of the mechanical arm body. According to the rail foreign matter removing device, automatic identification, accurate grabbing and safe removal of various foreign matters on the rail are achieved, and the automation degree, the operation efficiency and the safety of routing inspection and cleaning are improved.

The innermost layer of the filter screen is a conductive filter screen layer, the middle layer of the filter screen is a PTFE composite film layer, the outermost layer of the filter screen is a nano-cellulose layer, the PTFE composite film layer and the nano-cellulose layer form a moisture absorption filter screen, the nano-cellulose layer is a hydrophilic layer, a hydrophobic layer is formed on the surface of the PTFE composite film layer, and the conductive filter screen layer and the nano-cellulose layer form a moisture absorption filter screen. The nano cellulose layer and the PTFE composite film layer form a gradient pore structure, the conductive filter screen layer can be used for generating negative oxygen ions, and water outside the filter screen can be synthesized into hydrated negative oxygen ions with the negative oxygen ions after sequentially penetrating through the nano cellulose layer and the PTFE composite film layer. According to the filter screen, a gradient interface pore structure is formed through nanocellulose and a PTFE hydrophobic membrane, efficient transmission and water quantity control of water molecules on the moisture absorption filter screen are achieved, high-concentration hydrated negative oxygen ions are generated, and the hydrated negative oxygen ion generating device combines the water molecules with free oxygen atoms in advance through fiber surface micro-area charge distribution optimization, so that the water molecules are separated from the free oxygen atoms, and the high-concentration hydrated negative oxygen ions are generated. And the ozone-free hydrated negative oxygen ions are realized.

The invention discloses a PPS / PTFE composite filter material based on hot-pressing reinforcement and a preparation method thereof, and belongs to the technical field of industrial flue gas purification. The material is prepared by taking a PPS needled felt as a base material, coating the surface of the PPS needled felt with a PTFE (Polytetrafluoroethylene) foam coating containing nano silicon dioxide and carrying out hot-pressing treatment at 200 DEG C. According to the method, by optimizing the hot pressing process, the bonding strength of the PTFE coating and the PPS base material is remarkably enhanced, and the pore structure of the material is effectively improved. The filtering efficiency of the obtained filter material on particles with the particle size larger than or equal to 1.0 micrometer reaches 92.6% or above, the abrasion resistance is greatly improved, the abrasion loss of a coating is only 0.0325-0.0337 g after 300 times of abrasion, the filtering resistance is kept between 136 Pa and 160 Pa, and meanwhile the filter material has good temperature resistance and corrosion resistance and is suitable for efficient purification of high-temperature and high-corrosion industrial flue gas.

The invention relates to the technical field of semiconductor packaging, discloses a sintering method of a power chip, and aims to solve the problem of oxidation of a DBC / AMB substrate copper layer caused by residual oxygen during sintering of an existing single-layer thick PTFE film. The method comprises the following steps: carrying out hot pressing on the edge of a single-layer PTFE film to form an occlusion structure comprising an upper convex structure, a lower convex structure and a corresponding groove, so as to prepare a single-layer concave-convex PTFE film; after drying and deoxidizing by a vacuum or nitrogen oven, overlapping at least two membranes through an occlusion structure to form a PTFE composite membrane; after the chip is mounted on the substrate, the composite film is covered for pressure sintering. The thickness of the single-layer concave-convex PTFE film ranges from 0.1 mm to 1 mm, the convex structures are cubes or cylinders, and exhaust gaps are formed between the composite film layers. Through structural design and process optimization, oxygen residues in the films are reduced, slippage between the films is avoided, the yield and reliability of sintered products are remarkably improved, and the method is suitable for different sintering scenes.