68results about How to "Guaranteed dimensional stability" patented technology

The invention provides a robot joint dynamic cable made of a self-repairing polyurethane material and a preparation method of the robot joint dynamic cable, and belongs to the field of cables. Polytetrahydrofuran glycol and hexamethylene diisocyanate react to form a soft and hard segment structure, 1, 4-butanediol is added for chain extension, dopamine hydrochloride is introduced, the hard segment structure is enhanced, and a self-repairing hydrogen bond network is formed; carbon nanotubes are introduced, and through plasma treatment and silane coupling agent modification, the tensile resistance, fatigue resistance and electrical properties of the material are improved; montmorillonite is compounded with polyethyleneimine through organic treatment, so that the cracking resistance and wear resistance of the material are enhanced; epoxy groups are introduced to the surface of boron nitride, and dopamine hydrochloride is self-polymerized, so that excellent heat dissipation capability and dimensional stability are provided. Through the synergistic effect of the components, the composite material has excellent mechanical properties, electrical properties, heat dissipation, wear resistance and the like, is especially suitable for a dynamic cable of a robot, and can stably work in a complex environment for a long time.

The invention relates to the technical field of remanufacturing, in particular to a 1Cr17Ni3 gear pump casting shell end face superficial crack damage repairing method which comprises the steps that cleaning is conducted, and defect positions are determined; marking the defect position, then extending in a polyline form to form two rings, and connecting the two rings by using a line segment; polishing to form an outer ring groove, an inner ring groove and a line segment groove for connecting the inner ring and the outer ring; demagnetization is carried out; carrying out laser cladding repair; liquid nitrogen treatment; carrying out cladding repair and liquid nitrogen treatment on the test block to verify the hardness performance; the end face subjected to cladding repair is polished; and cleaning and carrying out penetrant flaw detection, and if no defect exists, successfully repairing. Local repair of a small area of the end face is avoided, local deformation is avoided, and the sealing performance is enhanced; the restoration quality deterioration caused by heat accumulation is avoided; the equal-hardness cladding repair is realized; the problem that after the shell has magnetism, the repairing quality is reduced due to the fact that powder adheres to the end face continuously in the cladding process is solved.

The invention provides an engineered wood veneer carbon-based light energy-saving material and a cabinet door plate product thereof. The engineered wood veneer carbon-based light energy-saving material comprises a carbon-based core material and an engineered wood veneer, the carbon-based core material comprises 25-60 parts of bamboo charcoal powder, 5-15 parts of bamboo activated carbon powder, 10-20 parts of bamboo powder, 40-70 parts of thermoplastic polymer master batch and 1-10 parts of processing auxiliary materials; the technical wood veneer comprises a technical wood veneer and a water-based environment-friendly heterogeneous adhesive. The material is prepared by preparation of a carbon-based core material and processing and compounding of a technical wood veneer, wherein the preparation of the carbon-based core material comprises the steps of batching and weighing, high-speed stirring, melting and granulating, re-mixing and molding and post-processing; technical wood veneer processing and compounding cover veneer preparation, adhesive blending, uniform gluing, assembly pre-pressing and three-section type cold pressing curing. According to the technical wood veneer carbon-based light energy-saving material and the cabinet door plate product thereof, through material formula design and preparation process planning, light weight, high strength, heat insulation, low formaldehyde release and diversified decoration are integrated, and the low-cost environment-friendly target of resource recycling is achieved.

The invention relates to the field of space remote sensing, in particular to a space camera body size stability testing device and method.The testing device comprises the space camera body size stability testing device, a body comprises a force bearing cylinder, a front frame and a rear frame, and the front frame and the rear frame are fixed to the two ends of the force bearing cylinder; the testing device comprises a laser, a front light path, six measuring arms, a testing board card and a data acquisition system, wherein the six measuring arms are divided into two groups and are respectively and uniformly distributed on a front frame and a rear frame along the circumferential direction; laser emitted by the laser enters the six measuring arms through the front light path, the laser is connected with the test board card through optical fibers, the six measuring arms are connected with the test board card through optical fibers, and the test board card is connected with the data acquisition system through a data line. The device has the advantages of high precision, small size, light weight, convenience in integration, real-time measurement and the like, an optical machine engineer can properly correct the current control measure according to a test result, and the size stability of the machine body is ensured to meet the optical tolerance requirement.

This utility model discloses a self-locking intermediate tensioning device for installing bridge housing parts, relating to the technical field of workpiece processing auxiliary devices. It includes a worktable, fixed seats, a fixed frame, fixed plates, a tensioning mechanism, and a fixing mechanism. Two symmetrically distributed fixed seats are fixedly connected to the upper surface of the worktable, and a fixed frame is fixedly connected between the two fixed seats. Two symmetrically distributed fixed plates are fixedly connected to the inner end face of the fixed frame. The fixed plates are fixedly connected to the upper surface of the worktable, and a tensioning mechanism is provided between the two fixed plates. The tensioning mechanism includes a hydraulic cylinder, a wedge-shaped tensioning plate, a moving block, and a central tensioning plate. This utility model features a tensioning mechanism where the hydraulic cylinder drives the wedge-shaped tensioning plate. Through the guidance of the T-shaped groove and the T-shaped plate, the vertical movement is converted into the horizontal expansion of the moving block and the central tensioning plate, thereby applying an adjustable tensioning force to the inner hole of the workpiece. This effectively ensures the dimensional stability and accuracy of the workpiece during subsequent processing such as press-fitting.

The present application relates to the technical field of high molecular antifogging coating, and particularly relates to a supermolecular coated shed film antifogging coating solution, a preparation method and application thereof, wherein acrylic acid, acrylamidoalkyl sulfonic acid, hydroxyalkyl acrylate and double-ene crosslinking monomer are used for tetra-copolymerization to construct a supermolecular matrix with carboxyl, sulfonic acid group, hydroxyl side group and crosslinking network, and a spandex antifogging agent is introduced in situ in the matrix, hydrogen bond and hydrophobic association synergistic effect between the side group functional groups and the spandex molecules are used to realize supermolecular coating, and then pH adjustment and functional additive compounding are performed to obtain the coating solution. The present application solves the problems of easy migration and precipitation of the traditional antifogging agent, coating brittleness, short effective period, and the obtained coating has comprehensive performances of long-acting antifogging, high light transmission, strong adhesion, flexible and bending-resistant, water-resistant and aging-resistant, and room temperature rapid curing, and is suitable for antifogging treatment of various agricultural shed films and greenhouse transparent materials.

The utility model is suitable for the technical field of engine oil pans, and particularly relates to an engine plastic oil pan which comprises a plastic oil pan, an oil pan installation end face is arranged at the opening position of the plastic oil pan, and a plurality of first installation through holes are formed in the surface of the oil pan installation end face. And a metal lining is arranged in the first mounting through hole. According to the plastic oil pan, the internal reinforcing ribs and the hollow cylinder located in the central area in the plastic oil pan are arranged, so that the product defect that the plastic oil pan shrinks inwards due to the fact that the wall thickness is too large after injection molding is avoided, and in the using process of the plastic oil pan, the durability and creep deformation reliability of the plastic oil pan are greatly improved, and the service life of the plastic oil pan is prolonged. And therefore, the dimensional stability of the oil pan can be ensured for a long time.

The present application relates to the technical field of metal laser cladding, and specifically discloses a high-performance pick and a method for preparing the pick by laser cladding. The high-performance pick comprises a pick body and a cladding layer clad on the surface of the pick body. The pick body is prepared by feeding preparation, molding degreasing, sintering treatment, and post-treatment. The cladding layer is prepared by a synchronous powder feeding method. The cladding layer has high hardness and wear resistance, and the coating has excellent mechanical properties. The prepared laser cladding layer has high bonding strength with the pick, small internal stress, low porosity of the cladding layer, no obvious cracks, pores and other defects, significantly improved hardness, toughness and wear resistance, and significantly improved service life of the pick.

The invention relates to a method for improving the comprehensive performance of a main shaft gear, which adopts the treatment process of cleaning, preheating, carburizing, high-temperature tempering, quenching preheating, quenching, subzero treatment, low-temperature tempering and gear grinding, so that not only can the depth of a carburized layer be accurately controlled, but also the use performance of a carburized part can be ensured. Wherein the preheating treatment before carburizing can refine grains, obtain a uniform metallographic structure and reduce thermal distortion of parts, the effect of controlling the size stability of the gear is achieved, then the toughness of a carburized layer is improved, and the service life of the gear is prolonged. And then high-temperature tempering after carburization can promote further uniform diffusion of carbon elements on the surface layer, the structure is balanced, and the internal stress of gear parts is reduced. And the preheating treatment before quenching can prevent the part from cracking in the subsequent quenching process. And a proper subzero treatment temperature gradient is selected according to material components, so that the content of retained austenite in a carburized layer is controlled, and the mechanical property and the comprehensive property of the material are improved.

The utility model discloses a kind of press quenching tool for synchronous device sliding sleeve with positioning boss, belong to the technical field of synchronous device sliding tooth cover, press quenching tool includes press quenching core shaft and feeding mechanism;The end of press quenching core shaft is provided with guide cone surface, the side surface of press quenching core shaft is formed with core shaft working surface, and the core shaft working surface is provided with several positioning boss grooves, and the other end of press quenching core shaft is provided with quenching oil circuit;Feeding mechanism includes feeding cylinder, and the lateral wall of feeding cylinder is provided with several positioning grooves, and the bottom of feeding cylinder is connected with mounting column;Feeding mechanism is installed in the feeding carousel of press quenching equipment by mounting column, and press quenching core shaft is installed in the press quenching station of press quenching equipment;Positioning groove is correspondingly arranged with positioning boss groove, so that the positioning boss of synchronous device sliding sleeve with positioning boss is transferred from feeding mechanism to press quenching core shaft, and correspondingly falls into positioning boss groove.The utility model can guarantee the effect of controlling thermal distortion of part in quenching process, realize automatic press quenching, and guarantee production efficiency.

The present application provides an electrical connector and a method for making the same, an electrical connection assembly, and an electronic device, and relates to the technical field of electronic products. The electrical connector uses a polymer elastomer as the main supporting structure, and disperses conductive fillers in a local area of ​​the polymer elastomer. The conductive fillers are directionally arranged along the height direction of the polymer elastomer and completely occupy the height space of the polymer elastomer. In this way, a conductive channel extending to the surfaces on both sides along the height direction can be formed in the polymer elastomer. Thus, the polymer elastomer electrically connects the structural parts located on both sides thereof through the conductive channel. In this way, the polymer elastomer isolates the salt solution outside the conductive elastic connection area of ​​the electrical connection assembly, prevents the formation of electronic and ion pathways in the electrical connection assembly, improves or even avoids galvanic corrosion, improves the connection reliability of the electrical connection assembly, ensures the structural strength and dimensional stability of the structural parts, and improves the reliability of the electronic device.

The utility model discloses a filling-free artificial turf which comprises a base cloth layer, an adhesive layer and a grass yarn layer, the adhesive layer is located at the bottom of the base cloth layer, the grass yarn layer is tufted at the top of the base cloth layer, and the grass yarn layer comprises two kinds of bent artificial turf fibers and at least one kind of straight artificial turf fibers. According to the filling-free artificial turf provided by the utility model, various bent artificial turf fibers are mutually wound to support the straight artificial turf together, so that the straight artificial turf fibers are prevented from lodging in use, and the straight artificial turf fibers and the bent artificial turf fibers can be matched to adjust the resistance required by rolling of balls, so that the filling-free artificial turf has the advantages that the service life of the straight artificial turf fibers is prolonged, and the service life of the straight artificial turf fibers is prolonged. It is guaranteed that the athletes do not consume redundant energy when doing exercises on the field, and the athletes are prevented from feeling tired.

The application belongs to the technical field of stainless steel preparation, and discloses a cold-deformable and heat-treatable hardening Ni-free high-strength stainless steel and a preparation method thereof. The stainless steel comprises the following components in percentage by mass: Cr: 13-15%, C: 0.25-0.4%, Mn: 0.5-2%, Cu: 0.1-3%, Mo: 2-3%, Si: 0-0.5%, and the balance of Fe and inevitable impurities. The stainless steel does not contain Ni element, has a low work hardening rate (strain hardening index n≤0.185) and a fracture elongation rate of more than 20% in a soft state (annealed state), is cold-deformable, and has low raw material and processing costs; after quenching and aging heat treatment, the stainless steel not only has an optimal combination of strength and toughness (yield strength and tensile strength are more than 1300 MPa and 1600 MPa respectively, and elongation is greater than 10%), but also has a high yield strength ratio.

The invention discloses an electroplating-grade polypropylene composite material and a preparation method thereof. The composite material is prepared from the following raw materials in percentage by weight: 30-70% of co-polypropylene; 20-40% of a coarsening agent; 0-30% of a filler; 0-30% of an elastomer toughening agent; 0-3% of a compatilizer; 0.1-2% of a stabilizer; and 0-5% of other additives. Through the synergistic effect of the coarsening agent and the filler, the rigidity and toughness of the composite material are guaranteed, meanwhile, the composite material has an excellent electroplating effect, application of a finished product is guaranteed, and compared with electroplating-grade PC / ABS and ABS materials, the composite material is lower in price and cost and has a good application prospect.

This invention provides a multilayer film, a metal-clad laminate, and a circuit board. The multilayer film has outer layers comprising multiple polyimide layers on both sides of an inner layer including an adhesive layer, ensuring dimensional stability while further improving dielectric properties. The multilayer film includes multiple polyimide layers and an adhesive layer, wherein the multilayer film satisfies: a) the total thickness of the thermoplastic polyimide layer and the non-thermoplastic polyimide layer stacked on one side of the adhesive layer is in the range of 2 μm or more and 20 μm or less; b) 65 < P P / P AD <1,550, by P P =P P1 +P P2 P P1 =(E' P100 +E' P200 )×thickness of polyimide layer [μm], P P2 =(E' P100 +E' P200 )×thickness of polyimide layer [μm], P AD =(E' AD100 +E' AD200 E' represents the thickness of the adhesive layer [μm]. P100 、E' P200 E' is the storage elastic modulus [GPa] of the polyimide layer at 100℃ and 200℃. AD100 、E' AD200 c) The storage elastic coefficient [GPa] of the adhesive layer at 100℃ and 200℃; c) As a whole multilayer film, the dielectric loss tangent at 20 GHz measured using an SPDR resonator is less than 0.0029.

The present invention relates to the field of material science and metal processing technology, and discloses a high-strength and toughening heat treatment process for thick-walled forgings for pressure vessels, comprising the following steps: S1, selecting a low-alloy steel material containing a specific proportion of vanadium, molybdenum, manganese, silicon and nickel; S2, gradually preheating the forging in a furnace to 450°C to 500°C, and continuously heating for 2 hours; S3, heating the forging to 870°C to 920°C, and adjusting the holding time according to the thickness of the forging to ensure that the heat is fully penetrated; S4, carburizing treatment is performed at 680°C to 720°C for 8 to 12 hours; S5, using oil for rapid cooling, and then air cooling to room temperature. The present invention significantly improves the hardness and toughness of the forging, while enhancing its corrosion resistance and fatigue life, and optimizing the microstructure of the material, so that the forging is suitable for the field of pressure vessel manufacturing with high requirements.

This invention relates to the field of industrial control technology, and more specifically, to a method for precise pressure adjustment in the injection molding holding process based on iterative learning control. The method includes: acquiring a reference holding pressure curve, an actual feedback pressure sequence, and injection molding holding control commands for the current holding stage; calculating thermal hysteresis characteristics characterizing changes in physical state; calculating a thermal drift evolution index characterizing the thermal drift rate; generating a nonlinear adaptive gain adjustment factor constrained within a safe range; and calculating and updating the injection molding holding control commands for the next holding stage. This invention more accurately reflects the comprehensive impact of changes in physical state, scientifically assesses the thermal drift rate and the difference between current and historical data, dynamically adapts to thermal drift to ensure control stability under different thermal conditions, effectively solves the problems of holding pressure overshoot, oscillation, and slow response, improves the dimensional consistency of injection molded products and the control accuracy of the holding process, and ensures production quality and efficiency.

The utility model discloses an annealing device which is characterized in that an annealing furnace is arranged on a frame, a plurality of passing rollers, a tension roller and a floating assembly are arranged on the incoming material side of the annealing furnace, a flattening roller and a traction assembly are arranged on the discharging side of the annealing furnace, and a heating module is arranged in the annealing furnace; a plurality of horizontal first heating assemblies and a plurality of horizontal second heating assemblies are arranged on a cover body of the heating module, a lifting structure is connected to the cover body, and the height of the heating module can be adjusted through the lifting structure. The heating module with the adjustable height is arranged in the annealing furnace, so that the thin film is heated more uniformly, local overheating or supercooling is avoided, the uniformity of annealing stability is ensured, the annealing effect is improved, the internal stress of the thin film is eliminated more thoroughly, and the dimensional stability of the thin film is ensured.

The invention relates to the technical field of packaging materials, in particular to a bio-based polyamide film for aluminum-plastic film packaging and a preparation method of the bio-based polyamide film. The film comprises a coating layer and a bio-based polyamide base material layer, the coating layer is formed by coating the surface of the bio-based polyamide base material layer with acrylic acid coating liquid, and the acrylic acid coating liquid comprises organic silicon modified acrylic resin, polyurethane microspheres, an aziridine cross-linking agent and water; the bio-based polyamide base material layer is composed of three layers of biaxially oriented bio-based polyamide films, and bio-based PA56 and bio-based PA5X in each layer are formed according to a certain proportion. The bio-based PA56 and the bio-based PA5X are cooperatively used and are matched with the acrylic acid coating liquid, so that the stretching ratio of the thin film is reduced, the strength, the toughness and the wear resistance of the thin film are ensured, the electrolyte resistance is improved, and the high pit flushing property of a flat film method is realized.

The invention relates to the technical field of resin processing and preparation, and discloses bromine-containing epoxy resin for an insulating plate, a preparation method of the bromine-containing epoxy resin and a preparation method of the insulating plate. The molar ratio of the epoxy chloropropane to the tetrabromobisphenol A is controlled to be 1: (0.46-0.54), and the mass of the organic solvent is controlled to be 21%-30% of the mass of the tetrabromobisphenol A. Compared with the traditional molar ratio control range of the epoxy chloropropane and the tetrabromobisphenol A and the mass control percentage range of the traditional organic solvent, the method is more accurate; in the step S103, the mass fraction of alkali in the alkali liquor material is controlled to be 35-45%, the temperature of the cyclization reaction is controlled to be 95-110 DEG C, the time of the cyclization reaction is controlled to be 1.1-1.4 h, the latitude of each reaction is greatly restrained, the relative molecular mass of the bromine-containing epoxy resin is greatly guaranteed, the density of the bromine-containing epoxy resin is guaranteed, and the effect of improving the performance is achieved; the gummosis risk of the bromine-containing epoxy resin is reduced to a great extent, and the dimensional stability and the mechanical property of a finished product of a subsequent insulating plate are guaranteed.

This invention relates to the field of semiconductor display device manufacturing technology, and discloses a reusable MicroLED chip transfer temporary carrier and its preparation method. The carrier includes a rigid support substrate layer, a peelable intermediate layer, and an elastic functional layer stacked sequentially from bottom to top. The peelable intermediate layer is a double-layer film material, including a bottom acrylic adhesive layer and an upper PVC substrate layer. The elastic functional layer is a polydimethylsiloxane layer cured on the surface of the PVC substrate layer. The preparation method includes plasma cleaning of the substrate, attaching the double-layer film material and rolling and cutting, vacuum degassing and homogenizing the adhesive, and thermal curing. By blocking the penetration of liquid adhesive through the PVC substrate layer, the aged elastic functional layer can be peeled off along with the intermediate layer, avoiding residual adhesive on the substrate. This enables the non-destructive recycling and reuse of the rigid substrate, effectively reducing chip transfer costs.

The application relates to the technical field of polypropylene, in particular to a high-strength creep-resistant high-water-pressure PPH pipe and a preparation method thereof. The pipe is prepared by extruding and two-stage cooling and shaping a polypropylene homopolymer material containing specific particle size N,N'-dicyclohexyl terephthalamide, low-viscosity and high-softening-point maleic anhydride grafted polypropylene wax added in steps and high-crystallization non-polar polypropylene wax added in a side-feeding mode. The method solves the problems of uneven dispersion of nucleating agents, weak interface combination and rough processing control in the prior art through nucleating agent particle size control, hierarchical interface construction, processing process cooperation and gradient cooling process, and significantly improves the long-term internal pressure resistance, creep resistance and slow crack growth resistance of the pipe.

The invention discloses a high-stability environment-friendly plywood base material cabinet door plate and a preparation method thereof, the preparation method comprises the processes of single plate carbonization, MDI glue bonding, single plate finishing, staggered joint assembly, plate blank continuous hot pressing and the like, a continuous plate is formed, and the continuous plate can be accurately cut according to the required size. The overall performance of the product is improved, the loss of the carbonized veneer is remarkably reduced, the production process flow is simplified, and the problems that an existing cabinet door plate is poor in stability and prone to deformation are effectively solved.

The application discloses a PLA copolymer polycarbonate biaxial stretching film and a preparation method thereof, and belongs to the technical field of high polymer materials. The film is prepared from 100 parts of PLA copolymer polycarbonate, 0.3-0.6 parts of a chain extender, 0.5-1.0 parts of an anti-hydrolysis agent, 0.1-0.2 parts of a lubricant, 0.1-0.3 parts of a primary antioxidant and 0.2-0.4 parts of a secondary antioxidant through melt extrusion, biaxial stretching and heat setting. The film has high heat resistance, high light transmittance, low haze and excellent processing stability through unique molecular structure design, synergistic system of additives and fine biaxial stretching process, the tensile strength retention rate of the film at 80 DEG C is greater than or equal to 80%, and the film can be used in the fields of optics, high-barrier packaging and industry.

The invention relates to the technical field of bridge structure safety device manufacturing, in particular to a hot bending forming process of a fixing plate for a beam falling prevention device, which comprises the following steps: blanking of the fixing plate for the beam falling prevention device: selecting Q355 hot rolled steel, cutting the Q355 hot rolled steel to a preset size by using a laser cutting machine, blanking, and reserving 3-5mm machining allowance on two sides; according to the hot bending forming process, laser cutting blanking and milling machine finish machining are combined, material waste is reduced while the precision is guaranteed, the high-frequency rapid heating and hot forging forming process is adopted, the machining efficiency and material plasticity are remarkably improved, meanwhile, oxidation burning loss is reduced, and the product quality is improved. Meanwhile, a special tool cavity, a water cooling system and a profiling detection and shape correction technology are matched, the forming precision and the size stability are ensured, in addition, the technology is achieved based on conventional equipment, the comprehensive advantages of procedure simplification, cost reduction, efficiency improvement, performance optimization, forming precision and the like are achieved, and the method is suitable for batch production and has good industrial popularization value.

This invention relates to the field of automotive interior parts manufacturing technology, and discloses a method for preparing INS trim panels based on a real wood molding process, comprising the following steps: Step S1: punching and forming an INS film to obtain a pre-formed film blank; Step S2: placing the film blank in a hot pressing fixture for real wood hot pressing molding for hot pressing to obtain a pre-formed film shell; Step S3: placing the pre-formed film shell in an injection mold for real wood injection molding, injecting plastic into the mold for injection molding, so that the plastic and the film shell are integrated to obtain an injection-molded semi-finished product; Step S4: placing the injection-molded semi-finished product in a milling fixture for CNC machining of real wood trim panels for CNC machining to obtain the finished INS trim panel. This invention prepares INS trim panels by using the hot pressing fixture, injection mold, and milling fixture of the real wood trim panel production line, without the need to develop new special molds, effectively saving economic, labor, and time costs, and realizing the efficient utilization of existing assets.

The invention discloses a processing method for controlling carburizing and quenching deformation of a thin-wall sleeve gear, which is characterized in that the thin-wall sleeve gear is slowly cooled along with a furnace in a vacuum environment after carburizing, deformation caused by thermal stress is favorably reduced, and then a solid carburizer is adopted for boxing protection, so that no oxidation and no decarburization of parts can be ensured; the part which is expanded after being heated is quickly sleeved into the cold-state quenching mold to restrain the free shrinkage of the part, so that the quenching deformation can be effectively controlled, and the dimensional stability of the part after being quenched is ensured; after the part is cooled to the room temperature, cooling continues, heat preservation is conducted for preset time, then air cooling is conducted, residual austenite can be reduced, and the hardness and abrasion resistance of the carburized surface are improved; and finally, the thin-wall sleeve gear is subjected to air cooling after low-temperature heating and heat preservation for preset time, quenching internal stress can be reduced, and brittleness is reduced. According to the method, carburizing and quenching deformation of the thin-wall sleeve tooth is remarkably reduced, the stability of the machining size of the part is improved, the wall thickness of the part does not need to be thickened, machining deformation is reduced, and the machining quality of the part is improved.

The present invention provides a resin film, a metal-clad laminate and a circuit substrate that can reduce transmission loss even in the transmission of high-frequency signals and have excellent dimensional stability. The resin film (A) includes: a liquid crystal polymer layer (L); a first adhesive layer (B1) laminated on one side of the liquid crystal polymer layer (L); and a second adhesive layer (B2) laminated on the side of the liquid crystal polymer layer (L) opposite to the first adhesive layer (B1). The storage elastic modulus of the first adhesive layer (B1) and the second adhesive layer (B2) at 50°C are independently 1800MPa or less, and the maximum value of the storage elastic modulus at 180°C to 260°C is 800MPa or less. The dielectric loss tangent of the entire resin film at 10GHz is preferably 0.005 or less.

The application relates to the field of boiler equipment construction, and discloses a multi-stage reference control anti-twisting hoisting method for a supercritical boiler spiral water-cooled wall, which comprises the following steps: demarcating a first-stage reference according to the column position of a boiler steel frame, and demarcating three-stage references on a spiral water-cooled wall module; hoisting a rigid beam into position, aligning the rigid beam according to the first-stage reference, and demarcating a second-stage reference on the surface of the rigid beam; hoisting the spiral water-cooled wall module into a field and suspending the spiral water-cooled wall module on the side of the rigid beam; applying a transverse traction force to the spiral water-cooled wall module through an operating chain fall, so that the spiral water-cooled wall module approaches the rigid beam until the three-stage reference and the second-stage reference meet preset alignment requirements; implementing temporary welding to fix the spiral water-cooled wall module and the rigid beam, and repeatedly executing the assembling steps in the height direction layer by layer. The application utilizes deformation absorption to cut off the physical path of the error transmission to high altitude, prevents the module from being twisted, and improves the assembling precision of the heating surface.

The invention discloses an EPDM buffer block material with excellent low-pressure-to-low-temperature performance and a preparation method thereof, which belongs to the technical field of EPDM buffer block materials. The material comprises the following raw materials in parts by weight: 40-60 parts of EPDM rubber, 40-60 parts of EBT rubber, 5-10 parts of zinc oxide, 2-6 parts of antioxidant, and 935P internal release agent. 1‑3 parts, 10‑20 parts of plasticizer, 50‑60 parts of filler, 3‑5 parts of cross-linking agent, and 11‑13 parts of dicumyl peroxide; the filler is composed of modified zirconium tungstate and SP5000 carbon black in a mass ratio of 1‑2:3‑4, the plasticizer is composed of polyethylene glycol 4000, paraffin oil KP6030 and dioctyl phthalate in a mass ratio of 1‑2:1:1, EPDM rubber and EBT rubber are mixed, and modified zirconium tungstate and compound plasticizer are introduced, so that the low temperature resistance of the finally obtained rubber product is reduced to below ‑50°C, and the rubber product has good mechanical properties and compression deformation properties.