34results about How to "Guaranteed dimensional stability" patented technology

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 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 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.

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.

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 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 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 a thermal insulation material for ultralow-energy-consumption system doors and windows and a preparation method of the thermal insulation material, and relates to the technical field of high polymer materials. The heat insulation material for the door and window of the ultra-low energy consumption system at least comprises the following raw materials in parts by mass: 55-65 parts of PA66 resin; 8 to 15 parts of thermoplastic polyurethane and 5 to 10 parts of polyamide-imide; 18 to 25 parts of activated chopped glass fiber; 3-6 parts of modified nano silicon dioxide coated aerogel microbead heat insulation filler; 2 to 5 parts of a diethyl aluminum phosphinate flame retardant coated with melamine cyanurate; 1-3 parts of a microcapsule expanded graphite flame retardant; 0.3 to 0.8 part of an antioxidant; 0.2 to 0.5 part of a light stabilizer; and 0.5-1 part of a lubricant. The thermal insulation material prepared by the invention has the advantages of ultralow thermal conductivity, efficient flame retardance, low smoke, no toxicity, high dimensional stability and excellent mechanical properties.

The invention relates to the technical field of ferrous metallurgical equipment maintenance and welding repair, and discloses a steel billet hydraulic shear cobalt-based alloy blade repair method which comprises the steps that S1, pretreatment is conducted, low-pressure sand blasting cleaning is conducted, a failure layer is removed, and a carburized layer of 0.05-0.2 mm on the groove wall is polished and removed; s2, a Co-Cr-W-C cobalt-based welding wire with a certain proportion is selected and used; s3, surfacing welding is conducted, specifically, a cutting edge is preheated to 280-320 DEG C, the temperature of a tool apron is strictly controlled to be not higher than 180 DEG C, multi-layer and multi-pass surfacing welding is conducted through a TIG welding machine, and stress relief annealing is conducted at the temperature of 560-600 DEG C after surfacing welding; and S4, machining and grinding to recover the geometric dimension. According to the method, through carburized layer removal, gradient temperature control and a special heat treatment system, the problems that cracks and air holes are prone to being generated in cobalt-based alloy welding and a tool apron base body is softened and deformed due to overheating are effectively solved, the metallurgical bonding strength, high-temperature abrasion resistance and thermal fatigue resistance life of a repaired blade are improved, and the service cycle of equipment is prolonged to a large extent.

The application belongs to the technical field of semiconductor manufacturing, and discloses a preparation method of a high-fidelity photoresist pattern. The method comprises the steps of spin coating, pre-baking, exposure, post-exposure baking and development. The development step comprises: applying a developing solution to the surface of a substrate at a first rotation speed to preliminarily develop the photoresist; adjusting the substrate to a second rotation speed, which is lower than the first rotation speed, to partially remove the developing solution; applying the developing solution to the surface of the substrate while the substrate is in a stationary state, and performing main development while the substrate is kept in the stationary state; and again applying the developing solution to the surface of the substrate while the substrate is in a stationary state, and performing supplementary development while the substrate is kept in the stationary state. The application solves the problems of pattern distortion and shrinkage in the traditional process by using a segmented development process, improves the fidelity and process stability of the photoresist pattern, and has good industrial application value without the need to increase special materials or complex equipment.

The utility model relates to the field of automobile part machining, in particular to an automobile part rolling machining device. Comprising a base and a workpiece, the base is detachably connected with a plurality of mounting plates, the mounting plates are rotationally connected with a first roller set, a second roller set and a third roller set, the first roller set, the second roller set and the third roller set are matched with the workpiece, and the first roller set is used for pre-bending the two sides of the workpiece; the second roller set and the third roller set are used for further bending the workpiece, the mounting plate is rotationally connected with a first forming roller and a second forming roller, the first forming roller and the second forming roller are used for pre-bending the middle of the workpiece, the mounting plate is rotationally connected with a side pressing roller set, and the side pressing roller set is used for extruding the two sides of the workpiece. By the adoption of the bending device, a workpiece can be accurately bent step by step, and the size precision and the shape precision of a product are improved.

The utility model discloses a pouring gate structure of an injection mold, which comprises a pouring head, a double-thread middle-section feeding head and a filter sleeve, the double-thread middle-section feeding head is assembled and mounted at the top end of the pouring head in a threaded manner, the filter sleeve is detachably mounted in the double-thread middle-section feeding head, and an internal thread right-angle connector is assembled at the top end of the double-thread middle-section feeding head in a threaded manner; an annular flange is integrally formed at one end in the internal thread right-angle connector, and a pressing ring is installed at the position of an opening in the top end of the double-thread middle-section feeding head below the annular flange. According to the utility model, a molten material is injected into the filter sleeve of the double-thread middle-section feeding head by utilizing the internal thread right-angle joint, the molten material treated by the filter sleeve enters the pouring head, and the molten material is fed into a cavity channel of an injection mold by the equidirectional three-section type material injection structure at the bottom end of the pouring head.

The utility model provides a kind of amorphous alloy continuous casting device, including the vacuum smelting bin and vacuum casting bin and continuous casting mechanism of sealed communication, vacuum smelting bin with the vacuum casting bin between being equipped with melt casting partition door, vacuum smelting bin is connected for maintaining the vacuum system of vacuum environment in bin;The continuous casting mechanism includes the casting cavity being located in the mobile groove below, the guide casting head being movably connected with the discharge end of casting cavity, and the pull casting seat being fixedly arranged at the end of guide casting head away from casting cavity.The amorphous continuous casting device provided in the utility model prevents raw material oxidation with vacuum double bin and vacuum system, and guarantees purity;Melting mechanism efficiently melts and directionally pours material, silicon carbide filter screen accurately removes impurities;Mobile groove accurately switches station, and sealing butt joint prevents pollution;Guide casting head and uniform speed pull casting seat guarantee ingot forming.

The invention discloses a die machining broaching device and broaching method, and belongs to the technical field of die machining. The die machining broaching device comprises a workbench, a first notch is formed in the side face of the workbench, a broaching drill is fixedly installed in a drill chuck, an overturning and adjusting assembly is arranged in the first notch, and a bottom removing assembly is arranged at the bottom of the first notch; an auxiliary discharging assembly is arranged between the bottom removing assembly and the overturning and adjusting assembly, and a clamping and pressing assembly is arranged at the bottom end of the mounting plate; the die plate can be turned over through the turning and adjusting assembly, and bidirectional reaming machining is carried out; cold air flow is evenly and finely blown out to the single side face after reaming through the bottom removing assembly, so that chippings are efficiently removed, meanwhile, cooling and heat dissipation are conducted on the die plate in the reaming process, after reaming machining of the die plate is completed, the arranged overturning and adjusting assembly rotates to a certain angle, an opening is made to be inclined downwards, and therefore the die plate is prevented from being damaged. And part of air flow in the bottom removing assembly is converted into one end blowing the mold plate through the auxiliary discharging assembly, so that the mold plate is rapidly taken out.

The invention discloses air suspension support assembly welding equipment and method.The air suspension support assembly welding equipment comprises a frame, a speed reduction turnover machine installed on one side of the interior of the frame and a side table installed at the driving end of the speed reduction turnover machine, and a transverse frame is fixed to the outer wall of the side, away from the speed reduction turnover machine, of the side table; an upper station and a lower station which are distributed in an up-down mirror symmetry mode are arranged on the transverse frame, bearing tables are installed at the positions of the upper station and the lower station, two V-shaped fixed clamps are installed on the outer wall of the side, close to the bearing tables, of the side table, and the V-shaped fixed clamps are used for containing and positioning a sleeve at one end of the H-shaped lower swing arm. The double-layer bearing table which is in mirror symmetry up and down is adopted to be matched with the V-shaped fixed clamp, the V-shaped hydraulic pushing clamp and the radial pushing hydraulic clamp to conduct bilateral synchronous clamping, the welding scheme design that stations are exchanged is achieved through the speed reduction turnover machine, and the problems that traditional single-station welding needs to be stopped for turning over, and the machining period of a single product is long are solved.

The utility model provides a kind of high-efficiency spray cooling setting device for CPVC pipe, including circulating water tank, lifting mechanism, lifting platform and rotating mechanism, circulating water tank can be connected with water source by pump, reach water circulation in water tank, guarantee the stability of water temperature in water tank, belong to prior art, wherein lifting mechanism and lifting platform are all arranged in the inside of circulating water tank, rotating mechanism is arranged at the top of circulating water tank, and there is guiding gap between the top of circulating water tank and lifting platform, since the driving device of the utility model drives pressurized wheel to do circumferential motion around heat conduction arc plate, it can stably and uniformly bend and form pipe material that has been heated and softened, completely replace the backward operation mode of needing to rely on artificial hand-held heating gun and cooperate with rotating rod to bend while heating in prior art, the structure effectively eliminates the problems such as pipe material bending deformation, unstable quality caused by insufficient artificial proficiency, significantly improves processing precision and production efficiency, reduces operation difficulty and dependence on skilled workers.

The application belongs to the technical field of flexible copper-clad plate production, and particularly relates to a PI glue, a PI film prepared from the PI glue and further discloses a warpage-resistant FCCL product prepared from the PI film. The raw materials for preparing the PI glue include dianhydride monomers, diamine monomers and sheet fillers, and the dianhydride monomers and the diamine monomers are in-situ polymerized on the surface of the sheet fillers. The PI glue adds appropriate sheet fillers as a skeleton and is dispersed in the PI glue on the basis of a traditional PI glue system, so that the coefficient of thermal expansion (CTE) of the PI glue is effectively reduced, the deformation of the PI glue during thermal cyclization to form a film is reduced, the dimensional stability of the PI film and the dimensional stability of a subsequent FCCL product are improved, and the application requirements of the FCCL product can be met.

The application discloses a method for preparing a mirror image boss structure special-shaped pipe by adopting carbon fiber composite materials, and comprises the following steps: 1, light film coating core mold; 2, pre-impregnated material coating the core mold with light film; 3, pre-impregnated material and glue film laying foam block; 4, boss block placement; 5, composite structure laying pre-impregnated material; 6, removing the core mold and placing into the air bag; 7, cleaning and preheating of the combined mold; 8, placing the prefabricated product into the lower mold; 9, combining the middle mold; 10, installing the upper mold, and carrying out inflation heating and curing; 11, adjusting the combined mold and repeating the above steps to obtain a left boss carbon fiber composite special-shaped pipe and a right boss carbon fiber composite special-shaped pipe. The application adopts mold pressing and air pressure forming, realizes single mold production of the boss structure mirror image symmetric carbon fiber composite special-shaped pipe, reduces the production cost, and solves the difficulty problem of mold entering and demolding of the carbon fiber composite special-shaped pipe with single or multiple boss structures.

The utility model discloses a trolley support suitable for variable cross section tunnel relates to trolley support technical field, including portal main part, telescopic spare is set up on portal main part, and it includes: the outer tube is axially horizontal and is arranged at the top of portal main part, and both ends are connected with outside, the threaded rod is coaxial and is arranged in the outer tube, and the annular gap is left between the outer wall of threaded rod and the inner wall of outer tube, the threaded cylinder is nested in the annular gap, and its inner wall is in threaded engagement with threaded rod. The utility model with the axial movement of threaded cylinder relative to outer tube in telescopic spare, can accurate regulation trolley support node's geometric size. Since the outer tube and threaded cylinder initial state both ends are flush, and the length is same, through rotating knob, can make telescopic output end's length of protruding according to actual demand change, thereby let same trolley support can match different size's tunnel section, need not for each kind of section alone custom-made trolley support, has greatly promoted the versatility of equipment.

The application provides a manufacturing method of a low-altitude aircraft landing gear cover plate, the landing gear cover plate comprising a cover plate body and an edge connecting part, the cover plate body is designed in a curved surface structure, the edge connecting part is distributed in a U shape along the left side, the right side and the bottom of the cover plate body, is smoothly and transitionally connected with the cover plate body and is in a plate structure, the edge is rounded, mounting holes are formed in the edge connecting part, mounting holes are also formed in the top of the cover plate body near the outer edge, carbon fiber SMC prepreg is used as a raw material for preparation during manufacturing of the landing gear cover plate, a mold is designed (the actual size of the mold cavity is 0.5%-1.0% larger than the actual size of the landing gear cover plate) and a process is controlled (precise control is performed on a forming process, temperature fluctuation is less than or equal to ±1℃, pressure fluctuation is less than or equal to ±0.1MPa, curing time error is less than or equal to ±5s, and a shaping tool cooling mode is adopted), so that the prepared landing gear cover plate is stable in size, easy to assemble and capable of guaranteeing the assembly quality of the low-altitude aircraft and flight safety.

The utility model discloses a buckle type plastic floor of tool -free splicing, relates to the field of buckle type plastic floor. A buckle type plastic floor of tool -free splicing, including plastic floor body, the front surface of plastic floor body is installed the clamping block, the rear side of plastic floor body is established the clamping groove, the left side of plastic floor body top is established T type recess. The utility model provides a buckle type plastic floor of tool -free splicing, through the setting of wear -resisting layer, because glass fiber has higher tensile strength and rigidity, make plastic floor body can obtain effective support when being stressed, reduce the risk of deformation and breakage, the existence of glass fiber still strengthens the connection between each layer of plastic floor body, can guarantee the size stability and seamless splicing effect of plastic floor body, avoid the deformation and cracking of the thermal expansion and cold shrinkage, can resist the impact and wear and tear of outside, prolong the service life of plastic floor body.

The invention discloses a flame-retardant PVC floor film and a preparation method thereof. The preparation method comprises the following steps: weighing raw materials in parts by weight; putting the pretreated raw materials into a high-speed mixer for stirring and mixing; feeding the cured dry mixture into a double-screw extruder, setting the temperature of a charging barrel in sections, starting a vacuum exhaust device, and extruding to form a flaky PVC base material; the PVC base material is guided into a three-roller calender, the roller temperature, the roller speed and the roller gap are set, and the PVC base material is rolled and stretched to the target thickness; and cooling the calendered film material, adjusting the tension after trimming the edge, and automatically coiling and packaging to obtain the flame-retardant PVC floor film. Through matching of various raw materials such as the PVC resin, the compatibility of the raw materials is improved, the mechanical property and the processing stability of the PVC floor film are improved, and the situation that the toughness and the wear resistance of a product are reduced due to addition of flame-retardant components is avoided; meanwhile, a flame retardant and a smoke suppressant are used for synergism and surface activation treatment, so that the flame retardance is enhanced, smoke is inhibited, and the high-flame-retardant and low-smoke requirements are met.

This invention relates to the field of polypropylene technology, specifically to a high-strength, creep-resistant, and high-water-pressure-resistant PPH pipe and its preparation method. The pipe is produced by extrusion and two-stage cooling and shaping of a polypropylene homopolymer containing N,N'-dicyclohexyl terephthalamide with a specific particle size, stepwise addition of low-viscosity and high-softening-point maleic anhydride-grafted polypropylene wax, and side-feed addition of highly crystalline non-polar polypropylene wax. This method systematically solves the problems of uneven nucleating agent dispersion, weak interfacial bonding, and coarse processing control in existing technologies through nucleating agent particle size control, hierarchical interface construction, synergistic processing, and gradient cooling. It synergistically and significantly improves the pipe's long-term internal pressure resistance, creep resistance, and resistance to slow crack propagation.