39 results about "Spherulite" patented technology

The invention discloses a polypropylene composite material as well as a preparation method and application thereof. The polypropylene composite material comprises the following components in parts by weight: 50-80 parts of polypropylene resin; 4-10 parts of high density polyethylene; 5-15 parts of a polyolefin elastomer; 10 to 20 parts of talcum powder; 1 to 4 parts of polypropylene grafted polysiloxane; and 0.05 to 0.3 part of a beta crystal form nucleating agent. According to the polypropylene composite material disclosed by the invention, polypropylene is grafted with high-molecular-weight polysiloxane, and a specific nucleating agent is added, so that the crystal form of polypropylene is optimized, a more uniform microstructure is formed, a large spherocrystal boundary is reduced, a more uniform dispersion environment is provided for silicone molecules, local enrichment is avoided, and the mechanical property of the polypropylene composite material is improved. Therefore, the injection molding floating problem is effectively improved, and meanwhile, the high scratch resistance of the material is guaranteed. The high-performance polypropylene composite material which has excellent scratch resistance and good appearance at the same time is realized.

The invention relates to the technical field of high polymer materials, and discloses a reactive phosphorus-nitrogen-containing graphene oxide flame retardant and a preparation method and application thereof. According to the invention, the phosphorus-nitrogen flame retardant and the graphene oxide are subjected to composite modification, and a phosphorus-nitrogen compound is grafted to the surface of the graphene oxide through chemical reaction, so that not only can the dispersity and compatibility of the graphene oxide in a polypropylene matrix be improved, but also the synergistic flame-retardant effect of the phosphorus-nitrogen flame retardant and the graphene oxide can be fully exerted; and the graphene oxide can reduce the size of the polypropylene spherocrystal. In addition, the reactive flame retardant can also improve other properties such as mechanical properties, thermal stability and the like of the material to a certain extent, and has a wide application prospect.

The application provides a high-drug-loading porous breviscapine crystal and a preparation method thereof. The crystal is prepared by a solvent diffusion method, does not contain auxiliary materials, and has high drug purity. The crystal is a highly porous, spherical, round, particle-size-controllable, large-particle-size crystal particle, and is easy to implement in an industrial scale. The process is green, and the crystal is crystallized in an aqueous solution. The solvents used can be recycled and reused. The porous breviscapine crystal prepared by the application has rapid in-vitro dissolution, improved flowability and compressibility, and is beneficial to further preparation molding.

The invention relates to a composite current collector and a lithium battery, the composite current collector comprises an organic polymer layer and a conductive layer which are laminated, the organic polymer layer comprises spherulites, in a slicing state, the maximum width of the spherulites is 2-20 [mu] m, the spherulites with the maximum width of 3-7 [mu] m are first spherulites, the spherulites with the maximum width of 3-7 [mu] m are second spherulites, and the spherulites with the maximum width of 3-7 [mu] m are third spherulites. The number of the first spherulites accounts for more than or equal to 40% of the number of all the spherulites. The mechanical strength and heat resistance of the composite current collector can be effectively improved by accurately controlling the sizes of the spherulites and the number proportion of the first spherulites. Appropriate spherocrystal size distribution can avoid local thermal stress concentration and reduce the risk of thermal deformation of the organic polymer layer when the battery emits heat, so that the safety performance of the battery is enhanced, meanwhile, stable combination of the conductive layer and the organic polymer layer is ensured, smooth current conduction is ensured, and the working reliability is ensured.

The invention relates to the technical field of biochemical engineering, in particular to calcium gluconate with a spherocrystal structure as well as a preparation method and application of the calcium gluconate. The calcium gluconate product with the spherocrystal structure can be prepared by adding 1.1 wt%-5 wt% of calcium carbonate ethanol water suspension into 5 wt%-20 wt% of gluconic acid ethanol water solution. Due to the unique spherocrystal structure, the calcium gluconate product has the remarkable advantages that the crystal form is regular, and the core performance of high dissolution rate, high bioavailability and good stability is achieved. The successful construction of the advantageous spherocrystal structure is characterized in that the reaction temperature, the reaction raw material input proportion, the concentration, the solvent system (ethanol-water) and the rotating speed are cooperatively regulated and controlled, and the regulation and control mechanism provides reliable technical support for stable formation of the spherocrystal structure. In addition, the preparation process disclosed by the invention is simple to operate, and has the advantages of environmental protection and no generation of pollutants.

This invention discloses a method for the resource utilization of phosphate ore sintering flue gas that can efficiently recover fluorine and sulfur resources, reduce treatment costs, and create resource benefits. The method includes the following steps: sequentially subjecting the sintering flue gas to dust removal, denitrification, and heat exchange to obtain a first gas and dust; reacting the first gas with water to generate a first solid-liquid mixture containing fluorosilicic acid and silica gel, and a second gas; performing solid-liquid separation on the first solid-liquid mixture to obtain a first solid phase mainly composed of silica gel and a first liquid phase mainly composed of fluorosilicic acid; reacting the first liquid phase with sodium sulfate to generate a second solid-liquid mixture containing sulfuric acid and sodium fluorosilicate; and performing solid-liquid separation on the second solid-liquid mixture to obtain a second solid phase mainly composed of sodium fluorosilicate and a second liquid phase mainly composed of sulfuric acid.

The application discloses a kind of ground well valve barrel cylindrical valve body chip rotary extrusion friction semi-solid additive manufacturing device and process, device includes U-shaped frame, crossbeam, first nut motor composite mechanism, second nut motor composite mechanism, T-shaped disc type double rotor motor type male die, first nut motor composite mechanism, second nut motor composite mechanism etc.;When working, first put chip into mould cavity, by the "friction heat effect" generated by T-shaped disc type double rotor motor type male die "rotary extrusion friction" and valve body lower die "reverse rotation friction", the forming of first layer semi-solid spherulitic material valve body barrel wall is realized, then repeatedly additive iteration is realized to form valve body barrel wall, after turning T-shaped disc type double rotor motor type male die, ground well valve barrel cylindrical valve body parts are formed by "vibration, rotary extrusion friction" mode.This device is compact in structure, process is simple, and part material grain is small and uniform, and the organization is dense, high in strength, with good internal organization performance.

The utility model discloses a vortex oscillation type reactor for preparing mesenchymal stem cell spheres, which comprises a base, a motor and an oscillation support are mounted on the base, a cam is connected onto an output shaft of the motor, the motor drives the cam and the oscillation support to rotate synchronously, and a container bottle fixing support is mounted on the oscillation support through a spring. The container bottle fixing support is used for installing a replaceable container bottle, the motor is provided with a controller, and the controller is used for controlling the rotating speed, the forward and reverse rotation direction and timing start and stop of the motor. According to the utility model, the cells are inhibited from adhering to the wall in a special vortex oscillation mode, the cells are promoted to naturally gather to form spheres, the direct shear damage of mechanical stirring to the cells is reduced, and the cell activity and the sphere forming efficiency are improved; the rotating speed and the direction of the motor can be controlled, the vortex intensity and the oscillation frequency are accurately regulated and controlled, the structure is simple and compact, operation is convenient and fast, and the device is suitable for small laboratories.

This invention discloses an underwater cooling process that enhances the coupling properties of thermoplastic composites, belonging to the field of composite material processing technology. For thermoplastic composite parts that have just been removed from the mold and are in a high-temperature state, a specific cooling solution is used for jet cooling through an optimized nozzle system. The core of this process lies in the synergistic effect of forced convection, phase change cooling, and dynamic heat conduction. This rapidly reduces the overall temperature of the part (suppressing the formation of large-sized spherulites) while mitigating the temperature gradient in the interfacial region, promoting the full diffusion and entanglement of polymer chains to the surface of the reinforcing fibers within the viscous flow window, thereby optimizing interfacial bonding. By balancing crystallinity and residual stress, this process can increase the interfacial shear strength (IFSS) of the composite material by 15-20%.

The present application relates to a kind of composite current collector and lithium battery, the composite current collector includes the organic polymer layer and conductive layer of laminated arrangement, the organic polymer layer includes spherulite, in slice state, the maximum width of the spherulite is 2~20 μm, and the spherulite of maximum width 3~7 μm is first spherulite, the number of the first spherulite accounts for the number of all the spherulite ratio ≥40%.By accurately controlling spherulite size and the number of first spherulite ratio, the mechanical strength and heat resistance of composite current collector can be effectively improved.Suitable spherulite size distribution can avoid local thermal stress concentration, reduce the risk of organic polymer layer thermal deformation when battery heating, thereby enhancing the safety performance of battery, while ensuring that the conductive layer and organic polymer layer are combined firmly, guaranteeing smooth current conduction and ensuring reliable operation.

Membrane material for loudspeaker drivers and material for dust caps of loudspeaker drivers, characterized in that it consists of pure or at least very pure β-polypropylene. The material preferably consists of isotactic polypropylene homopolymer. The crystallinity of the material is preferably between 40% and 65%. The crystals (β-polypropylene crystals) preferably have a size of 10 µm to 20 µm. For a crystal size of 15 µm, the side length is approximately 7.5 µm and the two large faces each have a size of approximately 146 µm. 2 The crystal's height is approximately 2.6 µm and its volume is approximately 380 µm³. 3 . The spherulites (clusters of crystals) of the material preferably have a size of 300 µm to 1200 µm.

This invention discloses a heat-resistant polypropylene cable insulation material, its preparation method, and its application, belonging to the technical field of cable insulation materials. The insulation material is made by melt blending long-chain branched polypropylene (LCBPP) with an elastomer, wherein the mass ratio of LCBPP to elastomer is 70~90:10~30. Long-chain branching modification enhances the chain entanglement between molecular chains, inhibiting phase separation between polypropylene and elastomer during heat aging. Simultaneously, the dense spherulitic structure of LCBPP hinders oxygen intrusion, reducing the oxidation rate. After heat aging at 135℃ for 1440 hours, the carbonyl index increases by only 134.2%, the average POE size increases by 29.0%, the breakdown field strength decreases by ≤11.3%, the tensile strength decreases by ≤29.1%, and the elongation at break remains above 550%, meeting cable application standards. This solves the technical problem of poor heat aging performance of traditional polypropylene blend insulation materials and can be widely used in cable insulation under high-temperature environments.

The invention relates to the technical field of cross-linked polyethylene overhead insulated power cables, and discloses a water-tree-resistant modified insulation process for a cross-linked polyethylene overhead insulated cable, which comprises the following steps: mixing a cross-linked polyethylene matrix and a polar modifier to generate a modified melt, introducing the modified melt into an extrusion flow channel provided with a convergence section, and carrying out extrusion molding to obtain the cross-linked polyethylene overhead insulated power cable. The extrusion resistance generated by the change rate of the convergence angle of the convergence section is utilized to induce the polar modifier to generate a layered grain orientation structure in the matrix, the layered grain orientation structure is frozen through gradient cooling, the cross-linking reaction heat is utilized to drive the polar modifier and the matrix to generate molecular chain segment interpenetration, and an interface cross-linked network is formed on a spherocrystal interface. According to the method, localized distribution of the polar modifier is realized by utilizing geometric constraint of an extrusion flow field, a continuous physical barrier is constructed in a matrix spherocrystal gap, a migration path of water molecules is blocked, a micro space for inducing water tree initiation is eliminated, and the aging resistance and charge purity of a cable insulation system are synergistically enhanced.

The application discloses a kind of high transparency low isotacticity thermoforming polypropylene resin and its preparation process, it is related to polypropylene resin technical field, including the following process steps: polypropylene, transparent nucleating agent, antistatic agent, antioxidant, lubricant and ultraviolet absorber melt blend, extrusion into sheet, thermoforming, obtain thermoforming polypropylene resin;The thermoforming polypropylene resin also includes modified polypropylene resin;The modified polypropylene resin is obtained by mixing, co-extrusion of polypropylene, graft and peroxide.The application utilizes graft to modify polypropylene, introduces polar long branched chain segment on nonpolar polypropylene molecular chain by chemical method, produces steric hindrance, destroys the local regular arrangement of methyl, polypropylene local conformation disorder, polypropylene molecular chain movement is limited, crystallization area reduces, spherulite is refined, light scattering, Mie scattering reduces, and the transparency of the prepared polypropylene resin rises.

This application discloses a short-process semi-solid closed-loop extrusion forging composite forming process for a scroll disk for a hydrogen circulation pump, relating to the field of scroll disk forming technology for hydrogen circulation pumps. First, the aluminum alloy cylindrical material required for forming the scroll disk is determined; then, the aluminum alloy cylindrical material undergoes cold heading rough deformation, and the cold-headed aluminum alloy billet is heated and held at a certain temperature to obtain a semi-solid fine spherulite material; next, the semi-solid fine spherulite material is quickly placed into the cavity formed by the outer and lower molds, and the upper mold is controlled to press down to extrude and deform the semi-solid fine spherulite material and hold the pressure, thereby forming a semi-solid scroll disk; finally, the upper mold is raised and controlled to forge the semi-solid scroll disk, ultimately obtaining a scroll disk part for a hydrogen circulation pump that simultaneously possesses a semi-solid spherulite structure and a forged deformed structure. This application features a simple process, low forming force, high material utilization, high product density, and good mechanical properties.

This invention provides a polyvinylidene fluoride (PVDF) membrane, its preparation method, and its applications, relating to the field of materials technology. The preparation method of the PVDF membrane provided by this invention includes: coating a casting solution onto a substrate to form a liquid film; then, holding the carrier in an environment of 30-80°C for 1-5 seconds; subsequently, immersing the carrier in a coagulation bath to solidify it into a film; and finally, washing with water to obtain the PVDF membrane. This preparation method is environmentally friendly, simple, and low-cost. The obtained PVDF membrane has a dendritic-spherulitic alternating porous structure with controllable pore size, and can be used in biotechnology applications such as protein imprinting and sterilization filtration.

The invention belongs to the field of biological medicine, and relates to a peptide-containing atomization conditioning composition, in particular to a composition comprising a cystic body wrapped by a biological membrane generated in mesenchymal stem cell culture. The invention provides an atomization conditioning composition. The atomization conditioning composition contains a bag-shaped body wrapped by a biological membrane, the cystic body wrapped by the biological membrane is generated in mesenchymal stem cell culture. The invention also provides a preparation method of the atomization conditioning composition. The nebulization conditioning composition acts on the lower respiratory tract of a conditioned person after being nebulized and inhaled, conditions breath, dredges obstruction, collapses stasis and energizes immunity, can effectively relieve lung cancer and tachypnea, fatigue and weakness, mobility inconvenience and great body function decline after lung cancer operation, is simple in use method, does not occupy space, and is suitable for popularization and application. Safety and reliability are achieved, and good experience of returning to normal life is brought to a user.

The invention discloses spherulitic cloxacillin sodium and a preparation method thereof, and belongs to the field of medicine synthesis. The spherocrystal is a spherical polycrystalline aggregate which is formed by radially growing towards each radial direction by taking a crystal nucleus as a center. The preparation method comprises the following steps: taking 6-APA, o-chloroacyl chloride and sodium isooctanoate as initial raw materials; the method comprises the following steps: adding water, NaOH and other solutions into 6-APA to form a 6-APA dissolving unit, then adding an o-chloroacyl chloride acetone solution to form an acylation unit solution, then adding dichloromethane, carrying out phase splitting, and then adding acetone into a lower layer phase to form an extraction unit solution; meanwhile, an acetone aqueous solution of sodium isooctanoate is used as a crystallization base solution. In the crystallization process, a part of the extraction unit solution is rapidly pre-added into a crystallization base solution, a seed crystal is added for pre-crystal growing, then the remaining extraction unit solution is added to complete a crystallization reaction and crystal growing, and the water mass is controlled to be 3%-8% in the crystallization process; and carrying out elution, filtration, washing and drying to obtain cloxacillin sodium spherulites. The method disclosed by the invention has the characteristics of easiness in suction filtration, low impurity content and high yield, and can obviously shorten the production period, improve the yield and improve the product quality.

The application relates to the technical field of high polymer materials, and discloses a spray-free high-gloss PP material and a preparation method thereof, which is prepared from the following raw materials in parts by weight: 100 parts of polypropylene resin, 8-18 parts of an acrylate core-shell structure copolymer, 0.1-0.3 parts of a beta crystal nucleating agent, 0.5-2 parts of nano-silicon dioxide, 0.1-0.5 parts of an antioxidant and 0.1-0.5 parts of a lubricant. The acrylate core-shell structure copolymer is used as a gloss modifier, the core layer of the acrylate core-shell structure copolymer provides elastic toughening for polybutadiene rubber, the shell layer of the acrylate core-shell structure copolymer provides high refractive index and good compatibility for polymethyl methacrylate, the beta crystal nucleating agent is used to induce the PP matrix to form fine beta spherocrystals, the material 60-degree gloss reaches more than 92% of the mirror surface high-gloss effect, and the problem of insufficient gloss of the spray-free PP material in the prior art is solved.

This invention discloses a high-transparency FDM 3D printing-specific PLA toughening filament, comprising, by weight: 96.7% PLA 101; 3% ATBC; and 0.3% compound antioxidant; wherein the compound antioxidant is prepared by compounding antioxidant 1010 and antioxidant 168 in a 1:1 ratio. A method for preparing the high-transparency FDM 3D printing-specific PLA toughening filament includes the following steps: the raw materials are vacuum dried and then mixed uniformly at 60℃ for 4 hours, directly fed into a single-screw extruder, with five temperature control stages of 180℃ / 190℃ / 200℃ / 205℃ / 215℃, a take-up speed of 100m / min, cooling water temperature of 60℃ in the first stage and 50℃ in the second stage, online diameter adjustment, and winding to obtain a 1.75mm±0.05mm filament. The invention achieves the following results: the oxidative degradation rate of PLA molecular chains is reduced by more than 65%, the average spherulite size is ≤5μm, and the crystallinity is controlled at 18%; the light transmittance of the consumable is ≥92%, the haze is ≤1.5%, the yellowing index ΔE after 72h accelerated aging is ≤1.0, the elongation at break is ≥12% (while also considering toughness), the printed parts have a smooth, hazy surface, the interlayer shear strength is ≥3.2MPa, and the dimensional accuracy is stable, meeting the requirements of high transparency scenarios such as medical models and transparent shells.

This invention discloses a method for preparing ductile iron with high-density ultrafine graphite spheres, comprising: Step 1, configuring raw materials according to mass percentages; Step 2, smelting the configured raw materials in a medium-frequency induction furnace to obtain molten iron; Step 3, subjecting the molten iron to inoculation and spheroidization treatment; Step 4, introducing the inoculated and spheroidized molten iron into a water-cooled crystallizer and casting it into hypoeutectic white cast iron; Step 5, performing graphitization annealing on the hypoeutectic white cast iron in a vacuum furnace to obtain ductile iron. This invention solves the problem of component deformation or cracking that easily occurs when using hypoeutectic white cast iron as ductile iron in the prior art.

A composite forming process for semi-solid extrusion and forging of fuel hydrant manhole covers induced by cold pressing of aluminum alloy chips is proposed. First, the dimensions of the cold-pressed aluminum alloy disc required for forming the manhole cover are designed. Then, ZL104 aluminum alloy chips are cold-pressed into the disc shape, and the disc is heated and held at a specific temperature to obtain a semi-solid fine spherulitic material. Next, the obtained semi-solid fine spherulitic material is rapidly placed into a U-shaped cavity formed by the outer and lower molds. The upper mold is pressed down, driving the precision forging mold to achieve rough extrusion deformation of the semi-solid fine spherulitic material and hold the pressure, thus forming a rough-extruded semi-solid fuel hydrant manhole cover. Then, while maintaining the pressure of the upper mold, the precision forging mold is controlled to forge the rough-extruded semi-solid fuel hydrant manhole cover, ultimately obtaining a fuel hydrant manhole cover part possessing both a semi-solid spherulitic structure and a forged deformed structure. This invention features a simple process, low forming force, high material utilization, high product density, and good mechanical properties.

The invention discloses a preparation method of a spherical glycine crystal, which comprises the following steps: cooling a glycine solution with the temperature of 70-80 DEG C and the concentration of 0.47-0.52 g / mL to 20-30 DEG C under the stirring condition with the stirring speed of 700-1200 rpm, and keeping the temperature for 1-4 hours to obtain spherical glycine; when the temperature is reduced to 20 to 30 DEG C, the density of the crystal slurry is 0.27 to 0.32 g / mL. Under the condition that no additive is used, water serves as a solvent for cooling crystallization, the crystallization mode in the crystallization process is changed, optimal control is achieved, the high-quality spherical glycine product with the complete crystal form is developed, and the good application prospect is achieved. The characteristic of a single particle of the obtained spherocrystal is 500-2000 microns, the HS roundness value is 0.91-1, the particle size distribution of the obtained spherocrystal is larger than or equal to 77%, the angle of repose is 29-35 degrees, and the caking rate is 1.11-7.68%.

The invention relates to a non-crosslinked self-temperature-control composite material without a negative temperature coefficient effect as well as a preparation method and application of the self-temperature-control composite material. The composite material is prepared from the following raw materials in parts by weight: 5 to 15 parts of conductive carbon, 5 to 10 parts of filling carbon, 8 to 12 parts of nucleating agent, 0.05 to 0.2 part of antioxidant, 30 to 45 parts of HDPE (High-Density Polyethylene), 10 to 20 parts of LLDPE (Linear Low Density Polyethylene) and 10 to 20 parts of PP (Polypropylene), wherein the nucleating agent is E / MAA-Na (maleic anhydride-Na) and PVB (polyvinyl butyral). The main components of the composite material are the nucleating agent E / MAA-Na and PVB, a large number of uniform heterogeneous nucleation sites are provided, the crystallization space-time randomness is broken, the effects of refining the spherocrystal size and improving the crystallization density are achieved, the melting intervals of PP / PE are overlapped, a continuous wide melting range is formed, conductive network collapse caused by local mutation in the melting process is avoided, and the conductivity of the composite material is improved. And finally, the NTC effect is completely eradicated and the PTC effect is improved under the non-crosslinking condition.

This invention belongs to the field of lithium battery technology, specifically relating to a PVDF-based composite solid electrolyte, its preparation method and application, and lithium batteries. The composite solid electrolyte comprises a PVDF-based polymer, lithium salt, amide substances, nano-metal oxides, and residual organic solvents. The nano-metal oxides and amide substances jointly regulate the solvation structure of lithium ions, weakening the interaction between the solvent and lithium ions. [Li (residual solvent)] x ] + The interaction forces with the polymer create a weak interaction environment for lithium ions, promoting the Li-polymerization process. + The process facilitates the transport of ions and simultaneously transforms the solvent-derived electrode-electrolyte interface phase into an anion-dominant derived phase, thereby improving interface stability. On the other hand, the nano-metal oxides reduce the crystallinity of the PVDF polymer, inhibit spherulite formation, and densify the electrolyte membrane. This contributes to the construction of uniform and continuous ion transport channels, improves mechanical properties, effectively suppresses the growth of lithium dendrites, and enhances the cycle stability of the battery.

The invention discloses a composite binder for a dry-method electrode and a preparation method and application thereof, and relates to the technical field of battery preparation. The composite binder comprises polytetrafluoroethylene and an auxiliary binder, the auxiliary binder comprises a fluorine-containing polymer with crystallinity changing along with temperature, and the fluorine-containing polymer is a polymer which can form a molten state under a heating condition and can crystallize and form a fine spherocrystal structure after being cooled. The invention also provides a dry electrode, which comprises a positive active material, a conductive agent and a composite binder. According to the invention, a polymer with crystallinity adjustable along with temperature is creatively introduced as one of binder components to be compounded with polytetrafluoroethylene, and the crystallization behavior of the polymer, which can be regulated and controlled through processing conditions, is utilized to actively control the crystal form and size of the polymer in a composite fiber network; the auxiliary polymer forms a fine spherocrystal structure, and the structure cooperates with the PTFE fiber to construct a rigid-flexible three-dimensional bonding network structure.

Provided is, for example, a thermoplastic elastomer composition having excellent heat aging resistance when exposed to a high-temperature environment for a long period of time, also excellent hardness and mechanical properties as well as excellent extrusion processability.A thermoplastic elastomer composition (I) including a cross-linked product of an ethylene / α-olefin / nonconjugated polyene copolymer (A) having a weight-average molecular weight of 350,000 or more, with a phenolic resin-based cross-linking agent (E), and including 360 to 460 parts by mass of a crystalline polyolefin (B), 2 to 6 parts by mass of a fatty acid-based lubricant (D), and 80 parts by mass or more of a softener (C1), relative to 100 parts by mass of the copolymer (A), in which the thermoplastic elastomer composition (I) has a ½ crystallization time at 120° C. of 200 seconds or less, and a polyolefin component included in the thermoplastic elastomer composition (I) has a maximum spherulite size in a range of 8 μm or less.

The semi-solid spin-extruded forging composite forming process for well valve cylindrical bodies involves the following steps: First, aluminum alloy 6061 chips are placed into a mold cavity. A medium-frequency induction heated convex upper die is lowered to flatten the chips, obtaining a disc-shaped billet. This disc-shaped billet undergoes a semi-solid isothermal treatment to prepare semi-solid spherulitic aluminum alloy material. Next, the medium-frequency induction heated convex upper die is controlled to perform "spin-extruded deformation" on the semi-solid spherulitic aluminum alloy material, forming a semi-solid spherulitic well valve cylindrical body. Then, a multi-stage telescopic hydraulic cylinder and the medium-frequency induction heated convex upper die are controlled to apply "spin-extruded forging" deformation to the semi-solid spherulitic well valve cylindrical body, obtaining a well valve cylindrical body with a composite structure of semi-solid spherulitic and forged fiber structures. This invention's process can save production costs, improve production efficiency, and produce high-quality well valve cylindrical bodies.

The application belongs to the technical field of crystal form compounds, and particularly relates to a spherulite of polylactic acid and a preparation method thereof. The application provides a spherulite of polylactic acid, which is a new crystal form of polylactic acid, and has characteristic peaks at diffraction angles 2 θ 17.9+0.2°, 20.2+0.2°, 23.5+0.2° and 32.7+0.2° in Cu-K alpha radiation X-ray powder diffraction pattern, and does not contain crystal water or other crystallization solvents, has concentrated particle size distribution and good fluidity, and is more suitable for industrial processing. The application also provides a preparation process of the spherulite, which comprises fully dissolving polylactic acid by using chloromethane, dropping into an alcohol solvent, making polylactic acid precipitate in the alcohol system, and drying to obtain the spherulite. The preparation method is simple, efficient and cost-effective, and has important significance for the application of polylactic acid.

An electrophotographic member comprising: at least a base layer; an elastic layer; and a surface layer in this order, wherein the surface layer comprises a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, at an endothermic curve upon performing two measurements at a ramp up rate and a ramp down rate both set at 20° C. / min using a differential scanning calorimeter (DSC) with a sample sampled from the surface layer as a measurement sample, an endothermic peak temperature in a second temperature raising process is 304° C. or less, an endothermic quantity in a first temperature raising process is 21 J / g or more, and D3 is 40 μm or less, where D3 represents an area average diameter of a spherulite at an outer surface of the surface layer.