236results about How to "Density controllable" patented technology

The invention provides a high-performance thermal insulation material and a preparation method thereof. The thermal insulation material comprises silicon dioxide aerogel and a fiber material, wherein, the silicon dioxide aerogel takes silicon dioxide hydrosol as a raw material, and is prepared by adding a catalyst. The method comprises the following steps: sol preparing, sol dipping, gelating, gel ageing, hydrophobization treating and drying and the like. The method can conveniently and selectively prepare the materials of planes, abnormal-shape surfaces and multiple sizes, has simple and convenient operation and small environmental pollution. The material has excellent mechanical performance, good high-temperature stability and heat insulation performance, and has wide application prospect in the fields of civilian industries, space flight and aviation industries, military industries and the like.

The invention relates to a preparation method for an expanded material of polylactic acid; the polylactic acid, a tackifying modifier, a chemical inhibitor, a vesicant, a foaming accessory ingredient, a abscess stabilizer and a parting agent are mixed under high temperature according to a certain proportion to obtain a basic mixture; then the basic mixture is arranged in a die to carry out moulding foaming on a vulcanizing machine with a certain temperature and a certain pressure to manufacture the foaming material of polylactic acid. The foaming material of polylactic acid manufactured by the method of the invention has excellent performances of being biodegradable, controllable density, easy processing as well as good barrier property, has similar foaming shaping performance and shock-absorbing capacity with polystyrene, can replace the foaming material of polystyrene, can be used as the materials for heat isolating, sound isolating and shock absorption and has broad application in the fields of cushion packaging, transportation, electric apparatus, refrigeration, agriculture and forestry and gardening.

The invention provides a foaming synthetic leather manufacturing technology based on waterborne polyurethane (WPU). In the manufacturing technology, the WPU is taken as a main raw material, and a hollow microsphere foaming agent is taken as a foaming material; and the technology can be widely used for manufacturing synthetic leathers such as clothing leathers, luggage leathers, shoe upper leathers, sofa leathers, home interior trim leathers and the like. The content of volatile organic compounds (VOC) in the finished leather is lower than 2mg/kg (leather), and the air permeability and moisture penetrability are good, thus meeting the EU (European Union) requirements for the ecological synthetic leather; and in addition, the foaming synthetic leather has the advantages of moderate foaming multiplying power, uniform and compact foaming holes, bulky and firm hand feel as well as good comprehensive performance which is equivalent to or superior to that of a solvent-borne product. The foaming synthetic leather manufacturing technology based on the WPU provided by the invention has the beneficial effects that by adopting the WPU instead of the traditional solvent-borne PU, organic pollution is eliminated from a source, organic solvent resources are saved, the comprehensive energy consumption is lowered, the employment environment of laborers is improved, and the ecological grade of the synthetic leather and the international market competitiveness of the product are enhanced, thus achieving obvious innovativeness and remarkable social and economic benefits.

The invention discloses an extrusion foaming thermoplastic polyurethane elastomer bead. The extrusion foaming thermoplastic polyurethane elastomer bead comprises the following components in parts by weight: 100 parts of thermoplastic polyurethane elastomer, 0.01-0.5 parts of a foaming nucleating agent, and 0.01-0.2 parts of an antioxidant, wherein a foaming process adopts supercritical fluid with the addition amount of 1-40 parts. The invention also discloses a preparation method of the extrusion foaming thermoplastic polyurethane elastomer bead. The extrusion foaming thermoplastic polyurethane elastomer bead and the preparation method have the advantages that the foaming process does not cause environmental pollution; the obtained foaming material is stable in quality and high in foaming ratio; and the operation method in production is easy and suitable for continuous industrial production.

The invention discloses a method for preparing silicon dioxide aerogel by using acidic silica sol and belongs to the field of preparation of inorganic heat-insulating materials. The method comprises the following steps of: directly forming gel under actions of acid and alkali catalysts by using acidic silica sol as a raw material, wherein the process for preparing the gel does not involve organic solvent so as to improve the security of production; and preparing SiO2 aerogel through supercritical or constant pressure drying after the gel is subjected to solvent replacement and surface silylation. According to the method, the process for preparing the sol by using organic silicon as raw material and a complicated process for removing salt in water glass are avoided; and because the acidic silica sol with low cost and stable performance is used as the raw material, the method has the advantages that the process is simple, the production cycle is short, the reaction process is controlled, and the requirement and investment of the equipment are low, so that the industrial production of SiO2 aerogel can be realized.

The invention provides a polylactic acid foaming material and a preparation method thereof. The polylactic acid foaming material is prepared from the following ingredients according to parts by weight: 45-93 parts of polylactic acid, 5-28 parts of toughener, 1-5 parts of nucleating agent and 1-10 parts of foaming agent. The polylactic acid is one of poly-L-lactic acid, poly-D-lactic acid and poly-DL-lactic acid or a mixture or a polymer thereof, and has the weight average molar mass of 0.8-3.5 million, molecular weight distribution of 1.2-2.5, and degree of crystallinity of 15-60 percent. The toughener is one of poly succinic acid butyl ester and poly adipate/butylene terephthalate or a mixture of two with random ratio. Other accessory ingredients can also be added. The preparation method comprises the following steps: evenly mixing the polylactic acid, the toughener, the nucleating agent, the foaming agent, the accessory ingredients and the like in a high mixing machine according to a certain proportion, then milling for 5-25 minutes at the temperature of 100-170 DEG C, and carrying out die pressing foaming on obtained materials at the temperature of 120-210 DEG C on a vulcanizing machine for 2-10 minutes to prepare the polylactic acid foaming material. The polylactic acid foaming material prepared by using the preparation method has the advantages of high resistance to shock, high elongation at break, high tensile strength and complete biodegradation after used.

The invention relates to a radar target intermediate frequency (IR) echo simulation system based on multi-beam amplitude-comparison angle measurement and a control method thereof, relating to the field of radar target echo simulation. The system comprises three target echo simulation boards and an arbitrary waveform generator instrument fixture, wherein the echo simulation boards are designed with a computer module PC104, a field programmable gate array (FPGA), direct digital synthesis (DDS) technique and a simulation circuit as cores; and the arbitrary waveform generator instrument fixture is designed with instrument programming control as the core. According to the invention, simultaneous 6-channel simulated target IR echo simulation of the radar of the multi-beam amplitude-comparison angle measurement system is realized, parameters of the simulated target echo such as distance, delay, echo amplitude, Doppler shift, pattern, direction pattern modulation, noise superposition and the like can be controlled, single-channel switching and output of dual-beam echo is realized, and the test use requirement of the radar signal processor of the system is met. In the invention, the arbitrary waveform generator instrument frock is utilized, thus improving the amplitude precision of the output echo signals; and the control program in the FPGA in the target echo simulation boards is designed by the soft IP core, thus providing convenience for hardware transplanting and clipping.

The invention relates to a process and an apparatus for continuous production of a closed-cell aluminum foam through blowing foaming. The process comprises the following steps: melting a raw material, adding with a ceramic tackifier and a moistening promoter, stirring to obtain molten aluminum with uniform component, carrying out continuous foaming with the apparatus for the continuous productionof the closed-cell aluminum foam with blowing foaming to obtain a molten aluminum foam with uniform foam size, and controllable density and productivity, and producing a foamed aluminum board by going through a net belt and transmitting with an arc transition mechanism and cutting. The apparatus is characterized in that: a simple crank link mechanism is adopted to realize the reciprocating motion of a horizontal outlet duct, and the arc transition mechanism allows the ascending lifting of the molten aluminum foam to be changed into horizontal transmission. According to the invention, the process and the apparatus are simple, the operation control is accurate, and a purpose that the pore size and the density of foamed aluminum products can be accurately controlled at a high efficiency anda low cost is realized because the foam size of the molten aluminum is adjusted by changing the frequency of the reciprocating motion of the outlet duct, the pressure and the flow of a compressed gasand the diameter of outlet micropores.

The invention relates to a light-weight, high temperature-resistance and heat-insulation ceramic fiber tile and a making method thereof. The heat insulation tile comprises ceramic fibers and boron oxide, wherein the ceramic fibers comprise quartz fibers, alumina fibers and yttrium oxide stabilized zirconia fibers. The making method of the light-weight, high temperature-resistance and heat-insulation ceramic fiber tile comprises the following steps: preparing a sintering aid suspension, preparing a ceramic fiber slurry, carrying out wet green body molding, drying the obtained wet green body, and carrying out pressurization sintering. The heat insulation tile has good heat insulation effect and mechanical performances, has light weight and resists high temperature; the density is controllable between 0.10g/cm<3> and 0.90g/cm<3>; the lowest apparent heat conduction coefficient at room temperature reaches 0.033W/(m.K); the compressive strength at room temperature is greater than 3.0Mpa; and the long-time use temperature can reach 1350DEG C.

The invention relates to a generation method of quadrilateral grids of a geometric model with any internal feature constraints, which outstandingly enhances the generation quality and efficiency of the quadrilateral grids and has convenience and practicability. The generation method comprises the following steps of: (1.1) building an entitative geometric model according to an entity to be analyzed by utilizing a computer; and determining the shapes and the positions of constraint lines and density lines of the entitative geometric model, the positions of constraint points and density points and the range and the inner and outer boundaries of each region; (1.2) generating grid nodes on the inner and outer boundaries, the constraint lines and the density lines of the entitative geometric model according to grid size information set by a user, and numbering the grid nodes; viewing the constraint points and the density points as newly generated grid nodes, and numbering the newly generated grid nodes; (1.3) viewing the constraint lines, the density lines, the constraint points and the density points as internal cavities with areas of zero, generating node rings on the inner and outer boundaries of each region, and transforming a multiply connected region with the internal feature constraints into a simply connected region; (1.4) dividing the quadrilateral grids in each region; and finally generating the quadrilateral grids with the internal feature constraints.

The invention relates to a corn/case polyurethane magnetic composite micro ball, and relative preparation, wherein it uses inorganic magnetic particles as corn, uses polyurethane as case, while its diameter reaches 800micrometer; and its production comprises that: planting -NH and -NH2 groups on the surface of magnetic inorganic powder; than polymerizing into polyurethane prepolymer; forming stable oil/water suspension in the disperser solution; then polymerizing into magnetic inorganic/ polyurethane magnetic composite micro ball. The inventive micro ball has X-ray contrast, high magnetic response and low density of polyurethane macromolecule, etc. And inventive production has simple process and low cost. Said micro ball can be used to prepare vessel plunge material and drug carrier.

The invention discloses a SiCN aerogel. The raw materials comprise polyvinyl silazane containing -CH=CH2 bond or also containing both -Si-H bond in the molecular structure, and divinylbenzene / dicumyl peroxide. A polymer precursor conversion ceramic preparation method and an aerogel preparation method are conduced to prepare the SiCN aerogel with specific surface area of 100-200 m<2>/g, porosity of 80-90% and density of 0.05-0.15 g/mL. The SiCN aerogel of the invention is a novel nano-porous ceramic material with extremely high porosity and specific surface area, and low density.

The embodiment of the invention provides a high pressure-resistant thermal insulation material and a preparation method thereof and relates to the technical field of thermal insulation materials. The preparation method is simple and convenient to operate and causes little pollution to the environment. The high pressure-resistant thermal insulation material has low heat conductivity coefficient and good temperature-resistant thermal insulation performance. The high pressure-resistant thermal insulation material is prepared by combining a fiber ceramic frame and sol and is subjected to drying and oven processing. The fiber ceramic frame is prepared by combining a fiber matrix and an enhancer and is subjected to drying and high-temperature processing. The fiber matrix is formed by dispersing at least one of quartz fiber, alumina fiber, mullite fiber and zirconia fiber to form a specific shape. The high pressure-resistant thermal insulation material is mainly used for aerospace industry, civil industry and the like.

The invention discloses a continuous density gradient low-density porous carbon bonding composite material.The composite material is prepared from, by mass, 12 parts of chopped viscose-based carbon fiber, 7-36 parts of fiber binder and 1.5-5 parts of fiber dispersing agent.A preparing method of the composite material comprises the steps of 1, preparing fiber size and conducting vacuum filtration formation on the fiber size; 2, heating and drying wet green obtained in the step 1 till weight does not change any more, and curing a mixture obtained after drying with the gradient curing technology under the vacuum condition; 3, conducting furnace cooling on the mixture obtained in the step 2 to indoor temperature, and then carbonizing the mixture obtained in the step 2 with the gradient carbonization treatment technology.The composite material has a high temperature resisting property and a heat insulating property, has a continuous density gradient feature in the thickness direction, and has high mechanical strength, anti-scouring performance and thermal protection/insulation efficiency.

The invention discloses a preparation method of a mullite fiber porous heat insulating material. The invention discloses a method for preparing a mullite fiber porous material by combining gel casting into a film and freeze-drying. The process is: first mix silica sol and agar powder, add deionized water to dilute and stir evenly under the condition of heating in a water bath at 78°C, then slowly add mullite fiber to the uniform mixture of silica sol and agar powder, and stir while adding , so that the mullite fiber is evenly dispersed in the sol; after stirring evenly, pour the obtained sol into a plastic beaker, put it in a 15°C water bath environment for gel treatment for 60s, and then freeze it at -196°C, and then put it into Drying in a freeze dryer; finally, heat-treating the dried body at 1500° C. for 2 hours to obtain a mullite fiber porous material. The invention has simple process and low energy consumption, and realizes the purpose of controlling the density of the prepared mullite fiber porous material, and prepares the mullite fiber porous material with low density and high specific strength.

The invention discloses a deep processing production technology of a sintered metal matrix friction sheet and a sintered metal matrix friction sheet prepared by the production technology. The sintered metal matrix friction sheet comprises a steel backing layer and one or two friction layers. The production technology includes the steps of powder spread, primary sintering, primary rolling, secondary sintering, secondary rolling, annealing treatment, and stamping to obtain the sintered metal matrix friction sheet. The defects that prior sintered metal matrix friction materials are large in production technology investment, complicated in processing, low in production efficiency, unstable in product quality, uncontrollable and the like are overcome, the method can be applicable to the production of iron-based and copper-based friction materials, the thicknesses of the steel layer and the friction layers can be controlled respectively, the control accuracy is high, the finished product qualities of the friction sheets are stable, the device investment is small, the operation is simple, and the production efficiency is high.

The invention provides a hollow microspheres-enhanced polyimide matrix foamed composite material and a preparation method thereof. The apparent density of the foamed composite material is 0.023-0.035g/cm<3>, the foam shrinkage rate is -35.0% to -20.0%, the compressive strength is 0.05-0.35MPa, the impact strength is 20-60KJ/m<2>, and the average sound absorption coefficient within the frequency range of 125-4,000Hz is 0.40-0.51. The preparation method comprises the following steps: mixing aromatic dianhydride with aromatic diamine and a surfactant to obtain a foaming precursor after esterifying the aromatic dianhydride; adding hollow microspheres and a foaming agent to a precursor solution, and heating the solution to obtain a foaming block; finally carrying out thermal imidization on the foaming block to obtain the foamed composite material. According to the method, the foamed composite material with good mechanical property, and excellent sound absorption and sound insulation can be prepared.