61results about How to "Good printability" patented technology

The invention discloses an additive manufacturing method of high-toughness alumina whisker toughened zirconia ceramic, and relates to a forming method of whisker toughened zirconia ceramic. Based on a photocuring additive manufacturing technology and an ultra-fast high-temperature sintering technology, fast additive manufacturing of the high-toughness alumina whisker toughened zirconia ceramic is achieved. The steps of pre-dispersing, freeze-drying and non-contact stirring are matched, so that the photo-cured ceramic slurry with good alumina whisker dispersion and good printability can be prepared on the premise of not damaging the whiskers; the non-reactive diluent added in the resin formula serves as a thermoplastic resin solvent and can be discharged at a low temperature, so that uniform pore channels are formed in a matrix, subsequent discharge of pyrolysis gas of resin is facilitated, and generation of defects is reduced; the added thermoplastic polyimide is resistant to high temperature and can be reserved to a sintering stage, the high-temperature toughness of the green body is improved, and the semi-degreased green body is prevented from being broken in the ultra-fast high-temperature sintering process.

The invention provides low-silver-content conductive paste for a low-temperature curing HJT battery and a preparation method of the low-silver-content conductive paste, and belongs to the technical field of polymer-based electronic paste materials and HJT efficient battery materials. The low-silver-content conductive paste is composed of the following components in percentage by weight: 52-80% of micron-sized silver-coated copper ball powder, 14-42% of submicron-sized spherical silver powder, 1-3% of an organic solvent, 0.5-2% of a curing agent, 2.5-4% of resin and 0-1% of an auxiliary agent. The micron-sized silver-coated copper ball powder is spherical, and the median particle size is 4-6 microns; the submicron spherical silver powder is in a spherical shape or a sheet shape or a combination of the spherical shape and the sheet shape. The median particle size of the submicron spherical silver powder ranges from 100 nm to 900 nm. The prepared HJT conductive paste can be cured at the low temperature of 150-200 DEG C and has good conductivity, printing performance and adhesive force, the silver content in the paste is only 30-50%, the production cost of a solar cell is greatly reduced, and popularization of the heterojunction solar cell is effectively promoted.

The invention provides thermocuring insulating glue as well as a preparation method and application thereof. The viscosity of the thermocuring insulation paste is 15-30 Pa.s, the thixotropic index TI is equal to 2-5, the TI is equal to eta 1 / eta 2, eta 1 is the viscosity of the thermocuring insulation paste at 6 rpm, and eta 2 is the viscosity of the thermocuring insulation paste at 60 rpm; the thermosetting insulating glue comprises the following components in parts by weight: 50-75 parts of epoxy resin, 15-35 parts of filler and 2-5 parts of a curing agent, wherein the viscosity of the epoxy resin at 25 DEG C is 8-80 Pa.s. The invention can solve the problem that the prior art is lack of thermocuring insulating glue which has a proper thixotropic index and is suitable for silk-screen printing.

The invention discloses a starch-based surface sizing agent as well as a raw material composition, a preparation method and application thereof. The starch-based surface sizing agent comprises the following raw materials in parts by weight: 30-70 parts of a hard monomer, 20-60 parts of a soft monomer, 11-6 parts of a functional monomer, 22-10 parts of a functional monomer, 0.5-3.0 parts of an acid catalyst, 70-90 parts of native starch, 5-20 parts of polyol and 3-7 parts of an initiator. According to the invention, through the reaction of the polyhydric alcohol and the native starch, the surface strength of the raw paper can be greatly improved, meanwhile, linting and dusting are reduced, and the sizing degree, smoothness and printability of paper can be effectively improved. And during monomer graft copolymerization, functional monomers are introduced, so that the Cobb value of raw paper can be obviously improved while the cross-linking capability of the surface sizing agent and paper pulp fibers is further improved. According to the invention, modified starch is replaced by native starch, and polyhydric alcohols and functional monomers are added, so that the product can be applied to paper pulp with different qualities, and the water resistance of paper is obviously improved.

The invention relates to the technical field of heat transfer films, in particular to a hot stamping foil with a heat storage function for cloth and a preparation method of the hot stamping foil. The invention relates to an anti-counterfeiting film which comprises a base layer, the top end of the base layer is provided with a release layer, the top end of the release layer is provided with an aluminized layer, the top end of the aluminized layer is provided with a coloring layer, the top end of the coloring layer is covered with a gluing layer, and the gluing layer adopts an acrylic resin binder. The coloring layer is obtained by drying a coloring agent, and the coloring agent comprises environment-friendly dye, an organic solvent, polyurethane resin and an accelerant. By optimizing the dosage of the coloring agent, the type of the resin binder and the production process, the binding power, the antistatic performance and the heat storage performance of the hot stamping foil for the heat storage functional cloth are comprehensively improved. Due to the improvement of the comprehensive performance, the product can better meet the modern diversified market requirements, and can be applied to daily clothes decoration, warm-keeping articles and application scenes related to electronic equipment.

The application discloses a preparation method of an electric field response self-assembly based photo-curing 3D printing ink, comprising the following steps: (1) mixing a photo initiator, a photosensitive resin and water to obtain a photosensitive resin aqueous solution; (2) uniformly mixing a polypeptide or an amino acid derivative with the photosensitive resin aqueous solution to obtain a mixed solution, and preparing the electric field response self-assembly based photo-curing 3D printing ink after self-assembly; the structure of the polypeptide is shown in the following formula (I)-(IV), and the amino acid derivative is shown in the following formula (V); the printing ink prepared by the application can self-assemble to form a certain microstructure (such as a tube, a fiber, a belt, a ball and the like), and under the action of an electric field, a structure with regular arrangement in macro and micro and enhanced mechanical properties can be obtained after 3D printing, so that the structure obtained by curing and forming the ink has excellent mechanical properties, good structural stability, a fidelity effect and good biocompatibility.

The invention discloses a preparation method of an impact-resistant elastic conductor material for 3D printing, and the method comprises the steps: taking silver particles / silver nanosheets as a conductive phase, and taking polyboron dimethyl siloxane as an impact-resistant material; by adding the polyhydroxy low-boiling-point solvent, the density of B-O dynamic cross-linking bonds in the polyboron dimethyl siloxane is reversibly adjusted, meanwhile, the number of silicon hydroxyl is reversibly increased, the hydrogen bond density is improved, the printability of the PBS is enhanced, and meanwhile, the cushioning effect of the PBS is not affected. According to the invention, the reduction and recovery of B-O density are controllable based on a reversible reaction principle of a polyhydroxy low-boiling-point solvent and a B-O dynamic cross-linking bond, and meanwhile, due to the seepage effect of silver powder particles / silver sheets, the Ag / PBS impact-resistant elastic conductor shows excellent conductivity. After the polyhydroxy low-boiling-point solvent in the printed pattern is subjected to vacuum drying, the B-O dynamic crosslinking bond density is recovered, and the Ag / PBS impact-resistant elastic conductor recovers good shear thickening effect, conductivity, sensing performance and self-repairing performance.

The present invention relates to the technical field of silicon wafer screen printing equipment, and specifically to a silicon wafer high-efficiency screen printing equipment and a control system thereof, comprising a screen printer, a loading structure, an outer frame, a linkage structure, a printing structure, a smearing structure, and a moving structure; the setting of the loading structure is convenient for driving the silicon wafer to rotate, and at the same time, the linkage structure is convenient for transferring the silicon wafer on the loading structure to a conveying component, the structure is simple, the transfer efficiency of the silicon wafer is improved, the distance between the printing structure and the silicon wafer is convenient to adjust, and the silicon wafer is convenient to be positioned by the printing structure in cooperation with the loading structure, so that the printing effect is better; the moving structure is provided with a smearing structure, and in the process of the moving structure driving the smearing structure to move, the scraper in the smearing structure can be automatically and alternately used, so that the structure is simple, the dependence on electrical components is small, and the cost is reduced.

The utility model discloses a roller printing device for processing tipping paper for cigarettes, which comprises a printing main body, the upper end of the printing main body is fixedly connected with a printing supporter, the inside of the printing supporter is fixedly connected with a dryer assembly, the inside of the dryer assembly is fixedly connected with a drying fan, and the drying fan is fixedly connected with a drying roller. The inner portion, close to the lower end of the drying fan, of the dryer assembly is fixedly connected with an electric heating wire structure, the inner wall of the printing supporting device is rotationally connected with a limiting structure, and the back face of the printing supporting device is fixedly connected with a printing motor. According to the technical scheme, through the arrangement of an electric heating rod, a first conveying pump and a heating water pipe, printing ink can be stirred, heating and heat preservation can be conducted at the same time, chromatic aberration generated by ink precipitation can be reduced, the effect of printing tipping paper for cigarettes is good, and the purposes of solving problems and improving the practical value are achieved through the technology.

The utility model discloses a metal roll plate printing device convenient to adjust, which comprises a rack, a rolling assembly and an adjusting assembly are arranged on the rack, the adjusting assembly comprises electric transverse guide rails arranged on two sides of the rack, each group of electric transverse guide rails is provided with a mounting plate, and the mounting plates are arranged on the rack. A fixing block and an electric longitudinal guide rail are arranged above each set of mounting plates, a printing plate roller is arranged between the two sets of fixing blocks, and a control assembly is arranged on one side of the rack. The winding assembly is arranged so that winding operation and unwinding operation can be conveniently conducted on a metal winding drum plate to be printed, meanwhile, the adjusting assembly is arranged so that the transverse distance and the longitudinal distance between the printing plate roller and the plate pressing roller can be accurately and rapidly adjusted, the device adapts to the metal winding drum plates with different thicknesses and printing requirements, the applicability of the device is improved, and the practicability is high. And through the arrangement of the control assembly, the printing pressure can be accurately adjusted, the printing effect is more ideal, and different printing process requirements are met.

This invention relates to a method for desiliconizing green liquor in papermaking, belonging to the field of papermaking pulping chemical regeneration technology. This method aims to solve the technical problem in existing technologies where direct carbon dioxide is introduced into green liquor for desiliconization, resulting in the formation of colloids from the generated silicic acid, making subsequent solid-liquid separation difficult. The key points of the technical solution are: first, solid-liquid separation of the green liquor is performed to obtain a clear green liquor; then, white mud slurry is added to the clear liquor as seed crystals, and carbon dioxide gas is introduced to carry out a carbonization reaction, generating an easily separable silicon-containing suspension; next, solid-liquid separation is performed on the silicon-containing suspension to obtain a silicon-containing filter cake and a causticizing mother liquor; finally, calcium hydroxide is added to the causticizing mother liquor to carry out a causticizing reaction, obtaining white liquor and recyclable white mud slurry. This method is mainly applied to the desiliconization and purification of green liquor during the alkali recovery process in papermaking, and can utilize carbon dioxide in industrial flue gas to achieve carbon resource utilization; the separated silicon-containing filter cake can be further processed into activated calcium silicate products.

The invention provides silver-based conductive paste for a flexible electronic device, a preparation method and application, and relates to the technical field of new materials. The preparation method comprises the following steps: carrying out surface modification treatment on original nano silver powder by adopting organic acid to obtain modified nano silver powder; preparing an organic silicon rubber carrier which is composed of an organic solvent, a silane coupling agent and an additive; the modified nano silver powder is mixed with an organic silicon rubber carrier, homogenization treatment is carried out, the silver-based conductive paste is obtained, and the silver-based conductive paste has excellent dispersity and stability. According to the preparation method, agglomeration of the nano-silver particles is effectively prevented, the conductivity and applicability of the nano-silver paste are remarkably improved, and the preparation method is suitable for multiple fields such as electronic packaging.

The invention relates to the technical field of additive manufacturing, in particular to a nickel-based high-temperature alloy for additive manufacturing, an additive manufacturing method of the nickel-based high-temperature alloy and an additive manufacturing part. The nickel-based high-temperature alloy comprises 17.2%-23.4% of Co, 7.2%-10.5% of Cr, 5.4%-6.1% of Al, 0.01%-0.1% of Ti, 1.5%-2% of Mo, 2%-4% of W, 6.1%-8.1% of Ta, 0.5%-1% of Nb, 0.5%-3.1% of Re, 0.02%-0.1% of Si, 0.13%-0.2% of C, 0.005%-0.01% of B, less than or equal to 0.2% of Hf, less than or equal to 0.01% of Zr and the balance Ni. The printability of the alloy is improved by controlling the variety and content of key alloy elements in the alloy, and the high-temperature performance of the alloy is improved through high Al, low Ti and a proper amount of Ta, Nb, Re and the like.

An object of the present invention is to provide a printing sheet having a coated layer for ink receiving on at least one surface of a substrate, in which the printing sheet has excellent printability and excellent antistatic performance, being less likely to cause paper jams or other troubles during printing, and has excellent properties such as water resistance and weather resistance, and a method for producing the same. The printing sheet includes a coated layer made by blending clay in a ratio of 35% by mass to 65% by mass and heavy calcium carbonate in a ratio of 5% by mass to 30% by mass in a continuous phase made of an acrylic polymer on one surface or both surfaces of a substrate, in which a volume average particle diameter of the heavy calcium carbonate is 0.05 um to 2.00 um.

The present invention relates to an ultraviolet-curable adhesive composition containing a maleimide derivative, an ultraviolet-polymerizable compound, a photopolymerization initiator, and an amine compound, and in a case where the maleimide derivative contains a maleimide derivative that does not have a structure that is hydrogen-bonded to a hetero atom, the photopolymerization initiator is a photopolymerization initiator that does not have a structure that is hydrogen-bonded to the hetero atom. The maleimide derivative does not contain a maleimide derivative having a structure that is hydrogen-bonded to a heteroatom, or the content of the maleimide derivative having a structure that is hydrogen-bonded to a heteroatom in the maleimide derivative is less than 50 mass%. When the maleimide derivative contains only a maleimide derivative having a structure that is hydrogen-bonded to a heteroatom, the content of the maleimide derivative having a structure that is hydrogen-bonded to a heteroatom is 9.8 parts by mass or less with respect to 100 parts by mass of the ultraviolet-polymerizable compound, and the content of the maleimide derivative having a structure that is hydrogen-bonded to a heteroatom is 9.8 parts by mass or less with respect to 100 parts by mass of the ultraviolet-polymerizable compound. The ultraviolet polymerizable compound contains 20% by mass or more of a monomer capable of becoming a hydrogen donor, and the photopolymerization initiator contains at least one type selected from the group consisting of hydrogen abstracting type photopolymerization initiators and polymer type photopolymerization initiators. The content of an amine compound that does not have a structure that is hydrogen-bonded to a heteroatom in the amine compound is 50% by mass or more, and the content of the amine compound is 0.1-10 parts by mass (inclusive) per 100 parts by mass of the total of the maleimide derivative and the ultraviolet-polymerizable compound.

The gift packaging paper intaglio printing equipment comprises a rack and an ink machine, the ink machine is assembled on the rack, a workbench is fixedly assembled in the rack, a printing mechanism is assembled on the workbench, a plurality of conveying rollers are assembled on the rack, a drying mechanism is assembled on the rack, and the printing mechanism comprises an ink bucket and a support. The printing ink bucket is assembled on the workbench, the printing ink roller is rotationally assembled on the inner side of the rack and located on the inner side of the printing ink bucket, the servo motor is fixedly assembled on the workbench, the support is fixedly assembled on the workbench, the ink scraping blade is fixedly assembled on the support, the pressing roller is rotationally assembled on the inner side of the rack and located on the printing ink roller, and the drying mechanism comprises two U-shaped covers. The two U-shaped covers are fixedly assembled on the machine frame and are arranged in an inverted mode, one U-shaped cover is located on the other U-shaped cover, a plurality of guide rollers are assembled between the two U-shaped covers and are rotationally assembled on the machine frame, and a plurality of electric heating pipes are fixedly assembled on the inner side of the U-shaped cover on the outer side.

The present invention discloses an aging-resistant PETG shrink film for protecting thin-film solar cells, wherein the shrink film layer structure is a three-layer structure of A / B / A; wherein the raw materials of the A layer include PET modified with NPG and a functional masterbatch; and the raw materials of the B layer include PET, PETG, an antioxidant and a light stabilizer. The present invention effectively reduces the production cost while ensuring the efficacy, and the surface layer of the film has good printability and heat-sealing properties, while also achieving the characteristics of high light transmittance, low haze and high transparency of the film, and improving durability.

The present invention relates to the technical field of silver paste for solar cells, and specifically to a method for preparing silver powder silver paste for heterojunction solar cells, which specifically comprises the following steps: 1) fully mixing and stirring an organic resin and a solvent; 2) sequentially adding a curing agent, a diluent and a accelerator, mixing and stirring to obtain an organic carrier mixture; 3) fully mixing the organic carrier mixture, a conductive silver powder and a conductive silver nanomaterial, and then adding a wetting dispersant to obtain a silver paste; 4) filtering the silver paste and then encapsulating it. The silver powder silver paste prepared in the present invention has good leveling, thixotropy and printability. Through the adjustment and combination of different epoxy resins, the organic carrier has good coating of the conductive silver powder and the conductive silver nanomaterial and the infiltration of the substrate. After curing, it shows good substrate adhesion performance and good conductivity, so that the solar cell has excellent electrical performance and photoelectric conversion efficiency, and the performance of the solar cell is enhanced.

This invention discloses a tungsten-copper electronic paste for medium-temperature co-fired ceramic substrates and its preparation method, belonging to the field of electronic pastes. By mass percentage, the paste consists of 80%–85% tungsten-copper powder, 5%–15% organic carrier, and 5%–10% binder phase. The preparation method includes: first preparing the organic carrier, then uniformly mixing the tungsten-copper powder and binder phase, followed by adding the organic carrier, and then thoroughly grinding and dispersing the mixture using a stirring and three-roll mill to obtain a uniform and stable tungsten-copper electronic paste. This invention, by optimizing the powder size and paste ratio, significantly reduces the sheet resistance of the conductive layer after sintering and improves conductivity while ensuring good co-firing compatibility with medium-temperature co-fired ceramics. The resulting paste exhibits excellent printability and rheological stability, with clear printed lines and a smooth surface. It shows no bubbling or delamination during sintering and is suitable for high-performance, high-reliability electronic packaging and substrate circuit manufacturing.

A biaxially stretched polyamide film, comprising a layer A containing 50 to 90% by mass of polyamide 6 and 10 to 50% by mass of polyamide 6 copolymer, a layer B containing 5 to 30% by mass of polyamide 6, 70 to 95% by mass of polyamide 6 copolymer, and 0 to 0.10% by mass of organic lubricant, and a layer C containing 70% by mass or more of polyamide 6 and 0.05 to 1% by mass of fine particles having an average particle diameter of 0.1 to 10 µm, wherein the layer B, the layer A, and the layer C are formed in this order; a critical surface tension on the layer B is 27.0 mN / m or higher; and on the surface of the layer B, a dispersion component yd of surface free energy is 27.0 mJ / m2 or higher and a hydrogen bond component yh is 10.0 mJ / m2 or lower.

The invention relates to the field of protective films, and discloses a printing stretch film and a preparation method thereof. The printing stretch film is prepared from the following raw materials in parts by weight: 95-105 parts of polyethylene resin, 5-10 parts of nano barium sulfate, 15-20 parts of tackifying master batch, 4-8 parts of a stabilizer, 3-5 parts of a lubricant and 2-4 parts of an antioxidant, the tackifying master batch is prepared from poly (ethylene 2, 5-furandicarboxylate), dibutyl itaconate, polyhydroxyalkanoate and cyclohexane-1, 2-dicarboxylic acid diglycidyl ester; the printing stretch film prepared by the invention has better printability, scratch resistance, elongation at break and difficulty in shrinkage deformation, has good applicability in protective films needing printing ink, and has better protectiveness and scratch resistance when being used in packaging cartons, PET (Polyethylene Terephthalate) films and other packaging materials needing color printing.

A primer composition for a process of inkjet printing includes a resin emulsion, a cohesion promoter, surfactant(s) (A), nonionic surfactant(s) (B), and water. The resin emulsion includes a polyolefin-based resin emulsion and / or a urethane-based resin emulsion. The surfactant(s) (A) include(s) an acetylene-based surfactant and / or a silicone-based surfactant. Each nonionic surfactant (B) has a HLB value of 10.0 or greater but under 15.5 and has multiple polyoxyalkylene groups in a molecule, and includes a polyoxyalkylene group-containing fatty acid glyceryl, a polyoxyalkylene group-containing aliphatic amine, and / or a polyoxyalkylene group-containing sorbitan fatty acid ester. The content percentage of the nonionic surfactant(s) (B) in the primer composition is 3.0% by mass or lower.

This invention discloses an aqueous acrylic emulsion comprising the following components in parts by weight: 570-640 parts of a base material, 290-350 parts of a monomer system, 2.5-4.5 parts of an initiator system, and 11-20 parts of a post-additive; wherein the base material is formed by uniformly mixing a high-viscosity acrylic resin liquid, an anionic surfactant, and deionized water in a mass ratio of (420-460):(2-4):(158-168); the monomer system is composed of styrene, butyl acrylate, isooctyl acrylate, hydroxyethyl methacrylate, and L-61 nonionic surfactant in a mass ratio of (38-50):(58-72):(190-210):(2-4):(9-11), after uniform mixing. The aqueous acrylic emulsion of this invention has the advantages of low film-forming temperature and high adhesion, and is mainly used as a binder for gravure printing inks and high-adhesion varnishes on plastic films. This invention also provides a method for preparing the aqueous acrylic emulsion.

The invention provides glass powder, dielectric paste and a thick film heating body. The glass powder is prepared from the following raw materials in percentage by weight: 15 to 40 percent of B2O3, 15 to 40 percent of MgO, 20 to 50 percent of CaO, 7 to 20 percent of SiO2 and 0.1 to 8 percent of glass powder additive, wherein the total weight of the raw materials of the glass powder is 100 percent. Based on the total weight of the dielectric paste being 100%, the dielectric paste comprises 55-80% of the glass powder, 0-5% of cobalt blue, 8-35% of an organic carrier, 3-15% of a diluent, 0.5-3% of an inorganic additive and 0.2-1% of an auxiliary agent. The invention also provides a thick film heating body prepared from the dielectric paste. A dielectric layer formed by the dielectric paste is compact, free of cracking, high in binding force with stainless steel, good in breakdown voltage resistance and excellent in electrical property.

The invention belongs to the technical field of printing ink, and particularly relates to thermosensitive transfer printing ink as well as a preparation method and application thereof. The modified ferroferric oxide composite material and the carboxylated kaolin are matched with other components to obtain the mixed filler, and meanwhile, the silicon-containing phenolic resin is introduced into a polymer system, so that the tinting strength and adhesion fastness of the ink are effectively improved, and good initial dryness is ensured.

The invention belongs to the technical field of preparation of silver-coated copper powder, and particularly relates to a preparation method of silver powder, which is characterized by comprising the following steps: (1) solution preparation: preparing a strain solution, a solution A, a solution B and a solution C; (2) silver powder synthesis is conducted, specifically, silver powder seed crystals are added into the solution C, the solution B is added after uniform stirring, then the solution A is dropwise added under the stirring condition, and a reaction is conducted for 15 min at the temperature of 10-30 DEG C; (3) silver powder surface treatment is conducted, specifically, a surface treating agent is added into the reaction mixed solution obtained in the step (2), a pH regulator is added to adjust the pH value to 6-7, and stirring is conducted for 10-15 min; and (4) silver powder post-treatment is conducted, specifically, after the reaction mixed solution in the step (3) is subjected to sedimentation and drainage, ethyl alcohol washing and drying are conducted, and the silver powder is obtained. The silver paste has the beneficial effects that the viscosity of the silver paste prepared from the silver powder is small, the viscosity increase is not obvious under high-speed stirring, and the thixotropy is good, so that the printing performance of the silver paste prepared from the silver powder is good.

The application discloses a method for screen printing on a substrate, a printing device and a solar cell, and aims to improve printing efficiency and obtain good printing effect. The method comprises the following steps: transmitting a substrate to be printed to a printing station; moving a screen plate to a predetermined printing position, the screen plate being located above the substrate to be printed, and paste being located on the screen plate; and controlling a printing device to move on the screen plate, so as to deposit the paste on the same surface of the substrate to be printed at least twice, and complete printing.

The invention discloses a preparation method of conductive paste for a solar cell, and relates to the technical field of solar cell preparation. The preparation method comprises the following steps: adding a copper source, a surfactant, a dispersant and a brightness modifier into a solvent to obtain a first mixed solution; adding a reducing agent and a chelating agent into a solvent to obtain a second mixed solution; the first mixed solution and the second mixed solution are mixed according to the preset volume ratio, a third mixed solution is obtained, and seed copper powder with the preset mass fraction is added into the third mixed solution; the third mixed solution after the reaction is sequentially subjected to sedimentation cooling treatment, centrifugal treatment, drying treatment and grinding treatment, micron-sized copper powder is prepared, a conductive silver layer is deposited on the surface of the micron-sized copper powder through chemical reduction reaction, silver-coated copper powder is prepared, and the conductive paste is prepared through the silver-coated copper powder. The micron-sized copper powder prepared through the method can meet the high target size interval yield, the preparation cost is low, and the process compatibility is high.

The utility model discloses a coaxial extrusion type biological 3D printer with controllable temperature and pressure, which relates to the technical field of 3D printing and comprises a base station, a deposition platform, a three-axis moving mechanism, a temperature control system and a slurry extrusion system. The three-axis moving mechanism comprises a reciprocating lead screw, a sliding block, a coupler and a stepping motor. The temperature control system comprises a cylindrical semiconductor chip, a cooling liquid cavity, a water pump, a condensate water tank and a pipeline; according to the utility model, through refrigeration and heating functions of the cylindrical semiconductor sheet, extrusion temperatures of three kinds of printing slurry are controlled. The utility model has the characteristics of wide printing applicability, high printer precision and the like, and can adjust the proper temperature in real time according to the viscosity of the inner and outer layers of slurry which are coaxially printed, thereby realizing the printing of high-viscosity and low-viscosity slurry, avoiding the problems of difficult extrusion of the high-viscosity slurry, salivation phenomenon of the low-viscosity slurry and the like, and improving the printing efficiency. And the selection range of the bio-extrusion 3D printing material is expanded.

The application provides an edible enzyme cross-linking color drawing coating, a preparation method and application, and belongs to the technical field of food packaging materials, and comprises the following components in percentage by weight: 4-10% of edible connecting material, 0.1-3% of biological cross-linking enzyme, 1-6% of microcapsule natural pigment, 1-5% of enzyme activity aid, 0.1-1% of rheological modifier, 1-5% of plasticizer, and the rest is solvent; the biological cross-linking enzyme comprises one or more combinations of glutamine transaminase, laccase, tyrosinase, polyphenol oxidase, peroxidase and lysine oxidase. The biological cross-linking enzyme is used to catalyze the connecting material and the casing substrate to form a covalent bond, so that the defects of weak adhesion and easy peeling of the traditional physical adsorption type coating are fundamentally overcome, the coating is non-toxic and non-residual, conforms to the clean label trend, realizes the perfect combination of food safety and excellent processing performance, and has high industrialization value.