66 results about "Surface strength" patented technology

The invention provides a raw material composition of an enhanced surface sizing agent for corrugated paper. The raw material composition comprises the following components in parts by weight: 2-10 parts of starch, 0.01-4 parts of amylase, 0.01-3 parts of carboxymethylcellulose and 5-30 parts of sodium sulfate. The invention also provides a preparation method of the enhanced surface sizing agent for corrugated paper, which adopts the raw material composition and specifically comprises the following steps: adding starch into a reactor, heating to a reaction temperature, and adding amylase for gelatinization reaction; after gelatinization is finished, reducing the temperature to room temperature, adding carboxymethyl cellulose, and stirring to fully mix the carboxymethyl cellulose and the carboxymethyl cellulose; adding sodium sulfate into the reactor, and fully stirring and reacting to obtain the enhanced surface sizing agent for the corrugated paper. The surface sizing agent is prepared by gelatinizing and modifying starch and adding carboxymethyl cellulose and sodium sulfate, and the surface strength of paper can be remarkably improved when the product is applied to corrugated paper. The preparation method is simple and obvious in effect.

The invention discloses a preparation method of a high-hydrophobicity liquid lead bismuth alloy nitride coating capable of increasing a high-temperature contact angle, which comprises the following steps of: pretreating a substrate, depositing a FeCrAl coating on the surface of the substrate by adopting magnetron sputtering, and nitriding the FeCrAl coating to obtain a nitride coating; the invention further discloses the high-hydrophobicity liquid lead bismuth alloy nitride coating for improving the high-temperature contact angle. According to the preparation method, the FeCrAl coating is nitrided, so that the surface strength and corrosion resistance of the FeCrAl coating are improved, the formed FeCrAl nitride layer with a compact structure has high lyophobicity on the liquid lead bismuth alloy, the material surface is in a non-wetting state all the time, the liquid lead bismuth alloy can be effectively prevented from permeating into an alloy matrix, and the service life of the material is prolonged. The material is suitable for being used as a cladding material of a lead-cooled fast neutron reactor.

The invention provides a special reinforcing agent for coated paper, which is prepared from the following raw materials in parts by mass: 10 parts of polyvinyl alcohol; 1 to 3 parts of cationic polyacrylamide; 1-5 parts of a bactericide; 1 to 5 parts of a defoaming agent; 5 to 10 parts of a VAE emulsion; 5 to 10 parts of paraffin emulsion; 1 to 3 parts of redispersible latex powder; 2 to 4 parts of borax; 1-3 parts of a filler; 0.5 to 1.5 parts of cellulose; and 43.5 to 73.5 parts of deionized water. The special reinforcing agent for the coated paper is used as a prime coat paint and is used for prime coat of common fiber papermaking to form a prime coat layer, so that the obtained coated base paper has higher surface strength and better moisture resistance and smoothness, and can be used for preparing high-quality coated paper.

The present utility model discloses a composite reinforced rockwool board and a production equipment for producing same. The composite reinforced rockwool board comprises a rockwool base layer, two backing layers, two first bonding layers, a surface layer, and a second bonding layer. The two backing layers are respectively located on two outer sides of the rockwool base layer along the thickness direction. The two first bonding layers each are disposed between the two backing layers and the rockwool base layer along the thickness direction to bond the two backing layers to the rockwool base layer. The surface layer is disposed on one side of the backing layer away from the rockwool base layer. The second bonding layer is located between the surface layer and the backing layer along the thickness direction to bond the surface layer to the backing layer. The 90° peel strength between the surface layer and the backing layer ranges from 4N / 75mm to 30N / 75mm. The present utility model can improve the surface strength and integrity of the board. By bonding the surface layer on the outer surface of the backing layer, the strength of the connecting structure of the surface layer can be improved, and the surface strength of the board can be further improved, which thereby improves the service life of the board.

A method for manufacturing a glass article includes etching a surface of the glass article with an etchant solution including hydrofluoric acid to produce an etched glass article. The glass article is a high refractive index glass containing a transition metal oxide and having a refractive index of greater than or equal to about 1.6 at a wavelength of 589.3 nm. The surface has surface and subsurface defects. The etching improves the surface strength of the surface of the etched glass article by removing or rounding the surface and subsurface defects, and the etching results in deposition of transition metal fluoride. The method includes cleaning the surface of the etched glass article with a cleaning solution having a pH greater than or equal to about 10 to remove transition metal fluoride from the surface of the etched glass article.

The invention provides a high-aroma and high-surface-strength reconstituted tobacco containing an ultra-low quantitative film base and an ultra-thin skin and a preparation method of the high-aroma and high-surface-strength reconstituted tobacco. The preparation method comprises the following steps: preparing an ultra-low basis weight film base by using a crescent-shaped papermaking machine; preparing a body coating liquid; transferring the body coating liquid to the upper surface and the lower surface of the ultra-low basis weight film base to respectively form a first body and a second body, and drying to obtain a reconstituted tobacco semi-finished product; preparing a skin coating liquid; transferring the epidermis coating liquid to the upper surface and the lower surface of the reconstituted tobacco semi-finished product to form a first epidermis and a second epidermis respectively so as to prepare the reconstituted tobacco; wherein the quantitation of the ultra-low quantitation film base is 8-20 g / m < 2 >, the quantitation of the first body and the quantitation of the second body are respectively and independently 15-40 g / m < 2 >, the quantitation of the first skin and the quantitation of the second skin are respectively and independently 1-4 g / m < 2 >, and the thicknesses of the first skin and the second skin are respectively and independently 10-200 microns.

The invention discloses a rapid manufacturing process of a 3D printing sand mold outer mold for a static pressure molding line, and relates to the technical field of casting. The process is different from conventional metal mold and wood mold manufacturing processes, an outer mold body blank is rapidly manufactured through the 3D printing technology, and then hardening and surface smoothing treatment are conducted through hardening liquid. Through hardening of the hardening liquid, the surface strength and hardness of the outer mold body can be greatly improved, the outer mold body can completely bear the molding pressure (1.2 Mpa) of a static pressure molding line, the hardened sand mold can pass through at least 300 molds without deformation, and the dimensional tolerance stability is good. The surface of the outer mold body is smooth through surface smoothing treatment, and the sand scrabbling defect is avoided. Surface treatment is matched with surface hardening, the manufacturing period of the outer mold can be shortened, the manufacturing cost of the outer mold can be reduced, and meanwhile the use requirement of a static pressure molding line can be met.

The application discloses a large-specification plane plate processing method and belongs to the technical field of plate processing. The application comprises the following steps: step one, selecting a plate blank and clamping the plate blank to a machine tool; step two, setting processing parameters of the machine tool, processing the plate blank, and processing to a corresponding size to obtain a plate; step three, taking down the plate obtained in step three and placing the plate on a cleaning and detecting device; step four, starting the cleaning and detecting device, cleaning a plate surface of the plate, and cleaning cutting fluid on the plate; and step five, spraying protective paint on the surface of the plate to form a protective coating on the surface of the plate to obtain a plane plate. The overall processing technology of the application is simple, the protective paint is sprayed on the plane plate, the obtained plane plate has excellent corrosion resistance and wear resistance, the surface strength is relatively high, the practicality is strong, and the application is applied to aerospace equipment.

The utility model relates to a wall surface strength detection device for constructional engineering detection, which relates to the technical field of building detection equipment and comprises a mounting box body, a rectangular lifting cylinder arranged in the middle of the mounting box body in a lifting manner, and a knocking assembly mounted at the top of the rectangular lifting cylinder, the knocking detection assembly comprises a mounting frame fixedly locked and mounted at the top of the rectangular lifting cylinder, a sliding groove is formed in one side of the mounting frame, a knocking block and a sliding block are arranged in the sliding groove in a sliding mode, and the rectangular lifting cylinder drives the knocking detection assembly to ascend to a designated position. A knocking block of the knocking detection assembly quickly reciprocates to knock the wall surface, so that whether the coating falls off or is sunken or not can be visually observed, and the strength of the wall surface is detected; and the sliding block reciprocates through the crank sliding block mechanism, and the sliding block and the knocking block are elastically connected through the knocking spring, so that the knocking force of the knocking block can be better controlled and buffered, and the knocking uniformity and efficiency are ensured.

The invention relates to the technical field of composite materials, and belongs to a multi-layer impact-resistant plastic plate and a preparation method thereof.The plate adopts three master batches as raw materials, specifically, the first master batch takes block polypropylene as the main component, and a plate layer A is prepared; the second type of master batch takes linear low-density polyethylene and low-density polyethylene as main components to prepare a plate B layer; and preparing a plate C layer by taking a cycloolefin copolymer or a special cycloolefin copolymer as a main component of the third master batch. The impact-resistant plastic plate with a multi-layer structure is obtained by accurately controlling the compounding proportion and characteristics of different layers of materials and carrying out in-situ hot-pressing compounding by utilizing a screw extruder. The plate not only has excellent impact resistance and bending property, but also has good surface strength and gloss. By reasonably designing the combination and compounding process of all layers of materials, the board has high attractiveness while meeting the high-strength protection requirement.

The invention relates to the technical field of structural materials, in particular to a gradient carbon-nitrogen-zinc-iron corrosion-resistant composite layer, a preparation method thereof and a connecting fitting. By adopting a specific carbonitriding process and controlling the iron content in the gradient Zn-Fe plating layer, the problem that a carbonitriding layer, the gradient Zn-Fe plating layer and a passivation layer are difficult to form a stable and effective structure is solved; the prepared composite layer not only can improve the strength, wear resistance and corrosion resistance of the surface of the matrix, but also is stable in performance.

The invention relates to the technical field of thermo-sensitive paper, and provides a thermo-sensitive paper surface adhesive and a preparation method thereof. The preparation method comprises the following steps: adding calcium carbonate, kaolin, nano silicon dioxide and expanded microspheres into deionized water, and adding a dispersing agent for dispersion treatment to obtain composite slurry; the preparation method comprises the following steps: adding chitosan into organic acid to prepare an acid solution of chitosan, then adding the acid solution of chitosan, cationic starch, polyvinyl alcohol and water-based acrylic emulsion into deionized water, stirring and dissolving to obtain a mother solution of the composite water-based adhesive; adding the composite slurry into a composite water-based adhesive mother solution, and stirring to obtain a surface adhesive coating solution; and coating the surface of thermosensitive base paper with the surface glue coating liquid, and carrying out drying treatment to obtain the thermosensitive base paper surface glue. According to the preparation method of the thermosensitive base paper surface adhesive, the heat insulation property, the surface strength, the flatness and the coating adaptability of the base paper are synchronously improved on the premise of not damaging the color development performance of a thermosensitive layer.

The application discloses an X80 pipeline steel electric arc additive-ultrasonic impact composite cladding coating and a preparation method thereof, and belongs to the technical field of protective coatings. The preparation method comprises the following steps: adopting CMT electric arc additive manufacturing to deposit X80 pipeline steel base material, and forming a homogenous cladding coating, wherein trace oxygen is introduced in the CMT electric arc additive manufacturing process, so that the trace oxygen reacts with Ni, Mn and Fe in the cladding welding wire to generate nanometer oxide particles which are dispersedly distributed, the dispersion strengthening of the cladding coating is realized, and meanwhile, the good compatibility of the cladding coating with the X80 pipeline steel base body is ensured; and the homogenous cladding coating is subjected to ultrasonic impact treatment, a plastic deformation hardening layer is introduced on the surface of the homogenous cladding coating, a composite cladding coating with the dual effects of nanometer grain and nanometer oxide particle dispersion strengthening is formed, and the surface strength, hardness and wear resistance of the X80 pipeline steel can be greatly improved.

The invention belongs to the technical field of papermaking, and particularly relates to a process method for improving the surface strength of uncoated cup paper. The process method for improving the surface strength of the uncoated paper cup paper comprises the following steps: respectively preparing surface layer slurry, core layer slurry and bottom layer slurry; wherein the surface layer pulp comprises bleached softwood pulp and bleached hardwood pulp, the core layer pulp comprises bleached softwood pulp, bleached hardwood pulp, bleached chemical thermo-mechanical pulp and broke pulp, and the bottom layer pulp comprises bleached softwood pulp and bleached hardwood pulp; respectively conveying the surface layer pulp, the core layer pulp and the bottom layer pulp to a surface net, a core net and a bottom net of a paper machine to carry out three-layer papermaking molding, and carrying out squeezing and pre-drying; and carrying out surface sizing on the paper sheet, and carrying out post-drying and calendaring treatment on the sized paper sheet to obtain the uncoated cup paper. According to the process method for improving the surface strength of the non-coated paper cup paper, the prepared non-coated paper cup paper is high in surface strength, and the process requirements of follow-up film spraying, printing and the like can be met.

This application discloses a method for printing copper-based liquid cooling components via grafting, and the copper-based liquid cooling component itself. The method includes: providing a base plate; machining positioning grooves on the base plate according to its external dimensions; etching the inner walls of the positioning grooves; sandblasting the upper surface of the base plate; embedding the sandblasted base plate into the positioning grooves; selectively laser melting the base plate; sequentially printing the bonding surface layer and the heat dissipation fin body layer using different printing strategies to obtain a blank; removing the blank from the positioning grooves and polishing it to obtain the copper-based liquid cooling component. This method solves the technical problems of base plate warping, low internal density, loose structure, and poor bonding surface strength in traditional laser additive manufacturing of copper-based liquid cooling components, achieving stable manufacturing of high-precision, high-performance copper-based liquid cooling components.

The invention provides a paper product, modified light calcium carbonate and a preparation method thereof. The preparation method of the modified light calcium carbonate comprises the following steps: carrying out surface charge modification treatment on light calcium carbonate; carrying out micro-polymerization treatment on the light calcium carbonate subjected to surface charge modification treatment; and carrying out pre-flocculation treatment on the light calcium carbonate subjected to micro-polymerization treatment. According to the preparation method of the modified light calcium carbonate provided by the embodiment of the invention, the light calcium carbonate is firstly subjected to surface modification (charge adjustment), then subjected to micro-polymerization (specific surface area adjustment) and finally subjected to pre-flocculation (overall form optimization), the modified PCC filler can be added into paper pulp for papermaking, and under the condition that the addition amount of the PCC filler is increased, the specific surface area of the PCC filler is increased, and the overall form of the PCC filler is optimized. The water filtering performance of the pulp is ensured, the retention characteristic is not deteriorated, and considerable paper physical property strength, surface strength and sizing performance are maintained. And on the premise of ensuring the running performance of the paper machine, the paper making raw material cost is reduced while the same paper quality is achieved.

The utility model relates to the field of ventilation systems, in particular to an inorganic veneering floating bead fireproof heat insulation plate air pipe, and aims to solve the problems that a traditional air pipe is made of non-metal materials, low in surface strength and easy to produce dust; the inorganic veneering floating bead fireproof heat insulation plate air pipe comprises an air pipe main body, the air pipe main body is provided with a windproof cover, the air pipe main body is composed of a plurality of floating bead fireproof heat insulation plates and a reinforcing assembly, and inorganic veneering coatings are arranged on the outer surfaces of the floating bead fireproof heat insulation plates; the reinforcing component comprises a floating bead fire-resistant heat insulation plate and a fixing frame, a threaded hole is formed in the surface of the floating bead fire-resistant heat insulation plate, a connecting hole matched with the threaded hole is formed in the fixing frame, a screwing piece penetrates through the connecting hole to be connected with the threaded hole for fixation, and the air pipe body is provided with a splicing part; the strength problem is solved, dust is easily produced, and the application range is wider.

The invention relates to the technical field of decorative paintings, and particularly discloses a color rubbing paper-plastic texture painting adopting a novel plastic paper process, which is used for improving the performance of paper and avoiding the defects of poor water resistance and poor rubbing effect of the traditional Chinese art paper material. The organic silicon and polyacrylate blended emulsion is sprayed on the surface of the paper, so that the surface strength, the wear resistance and the solvent resistance of the paper are improved, the water resistance of the paper is improved, the prepared paper has excellent stiffening effect and waterproof effect, and the rubbing prepared by paper rubbing is high in stiffening effect, good in waterproof performance and long in storage and service life; in addition, according to the technical scheme, a traditional rubbing technology is innovated, and the defects that the rubbing color is single, and the three-dimensional effect is weak are overcome; special treated paper is adopted for rubbing, three-dimensional lines are made, a multi-color spraying drawing mode is adopted, multiple layers of color textures are attached, a finished decorative picture is formed, the manufacturing effect of the decorative picture is more three-dimensional and attractive, and the decorative picture can be applied to various picture innovations in a derivative mode.

The present invention relates to manufacturing of a bag fabric and, more specifically, to a bag fabric using a high-density polyethylene (HDPE) sheet and a polyurethane sheet, and a manufacturing method therefor, the bag fabric being manufactured by laminating a HDPE sheet and a polyurethane film such that color reproducibility, color durability and surface strength of the fabric can be improved. To this end, the method comprises the steps of: preparing a colored polyurethane resin composition; fixing a release paper to a roller; applying the colored polyurethane resin composition onto the fixed release paper; drying and curing an applied polyurethane resin thin film; forming an adhesive layer on the cured polyurethane film; laminating a HDPE sheet onto the adhesive layer; and aging the laminated fabric.

The application discloses a surface sizing agent for corrugated paper and boxboard, a preparation method and application thereof, and belongs to the technical field of papermaking. The surface sizing agent is prepared by using water as a solvent, adopting an oxidation-reduction initiation system, combining with glyoxal post-crosslinking and polyaluminum chloride / aluminum sulfate post-treatment. The product has low foam, high stability and good paper machine adaptability. After the surface sizing agent is applied to the surface sizing of corrugated paper and boxboard, the ring crush index is increased by 18% to 25%, the Cobb value is reduced by more than 70%, the surface strength and breaking degree resistance are obviously improved, and the quality requirements of high-strength packaging paper are met. The preparation method is green and environment-friendly, and is easy for industrialized production.

This invention relates to the field of ceramic tile technology, specifically to a crystalline glaze powder, a crystalline glaze, crystalline ceramic tiles, and a preparation method. This application provides a crystalline glaze powder comprising the following raw materials in parts by weight: 8-16 parts quartz, 2-8 parts feldspar, 10-14 parts potassium feldspar, 30-46 parts sodium feldspar, 4-9 parts limestone, 4-8 parts dolomite, and 10-16 parts crystalline composite dry granule slurry; the crystalline composite dry granule slurry comprises the following raw materials in parts by weight: 75-85 parts ultrafine dry granules and 8-12 parts acidic yttrium aluminum composite. The crystalline glaze powder prepared by this application allows for a single firing during the preparation of crystalline ceramic tiles, ensuring the surface strength of the product, reducing overall production costs, and exhibiting good wear resistance and static friction coefficient after a single firing, with high surface smoothness. By spraying a protective glaze onto the tile surface, the crystalline glaze layer is prevented from being directly dry-polished by the grinding block during the polishing process of the semi-finished product; and color loss of the inkjet print is prevented during high-temperature firing in the kiln.

This invention discloses a high-acid-value reactive polycarboxylate and high-carboxyl fiber synergistic composition for electrostatic base paper and its application in surface sizing, belonging to the field of papermaking chemicals and paper surface sizing technology. The composition comprises water, dry solids components, and auxiliary agents. The dry solids components contain an effective component of a high-carboxyl copolymer obtained by free radical polymerization of aqueous solution. This effective component contains at least structural units derived from acrylic acid, maleic acid or maleic anhydride, and itaconic acid, and can form high-acid-value reactive polycarboxylate branches or water-soluble carboxyl copolymer branches for electrostatic base paper surface sizing. When this composition is compounded with surface starch and used in uncoated printing paper and electrostatic base paper, it helps reduce lint, dust, paper dust, and machine contamination, while also considering surface strength, water absorption, electrical stability, and repulping adaptability.

The invention belongs to the technical field of papermaking, and provides a double-coated copperplate paperboard capable of being in contact with food as well as a preparation method and application of the double-coated copperplate paperboard. The double-coated copperplate paperboard capable of being in contact with the food comprises a front surface coating, a front surface bottom coating, body paper, a back surface bottom coating and a back surface coating which are sequentially stacked from the front surface to the back surface, the body paper comprises a surface layer, a core layer and a bottom layer which are sequentially stacked from the front surface to the back surface, and the front surface bottom coating and the back surface bottom coating are obtained by coating a first coating; the front surface coating and the back surface coating are obtained by coating a second coating, the first coating comprises the following components: 65-grade ground calcium carbonate, first latex and a starch acrylate grafted copolymer, and the second coating comprises the following components: 95-grade ground calcium carbonate, second latex and a starch acrylate grafted copolymer. The double-coated copperplate paperboard provided by the invention has the advantages of high printing surface strength, high glossiness, low surface roughness, low two-side difference and low heavy metal content.

The invention provides an impact-resistant reinforced coating and a preparation method thereof. The shock-resistant strengthened coating is composed of a high-entropy alloy coating and a metal coating, the high-entropy alloy coating is a high-hardness single-phase high-entropy alloy, the high-hardness single-phase high-entropy alloy is formed by selecting high-entropy alloy elements according to the atomic size difference, the valence electron concentration, the mixed entropy and the mixed enthalpy, the atomic size difference is smaller than 7%, the valence electron concentration is smaller than 6.5%, the mixed enthalpy is smaller than 10%, and the metal coating is a metal coating. The high-entropy alloy coating is an NbHfVMo high-entropy alloy coating or a Cr < 0.15 > NbHfMoWZr < 0.1 > high-entropy alloy coating; the element in the metal coating is one of Al, Cu, Ti and Cr; according to the method, the surface strength of the tungsten alloy can be improved through the high hardness and the high elasticity modulus of the high-entropy alloy, the impact resistance of the surface of the tungsten alloy is improved through the metal coating with the low hardness, the low elasticity modulus and the high toughness, the implementation process is simple and easy to implement, and no special requirement for equipment exists.

A method includes treating a burled surface of an object using radiation or heat and setting parameters of the radiation or heat to effectuate a predetermined surface strength, hardness, roughness, coefficient of friction, chemical resistance, wear resistance, and / or corrosion of the burled surface.

The application provides a high-nickel ternary positive electrode material, which comprises a core and a coating layer, the structure of the core is whisker arrangement with internal order and outer disorder, and the outer layer of the core is further doped with an additive; the ionic radius of a doped element in the additive is 80*10 ‑12 ~120*10 ‑12 m. The high-nickel ternary positive electrode material provided by the application has a core with internal order and outer disorder, which guarantees lithium ion diffusion and improves particle strength; meanwhile, the surface strength is improved by introducing ion doping with moderate radius, which effectively improves the particle strength of the ternary positive electrode material as a supporting structure, effectively improves the comprehensive performance such as cycle and gas production of the positive electrode material, and the preparation method is simple, which is beneficial to rapid commercialization.

The utility model relates to a composite material film strength testing machine, which comprises a workbench provided with an electric control device, the fixing support is located on the workbench, and a film fixing clamp is arranged on the fixing support; the movable support is arranged on the workbench, and a detection distance is formed between the movable support and the fixed support; the detection assembly is arranged on the movable support and comprises a detection fixed plate, a detection movable plate movably connected with the detection fixed plate through a first buffer mechanism, a pressure sensor fixed to the front end of the detection movable plate, a contact rubber strip fixed to the pressure sensor and a detection movable threaded rod. One end of the detection movable threaded rod is fixedly connected with the detection movable plate, the other end is provided with a rotating handle, and the detection movable threaded rod is in threaded connection with the detection fixed plate; the rotating handle is operated so that the pressure sensor and the contact adhesive tape approach or move away from the film fixing clamp. The device realizes the function of detecting the front surface strength of the composite material film.

The present application relates to a kind of water-based quick-drying coating for casting and its preparation method, the water-based quick-drying coating is prepared by the following raw materials according to weight percentage, refractory aggregate 60~80%, binder 3~10%, suspending agent solution 0.5~5%, quick-drying aid 0.2~1.0%, dispersing agent 0.2~1.0%, defoaming agent 0.1~1.0%, water-reducing agent 0.2~1.0%, carrier liquid 14~25%.The water-based casting coating of the present application has the characteristics of short drying time, small gas evolution, high surface strength.

The utility model relates to the related technical field of composite boards, and discloses a high-performance rock wool composite board which comprises a heat insulation material, the heat insulation material is a rock wool base board, reinforced fiber gridding cloth is laid on the upper face and the lower face of the heat insulation material, and the reinforced fiber gridding cloth is basalt fibers. The heat insulation material and the reinforced fiber gridding cloth on the upper side and the lower side are sewn together through stitches which are vertically arranged, then at least one of the reinforced fiber gridding cloth on the upper side and the reinforced fiber gridding cloth on the lower side is evenly coated with a plastering adhesive coating material to form an adhesive coating layer, and the high-performance rock wool composite board of a complete structure is formed. According to the utility model, the rock wool base plate heat insulation material, the reinforced fiber gridding cloth and the stitches are fixedly combined into an integral structure through a three-dimensional coating reinforcement technology, so that the integrity of the plate is ensured, and the vertical drawing strength, the surface strength, the hardness, the flatness and the connection firmness of the composite plate are improved.

The invention discloses a preparation method and application of a composite paper surface reinforcing agent. The surface reinforcing agent comprises a cross-linked amphoteric polyacrylamide emulsion and an alkyl ketene dimer (AKD) emulsion. The cross-linking type amphoteric polyacrylamide emulsion is a cross-linking type polyacrylamide emulsion with an interpenetrating network structure, which is prepared by taking a polyvinylamine-co-sodium acrylate amphoteric polymer as a polymer emulsifier through soap-free polymerization. The preparation method comprises the following steps: firstly, taking N-vinylformamide and acrylic acid as raw materials, carrying out water solution free radical polymerization to obtain a poly (N-vinylformamide-co-acrylic acid) copolymer, and then carrying out alkaline hydrolysis to obtain a polyvinylamine-co-sodium acrylate amphoteric polymer; and performing soap-free emulsion polymerization on the amphoteric polymer serving as an emulsifier, an acrylamide monomer, a crosslinking monomer and the like to obtain the crosslinking amphoteric polyacrylamide emulsion. The surface reinforcing agent is compounded with AKD emulsion for use, the ring crush compression resistance, folding strength, bursting strength, tensile strength and surface strength of paper can be remarkably improved, and meanwhile, the surface reinforcing agent has good water resistance and moisture regain resistance and is environmentally friendly and non-toxic.