• Choosing of adhesive type
    Choosing of adhesive type

    2021-12-07

    Choosing of adhesive 1.Principles of adhesive selection Consider the type, nature and hardness of the bonding material Consider the shape, structure and process conditions of the bonding material Consider the load and form (tensile force, shear force, peel force, etc.) borne by the bonding part; consider the special requirements of materials such as high temperature and low temperature resistance. 2.Properties of bonding materials Metal: the oxide film on the metal surface is easily bonded after surface treatment; Because the two phase linear expansion coefficient of adhesive bonding metal is too different, the adhesive layer is easy to produce internal stress; In addition, the metal bonding part is prone to electrochemical corrosion due to water action rubber: the greater the polarity of rubber, the better the bonding effect. Nitrile neoprene rubber has great polarity and great bonding strength. Natural rubber, silicone rubber and isobutyl rubber have little polarity and weak adhesion. In addition, the rubber surface often has a release agent or other free out of the auxiliaries, hindering the bonding effect. Wood: porous material, easy to absorb moisture, resulting in size changes, which may result in stress concentration. In addition, polished materials bond better than rough wood. plastic: plastic with large polarity has good bonding performance. Glass: The surface of glass is composed of numerous evenly uneven parts from the microscopic point of view. Use wettability adhesive to prevent the possible bubbles in the concave and convex.In addition, the glass is si-O - as the main structure, its surface layer is easy to absorb water. Because of the strong polarity of glass, polar adhesive is easy to hydrogen bond with the surface, forming a firm bond. Glass is brittle and transparent, take these into account when choosing adhesives. 3.the characteristics and selection of adhesives Connect various materials with different elastic moduli and thickness, especially thin materials The bonding surface is smooth and the aerodynamics is good; Good sealing performance, good corrosion performance; Prolong the service life and reduce the weight of adhesive joints Low labor intensity, low cost, high production efficiency non-conductive adhesive heat resistant seismic insulation. Our company is specialized in the production of water-based glue manufacturers, welcome to email consulting sales staff

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  • Composition of water bases adhesive
    Composition of water bases adhesive

    2021-12-03

    Composition of water bases adhesive 1.adhesive: also known as adhesive agent, after the surface treatment of two or more adhesive materials firmly connected together, and has a certain mechanical strength of chemical properties, such as epoxy resin phosphate copper oxide white latex. 2.Solid material (base material): determines the main physical, chemical and mechanical properties of rubber joints, such as epoxy resin and phenolic resin. 3.curing agent: a) curing: liquid adhesives become solid through physical and chemical methods physical methods have dissolved volatile emulsion condensation melt cooling; b) hardener: chemical substance used in the curing process 4.curing accelerator: can promote curing reaction speed, shorten the reaction time of chemical substances, also known as catalyst 5.toughening agent: can improve the toughness of adhesive curing materials, mainly esters and elastic compounds 6.packing: can improve the mechanical strength of the joint. 7.Other auxiliary materials: colorant solvent (diluent) antiaging agent and coupling agent, etc Our company is specialized in the production of water-based glue manufacturers, welcome to email consulting sales staff

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  • What are the obvious advantages of superhydrophobic coatings
    What are the obvious advantages of superhydrophobic coatings

    2021-12-01

    What are the obvious advantages of superhydrophobic coatings Super hydrophobic coating has been developed in recent years. Its use effect is very strong, and it can make water substances such as rain and snow isolate products. What are the obvious superior properties of super hydrophobic coating?Today let's have a look. 1.Self - cleaning function of superhydrophobic coating If the outer wall of the building, outdoor billboards and so on, the surface of the object is like a lotus leaf, it can keep clean motor and other small parts can prevent oil and oil climbing car windscreens are no longer always full of dust and oil particles electronic digital products are not afraid of accidental fall into the water and damage, fabric is not easy to be polluted by dirt 2. Drag reduction function of super hydrophobic coating When ships travel on the surface, they need to consume a lot of energy to overcome the frictional resistance during the journey, even for underwater vehicles like submarines, up to 80%.For transport pipelines, such as oil (water) pipelines, almost all of the energy is used to overcome frictional resistance on fluid-solid surfaces.With the development of mems, the size of the mechanism becomes smaller and smaller, and the friction force of the solid-liquid interface becomes larger and larger. Frictional resistance problems such as microchannel flow have become important constraints for the development of related devices.Therefore, minimizing surface friction resistance is the main method to improve speed and save energy. Although the artificial preparation of superhydrophobic surface started late, it developed rapidly and its preparation methods became more and more effective, mainly including template method, electrostatic spinning method, phase separation method, self-assembly method, sol-gel method, etching method, hydrothermal method, chemical deposition and electrodeposition method, nano silicon dioxide method and corrosion method.

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  • Mechanism of action and development trend of defoaming agent for waterborne coatings
    Mechanism of action and development trend of defoaming agent for waterborne coatings

    2021-07-29

    Bubble control is necessary in many industries, such as papermaking, water treatment, pharmaceuticals, dyes and coatings.With the continuous upgrading of national environmental protection regulations and the continuous improvement of residents' environmental awareness, water-based coatings have made great progress.Emulsifying agent and wetting dispersant in waterborne coating formula reduce the surface tension of the system and stabilize the bubbles in the system easily.The existence of bubbles will have a negative effect on the production and coating of coatings.During the grinding process of paint, the "air bag" formed by bubbles around the filler reduces the transfer efficiency of shear force and increases the grinding time.After coating, the residual dry foam on the surface will not only affect the appearance of the coating, but also become the center of corrosion, reducing the durability of the coating.In order to eliminate these problems, almost all waterborne coatings need to add defoaming agent.The active component of defoaming agent can achieve the purpose of defoaming by interfering with and destroying the stabilizing effect of bubbles.Different types of defoaming agents act in different ways, so understanding the mechanism of action of defoaming agents can help to systematically adjust the key physical and chemical parameters, so that the main steps in the mechanism can be controlled to achieve the best defoaming efficiency. 1, the stability of bubbles Water - based coatings in the production process, mechanical mixing is easy to bring air into the system.In the process of coating construction, brush, roller and spray are easy to bring gas into the wet film.Other porous substrates, such as wood panels and cement, release gases into the film as the paint wets and penetrates.The gas brought into the coating system is surrounded by the liquid phase and forms a bubble, and relies on electrostatic action and surface tension gradient to maintain stability. 1.1 Electrostatic Action Water-based coating formula contains a variety of surfactant substances, the special point is that the molecule contains a polar or charged hydrophilic end base and a hydrophobic hydrocarbon chain.This unique molecular structure makes it easy for surface activators to form micelles in a directional arrangement at the gas-liquid interface, as shown in Figure 1, with the hydrophilic end facing the water phase and the hydrophobic end facing the air. Because the density of air is less than the paint, so once the bubble will rise to the paint interface.According to Stokes' law, the bubble rising rate depends on the radius of the bubble and the viscosity of the paint [4].The larger the half diameter of the bubble, the lower the viscosity of the coating, the faster the bubble rise.Microbubbles usually exist in coatings with large specific surface area, resulting in high surface freedom energy.Thermodynamically, microbubbles are so unstable that they spontaneously fuse wit...

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