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    Home > Coatings News > Paints and Coatings Market > Paint common sense: paint color problems and Solutions

    Paint common sense: paint color problems and Solutions

    • Last Update: 2020-04-03
    • Source: Internet
    • Author: User
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    Core tip: problem 1: the color matching formula has not changed, but the color difference is very large Reason: 1) Difference between batches of color paste (control range of coloring power: 100 ± 5%) 2) Differences between batches of coating raw materials (covering power, achromatic power and luster) 3) Difference of compatibility between color paste and coating (different compatibility, different colors and hues displayed) Solution: Try to use the same batch of color paste from the same manufacturer The raw materials of the coating shall be replaced as little as possible When changing the color paste, the compatibility test between the color paste and the coating shall be done first Do a small sample experiment before adjusting the large sample Question two: Paint knowledge how about Akzo Nobel Powder Coating Recommended introduction: powder coating is a kind of coating with different form from general coating, which is in powder form

    It is a new type of coating, because of its own advantages and more and more known by people

    Let's introduce Akzo Nobel Powder coating

    Akzo Nobel Powder coating is a cost-effective coating solution, which can be applied to different kinds of products

    After the treatment of static electricity and fire baking, a tough and durable coating surface will be formed, with the least impact on the environment

    Since the introduction of this technology, powder coating has been able to continue to maintain the Home of coatings: problem 1: the color mixing formula has not changed, but the color difference is very large: 1) the difference between batches of color paste (the control range of color power is 100 ± 5%); 2) the difference between batches of raw materials of paint (the difference of covering power, color fading power and luster); 3) the difference of compatibility between color paste and paint (the difference of compatibility, the difference of color and color displayed) solution: Try to use the raw materials of the same batch of color paste paint from the same manufacturer as much as possible

    When replacing the color paste, first do the compatibility test between the color paste and the paint

    First, do the small sample test before adjusting the large sample

    Second, the color floats on the surface when the color paste is added to the paint

    First, the surface tension difference between the color paste and the paint is too large In general, anionic or ionic polyelectrolyte dispersant is used for coating, while non-ionic or part of anionic dispersant is used for color paste to make the surface of white pigment and colored pigment absorb different wetting dispersant with different surface tension

    2) the compatibility between pigment and paint is not good

    The emulsifier outside the emulsion particles is not compatible with the surfactants outside the pigment and filler particles, resulting in flocculation of the pigment) 3) the hydrophile lipophilic balance between the color paste and the coating does not match the oil affinity material, the surface tension of the oil affinity end is small, and it is easy to float to the surface 4) the influence of thickeners is not good

    Some pseudoplastic associated thickeners have a great affinity with surfactants with higher HLB value, which makes them desorb on the surface of pigment, resulting in the aggregation and flocculation of pigment and floating color

    The solution: the best way to control the floating color is to choose a suitable wetting and dispersing agent, adjust the surface properties of particles, and adjust their movement balance No matter what causes the flocculation, floatation and color floatation of colored pigments, the wetting dispersant can be used to deflocculate, improve the surface properties of particles, prevent or control the color floatation

    In the process of controlling the color floatation, several kinds of color floatation phenomena can be transformed to control the color floatation

    If the color of the floating is the color of the color paste, it means that the HLB value of the coating is larger and more hydrophilic

    In the process of preparation of the base paint, the additive with low polarity and lipophilic is added to reduce the HLB value of the coating

    If the color of the floating is white, it means that the HLB value of the coating is smaller and more lipophilic

    In the process of preparation of the base paint, the additive with hydrophilic is added to increase the hydrophilicity of the coating

    Some systems can resist coating Floating color, adding anionic wetting dispersant in the finished paint, adsorbing on the surface of carbon black or organic violet pigment particles, improving the surface properties of pigment particles, enhancing the polarity, these nonpolarity weak polar particles have the same polarity as white particles, and have the same degree of adsorption flocculation as polymers, so they have the same movement ability in the film drying, controlling floating color

    In order to balance the surface tension and control the blooming, the surfactant which can reduce the surface tension is chosen, and the silicone surfactant is often used, which can transfer to the surface to form a single molecular film during the drying process of the film

    Add some additives that can produce thixotropic structure, such as kaolin, or silica, to form a network structure in the paint film, prevent pigment separation, control pigment flocculation, sedimentation and Bernard swirl flow, reduce the phenomenon of floating color and flower, so as to prevent floating color or flower

    Question three: there are obvious reasons for roller printing in roller painting process: 1) uneven thickness during brushing operation 2) no wet connection 3) compatibility problem 4) less than 5 in latex paint and less than 6 in latex paint) the wall is not a construction solution: mainly for compatibility problem solving 1) mechanical dispersion (paint)

    When the color of the paint is dispersed by a certain mechanical force, the color can be displayed

    2) after adding the wetting agent (color paint) and the wetting agent, the color becomes darker, which means that the color difference between the paint and the board becomes smaller, and there is no obvious brush mark after brushing

    3) adjust the paint formula (basic paint) and change the wetting dispersion thickening system of the paint to solve the compatibility problem between the paint and the color paste Question four: there are obvious rain marks on the surface of the varnish after the rain: 1) the poor water resistance of the base paint (too strong hydrophilicity, too much wetting agent or too much amount of hydrophilic additives), 2) too high moisture content of the substrate or 3 of the environmental humidity), sealing the primer, not achieving the effect 4

    1) Try to use less surfactant, try to use silicone and reduce the hygroscopicity 2) use fluorine modified resin or auxiliary, Enhanced water repellency and anti fouling

    3) use water resistant emulsion 4) to coat the varnish on the surface five: after the rain, the color of the varnish surface has obvious reasons for fading: 1) the construction time of the paint film is insufficient, and the rain water is less than 2 hours after the construction

    2) the coating PVC concentration is too high, that is, the emulsion is too low or the volume is too high 3

    1) increase the content of the emulsion 2) choose the water resistant emulsion problem six: after a period of time, the wall has obvious fading (flower) reasons: 1) the latex content of the coating is lower 2) the paint has poor water resistance 3) the paint house is focused on coatings, diatom mud, oil paint, coating technology, fire retardant coatings, news information and coatings, diatom mud, paint and coatings

    Coating technology, decoration knowledge and decoration effect drawing of fireproof coating,
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