In polyurethane waterproof coating construction often encounter some problems, so in the process of waterproof construction encountered different problems how to solve it?Sinograce waterproof with you to learn the following, polyurethane waterproof coating construction common problems and solutions. 1. viscosity (1) coating itself viscosity is very large, construction effort. (2) if the client applies roller coating and brush coating, less viscosity is needed to facilitate construction. Solution: it is recommended to use rubber or metal scraper scraping coating construction, not to use roller coating or brush coating construction.Add diluent, should do small test first. 2.A large number of bubbles or holes appear in the film Under the following conditions, the coating is prone to a large number of bubbles or holes: (1) wet or rainy weather.Do not be in wet or rainy day construction, after the rain to wait for the base dry construction, after the construction to do rain prevention measures. (2) low boiling point diluent is added to the product by the customer, and the diluent can volatilize quickly and easily. (3) the weather is hot, the base temperature is high, it is recommended to shade or evening construction. (4) loose porous base, should use special base treatment agent for base treatment, or paint appropriate dilution, the first thin coating, in order to close the base pores. (5) one-component product: the coating film is too thick at one time, so it is recommended to apply it with appropriate thin coating. (6) two-component products: construction shall be completed within the opening hours, especially in high temperature in summer;Avoid introducing a lot of bubbles by stirring at too high speed;If the ratio is not right, bubbles will also form. Solution: for the above reasons to produce a large number of bubbles or pores, it is recommended to remove and redo, or wait until the film dry, and then redo a waterproof layer on top.

The choice of solvent In the printing ink manufacturing process, in consideration of the overall solvent system of the ink volatility, to improve the printing ink solvent release and reduce the solvent organic solvent residue, the use of solvents are often several volatile mixed solvents.In the printing ink manufacturing process, the main organic solvents are toluene, butanone, cyclohexanone, ethyl acetate, butyl acetate, n-propyl acetate, isopropanol, etc., customers can adjust the volatility of the ink according to seasonal changes. The choice of pigment As a result of the market pigment grade difference, in polyurethane ink for the same resin manufacturers of the same pigment dispersion, ink stability and other aspects of the performance is often a big difference, so it is recommended that users according to their actual customer needs carefully choose pigment. The selection of additives Wax powder: in the production of polyurethane ink, the use of wax powder is often low molecular weight polyethylene wax, the relative molecular weight is generally 1000 ~ 6000, the organic solvent in the ink has a good solubility, and polyurethane resin affinity is good, at the same time has a good chemical stability.Mainly to increase the friction of the surface of the ink film, at the same time to properly alleviate the anti-viscosity of the ink itself. Dispersant: a class of surfactant, mainly used for wetting pigment surface, shorten ink manufacturing time, is conducive to the dispersion of pigment, and sometimes appropriate to reduce the oil absorption of pigment.In the production of high concentration of ink, ink yield can be reduced to prevent the ink pigment particles agglutination and precipitation has a certain effect. Polyurethane resin adhesion promoter: printing inks containing a large number of polar groups, BOPP, PE and so on nonpolar substrate surface even by corona surface treatment, surface tension in 38 dyne ~ 42 dyne, to improve the polyurethane ink on the substrate surface adhesion fastness, often need to add the appropriate ester titanate coupling agent or chlorinated polypropylene adhesion promoter. sinograce chemical is specially designed for polar base material water-based ink, with good adhesion and water-resistant printing, suitable for various materials of ink printing visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone               :+86 0551 63459511

One, extinction principle General can be divided into physical extinction and chemical extinction.Physical matting, is the addition of matting agent, so that the coating in the film when the uneven surface, reduce reflection and achieve low gloss. Two, the kind of matting agent Coating common matting agent can be divided into organic matting agent and inorganic matting agent two categories. 1.Organic matting agent Metal soap was a matting agent commonly used in early times, mainly some metal stearates, such as aluminum stearate, calcium stearate and magnesium stearate.Among them, aluminum stearate is used most.The extinction principle of metal soap is based on its incompatibility with coating components, suspended in the coating, film formation is distributed on the surface of the film, resulting in micro roughness, reduce the reflection of the film surface light to achieve extinction purposes.The disadvantage is that the polarity of the water-based resin is too different, it is difficult to disperse in the water-based system. Wax is an earlier and more widely used matting agent, coating film with the solvent volatilization, wax precipitation, with fine grains suspended in the film surface, resulting in increased scattering and matting effect.Wax as a matting agent is characterized by easy to use, and the film has a good handle and resistance to water, moisture and heat.However, the formation of wax layer will also prevent the solvent volatilization and oxygen infiltration, affecting the drying and coating film.At the same time in the water-borne resin dispersion is poor, poor compatibility, easy to demulsify or gel. Tung oil can also be used as a matting agent in the paint, the main use of tung oil in the high reactivity of the conjugate double bond, contact paint film of different medium surface: substrate and air oxidation crosslinking speed is different, so that the film surface become uneven and achieve matting effect. 2.Inorganic matting agent Diatomaceous earth, kaolinite, talcum powder and silicon dioxide are the functional fine materials used as extinction agent.When the film is dry, their tiny particles will form a micro-rough surface on the film surface, reducing the reflection of light to obtain a matte appearance.The matting effect of this kind of matting agent is restricted by many factors, the disadvantage is that the addition of matting agent reduces the coating's water resistance and alcohol resistance, the transparency of the varnish has a greater impact, can not be a good display of the surface texture of the coated object.

1.The cause of a back adhesion： (1)the paste itself anti-viscosity, especially in the wet weather easy to stick back; (2)After the printing is completed, it is packaged without perfect heat treatment; (3)adjust the slurry formula is not appropriate, adding too much transparent slurry easy to cause back adhesion; (4)transport or storage conditions are not good, in high temperature, high humidity conditions for a long time stack. Treatment methods for back adhesion: (1)choose good anti - sticky paste printing; (2)Good heat treatment for printing products; (3)Pay attention to the mixing formula, if the transparent pulp more than 80% is easy to cause back adhesion, so you can add an appropriate amount of curing agent or anti-adhesion agent for treatment; (4)Please pay attention to the improvement of transportation and storage conditions. (5)with anti - stick items to strengthen the whole processing. 2.Reasons for poor elasticity： (1)The selection of sizing technology and printing fabric do not match; (2)After printing drying treatment is not complete; (3)too much crosslinking agent will affect the size of the elasticity and softness. (4)add excessive destruction of resin tensile material (urea, ammonia). 3.Causes of color transfer phenomenon: (1)when mixing the selection of color species poor resistance to migration; (2)add excessive color species; (3)printing products dry processing; (4)transport or storage conditions are not good, in high temperature, high humidity conditions for a long time stack. Treatment of color transfer phenomenon: (1)selection of good color species resistant to migration to adjust the paste. (2)Good heat treatment for printing products; (3)In transportation and storage, as far as possible flat, do not fold together or with insulation paper. Sinograce Chemical produces water-based polymers for PE, BOPP and other film water-based inks, visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone               :+86 0551 63459511