Defoamer is a substance with low surface tension and high surface activity, which can inhibit and eliminate foam in the liquid, that is to say, defoamer can reduce the surface tension of water, solution, suspension, etc., to prevent foam generation or eliminate the original foam.Long-term defoaming is also known as defoaming, and the length of the defoaming time is the main sign of the quality of the defoaming agent. In most cases, the use of defoamer is to take advantage of its foam inhibition properties, rather than the initial defoamer.Defoaming and defoaming are relative, and the relative defoaming performance of products with good defoaming performance will be worse. In practical applications, it depends on the specific situation. Therefore, from the perspective of defoaming effect, defoaming agents include defoaming agents, defoaming agents and defoaming agents, which are collectively called defoaming agents. Some components of water-based adhesives are easy to produce bubbles, and have a tendency to be stable and durable. In addition, rapid mixing in production and high-speed brushing construction in use will also contribute to foam generation, so that production can not proceed normally, and affect product quality. The formation of foam to the production and coating tape to great difficulty, and make the rubber layer appear pores, affect the product outside and adhesive properties, so we must try to destroy the foam or prevent the production of foam, the most effective way is to use defoaming agent. There are many varieties of defoamer used in the water-based adhesive industry, but it mainly consists of two categories: polysiloxane defoamer and non-siloxane defoamer. Polysiloxane defoamer has strong defoaming and anti-foaming ability and is widely used in the coating industry. In the water-based adhesive industry, especially the emulsion type low viscosity system, such as film adhesive, pressure sensitive adhesive, etc., it is very easy to cause shrinkage and fisheye problems. In addition, after the emulsion film formation, due to the surface migration of silane, it will cause the later bonding strength to decline, affecting the bonding effect, so it is generally rarely used. Polysiloxane defoamer has strong defoaming and anti-foaming ability and is widely used in the coating industry. In the water-based adhesive industry, especially the emulsion type low viscosity system, such as film adhesive, pressure sensitive adhesive, etc., it is very easy to cause shrinkage and fisheye problems. In addition, after the emulsion film formation, due to the surface migration of silane, it will cause the later bonding strength to decline, affecting the bonding effect, so it is generally rarely used. In the water-based pressure sensitive adhesive and film adhesive industry, mineral oil defoamer is generally used. It is mainly composed of mineral oil, hydrophobic particles, low carbon alcohols, emulsifiers and so on. The quality of this kind of product is...

Water dispersion system is commonly used to analyze the relationship between surfactant structure and dispersion.As a hydrophobic solid particle, it can adsorb the hydrophobic group of the surfactant, and if it is an anionic surfactant, the outward-facing hydrophilic genes have the same charge and repel each other. Obviously, the adsorption efficiency of surfactants increases with the increase of the length of hydrophobic groups, so the long carbon chain has better dispersion than the short carbon chain. If the hydrophilicity of the surfactant is increased, its solubility in water is often increased, thus reducing the adsorption on the particle surface. This effect is even greater if the interaction between the surfactant and the particles is very weak.The effect is much greater. For example, when the dye water dispersion system is prepared, the highly sulfonated lignosulfonate powder for strong hydrophobic dyes can form a good thermal stability dispersion system. When the same dispersant is used for hydrophilic dyes, the thermal stability is poor, but the dispersive system with low sulfonation degree can be obtained. The reason is that the dispersant with high sulfonation degree has a large solubility at high temperature, so it is easy to separate from the surface of the hydrophilic dye which has a very weak effect, thus reducing the dispersion. If the dispersed particle itself has an electric charge, and a surfactant with an opposite charge is selected, flocculation may occur before the charge of the particle is neutralized. Only after the second layer of surfactant is adsorbed on the charge-neutralized particles can it be dispersed well. If the surfactant of the same charge is selected, it is difficult for the particles to adsorb the surfactant, and also only at high concentrations, there is enough adsorption to stabilize the dispersion. In fact, the ionic dispersants used often contain multiple ionic groups and are distributed over the entire surfactant molecule, while the hydrophobic groups contain unsaturated hydrocarbon chains of polar groups such as aromatic rings or ether bonds. The highly hydrated polyoxyethylene chain of polyoxyethylene non-ionic surfactant molecules extends to the aqueous phase in a curly shape, forming a good spatial barrier to the aggregation of solid particles. At the same time, the very thick multiple layers of polyoxyethylene hydrate greatly reduce the van der Waals attraction between particles, so it is a good dispersant. Especially the block copolymer of propylene oxide and oxyethylene, the polyoxyethylene chain length increases the solubility, and the hydrophobic group of polyoxyethylene increases the adsorption of solid particles, so both are long and are very suitable for dispersants. When ionic and non-ionic surfactants are combined, on the one hand, the molecules extend into the water phase, forming a spatial barrier to prevent particles from approaching each other; On the other hand, the strength of solid...

How to color printing ink? In the printing process, many of the color of the sample ink can not be used directly, the need for production enterprises to deploy according to the color of the sample, this process is called the color matching of the ink, and the printing plant is called the ink mixing. The color of printing ink is very important for printing, and it is also a difficult problem.The color of printing ink is very important for printing, and it is also a difficult problem. Usually the use of three kinds of primary color ink in different proportions to reconcile the special color of any color, is to follow the three primary color theory, there are certain rules.The ideal three primary colors have the same coloring force, and can be called black after equal mixing. In fact, there are optically insurmountable defects in the three primary colors, and the color mixed out is brown.Inks are mixed in different proportions to obtain different color complexions, which are biased toward one or two primary color ink mixtures with large proportions. The standard intercolor hue can be obtained by mixing two kinds of primary color inks in equal amount. Two kinds of primary color inks are mixed in different proportions, and the resulting intermediate color is biased to the primary color inks in large quantities. Printing ink color tips: (1)The color of the printing ink should be as far as possible using the same type of ink produced by the ink factory, the color saturation of the setting ink (chroma) is higher than the color saturation of the color of the two ink. (2)If you want to use several shades of ink color, should try to use the color close to the setting ink mainly to adjust the new color ink. (3)When matching colors, the variety of ink should be reduced as much as possible, because the more varieties of ink matching colors, the higher the color loss ratio, will reduce the brightness and saturation of the color matching ink (chroma), so it can be matched with a hue, do not use two colors of ink. (4)When deploying light-colored ink, white ink should be the main ink, and a small amount of primary color ink should be added. (5)When printing plastic packaging materials, in order to obtain light-colored ink and still maintain the viscosity required by the ink, diluent should be used, and try not to use diluent, because the plastic is not easy to absorb the solvent, the diluent is too much, the drying energy needs to be increased, and the bonding force is reduced because the solid content is too small. (6)Different manufacturers, different models and varieties of ink can not be mixed, otherwise it will affect the luster of the mixed printing, the fastness of the printing, and may even cause the ink gelation. 3.Make proper use of complementary color relationships.According to the principle of complementary color subtractive method, complementary color is added to achromatic. When mixing color inks, complementary colors should be used correctly.Sometim...

Pigment printing The printing method of coating printing is that the non-water-soluble substance particles with color or special effect are adhered to the fiber/fabric surface with a polymer adhesive to form the desired pattern. Paint printing characteristics 1.the process is simple and convenient, wide applicability to fibers; 2.Complete chromatography, bright color; 3.Clear outline and distinct hierarchy; 4.The disadvantage is that the feel is hard, the fastness is poor. Composition of pigment printing paste 1.Pigments (or color-changing pigments, pearlescent powder, functional powder, etc.); 2.Adhesive; 3.Thickener; 5.Water. The adhesive is known as a coarse and fine printing and dyeing aid. Rough refers to different from ordinary textile additives, the price is high, the amount of addition is small, the price of the adhesive is low, the amount is large, fine refers to the nature of the adhesive determines the key properties of the paint printing feel, contour, fastness and so on, is a high technical content of the auxiliary. Non-reactive adhesive 1.polyacrylate copolymer 2.butadiene copolymer 3.vinyl acetate copolymer Reactive adhesive Amino type, hydroxyl type, self-crosslinking type Raw materials used in adhesive: Monomer Emulgator Initiator Typical problems encountered by factories Environmental issues of emulsifiers: The NP and OP series emulsifiers widely used in the early years are prohibited for environmental reasons, and the current adhesive manufacturers generally replace them with AEO series and isomeric 13 alcohol ether series, but their emulsifying power is difficult to match the NP and OP series, and the cost performance is not high. Adhesive feel problem: Due to its product characteristics, paint printing feels worse than dye printing, domestic manufacturers generally increase the softness by adjusting the proportion of soft and hard monomers and adding silicone feel regulators, but it is difficult to perfectly balance the softness and fastness. Sinograce Chemical supply textile printing glue, as well as non-woven silk screen emulsion and nylon silk screen emulsion, welcome to buy and consult exchange