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...

UV plate digital jet painting on glass, ceramics, PMMA applications UV flat-panel digital painting print developing rapidly in recent years. According to the statistics of international authoritative consulting institutions, the annual growth rate of UV wide-format printing in the Chinese market is around 84%. Especially on hard substrates such as glass, ceramics, acrylic, etc., UV flatbed digital inkjet printing has shown great advantages over digital inkjet printers using solvent-based inkjet. However, UV flat-panel digital painting printer in glass, ceramics, acrylic on the further development and some problems need to solve. (1)UV plate digital inkjet market growth UV platform comprehensive UV curing ink print machine with the advantages of the two aspects of digital jet printing technology, represents the development trend of digital jet printing technology, is the key of the print at home and abroad vendors would product development platform of UV spray machine's work efficiency and printing quality is very high, can in a variety of material surface color printing, not only can printing soft material, but also to develop in the direction of diversification, such as in a glass on the wood floor ceiling materials such as ceramics can be printed out beautiful patterns .in 2005, the international authoritative advisory body had predicted,From 2005 to 2010, the average growth rate of UV wide-format inkjet printers around the world reached 68%, among which the Asian growth rate reached 73%. This year, China, which has occupied 50.5% of the Asian market share, will reach the highest average growth rate of 84% UV plate digital inkjet market growth. (2)Market positioning of UV flatbed digital inkjet The success of UV flatbed digital inkjet printing lies in its accurate positioning. In the fierce competition the printing market, competitors of UV flatbed digital inkjet mainly come from two aspects. On the one hand, solvent-based digital inkjet printing will continue to be a huge competitor for UV flat-panel digital inkjet printing because of the low price of printing machinery and consumables. The survey results show that, despite the decline, the market share of solvent-based wide-format inkjet printers is 33.6%, which is three times that of the UV-jet wide-format inkjet printer market share of 11.7%. There is no clear advantage in soft materials and other absorbable hard substrates UV-curable inks, while digital inkjet devices using  (3)solvent-based inks will maintain their current advantages. Screen printing is another competitor of UV flatbed digital inkjet. Unlike digital inkjet printing using solvent-based inks, screen printing can be used for printing a variety of soft and hard materials. However, due to the high cost of plate making, etc., screen printing is only suitable for medium and long version of job printing. UV plate digital inkjet printing complements the traditional screen printing process, not only for small print jobs, ...

Water-based wood lacquer can be used to apply. The characteristics of the brush method is simple, easy to master, fast coating speed, and can eliminate the brush method commonly seen bubbles and brush marks and other shortcomings. This is because the paint left on the surface of the wood is very thin and the pressure of the brush is high, which makes the air in the wood grain and micro hole easy to be removed and impossible to leave too much paint. Wipe the silk wadding group that besmear USES to ask to absorb fluid ability big, soft, do not drop fiber, after the group becomes a group, use clear water bubble first wet, squeeze go to redundant moisture, cannot drop water, ability dips in lacquer construction next. Wear rubber gloves when operating. Most of the water-based paint is too viscous and not suitable for direct rub, to add 10% ~ 30% of the tap water after dilution.In order to exempt wood grain because of water bilge rise and rise burr, had better besmear first dewaxing shellac is sealed bottom, after the sand paper of 600# above burnish level off, brush lacquer of lacquer of implement of water quality wood again.Old paint or wood surfaces suspected of being greased must be sealed with shellac. When erasing, start from one side of the woodwork and rub the entire line to the other side. At first the strength should be light, not excessive extrusion, in order to avoid too much on both sides of the silk Ⅲ extrusion coating, coating is too thick.Each line should be brushed to the other side with slightly less pressure. Wipe line by line, each waterborne wood paint line overlap 1 ~ 1. 5 cm wide. The corners of the silk floss can be squeezed into the corresponding shape of rub. Because brush besmear film is very thin, dry very fast, once discover leakage besmear or paint quantity is overmuch want to deal with immediately. Under normal circumstances half an hour after the second coat can be wiped, winter can be extended to more than 2h. Each coat should be sanded with 600# or more sandpaper and dusted with a damp cloth. The rub of lubricious paint besmear method is same, the lap that just wants to notice two lines of paint should be as far as possible little, otherwise lap the color slants deep. After lubricious lacquer goes up, had better cover a few varnish try to protect. Furniture lacquer finishes besmear after outfit, dry thoroughly, can undertake waxing polishing finally, make its exterior more beautiful.

      Plasticizer is widely used in industrial production of polymer materials auxiliaries, also known as plasticizers. All substances added to polymer materials that increase polymer plasticity are called plasticizers. The use of plasticizer can improve the properties of polymer materials, reduce production costs and improve production efficiency. is a class of important chemical product additives, as additives are widely used in plastic products, concrete, marl, cement, gypsum, cosmetics and cleaning agents and other materials, especially in polyvinyl chloride plastic products, in order to increase plastic plasticity and improve the strength of plastics, phthalates need to be added, which can sometimes reach 50% of the product.       The main plasticizer is compatible with the resin, its permeability is small and its volatility is low, which can improve the plasticizing efficiency. The main plasticizers commonly used are phthalates and phosphate esters. The secondary plasticizer is also called auxiliary plasticizer, and its main function is to use it with the main plasticizer to reduce the cost. The common secondary plasticizers are cold resistant and cyclic plasticizers such as aliphatic dicarboxylate.