Some stone when spraying sand drop more, serious when can reach about 1/3, resulting in waste. In addition to the reasons of the construction method. Raw materials and formulations may also cause the above phenomena. Currently used for stone sand with artificial sand and natural sand two, according to the survey, natural sand preparation really stone paint, sand drop volume compared with the artificial sand less. This may hardness, surface state and the related. In general, easy off the sand with high hardness, surface is close smooth sand. In addition, the preparation of paint, sand gradation is also very important. Graded appropriate lacquer spraying sand drop phenomenon not only less, but the coating more closely. So in the preparation of lacquer, as far as possible the use of natural sand, sand and make certain gradation. In addition, paint consistency on sand off phenomenon when spraying to also have certain effect. Coating is too thick, the construction is difficult, too thin it sand on the wall at the initial viscosity is too low, will cause the sand falling. Therefore, in the construction of no difficult circumstances, as far as possible to improve the coating consistency, it will help to solve the problem of falling sand.
Good coating quality of the paint should be very hard, nail cannot be pulled. If the weather conditions are good under construction three days later still available nails. Should be regarded as the coating is too soft. The cause of paint is too soft emulsion inappropriate choice is the main. Many manufacturers in the preparation of paint, with the preparation of emulsion paint the same, this is wrong. Real paint formulation of emulsion containing Tong is low, the film because there are a lot of sand makes the coating is not close enough. So we should choose higher bond, the minimum film forming temperature is higher for some of the emulsion. According to the research for the bond strength of the prepared emulsion paint shall not be less than the 3MPa. minimum minimum film-forming temperature may result in low temperature is not easy to film defect film temperature should not be lower than 2010 higher, can through the appropriate add coalescent to solve. Assistant of film forming can be completely volatile coating, drying, generally will not influence the properties of the coating. More use of emulsion paint production is drunk vinegar 12 in lacquer in use and has a good effect, the dosage is generally added every one hundred emulsion 5. Winter may be appropriate to add some.
As a stone into acrylate emulsion film additives should have good water resistance after drying, so the coated with water after drying should not occur white phenomenon. But some stonelike coating in every time it rains later. Will white, coating becomes loose, and in after the rain stopped, the sun drying, coating and the restoration of the original color. Through analysis, this is because the water resistance of the coating is not good, absorb the water caused by. From the analysis of structure of polypropylene acid cheese. Lacquer coating should have good water resistance. But because the acrylic MOET emulsion of surfactants in synthesis, some manufacturers in order to increase the stability of the emulsion, greatly exceeding surfactant used; some manufacturers in the preparation of carboxymethyl cellulose lacquer is added, the B tomb cellulose material as a thickening agent, and adding sodium benzoate as a preservative, these matter is water-soluble or hydrophilic, stay in the coating film, greatly reduces water resistance of coatings. Experiments show that, the pure acrylic emulsion mixed with quartz sand without any additives. Spray coating, and the water absorption rate was 0.42%; while in the paint with 0.4% hydroxyethyl cellulose, bibulous rate is increased to 4.3%. because of stonelike coating thickness, once absorbed moisture, not easily released in a relatively short period of time. Thus the appearance of hair white, coating porosity results. In order to solve the above problem, can improve raw materials and formulations. First, should choose the outstanding quality of emulsion, recent development of silicone modified acrylate emulsion (emulsion) itself has a hydrophobic good. Can invade effectively resist moisture. Secondly, should choose a thickening agent special. Thickener thickening effect is good, less dosage, so as not to cause substantial changes in properties of the coating. There are many thickener are available on the market. Preservatives also should choose a special material. Recently, the organosilicon waterproof liquid current market supply with lacquer. Received good results beat all. Rain on the surface of the coating is beads rolled without infiltration coating, can make the paint is not only decorative effect, and have waterproof function.