Research On The Preparation Of Artificial Marble By Gradient Compound Method

The existencing questions of the traditional compound artificial marble have been researched. First, to improve the thermal expansion of the external layer and structure layer through increasing different paddings, the low intensity, the big density and bad mechanics performance for instance. While being used, it is easy to be laminated for a long time and so on.Each influence factor considered, a best allocated proportion has been determined. What moreover, a transitional layer has been made between the external layer and the structure, and the component of transitional layer is changed gradiently, which can alleviate the thermal load under changing temperature, and can solve the lamination question of the product in the long term.The influence of the coefficient of the thermal expansion to the external layer of the compound artificial marble has been studied through different single filling materials and the mixture of the two different filling materials. The results show that when packed with single filling materials, the filling materials of different size may have different effects. After overall factors of intensity, operational and so on being considered, the best ratio of padding to resin is determined: mixing filling materials/resin is 2.5:1, the ratio that CaCO3 of 0.074mm/(0.125～0.1875mm) color sands is 2:1, the coefficient of thermal expansion is 1.85×10-5/℃。Take the MOC as the structure of artificial marble, the problem of the bad mechanic performance is overcomed. The thermal expansion of the structure layer has been improved through filling different single filling materials and the mixture of the two different filling materials. The results show that the coefficient of thermal expansion could be lowered through increasing of some filling materials of high coefficient of thermal expansion. With the increasing of the filling materials, the coefficient of thermal expansion is increased. The best ratio of padding to resin is determined: the mount of polystyrene grain is 35%, peanut shell grain is 5%, the coefficient of thermal expansion is 1.08×10-5/℃.Based on the research above, the method of vacuum emulsion impregnating has been taken to improve the water resistance of structure level. The best conditions of vacuum emulsion impregnating are determined: taking the mixed emulsion as the impregnating emulsion, the viscosity is 1050mPa·s, the time is 120min, vacuum degree is 0.07 MPa, softening coefficient is 0.95.Three material systems of the transitional layer are used, namely chlorine oxygen magnesium cement and polymer emulsion system, magnesium phosphate cement and polymer emulsion system, phosphoric acid aluminous cement and polymer emulsion system. The best formula of the transitional layer is determined: KT8034A and chlorine oxygen magnesium cement is mixed with the ratio of emulsion to cement as 10%, 20% and 30% and it is mixed with gradient method. Then the banding intensity is 3.2Mpa, the thermal expansion efficient is 1.21×10-5/℃.