Research Of The Production Of Polyethylene Wax Powder By Spray Drying Process

Polyethylene wax is refers to the low degree of polymerization which has low molecular weight. And in white or light yellow powder or flakes of waxy appearance and used in plastic, paint, printing ink and other industries as processing aid. It is mainly used as a pigment dispersant, processing release agent, lubricant, and paint the matting agent and so on. Common used methods of polyethylene wax was water emulsification method and direct blend using, etc., but after micronization, due to the particle size, narrow distribution, uniform quality, thus has a larger specific surface area, higher surface activity, faster dissolve (melting) speed and chemical reaction speed, can enlarge the using range of polyethylene wax and improve its effect as additives.General method of micronize polyethylene wax method is the airflow pulverization and solvent precipitation. In this paper, the spray drying of polyethylene wax powder prepared was first make raw material of the melt into liquid under certain temperature, and then make material liquid into tiny droplets through a special atomizer, the tiny droplets cooled into a fine powder at last. By spray drying method has the advantage of low energy consumption, less investment and good product granularity compared with the mechanical crushing and airflow smashing. But the aspect of the application research reports have seen very little. So this paper conducted some research and discussion on this, including the following aspects:(1)The paper research on the temperature sensitivity of the polyethylene wax though thermo-gravimetric analysis (TG)and analysis of differential scanning calorimeter(DSC). It come to a conclusion that the polyethylene wax it used in this paper was completely fused at above120℃, and under200℃material hardly happen oxidation decomposition and can use the method of spray drying production of polyethylene wax powder.(2)Studied the effect of the spray characteristics of average particle size of product and discusses the influence of the liquid pressure, gas pressure, gas flow rate to the particle size of product. It come to a conclusion that with the liquid pressure of5MPa, the gas pressure is0.8MPa, gas-liquid mass flow ratio is1.5, the airflow through the diameter of0.8mm-pressure type composite atomization nozzle it can get the products in average particle size of85μm.(3) The study have separately used raw materials and products in proportions of 5%and10%respectively to preparation of brilliant blue masterbatch. Then coloring masterbatch staining for polypropylene and through a microscope observation of the dispersion of pigment particles. Analysis of the effect of two kinds of polyethylene wax dispersed pigments and get a conclution that polyethylene wax which after micronization has better effect than flaky wax in pigment dispersion.(4)At last, the main problems and solutions with industrial production of polyethylene wax powder has been discussed. And designed a set of can be used for industrialized production of polyethylene wax powder production process, mainly includes the feed system and spray system and product collection system of main equipment and technological process.