Analysis of polyethylene pyrolysis
聚合法生成的聚乙烯蜡分子量分布窄， 相对分子质量大小可以人为控制，但必须在大装置上进行，资金投入大。国内厂家一般采用高分子量聚乙烯的热裂解法生产， 这种方法采用的原料可以是聚乙烯树脂，也可以是聚乙烯废塑料，前者制得的产品等级高，后者制得的产品等级低。高分子量聚乙烯在隔绝空气的条件下可以热裂解为低分子量的聚乙烯蜡， 这样制备的聚乙烯蜡与结构有关的性质（如结晶度、密度、硬度和熔点）都受到裂解原料的影响。裂解加工方法分为裂解釜法和挤出法。裂解釜法是间歇式加工方法，适合于生产量较低，产能较小的厂家；挤出法是连续化生产，适合于生产量大，产能高的企业。
The molecular weight distribution of polyethylene wax produced by polymerization is narrow, and the relative molecular mass can be controlled artificially, but it must be carried out on large installations with large investment. Domestic manufacturers generally use high molecular weight polyethylene to produce hot cracking. The raw materials used in this method can be polyethylene resin and polyethylene waste plastic. The former is made of high grade and the latter has low grade. High molecular weight polyethylene can be pyrolyze into low molecular weight polyethylene wax under the condition of isolation air. The properties of the polyethylene wax related to the structure, such as crystallinity, density, hardness and melting point, are affected by the cracking raw materials. Cracking process is divided into cracking kettle method and extrusion process. The cracking process is a batch processing method, which is suitable for manufacturers with low production capacity and small production capacity. The extrusion process is a continuous production, which is suitable for large production and high productivity enterprises.
Polyethylene wax can be prepared from recycled polyethylene solution. The raw materials of the technology are very rich and cheap, the process is relatively simple and the operation cost is low.