Analysis of Burning Phenomenon of Intermittent Small Bulk Polypropylene Powder

In recent years, China's small bulk polypropylene production industry has developed rapidly. In the domestic plastic packaging industry, the dosage is constantly expanding. However, the intermittent production process has many shortcomings in the small bulk polypropylene products. Because of the different amounts of propylene, catalyst, triethylaluminum (AIEt) activator (cocatalyst) and hydrogen added in each batch, these are not the same. The method of mixing raw materials, the time and the reaction parameters of the operation control are also different, and the difference in the equipment itself causes the yield and quality of each batch of polypropylene products to be different.

Among them, the phenomenon of local melt discoloration and agglomeration which occurs during storage and transportation of small bulk polypropylene powder is a serious quality problem. The small bulk polypropylene powder after the burning phenomenon has a brownish color, a crisp texture, and agglomeration. During the burning process, the small bulk polypropylene powder has a high internal temperature and emits a strong pungent odor. Most of the burning phenomenon occurs in the packaged products, but the small bulk polypropylene powder discharged on the spot occasionally has a burning phenomenon. When the summer temperature is high, the small bulk polypropylene powder stored outdoors has a burning phenomenon. More. The burning phenomenon not only causes some products to be unusable, but also causes a large change in the melt flow rate of the batch.

Through the analysis of the burning phenomenon of intermittent small bulk polypropylene powder, the reason of the burning phenomenon of intermittent small bulk polypropylene powder was found out.

Improve the quality and stability of the raw material propylene by strengthening technical transformation and production monitoring; adding an appropriate amount of triethyl aluminum (AlEt3) activator, that is, selecting a suitable molar ratio of activator (Al) to polypropylene catalyst (Ti), In order to reduce the residual amount of AlEt3 activator in the product and reduce the discharge temperature (discharge temperature should not exceed 45 °C), the problem of intermittent small bulk polypropylene burning material is basically solved.