What is special about the temperature control of polypropylene staple fiber?

Polypropylene staple fiber has a high spinning temperature (above 300 ° C), and the spinning temperature of various specifications varies greatly. Therefore, the selection and control of polypropylene staple fiber temperature is very important.

The spinning temperature is controlled too high. In addition to the possibility of broken ends of the wool, the strength of the finished product will obviously decrease, and the post-stretching will be abnormal. If the control temperature is too low, in addition to the occurrence of hard head wires and melt cracks, it will also deteriorate the tensile properties, and even fail to stretch. It is forced to reduce the draw ratio, or the stretched wire will shrink too much and cause the finished product. Elongation is too large. In addition to empirical observation, spinning temperature control is mainly based on testing the viscosity average molecular weight of oil-free filaments.

In general, the thermal insulation zone has the greatest effect on polymer degradation. Therefore, changing the temperature of this zone will change the molecular weight of oil-free silk faster. Controlling the spinning temperature is one of the keys to the production of polypropylene staple fibers.