1．Technology
The ultimate objective of technological requirements is to produce normally and maintain fibre diameter. The normal state depends on the temperatures in each part of extruder and the spinning box. Therefore, the physical and chemical properties of raw materials should be well understood. There are several methods to control fibre diameter, but the best way is to control with hot-air pressure. For example, change 10μm into 1μm and increase air pressure. However, when there is insufficient air pressure, the hot-air temperature or die head temperature should be increased. Sometimes, the temperature of spinning should also be increased. The higher the temperature is, the thinner the fibre diameter is. The larger the air pressure is, the thinner the fibre diameter is. Each raw material has its decomposition temperature, therefore, the temperature cannot be increased indefinitely. Also, the temperature of extruder and spinning box should be adjusted by the variations of environment temperature.

2.Equipment
Inspect the equipment state and product quality at any time. When there is problem, it should be settled in time. The spinning jet should be changed promptly, and regular inspection is required on the actual temperatures of extruder and spinning box. When the rotation speed difference of two electric motor of receivers increases 9-10, the product diameter should decrease 1mm. Every decrease of 9-10 rotation speed difference requires increasing 1mm in product diameter.