Temperature Control: The temperature of each section is set according to the polymer characteristics (type, molecular weight, etc.). Specific selection requires careful consideration of the polymer characteristics (such as polymer type, relative molecular weight and distribution, pellet size, etc.) and the structure of the screw extruder to prevent overheating degradation or incomplete melting.
Melt Viscosity: It needs to be controlled within a suitable range. Too high a viscosity will lead to uneven flow, while too low a viscosity will affect fiber formation.
Spinneret Design: Orifice diameter, aspect ratio, etc., affect the melt expansion ratio and need to be optimized to prevent melt fracture.
Cooling Conditions: Parameters such as wind speed and temperature regulate fiber orientation and crystal structure. The wind speed and temperature in the cooling chamber must be kept uniform and constant to ensure a constant temperature distribution, velocity distribution, and solidification point position of the melt stream during spinning, thereby stabilizing the fiber structure.
Solidification Point Control: The viscosity of the melt stream continuously increases during cooling. When the viscosity reaches a critical value and the winding tension is insufficient to further refine the fiber, the solidification point is reached. The location of the solidification point is crucial for fiber structure formation and is influenced by both cooling conditions and winding tension.
