Spinneret stretching in the wet forming zone 1. Characters of the stretched state of the spinning line in the forming zone (1) Spinneret stretch rate: a(%)= (VL-VO)/VO*100(2) Spinneret stretch ratio: ia= VL/VO= a/100+1(3) Average Axial Velocity Gradient: (x)a= (VL-VO)/Xe In the above formula

Affects solubility about stucture(一）Infuence of macromolecular chain structure1. The stronger the intermolecular force,the less likely the polymer is to dissolve.The intermolecular force is t,If the solution can weaken the forces between the macromolecules,it will increase the solubility of the

Dissolution of polymerCharacteristics and thermodynamic interpretation of the dissolution process（1）Characteristics of polymer dissolution processThe dissolution process of polymer is the process of polymer macromolecules under the action of solvent molecules, so that the interaction between macromo

Spinning waysWelt spinningWet spinningCompositiong of spinning systemunitary（high polymer）Binary(dry)high polymer+soventbinary(wet)high polymer+sovent+sedimentSolidification process theoryHeat transrferHeat transfer、mass transfer、diffusion、 phase separation heat Spinning speedHundreds to thousands p

Wet spinning process The spinning solution by mixing、filtering and defoaming after spining preparing ,send to the spinning machine. After computing by spinning pump,passing by candle filter gooseneck goes into the spineret.Solution from spineret pores to coagulation fluid. The solvent in the solut

Spinning solutions are prepared in two ways for solution spinning. One-step method:polymer is used to spin directly.It is why this is called one stop method.But it must use  homogeneous polymerization.Only wax nylon can be used in one step. Two-step method:First, the solution obtained by polymerization is separated into granular or powdery fiber forming polymer.After,The solution is dissolved into spinning solution.This method is called the two-step method.

Chapter I Overview