Automation of the calculation system for spinning of polyester fibres and thread

Abstract

Polyester fibres and thread are spun from polyethylene terephthalate (PETP) melt. Spinning from a melt is determined by the heat transfer and deformation of the spun fibre. Calculation of the dynamics of the processes, the basis of a mathematical model of spinning from a melt in the verticaldirection, called the "thin fibre theory," is a method of investigating spinning [1].There is a system of consistent differential equations in partial derivatives which correctly describe the dynamics of spinning from a melt in a wide range of variation of the parameters [2]. A numerical solution is possible for the given conditions, i.e., for a melt of any type of polymer with consideration of cooling, the effect of the forces of inertia, air drag, surface tension, and gravity for both steady-state and transient spinning processes. A two-dimensional sweep along axes x (vertical length of the spinning zone) and t (time) is one method of solution. A system of ordinary differential equations with equality of the derivatives in time to zero is solved in practical applications. The cause-effect relations of the model of formation of the f'dament and the results of some calculations are reported in [3].We investigated a model of steady-state spinning. The software system of engineering calculations of spinning from PETP melt is described.The system of spinning calculations (SSC) was constructed with the block-module principle. The software blocks ("Starting data," "Solution," "Physicomechanical indexes," "Output of results") which execute the individual procedures are combined in an automated system software module. The software developed is designed for calculating vertical spinning of polyester fibre with a spinneret draw ratio (Vr) within the limits of 1 < V r _< 1000. The density and heat capacity of the melt were set as in [4].The "Starting data" block was organized to work with the software with minimum information on the technological parameters of the process.Definition of one of the determining parameters -the consumption of polymer (Gll), spinneret draw ratio (Vr), final linear density (Dte x) -provide access for input of the starting data: The reference values of the variables (after running the software module) correspond to a variant of the practical calculation and are noted by equalities. The starting data in Dos. 27 are given at the stated intervals.All-Russian Scientific-Research Institute of Synthetic Fibres, Tver'.