Paper to the Polymer Processing Society Annual Meeting, Yokohama, Japan, 8th-12th June 1998, paper 10-04.

S F Bush with C G A Clayton and S Baillie Strong

Introduction

Earlier papers (1991, (1995a, (1995b) have described factory control systems based on relating the appearance of woven or knitted assemblies of textured, dyed or pigmented polyester or nylon fibres to variables in the spinning and texturising processes. As part of this programme quantitative relationships between changes in the appearance of woven or knitted dyed fabric and changes in process variables such as windup speeds, fibre cooling rates, and polymer intrinsic viscosity have been inferred from large quantities of factory data. The appearance of carpet or fabric made up of prepigmented filaments is generally less sensitive to process variation than is fabric made from dyed fibre. However, the quality of both classes of product are very dependent on minimising variations in polymer morphology, the effects of which are often only apparent in the hands of customers.

Because dyestuffs tend to accumulate in the less ordered regions of the polyester fibre, and the rate of diffusion differs markedly in the crystalline and amorphous regions, dye uptake within a given time may be taken as a sensitive indication of morphological development. Moreover different dye molecules respond differently to different morphologies and therefore provide an additional and sensitive way of validating the models. The present paper outlines the basis of a model which has been used to predict morphological development at spinning, drawing and texturing, and combinations of these processes.

References

[1] S F Bush and C G A Clayton: “Analysis and Control of Variability in the Fibre-Making Process”, 7th Ann Mtg Poly Proc Soc, Hamilton, Canada, April 11-14 (1991)

[2] S F Bush and C G A Clayton: “Intelligent Manufacture of Polyester Fibres on the Full Scale”, 11th Ann Mtg Poly Proc Soc, Seoul, Korea, 27-30 March (1995)

[3] S F Bush: “Characterization of Pigment Distribution in Extrusion of Synthetic Fibres”, Poly Proc Soc Euro Mtg, Stuttgart, Germany, 26-28 Sept (1995) KN1-01

See also the section on Systems Design & Control.