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.

Keynote paper of Composites Manufacturing Technology Symposium 6, Polymer Processing Society 9th Annual Meeting, UMIST, 5th-8th April 1993.

S F Bush

Introduction

The ultimate test of a polymer composite artefact is its entry into commercial production. It is the combination of material properties, geometrical design and manufacturing cost, not any of these separately, which will determine whether this occurs, or, having entered production will stay there.

Polymer products cannot, however, in general be defined in the way their precursor chemical monomers are, by a chemical structure, but only by effects, so that no one process either converting a monomer to a polymer, or a polymer into a solid artefact, is quite like another. More importantly, the effects specified can usually be obtained by several polymeric materials as well as possibly by metals and ceramics. An example is a pipe which can be achieved by man-made polymers, natural polymers, (e.g. wood), metals and ceramics (clays and cements), while the effects demanded may include mechanical, chemical, electrical properties, ease of installation, demountability and so on. Ultimately a polymer product provides a benefit to the customer at a cost which represents the full cost of the pathway from the feedstocks available and feedstocks themselves.

In the design of polymer product and process combinations, cost is thus an absolutely central consideration, every bit as important as material properties and thermodynamics, and without which consideration no sense can be made of the choices made by industry and no realistic view possible of the needs and opportunities for industry-linked research and innovation (Ref 1).

References

[1] R Malpas, Phil Trans Royal Society, London, A322 347-360 (1987)

[2] S F Bush, Development of new processes for the volume production of polymer composite artefacts, I Mech E Conf, Fibre Reinforced Composites, C400/029 237-243 (1990)

See also section on Systems Design & Control.

Paper to the Polymer Processing Society Annual Meeting, Hamilton, Ontario, 21st-24th April 1991

S F Bush with C G A Clayton

Introduction

Fibre-making is a multi-stage process of great complexity, which is part of an even larger, more complex process running from polymer manufacture at one end to the dyeing of woven or knitted fabric at the other. The ability of a woven fabric of say some 6000 fibres to dye uniformly is arguably the most searching test that can be applied to a fibre-making process. Since it is dependent on quite subtle features of the solid polymer structure which depends in turn on any or all of the conditions at polymerisation, drying, spinning, drawing, bulking, weaving or knitting and dyeing itself. As a material stream moves through the stages from polymerisation down to bulking, it is split between more and more material pathways, so that a fault in any one pathway at any time can infect the whole at the weaving or knitting stages where the material paths are re-integrated again.

The object of the work described was to improve and maintain the quality of bulked poly(ester terephthalate) or PET fibre, particularly as production speeds were increased. Quality here means essentially uniformity of appearance in woven or knitted fabric, and in particular the absence of stripes arising from the presence together of a few fibres which are different from their neighbours in the fabric. The crucial point is that such non-uniformity will only be apparent long after the product has left the producer’s factory. Much effort has therefore been expended by fibre-makers over the years to devise instrumental tests which can be used at the factory to predict the likely appearance in customers’ hands.

Paper to the Second International Materials Engineering Conference, the Institution of Mechanical Engineers, London,  5th-7th November, 1985

Proceedings of the I.Mech.E. 229 ISBN 085298 586.
S F Bush

Introduction

The variety of commercial polymeric materials is now so great, and still increasing, that it has become difficult for engineers concerned with the design of systems and artefacts to discern the dominant trends which should guide their choice of materials. This paper is essentially concerned with the thinking involved in a major redesign of an artefact and therefore with trends in materials cost and processing technology which display themselves over a period of up to a decade or more. This timescale is seen as important: companies contemplating a major change in a product design will look to this length of time to recover the costs involved in the purchase or substantial modification of equipment and the retraining of staff in new materials, production and servicing technologies.

While the word plastics has become embedded in everyday language to describe a familiar class of wholly or partially synthetic materials, there is in fact a continuum based on the synthetic polymer principle which embraces synthetic rubber, man-made fibres, film and sheet, GRP, composites, thermoplastics and thermosets. Oddly, the familiar term glass reinforced plastic (GRP) refers to glass embedded in a rigid crosslinked thermoset matrix which is anything but plastic. The term Synthetic Polymeric Material (SPM) will be used to describe the whole family.

The purpose of this paper is to suggest a number of the basic principles which ultimately govern the application of SPMs, and to indicate how these principles might be organised into a system for optimising design choices in the sense of the first paragraph. The organising framework is that part of Artificial Intelligence (AI) known as an Intelligent Knowledge Based System (IKBS).

See also the section on Systems Design & Control.

Report by the Working Party of the Science and Engineering Research Council, Engineering Board Computing Facilities Committee, October 1985, ISBN 0 902376 00 4.

The committee were Professor S F Bush (Chairman) UMIST, Mr R D Crook, ICI plc, Professor D Lewin, University of East Anglia, Professor C McGreavy, University of Leeds, Professor A R S Ponter, University of Leicester, Professor I M Smith, University of Manchester, Professor E B Spratt, University of Kent and Dr R D Mount (Secretary) Rutherford Appleton Laboratory.

Preface

This report is about the provision the Engineering Board needs to make over the next decade for computing facilities for the community it supports in universities and polytechnics. SERC provision for computing dedicated specifically to engineering research was first reported on twelve years ago. Following this, in 1975, the Engineering Board set up a technical group under the chairmanship of Professor Howard Rosenbrock. The outcome of the technical group’s report was the establishment of the Interactive Computing Facility (ICF) at the Rutherford Appleton Laboratory. The ICF has had and continues to have a powerful influence on the way engineering research is conducted in the academic community. Since then the provision of computing services by SERC for engineers has diversified and there have been important developments in computing technology and engineering practice. It is therefore timely to carry out a review of engineers’ needs for computing that will enable the Board to plan for the necessary provision over the next decade.

We have consulted widely to reach our conclusions, and the main items of evidence are listed in Appendix 3 of this report. The conclusions of our study and our recommendations are listed separately at the beginning of the report, with expansions on the reasoning behind them in Chapters 3 and 4. Chapter 1 presents a summary of existing Engineering Board computing provision and Chapter 2 discusses submissions received by the Working Party.

See also the section on Systems Design & Control.