Prosyma Research Ltd report to CaMac Corporation

S F Bush

Summary

A visit was made to CaMac’s factory at Bristol, Virginia, during the week 5-9 July 1993. Subsequently one day was spent checking on some of the polymer mechanisms and systems which the visit suggested might have a bearing on the operations involved.

Given the complexity of the operations at CaMac, and the short time expended, this assessment risks being superficial. Nonetheless in accordance with the brief the scope is broad. Comments are made on organisation, the performance of the three new fiber-making processes (Nylon 6, Nylon 6.6, Polyester (PET) and Polypropylene (PP)), the relation of technology to markets, color and the application of a systems approach to production control and product quality.

My thanks are due to the many CaMac staff I talked to and to Drs Britton and Studholme from CTC, all of whom unfailingly did their best to answer my questions.

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.