I. Porat

The Objective Assessment of Fabric Pilling. Part I: Methodology

The paper describes the application of laser triangulation to the grading of fabric pilling. Part II goes further to compare the experimental results with the corresponding gradings as assessed by a panel of experts.

Measurement of Fabric Roughness by a Non- contact Method

The paper describes the method of using a laser sensor for the measurement of surface roughness and compares the results with those obtained by conventional contact methods. It goes further to study the anisotropy of roughness in ten plain woven fabrics.

A Scanned-laser Technique for Monitoring Fibrous Webs and Nonwoven Fabrics

This paper follows the development of a practical system for the uniform monitoring of fibrous webs and nonwoven fabrics. Both cover factor and weight can be monitored. The approach adopted to reduce long-term system drift, the over-all system accuracy, its reliability, and its limitations are discussed.

A Study of Positive Needle Thread Feed during Chainstitch Sewing

The paper compares the effect of sewing variables and fabric parameters on the shrinkage of chainstitch (ISO 401) seams sewn by two different thread feeding systems; (a) conventional method; and (b) positive feed.

Factors Affected by Machine Settings and Fabric Properties in Knitwear Production. Part I: Seam Shrinkage and Thread Consumption

This paper investigates the combined effects of machine variables and compressional parameters of knitted fabrics on seam shrinkage and thread consumption during chain-stitch sewing. The approach is based on the analysis of energies and the formation of dimensionless groups. It also briefly discusses the factors which affect the dynamic peak, average thread tension and the movements of the pressure bar as an appendix.

Constant-bulk False-twist Texturing. Part I: Principle and Method

Current false-twist texturing processes are all carried out under constant-temperature conditions. White the product is good and commercially acceptable, changes in bulk and hence in dyeability do occur, due, for example, to alterations in yarn properties caused by changes in package build from inside to outside. New work described in this paper shows that, by texturing at constant bulk, substantially improved yarn and fabrics can be obtained. The new process developed at UMIST uses very small heaters (4–8 inches in length) under feedback control. The bulk and dyeability of the textured yarn are monitored on-line. A closed-loop system is used, and texturing conditions are automatically changed to keep the bulk and dyeability of the textured yarn constant. In this new process, the texturing temperature is changed in such a way as to keep the bulk constant. The process is therefore non-isothermal, in contrast to the isothermal, constant-temperature approach of all current false-twist texturing equipment. Th...

The Computerised Weaving of Preforms for Composites Part I: The Flattening of 3-dimensional Preforms

This is the initial paper of a series which examines the computerised weaving on conventional looms of fabric structures which already have most of the geometrical properties of the desired fabric preform; the design can be easily transformed into an actual preform by use of a simple opening up or unfolding procedure. A further aim of the work is to transfer to a computer the complete process of generating the necessary weaving instructions once the ultimate product geometry has been chosen. In this way, the costly manual process of conversion is avoided. Part I describes the methodology of flattening and examines how it is used to develop the software program needed to allow the flattened design to be woven on a conventional loom. A substantial range of useful preforms can be woven on the basis of the approach outlined in this first paper.

The Computerised Weaving of Preforms for Composites Part II: Feature Analysis of the Flattened Structures

In Part 1 of this series of papers, it was shown how the three-dimensional design of the target preform is transformed into a substantially two-dimensional one which can then be woven on a conventional weaving machine. The present paper explains how the features of the flattened structure are analysed for the purpose of generating the weaving instructions. In the weaving of preforms, the traditional shuttle loom offers many advantages over the shuttleless one and therefore, with regard to contents and terminology, this paper is orientated primarily but not exclusively towards shuttle weaving. Where shuttleless weaving is appropriate, the term “shuttle” can be taken to refer to any weft insertion element such as a projectile, rapier or air-jet.

Some Aspects of Control of Textile Processes

This chapter describes the application of feedback technology to a number of textile processes. Although the actual implementations vary enormously some common features can be observed.

Measurement of Fibre Tuft Weight in an Air Duct using Optical Methods

The feasibility of using a Charge-Coupled Device (CCD) linescan camera to evaluate the weight of fibre tufts moving in an air duct is reported. A theoretical study of the measurement of the light transmission of fibre tufts is presented and the theoretical models are verified by experimental results. The accuracy of the results is improved by a modification of the air duct shape. The fibre tuft speed and the optical uniformity are also discussed.