Advances in Yarn Spinning Technology

C A Lawrence

• Publisher: Woodhead Publishing
• Year: 2010
• Print ISBN: 9781845694449
• eBook ISBN: 9780857090218
• Topic: Technology & Engineering
• Subtopic: Industrial Engineering
• Index: Technology & Engineering

This book provides an invaluable single source of information on the advances in yarn spinning technologies. Advanced spinning systems are described and comparisons are made of the properties of the yarns produced, and resultant finished products, with those from conventional systems.Part one provides an introduction to yarn fibre spinning and structure. Chapters discuss the principles of ring spinning and open-end spinning of yarns. Yarn structure and properties from different spinning techniques and yarn structural requirements for knitted and woven fabrics are also examined. Part two covers advances in particular yarn spinning technologies. Topics range from siro spinning to compact spinning technology and air-jet spinning. Final chapters explore how to minimise fibre damage which occur during spinning and the use of spin finishes for textiles.With its distinguished editor and array of international contributors, Advances in yarn spinning technology is an important text for spinners, yarn manufacturers and fabric producers, as well as researchers, technicians, engineers and technologists in this sector of the textile industry. - Documents advances in spinning technologies and presents comparisons between systems - Assesses particular textile spinning technologies with specific chapters focusing on siro, compact, rotor, friction and air-jet spinning - Reviews measures to minimise fibre damage caused by spinning are investigated with specific relevance to rotor and friction spinning

Part I

Introduction to yarn spinning and structure

1

Overview of developments in yarn spinning technology

C.A. Lawrence, University of Leeds, UK

Abstract:

An historical account is given of the development of the yarn spinning process, from its initial beginnings as a hand craft, to the mechanisation of the process during the Industrial Revolution, and through into the twentieth century when a wide range of different spinning techniques were developed. The basic equations generally applicable to spinning technology are presented and descriptions given of the various techniques currently used commercially, classified according to the fundamental principles of the method on which they are based.

Key words

staple-spun yarn

drop spindle

distaff

spinning wheel

spinning jenney

saxon wheel

water frame

spinning mule

ring spinning

open-end spinning

self-twist

wrap spinning

1.1 Introduction

The term ‘spinning’ may be defined [1] as the process or processes used to

• produce either fibres or filaments from natural or synthetic polymers, or

• convert natural or man-made fibres (mmf) and filaments into yarns by twisting or other means of binding together the fibres or filaments. This provides a relatively fine continuous length of thread that has properties suitable for conversion into a fabric form or for use directly for sewing or rope making.

The spinning processes employed to make fibres or filaments may be generally classed as polymer extrusion methods. Typical extrusion processes are melt-spinning, wet-spinning and dry-spinning; there are also variants of these [2, 3]. For melt-spinning, a thermoplastic polymer, such as polyester, polypropylene or nylon, is in principle heated to a molten state and pumped through precision-machined holes in a metal plate, referred to as a spinneret; the issuing molten streams are then cooled to form a group of up to, say, 1000 filaments or a tow of 300,000 filaments; the latter is subsequently cut into staple fibres. Polymers that are thermally difficult to melt-spin may be dissolved in a suitable solvent to produce a viscous liquid or dope. In wet-spinning the dope is extruded into a bath containing a liquid coagulant, which enables polymer streams to congeal into filaments or subsequently to be converted to staple fibres. With dry-spinning the dope is extruded into heated gas, which facilitates evaporation of the solvent from the molten stream to form the filaments. Each extrusion method has specific technological and commercial advantages, the discussion of which is outside the scope of this book. The focus of this book is on a subsection of the second category of the spinning definition, called staple-fibre spinning. The twisting, or processing by other means, of filaments into yarns therefore will not be discussed and the reader may wish to refer to the cited literature [4–6] for information on the technology involved in filament yarn production.

It can be reasoned from the short description above of staple-fibre production that staple-fibre spinning is concerned with the means of consolidating a collection of discrete lengths of thin natural or man-made polymer materials into a yarn. Such a yarn would be called a staple-spun yarn or spun-staple yarn, and therefore may be defined as follows:

A staple-spun yarn is a linear assembly of many fibres in the cross-section and along the length, held together usually by the insertion of twist to form a continuous strand, small in diameter but of any specified length. It is used for interlacing in processes such as knitting, weaving and sewing. [1]

Before presenting an overview of the various staple-fibre spinning processes, it is useful to give a short explanation of the concept ‘staple fibres’. It was explained earlier that an extruded tow of filaments can be cut or broken into discrete lengths to produce staple fibres. Staple-fibre spinning systems, however, were originally developed for converting natural fibres into spun yarns and therefore tows are generally cut to give similar length characteristics, particularly when a yarn blend of natural and mmf is to be spun. The filaments are often extruded to correspond to the fineness of the natural fibres. In the commercial production of staple-spun yarns from natural fibres it is essential that certain of the fibre properties are known, in particular the length characteristics, fibre fineness, colour and cleanliness. Natural fibres are therefore sold by grades based on these measured properties. A detailed account of the importance of these properties in yarn production is given elsewhere in the published literature [7–10].

1.2 Early history

1.2.1 Hand spinning

Historically, staple-fibre spinning is an ancient craft. Although the precise date of its origin has yet to be known, there is archaeological evidence of ‘string skirts’ dating back around 20,000 years ago, to Paleolithic times [11]. The early skill of spinning a thread from staple fibres, however, is believed to have been in existence at least some 8000 to 10,000 years ago. The weaving of yarns can be dated back to Neolithic times, around 6000 BC, and both skills are said to predate pottery, which can be traced to around 5000 BC. It is likely that one of the earliest fibres to be spun was wool, since sheep existed about 1 million years ago during the early Pleistocene period. The domestication of sheep can be traced back to 9000 BC. in northern Iraq at Zam Chem Shanidar.

The early spinning technique seems likely to have been accomplished without the use of tools, by stretching out a thin bunch of fibres with one hand (the attenuating action being referred to as drawing) while twisting together the fibres of the attenuated length between the fingers of the other hand. To gain more twist the yarn would then be fastened to a stone – called a whorl – which was twirled by hand and allowed to drop vertically, thereby generating the twisting torque. With the yarn now aligned with the axis of rotation, the torque inserts the twist into it. This may be classed as ‘on-axis twisting’.

It is also possible that the first stage of the twisting process was more easily achieved by rolling the attenuated length between the outside of the spinner’s thigh and the palm of the hand used to insert the twist: see Fig. 1.1 [11]. It is not difficult to appreciate then that the latter technique would have been developed whereby a long straight stick of wood, a twig say, was rolled between the thigh and palm, with the attenuated length attached to the upper end of the stick. The use of such a stick would also enable the spinner to subsequently wind a spun length aroun...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributor contact details
• Woodhead Publishing Series in Textiles
• Part I: Introduction to yarn spinning and structure
• Part II: Advances in particular yarn spinning technologies
• Index