1.6 Text Yarn and fabric
1.Yarn
Yarn is an assembly of fibres and/or filaments.In the book of Textile Terms and Definitions，yarn is defined as a product of substantial length and relatively small cross-section consisting of fibres and/or filaments with or without twist.[1] There is very little restraint on what could be classed as a yarn.This is because the definition must hold true for every single yarn，no matter how obscure.
Yarns can be broadly divided into three types：spun-staple yarn，continuous filament yarn and composite yarn，which can be subdivided further.
Spun-staple yarns，which are also known as staple fibre yarns，consist of staple fibres assembled and bound together by various means to produce the required characteristics such as strength，handle and appearance.[2] Staple fibres yarns can be subdivided in a number of ways：by fibre length（short staple being less than 60 mm，long staple greater than 60 mm），by yarn construction（single，piled，cabled，multiple，fancy），and by spinning method（ring spun，rotor spun，twistless，fascinated，core spun，self-twist，friction spun yarns，etc.）.
Continuous filament yarns are produced either by combining the required number of filaments together as in the silk throwing process or，more commonly，by producing the required number of filaments and thickness of filaments simultaneously in one spinning operation，as in the case of man-made fibres.[3]The typical filament yarn is therefore，a collection of parallel filaments lying closely together and running the whole length of the yarn.As the filaments are as long as the yarn itself，there is no need for them to be bound together.Yarns with one filament are referred to as monofilaments and those with more than one as multifilaments.The range of filament yarns is not as diverse as that for spun-staple fibre yarns.Continuous filament yarns is usually divided into flat continuous filament yarns and textured continuous filament yarns according to whether the filaments are modified.The textured continuous yarns are the yarns that have been modified by subsequent processing to introduce durable crimps，coils，loops or other distortions into the filaments.Flat continuous filament yarns are also known as Standard-filament yarns.In contrast to the textured yarns，the filaments in the flat filament yarns are straight and smooth，without any distortions.Filaments can be produced from two different components forming a bicomponent filament yarn，or sheets of polymer can be cut into strips forming tape yarns.[4] In addition，the filaments may be dull or lustrous according to requirements.
Composite yarn is a yarn composed of both staple and continuous-filament component，for instance core-spun yarn.
A yarn is often described from two aspects，i.e.the thickness of the yarn and the degree and direction of twist.
It is difficult to measure the diameter of a yarn because not all yarns have a circular cross section，and some are easily deformed during measuring.The accepted way to indicate the thickness of a yarn is to give the count or linear density.The count is expressed as the length per unit mass.The linear density is expressed as mass per unit length.A length of the yarn is measured out，and then weighted.
Twist can be inserted in either of two directions，clockwise or anticlockwise.The usual designation for twist direction is to use the letters S or Z.A single yarn has S twist if，when it is held in a vertical position，the fibre inclination to the axis of the yarn forms the center of the letter S.[5] Similarly，the yarn has Z twist if the fibre direction forms the center of the letter Z.The twist level is usually denoted as the amount of twist（turns）per unit length，that is turns per metre or turns per centimeter.
2.Fabric
Fabric is defined as a manufactured assembly of fibres and/or yarns that has substantial surface area in relation to its thickness and sufficient cohesion to give the assembly useful mechanical strength.Fabrics are most commonly woven or knitted，but the term includes assemblies produced by felting，lace-making，net-making，non-woven processes，and tufting.[6]
Woven fabric is produced by interlacing of warp and weft.The major reasons for variations in the appearance of woven fabric are the yarn structure and the fabric structure.The aspects of yarn structure that are most likely to affect the final appearance and properties of the fabric include the degree of hairiness of the yarn，its smoothness and luster，its extensibility and twist，while its strength will be critical in ensuring satisfactory performance in use.Fabric structure also affects the final appearance and properties of the fabric.According to fabric structure，fabrics can be divided into many types，such as plain，twill，satin，sateen，denimi，etc.
Plain weave is the simplest interlacing arrangement possible.[7]Square plain weaves have the same warp and weft specification；warp-faced plains have a greater cover factor in the weft.This weave can be ornamented by altering the set，crimp，yarn linear density or type，or introducing coloured yarn or highly twisted yarn.
Twill weaves show diagonal lines in the fabric and may be S or Z twill.Twills can be ornamented，for example pointed twills，herringbone，diamonds and elongated twills.
Knitted fabrics are produced by knitting，which is the production of fabric by forming loops with yarns，which are interlaced in a variety of ways to form the fabric.[8] The knitting industry is divided into two distinct sectors，weft knitting and warp knitting.The basic types of weft knitted fabric include plain single jersey fabrics，rib fabrics，purl fabrics and interlock fabrics.While the basic types of warp knitted fabric include tricot stitch fabrics，reverse locknit fabrics and locknit stitch fabric.
One of the oldest non-woven fabrics is felt，which is formed from a web or batt containing animal hair or wool，consolidated by the application of moisture，mechanical action and heat which cause the constituent fibres to mat together.Wool and hair fibres，due to their unique surface scales，are the only fibres with this ability to felt.
In general，non-woven fabrics can be defined as textile structures made directly from fibre rather than yarn by bonding using various techniques，including adhesive bonding，mechanical interlocking by needling or fluid jet entanglement，thermal bonding and stitch bonding.[9] Fabric properties of non-woven fabrics range from crisp to fluid，soft-to-touch to harsh，impossible-to-tear to extremely weak.This lead to a wide range of end-products—nappies，filters，teabags，geotextiles，some of which are durable，others disposable.
Composite fabrics are two or more layers of fabric.Examples include spun-laid webs with a scrimi base and needle-punched web and scrim compounds.
The parameters used to describe the properties of a fabric include：construction，thread density，width，thickness，mass per unit area，etc.Fabric construction refers to whether the fabric is woven，knitted or non-woven，and its structure.Thread density is the number of threads per unit length and width in the fabric.Length and width of a fabric are usually expressed in metres or feets and measured using a metre ruler.It is important to know if the width of the fabric is correct so that when it is made into garment the pattern will fit across the width without too much waste.Thickness of a fabric is obtained by placing the specimen of the fabric between two small plates，then applying a given pressure to flatten the surface of fibres，and then measuring the distance between the plates.Fabric thickness is usually not important；but it can be critical for felts and belts.Mass per unit area is expressed in grams per square metre.This combines the fabric parameters of pick count，linear density and crimp.
New words
1.piled[paild]adj.有绒毛的
2.cabled['keibled]adj.多股的，复捻的
3.fancy['fænsi]adj.花式的
4.twistless[twistles]adj.无捻的
5.fascinated['fæsineitid]adj.包缠的
6.self-twist[selftwist]adj.自捻的
7.monofilament['mɔnəu'filəmənt]n.单纤丝
8.multifilament[,mʌlti'filəmənt]n.复纤丝
9.crimp[krimp]n.卷曲，织缩
10.coil[kɔil]n.圈，纱圈，线圈
11.loop[lu:p]n.线圈，毛圈，绒圈
12.bicomponent[,baikəm'pəunənt]adj.双组分的 n.双组分
13.count[kaunt]n.支数，号数，织物经纬密度
14.turn[tə:n]n.转，圈，捻回
15.cohesion[kəu'hi:ʒən]n.凝结，内聚力
16.woven['wəuvən]adj.机织的 n.机织织物
17.felting['feltiŋ]n.毡化，毡合，缩呢，毡
18.lace-making[leis'meikiŋ]adj.花边构造的
19.net-making[net'meikiŋ]adj.网眼构造的
20.tufting['tʌftiŋ]n.簇绒，簇绒法
21.interlacing[,intə（:）'leisiŋ]n.交织，编织，隔行
22.plain[plein]n.平纹织物 adj.平纹的，平的
23.twill[twil]n.斜纹织物，斜纹
24.sateen[sæ'ti:n]n.棉缎
25.denim['denim]n.粗斜棉布，劳动布
26.set[set]n.定形，调整；织物经纬密度；批（指原料）
27.herringbone['heriŋbəun]n.人字形；鲱鱼鱼骨 adj.人字形的，箭尾形的
28.knitting['nitiŋ]n.针织，针织品
29.felt[felt]n.毛毡，毡 v.毡化，缩绒
30.web[web]n.棉网，毛网，纤维网
31.batt[bæt]n.制毡毛层，棉絮
32.mat[mæt]n.席，垫；消光 v.使……缠结捆或交织成厚厚的一团
33.needling['ni:dliŋ]n.针刺，针刺法
34.soft-to-touch[sɔfttu:tʌt∫]adj.手感柔软的
35.impossible-to-tear[im'pɔsəbltu:teə]adj.撕不破的
36.nappy['næpi]n.尿布 adj.起绒的，起毛的
37.teabag[ti:bæɡ]n.袋泡茶
38.geotextile['dʒi:əu'tekstail]n.土建布，土工布
39.scrim[skrim]n.稀松棉布
Phrases and expressions
1.hold true 适用，有效
2.spun-staple yarn 短纤纺制纱
3.continuous filament yarn 复丝，长丝纱
4.composite yarn 复合纱，包芯纱
5.ring spun 环锭纺的
6.rotor spun 气流纺的
7.core spun 包芯纺的
8.friction spun yarn 摩擦纺的纱
9.throwing process 捻丝工艺
10.flat continuous filament yarn 连续直长丝纱
11.textured continuous filament yarn 变形长丝纱
12.standard-filament yarn 标准长丝纱，直长丝纱
13.tape yarn 带状纱，扁丝
14.linear density 线密度
15.non-woven process 非织造工艺，无纺织工艺
16.square plain weave 平衡平纹织物
17.warp-faced plains 经面平纹织物
18.cover factor 布面覆盖系数
19.pointed twill 人字斜纹
20.elongated twill 急斜纹或缓斜纹
21.weft knitting 纬编
22.warp knitting 经编
23.plain single jersey fabric 单面平纹针织物
24.rib fabric 罗纹针织物
25.purl fabric 双反面针织物
26.interlock fabric 双罗纹针织物，棉毛布
27.adhesive bonding 黏合，黏合法（非织造织物工艺）
28.fluid jet entanglement 液流喷射缠结
29.stitch bonding 缝编（法），线圈结合
30.spun-laid web 纺丝网
31.needle-punched web 针刺网
Notes
[1] In the book of Textile Terms and Definitions，yarn is defined as a product of substantial length and relatively small cross-section consisting of fibres and/or filaments with or without twist.
在《纺织术语及其定义》一书中，纱被定义为：长度大横切面小，由加捻或不加捻的纤维/长丝所组成的产品。
句中“and/or”表示“和”、“或”两个意思。“fibres and/or filaments”可译成“纤维/长丝”。
[2] Spun-staple yarns，which are also known as staple fibre yarns，consist of staple fibres assembled and bound together by various means to produce the required characteristics such as strength，handle and appearance.
纺织短纤纱也叫短纤纱，由短纤维组成，短纤维通过各种方法组合和黏结在一起，产生必要的特性如强力、手感和外观等。
[3] Continuous filament yarns are produced either by combining the required number of filament together as in the silk throwing process or，more commonly，by producing the required number of filaments and thickness of filaments simultaneously in one spinning operation，as in the case of man-made fibres.
连续长丝纱的生产方法有两种，如像在捻丝工艺中那样将所需数目的长丝合并在一起，或更普遍的是像在化学纤维生产中那样在同一纺纱操作中同步生产所需数目和细度的长丝。
[4] Filaments can be produced from two different components forming a bicomponent filament yarn，or sheets of polymer can be cut into strips forming tape yarns.
长丝可由两种不同组分加工成双组分长丝纱，也可由聚合物薄膜切成条形加工成扁丝。
“forming a bicomponent filament yarn”，和“forming tape yarns”均为分词短语，分别修饰“components”和“strips”。
[5] A single yarn has S twist if，when it is held in a vertical position，the fibre inclination to the axis of the yarn forms the centre of the letter S.
S捻即是：单纱在垂直方向沿轴线倾斜，如同字母S的写法。
[6] Fabrics are most commonly woven or knitted，but the term includes assemblies produced by felting，lace-making，net-making，non-woven processes，and tufting.
常见的织物种类有机织物和针织物，也包括由毡化、花边织、网状织、非织造加工及簇绒法生产的各种织物。
句中“term”指“fabrics”。
[7] Plain weave is the simplest interlacing arrangement possible.
平纹组织可能是最简单的织造结构。
“possible”是“可能的”的意思，表示推测。
[8] Knitted fabrics are produced by knitting，which is the production of fabric by forming loops with yarns，which are interlaced in a variety of ways to form the fabric.
针织物由针织工艺生产，先由纱形成线圈，再通过各种方式交织成织物。
“which is the production of fabric by forming loops with yarns”为非限定性定语从句，修饰“knitting”；“which are interlaced in a variety of ways to form the fabric”也是非限定性定语从句，修饰“loops”。
[9] In general，nonwoven fabrics can be defined as textile structures made directly from fibre rather than yarn by bonding using various techniques，including adhesive bonding，mechanical interlocking by needling or fluid jet entanglement，thermal bonding and stitch bonding.
通常，无纺布可定义为直接由纤维而非纱黏结而成的织物组织，这些黏结技术有黏合法、通过针刺或液流喷射缠结的物理连结法、热合法和缝编法。
Exercises
Ⅰ.Answer the following questions.
1.How do we indicate the thickness of a yarn？
2.What is the twist？And how to express the twist direction？
3.What are the main reasons for variations in the appearance of woven fabrics？
4.What is the felt？
5.What are the parameters used to describe the properties of a fabric？
Ⅱ.Translate the following sentences into Chinese.
1.Staple fibres yarns can be subdivided in a number of ways：by fibre length（short staple being less than 60mm，long staple greater than 60 mm）；by yarn construction（single，piled，cabled，multiple，fancy）；and by spinning method（ring spun，rotor spun，twistless，fascinated，core spun，self-twist，friction spun yarns，etc.）.
2.The textured continuous yarns are the yarns that have been modified by subsequent processing to introduce durable crimps，coils，loops or other distortions into the filaments.
3.The accepted way to indicate the thickness of a yarn is to give the count or linear density.
4.The aspects of yarn structure that are most likely to affect the final appearance and properties of the fabric include the degree of hairiness of the yarn，its smoothness and luster，its extensibility and twist，while its strength will be critical in ensuring satisfactory performance in use.
5.This weave can be ornamented by altering the set，crimp，yarn linear density or type，or introducing cloured yarn or highly twisted yarn.
6.The parameters used to describe the properties of a fabric include：construction，thread density，width，thickness，mass per unit area，etc.
Reading material Primary and secondary motions of loom
Every loom requires three primary motions to produce woven fabric，shedding，weft insertion and beating-up.
Shedding is the name given to the motion which moves the healdrames up and down in order to separate the warp sheet into two layers and create a triangle in front of the reed（referred to as the‘shed’）through which the weft can be passed.Weft insertion（originally referred to as picking）is the mean by which the weft is projected through the shed.This was traditionally by shuttle，but more recently it is done by projectile，rapier，air jet or water jet.Beating-up is where the reed，mounted in a reciprocating sley，pushes the weft into the fell of the cloth to form fabric.This requires considerable force，hence the term beating-up.
There are three secondary motions in weaving：let-off，take-up，and weft selection.The let-off motion ensures that the warp ends are controlled at the optimum tension for the fabric that is being woven.The cloth take-up motion withdraws cloth from the fell and then stores it at the front of the loom.A weft selection or patterning mechanism is only necessary when it is desired to vary the weft being inserted.