Task 5 To describe the properties of various types ofsynthetic fibers描述各种合成纤维

General information 2 Synthetic fibers合成纤维

It was not until the 1920s and 1930s that man first learned how to build long chain molecules from simple substances.The war stimulated the synthesis of additional fibers.Gradually a wide variety of synthetic fibers were introduced for public consumption.

Although each of the synthetic fibers has many individual qualities or characteristics，synthetic fibers as a class possess some common properties.One of the more widely shared characteristics of synthetics is thermoplasticity or sensitivity to heat.Many synthetic fibers are thermoplastic，so that when exposed to heat，they may shrink.To prevent this shrinkage，most synthetic fibers are treated with heat after spinning to“set”them into permanent shape.Not only can fibers be heat-set to make their dimensions permanent but many synthetic fabrics can also be heat-set into pleats，creases，or other permanent shaping.

When viewed under the microscope longitudinally，synthetic fibers usually appear as glass rods with either a smooth or striated surface.The fibers appear sufficiently alike that solubility tests are the only means of certain identification.Synthetics tend to be hydrophobic or water resistant，and，therefore，less absorbent than the natural fibers.Lower absorbency may lead to a decrease in comfort when synthetic fibers are worn next to the skin.On the other hand，many synthetics dry quickly after laundering.Low absorbency also creates difficulties in finishing and dyeing.Static electricity buildup is common among synthetics.Fibers that are more absorbent tend to conduct electricity more readily.More conductive fibers build up electric shocks less readily.

Many synthetics are rather smooth and slippery to the touch.Fibers may pill，because their strength prevents the wearing away of the tangled ends.This tendency can be reduced by some of the special texturizing of yarns that is done in manufacturing.It is usually more difficult to remove oil and grease stains from synthetics，as they have an affinity for these substances.Stain removal is made more difficult by low absorbency.Once the stain has penetrated fibers，the fibers’resistance to water and other liquids will prevent soil removal during laundering or cleaning as the soil is held inside the fiber while the water is kept out.

Many of the aforementioned characteristics that present problems to the consumer can be overcome by special finishes or by blending fibers.

New Words and Expressions

synthetic fibers 合成纤维

nylon 尼龙，锦纶

marketing 销售

stimulate 促使，激发

additional 另外的，附加的

quality 品质，特性

consumption 消费

thermoplasticity 热塑性

sensitivity 灵敏性

expose 暴露

shrink收缩

permanent永久的，持久的

pleat 褶裥

crease褶裥

microscope 显微镜

longitudinally 纵向地

striate 有条纹的

identification 检验，辨认

solubility 可溶性

hydrophobic 疏水性，憎水性

dye 染色

slippery 光滑的

pill 起球

tangle 缠结

texturize 变形处理

stain 沾污

oil油

grease油脂，脂肪

affinity 亲和性

aforementioned 上述的

Notes

1.It was not until the 1920s and 1930s that man first learned how to build long chain molecules from simple substances.

“直到20世纪20年代和20世纪30年代，人类才开始学会怎样用简单物质制成长链分子。”

本句系It引导的强调句，所强调的成分是not until the 1920s and 1930s.

2.To prevent this shrinkage，most synthetic fibers are treated with heat after spinning to“set”them into permanent shape.

为了防止这种收缩，大多数合成纤维在纺丝后用热进行处理，以“定”成永久形状。

3.Synthetic fibers usually appear as glass rods with either a smooth or striated surface.

合成纤维一般表现为具有光滑表面或条纹表面的棒状物。

Exercises

Part 1 Put the following expressions into Chinese

1.Synthetic fibers as a class possess some common properties.

2.The fibers appear sufficiently alike that solubility tests are the only means of certain identification.

3.Lower absorbency may lead to a decrease in comfort when synthetic fibers are worn next to the skin.

4.Low absorbency also creates difficulties in finishing and dyeing.

5.Fibers that are more absorbent tend to conduct electricity more readily.

6.Many synthetics are rather smooth and slippery to the touch.

7.This tendency can be reduced by some of the special texturizing of yarns that is done in manufacturing.

8.It is usually more difficult to remove oil and grease stains from synthetics，as they have an affinity for these substances.

Part 2 Questions

1.What stimulates the synthesis of additional fibers?

2.What is one of the more widely shared characteristics of synthetics?

3.How do synthetic fibers usually appear when viewed under the microscope longitudinally?

4.How does the absorbent of synthetic fibers affect the properties of fabric?

5.Why is it usually more difficult to remove oil and grease stains from synthetics?

Unit 1 Polyester涤纶

Polyester is a strong fiber that is resistant to crease and thus keeps it shape.Polyester melts at medium to high temperatures.Polyester remains a versatile and important man-made fabric.Blends of polyester give cotton a permanent press property and extend the wear of these blended garments.It became popular as a textile because of its easy care，its drape and its versatility.In fact，polyester in different forms is used widely in textile application to make polyester（PET）resin and filament yarn such as Partially Oriented Yarn（POY），Polyester Drawn Textured Yarn（DTY），Polyester Fully Drawn Yarn（FDY），Polyester Staple Fiber（PSF），Polyester Spun Yarn（PSY），Technical Yarn，Tire Cord and Mono Filaments Yarn.

The most popular cross-section for polyester is round.The fiber morphology is shown in Fig.1.21.

Properties of polyester：

Polyester fabrics and fibers are extremely strong.

Polyester is very durable：resistant to most chemicals，stretching and shrinking，wrinkle resistant，mildew and abrasion resistant.

Polyester is hydrophobic in nature and quick drying.It can be used for insulation by manufacturing hollow fibers.

Polyester retains its shape and hence is good for making outdoor clothing for harsh climates.

It is easily washed and dried.

New Words and Expressions

polyester聚酯，涤纶

crease 起皱

polyester resin聚酯树脂

POY预取向丝

DTY拉伸变形丝

FDY全拉伸丝

PSF涤纶短纤维

PSY涤纶短纤纱

Unit 2 Nylon锦纶

Nylon is stronger yet weighs less than any other commonly used fiber.It is elastic and resilient and responsive to heat setting.Nylon fibers are smooth，non-absorbent and dry quickly.Dirt doesn’t cling to this smooth fiber and it is not weakened by chemicals and perspiration.Extensive washing and drying in an automatic dryer can eventually cause piling.Nylon whites should be washed separately to avoid graying.

Nylon melts at high temperatures.If ironing is necessary，always use a low temperature on the wrong side.

Nylons are also called polyamides，because of the characteristic amide groups in the backbone chain.The nylon in the Fig.1.22 is called nylon 6，6，because each repeat unit of the polymer chain has two stretches of carbon atoms，each being six carbon atoms long.Another kind of nylon is nylon 6（see in Fig.1.23）.It’s a lot like nylon 6，6 except that it only has one kind of carbon chain，which is six atoms long.Other nylons can have different numbers of carbon atoms in these stretches.

Properties of nylon：

Easy to wash.

Can be precolored or dyed in wide range of colors.

Low in moisture absorbency.

Very good physical properties.

Very good heat resistance.

Excellent chemical resistance.

Excellent wear resistance.

New Words and Expressions

polyamide聚酰胺

backbone chain主链

monomer单体

aqueous水的，含水的，多水的

draw-texturing拉伸-变形（工艺）

polymerization聚合

heat resistance耐热性

precolored预染色的，预着色的

wear resistance耐磨性，耐服用性

chemical resistance化学稳定性，耐化学药品性

perspiration 汗液

physical property物理性能

Unit 3 Acrylic腈纶

Acrylic is a fine soft and luxurious fabric with the bulk and hand of wool.Light weight and springy，this fabric is non-allergenic，dries quickly，draws moisture away from the body and is washable.Acrylic does not take even a moderate amount of heat.

In apparel the acrylic fibers are used，for instance，in jumpers，waistcoats，cardigans，jackets，socks，knee-high stockings，training and jogging suits，either pure or in blends for example with wool.The modacrylic fiber，a modified form of acrylic，is found in flame-retardant garments，children’s and baby wear，and in dolls clothes and soft toys.

The draw-rate and process affects the fiber diameter，birefringence，and the cross-sectional shape，from nearly round，to bean shaped，to dog-bone，to slightly crenulate.The typical shapes see in Fig.1.24.

Properties of acrylic：

Feels like wool，with high bulk.

Very good heat retention and fastness to light.

Very good shape retention，durability，easy care and quick dry qualities.

New Words and Expressions

acrylic腈纶，聚丙烯腈系纤维

springy有弹力的

jumper工作服，短上衣，无袖套领罩衫

waistcoat西装背心，马甲

cardigan羊毛衫，开襟绒线衫

sock短袜

knee-high stocking中筒女袜

training and jogging suit运动衣

modacrylic改性聚丙烯腈

flame-retardant阻燃的

garment衣服

spinneret喷丝头

spinning chamber纺丝仓，（纺丝）丝室

coagulating bath凝固浴，纺丝浴

birefringence 双折射

bean shape豆形的

dog-bone狗骨头

high bulk高蓬松

crenulate细圆齿状的，小圆齿状的

shape retention形状保持性，定形性

Unit 4 Spandex氨纶

As we know，Lycra® is a type of stretch fiber，or spandex，which is a registered trademark of Invista，formerly DuPont.It is the most recognized and popular brand of spandex throughout the world，and many designers and clothing manufacturers use Lycra?in their products.

Spandex is a synthetic fiber known for its exceptional elasticity.These fibers are superior to rubber because they are stronger，lighter，and more versatile.In fact，spandex fibers can be stretched to almost 500%of their length.

First produced in the early 1950s，spandex was initially developed as a replacement for rubber.Although the market for spandex remains relatively small compared to other fibers such as cotton or nylon，new applications for spandex are continually being discovered.

New Words and Expressions

Lycra莱卡，氨纶

spandex氨纶

registered trademark注册商标

Invista英威达公司

DuPont杜邦公司

elastane弹性纤维

Unit 5 New fibers新型纤维

There are so many new fibers appeared in recent years，in this unit，we will introduce soybean fiber，bamboo fiber and PLA fiber.

Soybean fiber

Soybean fiber（Fig.1.25）was invented by Henry Ford in 1937.

The main component of soybean fiber is quite similar to those of cashmere and silk，featuring fine denier，low density and good tenacity&elongation.The resulting fabric can give us cashmere-like hand touch，silk-like luster，cotton-like moisture conduction and wool-like warm retentiveness.As long as we pay attention to the option of makeup of blended yarn as well as processing technology，the soybean yarn can have strong competitiveness on its novelty and functions.

Bamboo fiber

Bamboo fiber（Fig.1.26）is a cellulose fiber extracted and made from the pulp of natural bamboo plants.It is a synthetic viscose made from the bamboo cellulose.As a quick-growth plant cellulose material，the bamboo does not require irrigation，fertilization，and medicine scattering during its growth，and is resistant to drought and water logging.It can be planted in a dense manner，and regular felling is needed.The material derives the nature and can be reverted to the nature after biological degradation.This completely demonstrates that bamboo is a raw material which is easily acquired，available and environment friendly.So，bamboo gained popularity as a“green”fiber.

The cross-section of the bamboo fiber is filled with various micro-gaps and micro-holes，shown in Fig.1.27.

Apart from the intrinsic characteristics of bamboo including anti-bacteria，anti-ultraviolet，excellent penetrability and coolness，bamboo fiber has also the functions of moisture absorption and desorption，thus it is called breathable fiber.As promising cellulose fiber，it is featured by biological degradation，soft handle，good drapability，easy tintage and beautiful coloration.

Poly lactic acid（PLA）fiber

A manufactured fiber in which the fiber-forming substance is composed of at least 85%by weight of lactic acid ester units derived from naturally occurring sugars.

The fundamental polymer chemistry of PLA allows control of certain fiber properties and makes the fiber suitable for a wide variety of technical textile fiber applications，especially apparel and performance apparel applications such as：

（1）Low moisture absorption and high wicking，offering benefits for sports and performance apparel and products.

（2）High resistance to ultra violet（UV）light，a benefit for performance apparel as well as outdoor furniture and furnishings applications.

（3）Lower specific gravity，making PLA lighter in weight than other fibers.

（4）In addition to coming from an annually renewable resource base PLA fibers are readily melt-spun，offering manufacturing advantages that result in greater consumer choice.

New Words and Expressions

soybean fiber大豆（蛋白）纤维

denier 旦尼尔

water logging涝，水浸

biological degradation生物降解

anti-bacteria抗菌

anti-ultraviolet抗紫外线

tintage染色

PLA fiber聚乳酸纤维

lactic acid乳酸

wicking芯吸性

ester酯

Extension of practice&reading Specialty fibers特种纤维

Most of specialty fibers have been developed for specific end uses.The descriptive terms specialty and high-performance fibers are used for many of them.High-performance fibers are a growth market for the textile industry.

Glass Fiber

Although，hard and rigid by nature，glass can very well be made into fine，shiny and translucent fibers which more or less look and feel like silk fibers.These glass fibers are commonly known as fiberglass（Fig.1.29）.

Glass fiber is a kind of excellent inorganic non-metallic materials，It is usually used as the reinforcing material in compound material，electrical insulation and heat insulation material.

Carbon Fiber

Carbon fibers（Fig.1.30）are an important part of many products，and new applications are being developed every year.The United States，Japan，and Western Europe are the leading producers of carbon fibers.

Carbon fiber is very expensive，but has a fantastic weight-to-strength ratio.The material is employed in high-quality cars，boats，bicycles，and planes，including popular Formula One racecars.Depending on the orientation of the fiber，the carbon fiber composite can be stronger in a certain direction or equally strong in all directions.A small piece can withstand an impact of many tons and still deform minimally.The complex interwoven nature of the fiber makes it very difficult to break.

Aramid Fiber

A manufactured fiber in which the fiber forming substance is a long-chain synthetic polyamide in which at least 85%of the amide（—CO—NH—）linkages are attached directly between two aromatic rings.

The most popular aramid fiber on the world market is Kevlar（Fig.1.31）.Kevlar aramid fibers has an extremely high tenacity，approximately 22 grams per denier，which is more than five times the strength of a steel wire of the same weight and more than twice the strength of high-tenacity industrial nylon，polyester，or glassfiber.It has an unusually high initial modulus of 476 grams per denier.This is about two times greater than glassfiber or steel，four times greater than industrial polyester，and nine times greater than industrial nylon.Moisture regain is about 7 percent.Elongation is low，only about 4 percent.

Thermal properties of Kevlar are superior.It has outstanding stability to heat，retaining a high percentage of strength after exposure to temperatures to 260℃.

Kevlar is used in a variety of applications.One of the most interesting and important uses is in body armor or bulletproof vests.Other uses for the fibers include：bracing belts，high-pressure hoses，conveyor belts，rope and cables used as antennae supports，oceanographic cables，crane ropes，boat rigging，helicopter hoist cables，special cables for deep-sea workstations，reinforcement for concrete in various types of constructions，many parts of the space shuttles，space vehicles，body panels for race cars，boats of various types.

New Words and Expressions

Formula One racecar一级方程式赛车

interwoven交织的

aramid fiber芳纶

aromatic ring芳香环，芳族环

initial modulus初始模量

armor盔甲，装甲

bulletproof vest防弹背心

bracing belt撑杆带

high-pressure hose高压水带

conveyor belt传送带

oceanographic cable海洋电缆

crane rope起重机吊索

boat rigging 船缆

helicopter hoist cable直升机葫芦电缆

space vehicle宇宙飞船，航天器

body panel车身板件