CONTENT 1. 2.

Preface Acknowledgement

3.

Teacher Student's Support Material (TSSM) i) Introduction



–



ii)

Classification of Fibres



iii) Sources of Fibres



a)



Activity 1

– Cotton

b)



– Worksheet 2

– Jute



– Worksheet 1

– Linen



1

Plant Fibres



1

– Worksheet 3

Animal Fibres

3 5 6 8 9 11 12

– Wool



– Activity 2

16



– Worksheet 4

17



– Worksheet 5

19



– Silk



– Activity 3

20 22

2.

Post Content Worksheets

25

3.

Glossary

27

4.

References

Preface The Curriculum initiated by Central Board of Secondary Education -International (CBSE-i) is a progressive step in making the educational content and methodology more sensitive and responsive to global needs. It signifies the emergence of a fresh thought process in imparting a curriculum which would restore the independence of the learner to pursue the learning process in harmony with the existing personal, social and cultural ethos. The Central Board of Secondary Education has been providing support to the academic needs of the learners worldwide. It has about 11500 schools affiliated to it and over 158 schools situated in more than 23 countries. The Board has always been conscious of the varying needs of the learners and has been working towards contextualizing certain elements of the learning process to the physical, geographical, social and cultural environment in which they are engaged. The CBSE-i has been visualized and developed with these requirements in view. The nucleus of the entire process of constructing the curricular structure is the learner. The objective of the curriculum is to nurture the independence of the learner, given the fact that every learner is unique. The learner has to understand, appreciate, protect and build on knowledge, values, beliefs and traditional wisdom. Teachers need to facilitate the leaner to make the necessary modifications, improvisations and additions wherever and whenever necessary. The recent scientific and technological advances have thrown open the gateways of knowledge at an astonishing pace. The speed and methods of assimilating knowledge have put forth many challenges to the educators, forcing them to rethink their approaches for knowledge processing by their learners. In this context, it has become imperative for them to incorporate those skills which will enable the young learners to become 'life long learners'. The ability to stay current, to upgrade skills with emerging technologies, to understand the nuances involved in change management and the relevant life skills have to be a part of the learning domains of the global learners. The CBSE-i curriculum has taken cognizance of these requirements. The CBSE-i aims to carry forward the basic strength of the Indian system of education while promoting critical and creative thinking skills, effective communication skills, interpersonal and collaborative skills along with information and media skills. There is an inbuilt flexibility in the curriculum, as it provides a foundation and an extension curriculum, in all subject areas to cater to the different pace of learners. The CBSE introduced the CBSE-i curriculum in schools affiliated to CBSE at the international level in 2010 at primary and secondary level in classes I and IX and subsequently in the session 2011-12 initiated the curriculum at Class II, VI and class X. The current session will take the curriculum forward to classes III, VII and XI. An important feature of the Senior Secondary Curriculum is its emphasis on the specialisation in different fields of study and preparing a student for higher professional life and career at the work place. The CBSE-i, keeping in mind, the demands of the present Global opportunities and

challenges, is offering the new curriculum in the subject of English, Physics, Chemistry, Biology, Geography, Accountancy, Business Studies, Information and Communication Technology, and Mathematics at two levels, Mathematics-I for the students of pure sciences and Mathematics-II for the students of Commerce and other subjects. There are some non-evaluative components in the curriculum which would be commented upon by the teachers and the school. The objective of this part or the core of the curriculum is to scaffold the learning experiences and to relate tacit knowledge with formal knowledge. This would involve trans-disciplinary linkages that would form the core of the learning process. Perspectives, SEWA (Social Empowerment through Work and Action), Life Skills and Research would be the constituents of this 'Core'. The Core skills are the most significant aspects of a learner's holistic growth and learning curve. The International Curriculum has been designed keeping in view the foundations of the National Curricular Framework (NCF 2005) NCERT and the experience gathered by the Board over the last seven decades in imparting effective learning to millions of learners, many of whom are now global citizens. The Board does not interpret this development as an alternative to other curricula existing at the international level, but as an exercise in providing the much needed Indian leadership for global education at the school level. The Curriculum envisages pedagogy which would involve building on learning experiences inside the classroom over a period of time. The Board while addressing the issues of empowerment and capacity building of teachers believes that all school must budget for and ensure teachers involved with CBSE-i are continuously updated. I appreciate the sincere effort put in by Dr. Sadhana Parashar, Director (Training) CBSE, Dr. Srijata Das, Education Officer, CBSE and the team of Officers involved in the development and implementation of this material. The CBSE-i website enables all stakeholders to participate in this initiative through the discussion forums provided on the portal. Any further suggestions are welcome. Vineet Joshi Chairman, CBSE

Acknowledgements Advisory Shri Vineet Joshi, Chairman, CBSE Dr. Sadhana Parashar, Director (Training), CBSE

Conceptual Framework Shri G. Balasubramanian, Former Director (Acad), CBSE Ms. Abha Adams, Consultant, Step-by-Step School, Noida Dr. Sadhana Parashar, Director (Training), CBSE

Ideators VI-VIII Ms Aditi Mishra Ms Guneet Ohri Ms. Sudha Ravi Ms. Himani Asija Ms. Neerada Suresh Dr. Rajesh Hassija Dr. Rajesh Hassija

Ms Preeti Hans Ms Neelima Sharma Ms. Gayatri Khanna Ms. Urmila Guliani Ms. Anuradha Joshi Mrs. Sonali Sinha  Mrs. Sonali Sinha 

Ms. Charu Maini Dr. Usha Sharma Prof. Chand Kiran Saluja Dr. Meena Dhani Ms. Vijay Laxmi Raman Mrs. Avanita Bir Mrs. Avanita Bir

Ms. Malini Sridhar Ms. Leela Raghavan Dr. Rashmi Sethi Ms. Seema Rawat Ms. Suman Nath Bhalla Prof Om Vikas Prof Om Vikas

Material Developers Groups: Classes VI-VIII English : Ms Neha Sharma Ms Dipinder Kaur Ms Sarita Ahuja Ms Gayatri Khanna Ms Preeti Hans Ms Rachna Pandit Ms Renu Anand Ms Sheena Chhabra Ms Veena Bhasin Ms Trishya Mukherjee Ms Neerada Suresh Ms Sudha Ravi Ms Ratna Lal Ms Ritu Badia Vashisth MsVijay Laxmi Raman Core- Research Ms. Renu Anand Ms. Gayatri Khanna Dr. N K Sehgal Ms. Anita Sharma Ms. Rashmi Kathuria Ms. Neha Sharma Ms. Neeta Rastogi Ms. Manjushtha Bose Ms. Varsha Manku Dr. K L Chopra

Chemistry : Ms. Poonam Kumar Mendiratta Ms. Rashmi Sharma Ms. Kavita Kapoor Ms. Divya Arora Physics : Ms. Vidhu Narayanan Ms. Mukta Kaushik Ms. Patarlekha Sarkar Ms. Neelam Malik Biology: Mr. Saroj Kumar Ms. Rashmi Ramsinghaney Ms. Prerna Gosain Ms. Seema Kapoor Mr. Manish Panwar Ms. Vikram Yadav Ms. Monika Chopra Ms. Jaspreet Kaur Ms. Preeti Mittal Ms. Shipra Sarcar Ms. Leela Raghavan

Mathematics : Ms. Deepa Gupta Ms. Gayatri Chowhan Ms. N Vidya Ms. Mamta Goyal Ms. Chhavi Raheja Hindi: Mr. Akshay Kumar Dixit Ms. Veena Sharma Ms. Nishi Dhanjal Ms. Kiran Soni CORE-SEWA Ms. Vandna Ms. Nishtha Bharati Ms. Seema Bhandari Ms. Seema Chopra Ms. Reema Arora Ms. Neha Sharma ICT Mr. Yogesh Kumar Ms. Nancy Sehgal Ms. Purvi Srivastava Ms. Babita Mahajan Ms. Ritu Arora Ms. Swati Panhani Ms. Chanchal Chandna

Geography: Ms Suparna Sharma Ms Aditi Babbar History : Ms Leeza Dutta Ms Kalpana Pant Ms Ruchi Mahajan Political Science: Ms Kanu Chopra Ms Shilpi Anand Economics : Ms. Leela Garewal Ms Anita Yadav CORE-Perspectives Ms. Madhuchhanda, RO(Innovation) Ms. Varsha Seth, Consultant Ms Neha Sharma

Chief Co-ordinators: Dr. Srijata Das, EO Co-ordinators Ms. Sugandh Sharma, EO

Ms.S. Radha Mahalakshmi,

Dr Rashmi Sethi, E O

Ms. Madhu Chanda, R O (Inn)

Mr. Navin Maini, R O (Tech)

Shri Al Hilal Ahmed, AEO

Mr. R P Singh, AEO

Ms. Anjali, AEO

Ms. Neelima Sharma, Consultant (English)

Shri R. P. Sharma, Consultant (Science)

Mr. Sanjay Sachdeva, S O

E. O.

NATURAL FIBRES AND FABRICS TEACHER STUDENT'S SUPPORT MATERIAL (TSSM) NATURAL FIBRES We prefer wearing cotton clothes during summers and woolen clothes in winters. Have you ever wondered how a cotton fabric or a woolen yarn is obtained? How does the cotton we use to make a wick or ear bud gets converted to a shirt? How does wool we see over a sheep’s body gets converted to the yarn used to knit sweaters? Let us explore and answer these interesting questions.

Activity 1 Aim: To study that fabrics are made up of fibres. Material required: A small piece of cotton or jute or linen fabric and a scissor. Steps: 1. Cut a small piece of fabric using scissors. 2.

Pull few threads/yarns out of them.

3. Press one end of the thread with your thumb and scratch the other with your nails or pin/ needle. Observation: You will see loose threads or yarns at the edges. Notice that the cloth is made of a number of such strands woven together. You will also observe that yarn splits into thin strands which on further scratching, splits into still thinner fibres. Conclusion: Fabrics are made of yarns woven together and yarns are made up of fibres. Now the question comes how these strands of fibres made into are yarns and how are yarns made into fabrics? Explore.

FIBRES ------------> YARN ------------> FABRIC 1

Natural fibres are substances produced by plants and animals. Cotton, Wool, Jute are some examples of natural fibres. These can be spun into threads or ropes or can be woven and knitted to form fabrics.

Synthetic fibres are man-made fibres that are produced artificially by processing and chemical treatment of certain substances. E.g. Rayon is made from cellulose

2

PLANT FIBRES A. COTTON Cotton is the most important of all plant fibres used to make clothes. It has special properties that make it the best choice for people to wear it especially during summer season. Properties •

Cotton fibres have a natural twist that makes them suitable for spinning into a very strong yarn.

•

It is a soft and fluffy fibre.

•

Water reaches the core of the fibre easily and removes the dirt from the cotton garments. Its crease can easily be removed by ironing.

•

Due to its ability to absorb moisture cotton fabric is comfortable to wear during humidity.

•

They are porous in nature and allow air to penetrate and keep the body cool.

•

They are eco-friendly as they are biodegradable.

COTTON CULTIVATION AND PROCESSING It is a warm season crop and needs a moderate rainfall and black soil for best production. The fibres grow in a ball around the seeds of a cotton plant. Cotton seeds are planted in early spring. Cotton seeds grow steadily and within a span of two months become bushes. They start bearing yellow or white flowers, which turn pink within a week. At this moment green pods appear which may contain two or more seeds. The seeds develop within the pods and are gradually covered with white fibrous material which is called cotton. The pods then grow into spherical structures of the size of walnut, and are commonly called cotton balls.

A cotton ball

After maturing the cotton balls are picked up from the fields either manually, using hands or mechanically, using machines. The seeds are separated from them by combing. This process of separation of seeds from cotton balls is known as ginning. The process of making a yarn from fibres is called spinning. In spinning the fibres from a mass of cotton wool are drawn out and twisted. This brings the fibres together to form a yarn.

Ginning machine

3

You can try spinning and making a yarn yourself. Take some cotton and start pulling out a few fibres. While pulling, twist them too. You will notice that yarn is formed. Spinning can be done by a charkha (spinning wheel) or a takli (spindle).

Weaving is interlacing of two sets of yarns at right angles to make a fabric. Weaving is done on looms. Hand operated looms are called handlooms and the ones which are power operated are called power looms.

4

WORKSHEET 1 1.

Why Cotton clothes are considered as bio degradable?



_____________________________________________________________________



_____________________________________________________________________



_____________________________________________________________________

2.

The fruit of cotton is also called ____________.

3.

Name the following:



a)



_____________________________________________________________________



b)



_____________________________________________________________________

4.

Name the process by which seeds are removed from cotton balls.



_____________________________________________________________________

5.

When are cotton seeds sown in the soil? And when do they start bearing flowers?



_____________________________________________________________________



_____________________________________________________________________



_____________________________________________________________________

A simple device used for spinning cotton.

Process of removing seeds from cotton fibres.

5

B. Linen Linen is a textile made from the fibres of the flax plant. Today linen is usually an expensive textile. Its individual fibre length is longer than cotton and other natural fibres. Many products are made of linen: apron, bags, towels, napkins, bed linen, linen table cloth, chair cover, men’s and women’s wear. Properties •

Linen fabric feels cool to touch.

•

It has a smooth texture, and softens with each wash.

•

 inen fabrics have a high natural lustre; their natural color ranges between shades of L ivory, tan, or grey.

•

When properly prepared, linen fabric has the ability to absorb and lose water rapidly.

•

It is a very durable, strong fabric, and one of the few that are stronger when wet than dry.

Linen Production Flax is one of the few crops still produced in Western Europe, with nearly 130,000 acres under cultivation annually. Climatic conditions in this region are perfect for growing flax. Flax cannot endure very hot weather; thus in many parts of the world, flax are sown in winter because of heat in early spring. The growing cycle is short. To preserve the full potential of each plant, flax is never mowed but must be uprooted. Earlier this was an exhausting process done by hand but today, mechanical grubbers do this tiring work. Therefore while harvesting; flax is always pulled up, never cut, to preserve the maximum fibre length. After pulling, the flax is tied in bundles known as ‘sheaves’ or ‘beets’ and taken to a field to dry. The bundles are untied and the stems are laid out thinly on the field, this process is known as ‘grassing’. Once dried, the seeds are moved through a mechanized process called “rippling” or by “winnowing”.

6

A process called ‘retting’ is employed to loosen the fibres from the stalk. In this process, certain bacteria (micro-organisms) are used to decompose (or break down) the binding material responsible for keeping the fibres together. The fibres are thus loosened from the stalk to separate the loosened fibres from the stalk; the process of ‘Scutching’ is used. Scutching can be done either by hand or by machine. It involves scraping down and pulling away pieces of stalk separating the fibres. The fibres are then ‘heckled’. On passing through ‘heckling combs’, the short fibres and impurities are separated. The long, clean fibres are thus separated, ready to be spun. After ‘spinning’, it can be used for ‘weaving’ into Linen.

7

WORKSHEET-2 1.

Name the following:



a)



_____________________________________________________________________



b)



_____________________________________________________________________



c)



_____________________________________________________________________



d)



_____________________________________________________________________



e)



_____________________________________________________________________



f)

Plant from which linen fibres are obtained

Part of the plant from which fibres are obtained

Process of loosening fibres from the stem

Device by which fibres are aligned for spinning

Stage at which Harvesting is done

Months of sowing flax plant

2. Arrange the following processes in the sequence in which they are performed to make linen fibres from flax plant:

8



Scutching, retting, harvesting, dyeing, heckling, and spinning



_____________________________________________________________________



_____________________________________________________________________

3.

At what stage of production of linen are micro-organisms used and how?



_____________________________________________________________________



_____________________________________________________________________



_____________________________________________________________________

C. Jute Another plant fibre about which we will learn is jute. As we take the journey from jute fibre to jute fabric you will find many similarities between the processing of jute and linen. Jute is a natural vegetable fibre. Jute is obtained from the stem of a plant called Patsun. Since ancient times, it has been traditionally grown in the eastern part of the Indian subcontinent, which is the present day West Bengal of India and plains of Bangladesh.

Jute rope Properties

Jute fibre is being dehydrated after retting alongside a road



It is one of the strongest and most durable natural fibre.



It is biodegradable.



It has superior heat insulation properties.



I t has a high tensile strength and ensures better breathability of fabrics. Therefore, jute is very suitable in agricultural commodity bulk packaging.

After cotton, jute is second most important fibre in terms of usage, global consumption, production, and availability. Because of its natural golden colour and silky shine it is known as The Golden Fibre. The best source of jute in the world is the Bengal Delta Plain in the Ganges Delta, most of which is occupied by Bangladesh. Conditions for growing Jute Jute needs a plain alluvial soil and standing water. Jute flourishes best under warm and humid climate with temperature ranging from 24 to 37 degree centigrade. Jute can be grown on all kind of soils from clay to sandy, loam but loamy alluvial soil suits it most.

9

Jute Production Jute crop can be harvested between 100 – 120 days. After harvesting the jute bundles are kept in the field for 2 -3 days to allow leaf shedding. As in case of linen, fibres need to be separated from their stem by ‘retting’. After the retting process, stripping begins. In the stripping process, non-fibrous matter is scraped off, thus the fibres are obtained. India, Pakistan, China are the large buyers of local jute while Britain, Spain, Ivory Coast, Germany and Brazil also import raw jute from Bangladesh.

Jute fibre is extracted from retted stem of jute plants The primary fiber is pressed into a highly compressed bale, similar to other fibers like cotton and wool.

10

WORKSHEET 3 1.

Name the following:



a)



_____________________________________________________________________



b)



_____________________________________________________________________



c)



_____________________________________________________________________



d)



_____________________________________________________________________

2.

How is retting done?



____________________________________________________________________



_____________________________________________________________________



_____________________________________________________________________

3.

Why are jute fibres called ‘golden fibre’?



_____________________________________________________________________



_____________________________________________________________________



_____________________________________________________________________

4.

Why jute is suitable for bulk packaging?



_____________________________________________________________________



_____________________________________________________________________



_____________________________________________________________________

5.

Which season is most suitable for cultivation of jute and why?



_____________________________________________________________________



_____________________________________________________________________



_____________________________________________________________________

Plant from which jute is obtained

Part of the plant which yields jute fibres

Soil suitable for cultivation of jute plant

Process by which non fibrous material is scraped off

11

ANIMAL FIBRES A. Wool Wool is majorly obtained from sheep. List five items that are made of wool ____________

,

______________

,

______________

______________ , ______________ .

,

Did you know? Bedouins and Turaeg use woolen clothes to keep the heat out.

Characteristics of wool •

It is crimped (the natural wave of wool fibre).

•

Wool is naturally fire resistant.

•

Wool has the ability to stretch and then return to its natural length.

•

Wool readily absorbs water and can also release it.

Because of the crimp, wool fabrics have greater bulk than other textiles and retain air, which causes the product to retain heat. •

Wool is a natural fibre and renewable resource

•

Other animals that produce wool

Angora Rabbit Found in Angora, Turkey. Produces fine quality of white or coloured wool called mohair. Mohair is used in making carpets, scarves, winter hats, suit, sweaters, coats and socks.

Alpaca Camel Found in Peru and other areas of South America. Alpaca camel wool is very fine and of yarn quality and so it is used for shawls, stoles and carpets.

12

Angora goat is a descendant of wild goats from the Angora region in Asia Minor, near present-day Ankara, Turkey. Called by some “the most efficient fiber producers on Earth”, angora goats are docile and “personable” creatures that contribute a wonderful dimension to our farm.

From fibre to wool Processing of wool involves the following steps. a)

Shearing of wool

b)

scouring

c)

sorting

d)

grading

e)

dyeing

f)

spinning weaving and knitting

a) SHEARING – The process of removing fleece from the sheeps’ body is called shearing. The person who shears the sheep is called shearer. Shearing is usually done in spring or non winter months as it is not cold and the sheep can live without its fleece. Shearing is done by hands using clippers or a pair of scissors. Machines are also used to make shearing easy and fast. The fleece has to be removed in a single piece and therefore requires a skilled person. Shearing does not hurt the sheep as the uppermost layer of the skin is dead and the hair of the sheep continues to grow just as our hair grows.

Shearing

13

b) SCOURING – After shearing the fleece is washed thoroughly in tanks to remove dust, dirt and grease. This process is called scouring. Nowadays machines are used for this purpose.

Scouring

c) SORTING – Scouring is followed by sorting. It is done in factories where hair of different textures are separated and sorted. The small fluffy fibres are then picked out from the hair. You can also observe them in the form of wool burrs in your woolen clothes.

Sorting of wool

d) GRADING – In this process the wool is grouped according to its length, colour, texture and ease of drying.

Grading

14

e) DYEING – The colour of natural fleece of sheep hair is black, brown and white. So, the processed fibres are dyed in various colors depending on our choice.

Dyeing

e) SPINNING, WEAVING AND KNITTING – After dyeing the fibres are dried and then straightened combed and rolled into yarn. The shorter fibres are spun and woven into fabrics of desired shape or size. The larger fibres are spun and knitted into woolen garments.

Spinning of wool

Knitting of wool

Knitting of wool

Some breeds of sheep Name

Wool

Country

Afrino

Fine wool

South Africa, Australia

Altay

Carpet wool

China

Apennine

Medium wool

Italy

Barki

Long wool

Middle east

Aragonesa

Medium wool

World wide

Awassi

Carpet wool

World wide

15

Activity 2 Read the labels of different wool items:

16

A)

Identify the places where it is manufactured.



_____________________________________________________________________



_____________________________________________________________________

B)

How are these to be maintained?



_____________________________________________________________________



_____________________________________________________________________

C)

What properties of the wool do you infer from it?



_____________________________________________________________________



_____________________________________________________________________

WORKSHEET 4 1.

Match the following: Column I

Column II

i.

Cloth

a)

Fibres

ii.

Very thin hair like threads from which fabric is made

b)

Silk

iii.

Twisted fibres

c)

Takli

iv.

Synthetic fibre

d)

Fabric

v.

Spinning device

e)

Weaving

vi.

Making yarn from fibres

f)

Cotton

vii.

Animal fibre

g)

Ginning

viii.

Separation of cotton fibres from its seeds

h)

Nylon

ix.

Interlinking two sets of yarn

i)

Spinning

x.

Plant fibre

j)

Yarn

2.

Correct the following statements and rewrite in space provided.



a)

Fibre is a material that is woven from threads.



_____________________________________________________________



Wool is obtained only from sheep.

b)



_________________________________________________________________



Merino wool is obtained from camels.

c)



_________________________________________________________________



Bactrian sheep give the best quality wool.

d)



_________________________________________________________________



Cashmere goat gives fibre called mohair.

e)



_________________________________________________________________



Angora goat gives us mohair fibres.

f)



_________________________________________________________________

17

3.

Find out and write examples of:



a)



____________________________________________



Camel that gives us wool

b)



___________________________________________



Goat that gives us wool

c)



_______________________________________________



Countries manufacturing wool garments

d)



_______________________________________________



Types of silk

e)



18

Animal fibres

_______________________________________________

WORKSHEET 5 Q1 Fill in the blanks with appropriate words

a)

The _______________ of sheep is spun to make yarn.

b)

Wool is a _________________ which we get from sheep.

Q2 Why do you think shearing should be done in summers?

____________________________________________________________________



____________________________________________________________________

Q3 Define the term ‘scouring’ and ‘grading’.

____________________________________________________________________



____________________________________________________________________

Q4 Write S for man made and N for natural fibre.

a)

Nylon ________

b)

Cotton __________



c)

Wool _________

d)

Silk _________

Q5 Which of these is not a natural fibre?

a)

Nylon

b)

Jute

c)

Wool

d)

Cotton

19

B. SILK Silk is the most beautiful of all textile fibres. It is also called the queen of textiles. Silk is also a protein fibre obtained from various insects and spiders. The best known type of silk used in commercial textiles is produced from the cocoons made by larvae of the Bombyx mori moth. Properties of silk 1. Silk has shimmering appearance which comes from the fibres triangular prism like structure which allows silk cloth to reflect incoming light at different angles. 2.

It is versatile and comfortable to wear.

3.

Can be easily dyed into different colors.

4. Silk is a bad conductor of heat and so it is cool to wear in summers and warm in winters as compared to cotton and linen. 5.

It is the strongest natural fibre.

6.

It burns with smell of hair.

The four commercially known varieties of silk are: mulberry silk, tassur silk, eri silk and muga silk. Do you know from where the silk come from? Silk is obtained from cocoons of silk moth. What are cocoons? To understand it we have to study the life cycle of silk moth. The lifecycle of silk moth starts when a female silk moth lays its eggs on the leaves of a mulberry tree. These eggs then hatch into larvae. What are these larvae known as ... Any guesses? The larva is not a worm at all but a caterpillar. Larvae eat voraciously and grow fast. During this stage they shed their skin four times which is called moulting.

Did you know? Until World War I, bullet proof vests were also made from silk.

The cultivation of cocoons of silkmoth to obtain silk filaments is called

sericulture.

After four to six weeks the larvae achieve their maximum size and stops eating. A fully grown larva attaches itself to a twig. At this stage it is called Pupa. The pupa starts secreting fibres from the glands in its head. It moves its head in the shape of number 8 and keeps secreting silk fibres until it is completely covered with them. The fibres harden when exposed to air and form 20

a shell like structure around the pupa. This hard covering is known as cocoon. The further development of moth starts inside the cocoon. If the adult moth were allowed to emerge from the cocoon naturally, it would secrete a chemical, which would eat the cocoon and the silk fibre will get damaged. Therefore the silk worms are killed by dipping them in boiling water, steaming or drying in an oven. The silk fibre obtained by cocoon undergo following steps in the silk producing factories:

Processing of silk a) Sorting of cocoons: The cocoons are sorted according to the color, size, shape and texture as these define the quality of silk. b) Softening of sericin: silk filaments are bound together by gummy substance called sericin. After sorting, cocoons are put through a series of hot and cold immersions to soften the sericin. This allows the unwinding of filament as a continuous thread. c) Reeling of filament: Reeling is the process of unwinding the filaments from the cocoon. As the silk fibres are very fine, they are combined together to make a thread of raw silk. Three to ten 21

strands are usually reeled at a time to produce the desired thickness of raw silk. d) Bailing of filament: The reeled silk is packed in small bundles called books. These books are put into bales weighing about 60kg. These are then transported to the silk mills for silk production. e) Weaving: Weaving is a method of fabric production in which two distinct sets of yarns of threads are interlaced at right angles to form a fabric or cloth. The other methods are knitting, lace making and felting. The longitudinal threads are called the warp and the lateral threads are the weft or filling. (Weft is an old English word meaning “that which is woven”.) The method in which these threads are interwoven affects the characteristics of the cloth.  loth is usually woven on a loom, a device that holds the warp threads in place while filling C threads are woven through them.

Silk weaving is similar to the weaving of other types of yarns: warp and weft threads are intertwined according to a pattern to produce a woven fabric. Sheer, soft fabrics like chiffon or lightweight crepe de chine; satin, taffeta, twill, damask, and brocades; even velvets are all woven from silk.

Activity: 3 Aim: To study different stages of life cycle of butterfly or moth. Material required: Any infested vegetable like pea, brinjal or cauliflower, one wide mouthed bottle, muslin cloth. 22

Procedure: 1. Take infested vegetable, and collect the green wriggling worm like creature called larva/ caterpillar from it. 2. Place the caterpillar in the bottle along with some small pieces of vegetable from where you have collected the caterpillar. 3.

Cover the mouth of the bottle with muslin cloth.

4.

Record you observations in a notebook.

Observation: You will observe that after few days caterpillar will transform into a dark brown stationary structure called pupa or cocoon. After another few days adult moth will emerge out from the cocoon Uses of silk 1.

in the manufacture of clothes, dress materials, curtains and upholstery.

2.

for handicrafts and items like parachutes, bicycle tyres, comforter filling.

3. Through a special manufacturing process, it is made suitable for use as non-absorbable surgical sutures. 4.

Doctors also use it to make prosthetic arteries.

Demonstration Aim: Identification of Fibres with the help of burning test. Materials required: different types of fibres, matchbox and a candle Procedure: - For the burning test:1.

Take out a yarn from the fabric.

2.

Burn one end of the yarn either with a match stick or burning candle.

3.

Check the following:



a)

How the fibre catches fire.



b)

Type of flame.



c)

Smell after burning.



d)

Observe and comment upon ash left behind. 23

Answers to all these points will help to identify fibres FIBRE COTTON RAYON

24

INFLAME AND Catches fire easily

TYPE OF FLAME

SMELL

ASH

Continues to burn Smell of burning Light feathery ash with a bright Yellow paper flame

SILK AND WOOL

does not catch fire Burns with a yellow Smell of burning Black easily flame. Does not hair bead continue to burn

NYLON

does not catch fire

Shrinks away

POLYSTER ACRYLIC

easily, melts away

flame. Burns with sputtering

No definite Smell

Hard, bead

crushable

uncrushable

POST CONTENT WORKSHEET 1.

Choose the correct alternative to answer the following questions:



(i)

Which of the fabric is most suitable for summer?



(a)



(b) Nylon



(c)



(d) TERYLENE



Cotton

Silk

(ii) Which of the following fabrics does not take stains easily?



(a)



(b) Nylon



(c)



(d) Silk



Cotton

Wool

(iii) Which of the following fabrics is a bad conductor?



(a)



(b) Wool



(c)



(d) Cotton



Nylon

Rayon

(iv) Which fabric is made of staple fibre?



(a)



(b) Nylon



(c)



(d) Silk



Cotton

Polyester

(v) Which is the strongest fibre?



(a)

Cotton



(b) Nylon



(c)



(d) Wool

Rayon

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(a)



(b) Polyester



(c)



(d) Wool



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(vi) Which fabric has a dull surface? Nylon

Silk

(vii) Cotton is most desirable fabric for making undergarments because it is:



(a)

Absorbent



(b) Dull



(c)



(d) Strong

Shinning

2.

Name four wool yielding animals. _______________________________________________________________________



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3.

Name three vegetable fibres.



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4.

Which complex compounds are animal fibres made of?



_______________________________________________________________________



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5.

List few properties of fibres.



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6.

Why linen is a suitable fabric for making body or wash towels?



_______________________________________________________________________



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7.

What type of soil and climate is required for cultivation of flax?



_______________________________________________________________________



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8.

Write in brief about retting of flax fibres.



______________________________________________________________________



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9.

What is Scutching? How is it done?



______________________________________________________________________



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10. Write a short note on spinning of linen fibres.

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11. How does wool fibre keep our body warm?

______________________________________________________________________



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12. We wear clothes suited to the weather. Explain the statement giving suitable examples.

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13. Draw the diagram of life cycle of a silk moth.

14. For obtaining silk fibres from cocoons why are cocoon put in boiling water?

______________________________________________________________________



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15. Why are mulberry leaves required during larval stage of silkworm?

______________________________________________________________________



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16. What is the meaning of ‘books’ in relation to sericulture?

______________________________________________________________________



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17. Name the natural varieties of silk.

______________________________________________________________________



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18. What is the difference between weaving and knitting?

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19. Your mother goes to buy a woolen shawl from the market. The shopkeeper takes out a small strand of yarn from the shawl and burns it. It smells of burning plastic. Will it be a good decision to buy the shawl? Give reason for your answer.

_______________________________________________________________________



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20. List various stages in the life cycle of silkworm. Can you name some other insects that have similar life cycle?

_______________________________________________________________________



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21. Differentiate between;

a)

Shearing and scouring



b)

Cashmere and angora



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22. Raghu took out a torn shirt. He pulled out few strands called ’X’ from his shirt. When he untwisted them, he found very thin strands called ‘Y’. Identify ‘X’ and ‘Y’.

_______________________________________________________________________



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23. List four types on natural fibres and their sources.

_______________________________________________________________________



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24. Why is the trade of animal products usually banned in many countries?

_______________________________________________________________________



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25. Why is sericulture not considered an eco-friendly practice?

_______________________________________________________________________



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Glossary Fabric – material that is made from fibres either natural or artificial Spinning – twisting of fibres to obtain yarn Yarn – thread obtained after spinning of fibres which is ready to be weaved. Weaving – interlacing two sets of yarns to make a fabric. Sheaves – bundles of flax. Rippling – process of removing seeds from dried flax. Retting – microbial decomposition of stem to loosen the fibres. Scutching – process of removing straw and other woody material from the flax fibres. Mohair – a kind of fine wool obtained from Angora goat. Shearing – process of removal of wool from the skin of an animal with the help of razors. Scouring – removal of dust dirt and grease by using chemicals. Sericulture – commercial rearing of silk to obtain silk.

Resources : http://www.youtube.com/watch?v=n5i8KRcccDw (link for hand spinning wool) http://www.authorstream.com/Presentation/Justine-37887-Cotton-as-Education-ppt-powerpoint/ (ppt on processing of cotton fibres) galaxysite.weebly.com/uploads/6/4/9/5/6495197/3fibretofabric.ppt (ppt on fibre to fabric) http://www.authorstream.com/Presentation/yashrastogi-749387-sericulture-by-yash/ sericulture)

(ppt

on

http://www.authorstream.com/Presentation/98Anshul-761112-wool/ (ppt on wool) www.avs.uidaho.edu/avs476/IntroWoolNX.ppt (ppt on wool) www.jute.org/.../Int.%20Con.%20Feb-2009%20H.%20S.%20Sen.pp (ppt on jute) http://www.youtube.com/watch?v=yBeHpDqnqMk (video on cotton harvesting and processing) http://www.youtube.com/watch?v=aSe1gQNl4Ns (spinning of cotton) http://www.youtube.com/watch?v=RUHMTsfhshY (spinning with the help of takli)

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