Monday, July 4, 2011

Steps in Processing Wool into Yarn


1. Sheep
Wool comes from sheep. They grow a wool coat and once a year this wool coat is sheared off the animal. In W isconsin, this is frequently done in the early spring shortly before they have their lambs. A shorn ewe will be more likely to stay out of the wind and bad weather and protect her new-born lamb if she does not have a thick wool coat on her.

2. Fleece
The shorn wool coat is called a fleece. It is also called "grease wool" because of all the oil and lanolin in the wool. This fleece must be cleaned before it can be processed into wool yarn. There is much vegetable matter, manure and natural oil that must be removed. Sometimes as much as 50% of the weight of the fleece is not wool.

3. Skirting a fleece
The wool from the back end of the sheep, their legs and sometimes their belly is too full of manure to use. These are referred to as "tags" (as in the phrase "tag end"). These are removed first before washing the fleece; this process is called skirting, as all the edges of the wool coat are removed. The fleeces are also sorted into the various types: fine from coarse and short from long.

4. Washing the wool
The grease must then be removed from the wool. This can be done using soap or detergent and a lot of water or it can be done by submerging the wool in an acid bath which dissolves all the vegetable matter as well as the grease (this is called scouring).

5. Picking
The washed and dried wool is then "teased" or "picked" which is the beginning of the process of opening up the locks of wool and turning it into a consistent web. The wool is put through a picker which opens the locks and blows the fluffy wool into a room. At the same time a special spinning oil is added which helps the wool fibers slide against each other but also helps them stick together as a fine web through the processing.

6. Carding
The wool fibers are then put through a series of combing steps called carding. This can be done with small hand cards that look much like brushes you would use on a dog. It can also be done on a larger scale with machine driven drums covered with "card cloth" which combs the wool many times by transfering it back and forth from one drum to the other as it is passed down the series of drums. We have "woolen"cards which produce a wool web with the fibers coming off in random alignment. This is in contrast to "worsted" combing that lines up all the fibers (as you would see in thread).

7. Roving
The final step in the carding process divides the web into small strips called pencil rovings. These are collected on large spools on the end of the card. These spools of pencil roving will be placed on the spinning frame to make yarn.

8. Spinning
The roving as it comes off the card has no twist. It is held together by the oil and natural hooks that exist on the surface of the wool fibers. The spinning frame will put the actual twist on the roving and turn it into yarn. This is collected on wooden bobbins. The frame we have is small but it can spin up to 90 threads at one time.

9. Wind and/or skeining
When the wooden bobbins are full of yarn, they are placed on a cone winder and the yarn is transferred to paper cones for use in weaving and knitting machines. It could also be put into skeins of yarn which are the form that knitters like to use.

10. Finishing
There are many ways of finishing the yarn. It is sometimes necessary to remove the lubricant by washing, which also "sets the twist" which allows the fibers to open up, fluff out and make a loftier yarn. Sometimes the wool is woven or knitted directly from the cone and is washed and blocked in its final form (as cloth, socks, sweaters, etc.).

The life cycle stages of the silkworm moth

OVA: Incubation 10-14 days

IMAGO: 5 - 7 DAYS

LARVA: 27 DAYS

PUPA: 14 DAYS

The life cycle stages of the silkworm moth Bombyx mori Phylum, Arthropoda; Class, Insecta;

Order, Lepidoptera

Newly laid eggs are a creamy yellow, after a few days the fertile live eggs will be gray

STAGE 2 - LARVA: 27 DAYS (5 instars)

After four days the first molt will occur.

After hatching the tiny larvae grow the best if they are fed on thnew soft leaves of the mulberry tree. Switch over to larger leaves as they grow. The silkworms(larvae) do nothing but eat. Keep them in a flat open box. They will not crawl away. Simply place leaves in the container and place the silkworms on the leaves. Keep them at room temperature, but not in direct sunlight.

STAGE 3 - PUPA: 14 DAYS

The silkworm will spin a silk cocoon as protection for the pupa. Cocoons are shades of white, cream and yellow. The glistening shine of the silk gives an impression of silver and shades of gold. After a final molt inside the cocoon, the larva change into the brown pupa. Further changes inside the pupa result in an emerging moth

STAGE 4 - IMAGO: 5 - 7 DAYS

An adult silk moth emerges from the cocoon about two weeks afte r completion. This is the adult stage of the silkworm, Bombyx mori. The body of the moth is covered in short fine hair and wings are creamy white with faint brown lines. Moths can not fly or consume nutrition. Females are larger and less active than the males. Male moths move about beating their wings seeking females

How Silk is Made


Silk - the most beautiful of all textile fibers is acclaimed as the queen of textiles. It comes from the cocoon of the silk worm and requires a great deal of handling and processing, which makes it one of the most expensive fibers also. Today China is the leading silk producer of the world. Other major silk producing countries include Japan, India and Italy.

Production of Silk
Characteristics of Silk
Identifying of Silk
Four Varieties of Natural Silk
The Silk Worm
Production of Silk from Cocoon to Factory
Sericulture: The production of cocoon for their filament is called sericulture. The species Bombyx mori is usually cultivated and is raised under controlled condition of environment and nutrition. The life cycle of silk worm encircle in the four stages. The egg, the silk worm, the pupa and the moth. The silk worm which feeds on mulberry leaves forms a covering around it by secreting a protein like substance through its head.

This stage is called cocoon, the desirable stage for the silk producers.
Filature operations: The cocoons raised by the farmer are delivered to the factory, called a filature, where the silk is unwound from the cocoons and the strands are collected into skeins. Some cocoons are scientifically bred in such factories. The filature operations consist of the following stages.

a) Sorting cocoons :
The cocoons are sorted according to the color, size, shape and texture as these affect the final quality of the silk. Cocoons may range from white and yellow to grayish.

b) Softening the Sericin : Silk filament is a double strand of fibroin, which is held together by a gummy substance called sericin or silk gum. After the cocoon has been sorted, they are put through a series of hot and cold immersions, as the sericin must be softened to permit the unwinding of the filament as one continuous thread.

c) Reeling the filament : Reeling is the process of unwinding the silk filaments from the cocoon and combining them together to make a thread of raw silk. As the filament of the cocoon is too fine for commercial use, three to ten strands are usually reeled at a time to produce the desired diameter of raw silk which is known as "reeled silk". The useable length of reeled filament is 300 to 600 m.

d) Bailing : The silk filament is reeled into skeins, which are packed in a small bundles called books, weighting 2 to 4.5 kg. These books are put into bales weighing about 60 kg. In this form raw silk is shipped to silk mills all over the world.

Characteristics of Silk

Silk is very strong in terms of tensile strength, meaning it can withstand a lot of pulling type pressure without breaking. This should not, however, be confused with wear ability or abrasion resistance. Silk will not stand up to the heavy wear that other fibers will.

Silk can take on many different appearances. A raw silk fabric may fool you into thinking that it is cotton or synthetic. The more refined the silk and the smaller the yarn, the more it resembles the look and feel that we know as silky.

Silk is a protein fiber like wool. This gives it many of its characteristics. It is sensitive to a range of chemical situations and cannot withstand prolonged exposure to either high alkalinity or to acid or oily soils. It will become brittle with age and exposure to sunlight.

Identifying Silk
The burn test is the best way to be sure. Burning silk will leave a powdery ash and will extinguish itself when the flame is removed, just like wool. The easy way to tell silk and wool apart in the burn test is the smell. Where wool will have the smell of burning hair, the silk will have a much more disagreeable smell.

Four Varieties of Natural Silk
Out of the numerous species of silk moths, scientists have enumerated about 70 silk moths which are of some economic value. But of these only a very few have commercial value. The four commercially known varieties of natural silk are (1) Mulberry silk (2) Tasar silk (3) Muga silk and (4) Eri silk. Although the bulk of world silk supply comes from the silk moth Bombyx Mori which is domesticated, the other varieties of silk are known as wild silk, as they are grown in remote forest trees in natural conditions.

A wide range of silk fabrics are produced at different production centers both Handloom and Powerlooms. A brief account of the range of fabrics is furnished below, as is known by its popular names.
Mulberry Varieties
Some important mulberry varieties are discussed below:
(a) Plain Silk Fabrics
A range of thin silk to deluxe qualities are produced in this category using filature. Fabrics ranging from 20 gm to 70 gm are produced in this category using both handloom as well as powerloom. The fabrics is available as per the requirements in different shades as well as in checks and stripes. Beautiful pin stripes are a specialty for shirting. Plain silk is mostly used by exporters for making ladies blouses, fashion garments, made-ups and scarves. Deluxe and super deluxe qualities are also produced as per specific orders.
(b) Dupion Fabrics
A specialty of Bangalore Handlooms, Dupion is the craze of the west. Produced out of twisted filature warp and dupion weft is available in different quality ranges and shades. Dupion checks and stripes are elegant in look. Mainly used for dress material and cushion covers and furnishings, dupion is a popular name among the overseas silk importers.
(c) Charka Silk
Using filature in warp and Charka in weft a thicker fabric is made on handlooms. For most of the zari decorative sarees charka yarn is popularly used by the sari manufactures.
(d) Chiffon
Using highly twisted yarn, a thin but strong fabric is produced on power looms, which after processing and finishing attains a soft and smooth texture. Chiffons are used for varied end-uses for ladies garments and scarves/stoles.
(e) Chinnon
This is also produced from highly twisted yarn of filature in power loom. After the final processing and finishing the fabric gets a soft but crimp effect. Chinnon is ideal for ladies dresses and scarves/stoles.
(f) Crepe
Produced from 2-ply twisted yarn of 's' and 'z' twist and woven on power loom, crepe is used for varied uses. Mysore crepe saris are very popular in domestic and export front.
(g) Organza
A very thin fabric produced from highly twisted yarn. After a starchy finish the fabric gets a rough texture. Organza is used as sari material as well as for embroidered garments.
(h) Satin
Silk satins are a popular variety of fabric used for a varied end use. When made into dresses satin gives an elegant Look. Banarasi Satin Saris are popular for export and domestic markets.
(i) Tabby Silk
A type of plain silk fabric produced in Kashmir. Tabby silk is mostly used for printed saris and scarves.
(j) Murshidabad Silk
A popular silk fabric produced in the Murshidabad district of West Bengal. Used mainly for saris and scarves, the fabric is available in different qualities known as 16s, 18s, 20s, and so on .
(k) Matka Fabric
Using Matka yarn for both warp and weft, a thicker fabric is produced mostly for furnishing. The fabric mostly produced in Bhagalpur is a very popular export item at present. By using multiple yarns the texture and thickness of the fabrics can be modified according to the end use.

synthetic fibre

All fabrics are materials made from many fibres.
Cotton is a natural fibre obtained from the cotton plant.
All synthetic fibres are man-made fibres that are prepared by a number of processes using raw material of petroleum origin, called petrochemicals.

A polymer is made up of many repeating units called monomers.
Cotton is a form of polymer called cellulose, which is made of a large number of glucose units.
Characteristics of synthetic fibres:

Dry quickly
Very durable
Less expensive
Easy to maintain
Readily available

Fibre obtained by chemically treating wood pulp is called rayon or artificial silk. Rayon cannot be called a natural fibreas it is man-made.

Characteristics of rayon:
Cheaper than silk and can be woven like silk fibres.
Highly absorbent, soft and comfortable.
Easy to dye in a wide range of colours, and drapes well.

Uses of rayon:

Widely used in all types of clothing and home furnishings.
Mixed with cotton to make bed sheets and curtains, or withwool to make carpets.

Nylon is a synthetic fibre made from coal, water and air.
Nylon is b, elastic, light, very lustrous and easy to wash. Itdries quickly and retains its shape.

Uses of nylon:

To make seat belts in cars, curtains, sleeping bags, tents, tooth brushes, socks and ropes,
To make parachutes and ropes for rock-climbing.

Polyester is a synthetic fibre, derived from coal, air, waterand petroleum.
Polyester is made of repeating chemical units called esters.

Polycot is a mixture of polyester and cotton, and polywool is a mixture of polyester and wool.
Fabric made from polyester retains its shape and remains crisp. Polyester is easy to wash and dry.

Terylene is a popular form of polyester, which can be drawn into very fine fibres. These fibres can be woven like any other yarn.
PET, or poly-ethylene terephthalate, is another familiar form of polyester, which is used to make bottles, utensils, films and wires.
Polyester is also used for making hoses, ropes, nets, thread, raincoats, fleece jackets, clothing and medical textiles.
Acrylic is a synthetic polymer of methyl methacrylate.
Fabric made from acrylic is warm to wear, retains its shapeand is durable.

Acrylic is easy to wash and dries quickly.
Acrylic is used in apparel like sweaters and socks, and inhome furnishings such as furniture, carpets, blankets andupholstery fabrics.
Industrial uses of acrylic include craft yarns, awnings, boat and vehicle covers, and luggage.

green house effect

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lightening

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DOUBLE CIRCULATION


Blood from the body enters the right atrium of the heart. Its pumped out of the right ventricle towards the lungs to pick up oxygen.

The blood is now oxygenated.It returns to the left atrium and passed into the left ventricle. Here it gets another harder pump which carries it around the rest of the body.

The left ventricle has a thicker wall of muscle than the right, because it has to pump blood to the whole of the body.

The right ventricle only pumps as far as the lungs.As the blood passes around the body it gradually gives up its oxygen to the cells.It becomes deoxygenated.

The blood the returns to the right atrium again.

So blood passes through the heart twice on every circuit of the body. This is called a double circulation.

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Monday, June 6, 2011

excretory system

Human Excretory System


¨ Excretion - Excretion is the removal of the metabolic of an organism. Removed wastes include carbon , water, , urea and uric acid. All excreted wastes travel at some time in the stream.

¨ Organs of the Excretory System

1. Lungs – removal of excess

2. Liver – produces urea and uric acid as a by-product of the breakdown of proteins

3. Skin – removal of excess , salt, urea and uric acid

4. Urinary System – kidneys filter the blood to form , which is excess , salt, urea and uric acid

The Skin


¨ 2 Layers of the Skin

1. Epidermis – protective layer without blood vessels

2. Dermis – inner layer containing blood vessels, sensory nerve endings, and oil glands, hairs, and fat cells

¨ Functions of the Skin

1. Excretion – Wastes such as excess water, salt, urea and uric acid are removed from the body in .

2. Waterproofing

3. Protection from Disease-causing Micro-organisms

4. Protection from Ultraviolet Rays

5. Regulation of Body Temperature – The thin layer of fat cells in the dermis insulates the body. Contraction of small muscles attached to hairs forms ‘goosebumps’ and creates an insulating blanket of air. Also, sweat uses excess body heat to , providing a cooling effect.

6. Sensory Detection – The nerve endings or receptors in the dermis detect heat, cold, touch, pressure and pain.


Human Urinary System


Urine

¨ The first nitrogenous waste to be formed from the breakdown of protein is ammonia, a highly toxic chemical that is quickly converted by the to urea and uric acid. These are less toxic than ammonia and are transported in the blood to the kidneys for excretion in urine. Urine consists of excess water, excess , urea and uric acid.

Parts of the Urinary System

¨ R A – 2 renal arteries constantly transport blood to the kidneys.

¨ K – 2 kidneys composed of millions of nephrons constantly filter about 170 to 200 litres of blood to produce about 1.5 to 2 litres of urine each .

¨ R V – 2 renal veins return useful nutrients back into the .

¨ U – 2 ureters carry urine from the to the urinary bladder.

¨ U B – The urinary bladder temporarily stores until it is released from the body.

¨ U – The urethra is the tube that carries urine from the urinary bladder to the of the body.

Draw a labelled diagram of the urinary system.

clarification regarding HHW

U HAVE TO WRITE 40 QNS FROM LIFE PROCESS AND 1ST CHAPTER

clarification regarding HHW

U HAVE TO WRITE 40 QNS FROM LIFE PROCESS AND 1ST CHAPTER

Thursday, May 5, 2011

HOLIDAY HOMEWORK OF SCIENCE

KENDRIYA VIDYALAYA , FORT WILLIAM ,KOLKATA-21,2011-12

SCIENCE HOLIDAY HOMEWORK

CLASS-VII-C, D

1.PREPARE 30 QUESTION FROM CHAPTER 3,4,5,6,7 EACH

2.Project- 1) draw the life cycle of silkworm in ¼ drawing sheet.

2) Show in the map of India where the silk production done and what are the different types of silk found in India.

3) Draw a clinical thermometer.

4) Measure the temperature of family

CLASS- VIII

1) CHAP. 3,4,5,6 make fifty questions from each chapter. Do not write answer only question in classmate 4 no copy.

2) Draw the nitrogen cycle for 5 times.

3) In the scrap book paste 15 pictures of different types of microorganisms.

4) Paste different types of fibres and plastic in the scrap book.

5) In the thinkquest create one page tittled (CCE class 8 science)

5.1) PPT from chapter 1,2,3,4 [any one topic]

5.2) One article on chemistry in Everyday Life

CLASS VI-D SCIENCE

1) Scrap Book work

2) Paste any five types of clothes.

3) Paste Natural fibres and synthetic fibres

4) Read chapter 5 and 7 and 30 questions.

5) In a scrap book fix or draw pictures of components of food like carbohydrates , fat, proteins, vitamins and minerals.

6) Make a table to show deficiency decrease.

CLASS X SCIENCE

1) Create one page on thinkquest title- CCE CLASS- X SCIENCE FAII

a) One power point presentation on chapter 1,2,3 Life process, Electricity.

b) One article on chemistry in every day life/ biodiversity.

2) Investigatory project on

a) Respiratory disease.

b) Water- borne disease.

3) Frame forty questions from chapters.