The addition of silk fibre (3-15 wt%) reduced the percentage mass loss (59.7-45.5%) . Answer (1 of 2): silk is one of the popular fabrics for apparel because of its unique properties. Shape and appearance: Silk filaments square . 4. Wool is resistant to acids. China is the largest silk producer and consumer in the world followed by India where Indian sarees made from silk are famous. The raw silk threads undergo a series of processes such as rolling, warping and twisting before being woven into a fabric on a loom. But there is a huge difference between silk vs wool. Silk threads are made from a sticky secretion secreted by the larvae of the silkworms. Suggest Corrections. Silk fibres are converted into silk yarn . The cost of silk varies widely, depending on the country in which it was produced, the method of collection, the nature of the fiber and so on. Silk takes well to dyes, which results in colourful fabrics. 5. E) None of these . silk tends to fall naturally and hangs delicately on the . b) It can be dyed easily and takes the highest lusture. Question 1. 2. What is shearing? common silk moth among all is the mulberry silk moth . It's cotton i.e. Cultivated silk is from silkworms fed only mulberry leaves. Why cannot a single silk fibre form a thread? Wool is the most commonly used animal fibre. Wool. Question 5. Gravity: 1.48 - 1.51 g/cm 3. 1. 5. Natural silk is an animal fibre. Silk is often used for clothing such as formal dresses, shirts, blouses, ties, lining, pajamas, dress suits, lingerie, high fashion clothing and Eastern traditional costumes. silk tends to fall naturally and hangs delicately on the body. Silk fibre is made of a protein. Like animal hair, silk does not conduct heat and is . This silk cloth is then used for making sarees and other dresses. This strength comes from the continuous length of the fibre. Silk fibre with the average fibre diameter of 100 m was supplied by Ocean Verve Ltd., Hong Kong. Strength: Silk is that the strongest fibre. Silk is resistant to organic acids but damaged by mineral acids. Silk cotton is softer than regular cotton. However, only silk from the silkworms is used for textile purposes. The biodegradable polymer-PLA as a matrix under investigation in the current study is a neat grade commercialized by Cargill-Dow under the brand name NatureWorks PLA Polymer. Characteristics of silk fibre:-(i) It is the strongest natural fibre. Silk has a soft feel, and in appearance, it has a sheen and luminosity that makes it look luxurious. Name the four given fibres marked 1,2, 3 and 4. Flax is a bast fibera woody fiber obtained from the phloem of plants. Very long filament (up to a mile long) Spun by a caterpillar called a silkworm (but not actually a worm). The cocoons are put in boiling water to loosen the silk fibre. The Class 7 Science, Chapter 3 - Fibre to Fabric helps us understand how the fabric that we use in our day-to-day lives is produced from the fibre.In this chapter, we study the concepts of natural and man-made fibres. Silk fibers are made from a protein produced by the silkworm, Bombyx Mori. It's filament density is 1.34 g/cm which make it a medium weight fiber. Flax fiber is not so fine as cotton, is longer than cotton. The silk fibres so obtained are weaved to make silk cloth. It is also very elastic, which means it can be stretched to its limits. Decades later even though the methods used to make fabrics from fibres may have changed greatly, their functions remain the same: Most natural fibres are still . Characteristics of Silk. Silk is a natural protein filament. Cultivation of silkworm is known as sericulture. Saris and other garments are made from silk. The female died immediately after producing the eggs while the male moth died a short period after that. Ans: Egg: The female silk moth lays large number of eggs. 2. Silk fibre reacts with acids more quickly. The eggs took about 10 days to become larvae. The most common silk moth is mulberry silk moth. Silk is a luxurious fabric spun from the cocoons of a moth, Bombyx mori. First of all, silk takes well to dyes, both natural and synthetic, which results in colorful fabrics. Silk is a fine, strong, soft and shining fibre produced by silkworms in making their cocoons. 2. If they are not killed and allowed to grow, they will break the . It is slightly affected by diluted organic acids at room temperature. Wool is used to make sweaters, shawls, and other woollen fabric. The sources of obtaining fibres are plants and animals. The filaments are 300-1800 yards long. Below 7 is acid, and above 7 is alkaline. Maturity ratio: varies from 0.7-0.9. Ans. IV. Natural Fibres. They may be woven, knitted, matted or bonded. Heat conductivity: Wool fibre is a part that is a poor conductor of heat and therefore the fabrics made from the fibre are considered most suitable for winter wear. Moisture Content: 8.5%. 4. Other insects can also produce silk. The rearing of silkworms to obtain silk is termed as sericulture. Ans: The characteristics of wool fibre are - a) Silk is extremely elastic,the smoothest and finest of all fibres. Silk. Silk has a soft feel, and in appearance, it has a sheen and luminosity that makes it look luxurious. The use of linen in Egypt between 3000and 2500B.C. Silk is a filament spun by the caterpillars of various butter flies. Stronger than cotton or linen. Color: Light yellow or brown. Silk cotton is a plant fibre from the KAPOK tree used for stuffing for pillows and lifejackets and insulation. The sub-topics covered are animals that yield wool, fibres to wool and the rearing and breeding of sheep. The silk yarn is then woven on looms into silk cloth by the weavers. Wool yielding animals are sheep, yak, llama, alpaca, angora goat, angora rabbit and camel. Properties of Silk. A silk saree. Wool and silk are hence animal fibres. Answer: Wool, jute, cotton, flax, etc. Question 4. Step 5: Dyeing: After sorting and picking out of burrs, these are dyed in desired colors. Answer: Fibre (marked 1) which is used in filling quilts is cotton and fibre (marked 2) is . Effect of alkalis: The soft silk thread is as strong as a comparable steel thread. Silk is an elastic, lustrous protein fibre. Silk fibres are converted into silk yarn which is used for making silk cloth. Name some natural fibres. The protein is called Sericanin and is solely produced by this insect. All you need of Class 8 at this link: Class 8. Some most common Ccharacteristics of Silk Fibers are: (i) As the silk fibers can retain some moisture, the clothes made of silk can be used in both the winter and summer seasons. Silk cotton tree has softwood, red flowers, a large number of seeds and smaller filaments. Silk is composed of 80% of fibroin, which is a protein substance and 20% of sericin, which is a silk gum. Ans: The two characteristics of wool fibre are - Chemical, mildew & moth resistance - ph levels in your cleaning and dyeing baths can damage some of your fibers. and its culture and weaving was a guarded secret for more than 2500 years by the Chinese. What are the characteristics of silk fibre? It gets yellowish when it comes into contact of Nitric acid. Some examples of fibres are cotton, wool, silk, flax, jute, nylon, polyester and polyacrylic. . has been verified. Most valued for its "silky" feel. How is natural silk and artificial silk made? The most. It's Latin name is Bombyx mori. 1. As of . Silk: Silk is a protein fiber and only one natural continuous filament made by the silkworm, produced by caterpillars belonging to the genus Bombyx.The most beautiful among all textile fibers is silk, which is claimed as the queen of textiles. A female silk moth produces about 300-400 eggs at once. Artificial silk (called rayon) is obtained from wood pulp and it is made of modified plant material . The finest wool is obtained from Merino sheep. Ans: The fibre of a single cocoon is too fine to handle as a result of which a single silk fibre cannot form a thread. Silk Fibre class 7 is the most durable and reliable type of fibre available. Silk is an elastic, lustrous protein fibre. silk tends to fall naturally and hangs delicately on the body. Question 2. SILK. 12th Class; 11th Class; 10th Class; 9th Class; 8th Class; 7th Class; 6th Class; 5th Class; 4th Class; 3rd Class; 2nd Class; . Silk takes well to dyes, which results in colourful fabrics. d) It can be stretched to almost 25% of its original length. it's a purpose of two.4 to 5.1 grams per denier. Name two varieties of cloth materials which are commonly used. (ii) It is a natural fibre. Silk is an elastic fibre which can be stretched from 10% to 20% of its original length . Silk is a universally accepted luxury fibre. Cellulose fibers are harmed by acids - even vinegar can do some damage. The fibre of a single cocoon is too fine to handle, so up to ten cocoons are wound together onto a reel by hand. These cocoons are spun to produce a continuous silk filament with a natural gum that lends it to have an appealing sheen. Step 4: After sorting, fluffy fibers, called burr, are picked out from hair. 3. Very light weight silk textile materials may be manufacturing from silk filaments. What are the characteristics of silk Class 7? Properties of Silk Silk is an elastic, lustrous protein fibre. According to a survey, a lot of silk was collected from silkworm farms instead of the wild as of 2010. Which characteristics of fibre are given below? Microscopic properties of silk. Another property of silk is its soft feel, and it retains it shape well, even after having . Burr is the fiber that gives wool. The concentrated organic acids dissolve the silk fibres. Silk is an elastic, lustrous protein fibre. Fibres obtained from plants and animals that can be spun into filament, thread or rope are termed as 'Natural fibres'. What Are The Characteristics Of Silk Fibre Class 7? Main inner portion (70 80%) is made up of fibroin (true fibre) which is surrounded by a thin covering of . Wool and silk are animal fibres. e. Why are the cacoons boiled in hot water or treated in ovens. So, silk is an animal fibre. Silk fiber has a double rod-like structure, covered with lumps of gum. Detailed Solution for Important Questions Test: Fibre To Fabric - Question 2. Properties of Silk. c) It is the strongest natural fibre. Fineness: The value varies 3-6. Silk's shine also makes it . Silk as a wearable fiber was first discovered by the Chinese emperor Xi Ling shi during 2,640 B.C. It is separated from cacoons of silkworms which is made of protein. Characteristics of Silk Fibers and Products. To kill the pupa inside cacoons, these are boiled in hot water. The strength of the spun silk yarns depends on the length of silk staple. The soft silk thread is as strong as a comparable steel thread. The soft silk thread is as strong as a comparable steel thread. In the first place, this fiber is popular all over the world for its valuable and outstanding appearance.It is also popular to make children's wear, ladies' wear, tie suits, and other applications. Uses of Silk Fiber: The silk fiber is a different type of textile fiber.When silk fiber has various uses in the textile and apparel manufacturing industry. It is a solid fiber. Price of Silk Fabric. Fibre to Fabric Class 7 Science Extra Questions Very Short Answer Type. Silk is an elastic, lustrous protein fibre. Characteristics of Silk. They are very thin but strong having high elastic property. Silk takes well to dyes, which results in colourful fabrics. Wool is a modified form of hair that grows with a waviness. A protein fiber. Effects of Alkali: Unaffected or undamaged by alkaline solution. Silk is a fine, strong, soft and shining fibre obtained from silkworms. Cultivated silk is smooth, cylindrical and generally uniform in thickness, like glass rods. Silk culture began in china in 2640 BC, and later spread to Korea and Japan, westward to India and Persia, then to Spain, France and Italy. (i) Soft in touch. This decrease in mass loss and the resultant increase in thermal stability is attributed to the higher thermal stability of silk fibres, which on interaction with the polymer matrix act as barriers for better heat insulation and lower the rate of . Fabrics made from silk fiber are light but it can keep its wearers warm. . Silk and Wool are both fibers are from animal origin. (ii) The silk is non-conductor of electricity, and therefore can be used as an insulator covering of electric wires. The production of silk in Europe began in 590 AD and around 300AD in India. Name the sources of obtaining fibres. What is silk give some characteristics of the silk fibre Class 7? Then, the chapter moves on to explain a very useful fibre - wool. Silk textiles may be weakened if it is exposed to too much sunlight. Mention two characteristics of wool fibre. 2. silk is an elastic fibre an. Silk fiber is a protein fiber from silk glands of an insect. INTRODUCTION Silk is a natural protein fibre produced by the larve of a moth, like wool. Resiliency: Wool is highly resilient and comes to its original shape when hanged after wrinkled or created. Silk has a soft feel, and in appearance, it has a sheen and luminosity that makes it look . 3. Fibres are very thin, thread-like strands from which fabrics (or cloths) are made. Wool is the soft, wavy (or curly) hair which covers the body of a sheep. Question 3. The fibres are spun into yarn (long continuous thread) which can then be woven on a loom to make a fabric (or cloth). This fiber, also called raw silk, is spun into silk yarn and threads. Name some wool yielding animals. Silk is a strong natural fibre possessing good tensile strength. Different types of silk: Silk is usually referred to as the queen of the fibers. Use Code STAYHOME200 and get INR 200 additional OFF. The soft looking silk yarn is as strong as a comparable thread of steel. Effects of Acids: Cotton fibers are weakened by cold weak dilute acids and degraded by strong acids. Differentiate between a biodegradable and a non-biodegradable material.
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