SUBJECT: HOME SCIENCE Class: 10

Transcription

1 Chapter 15: Laundering Chapter 16 : Laundry Materials SUBJECT: HOME SCIENCE Class: 10 Chapter 15: Laundering Answer the following questions. 1 What is laundering? OR Define laundering Ans Laundering includes not only washing the clothes with soap or detergent and rinsing with water to remove dirt, grease, stains etc. but also restoring the freshness, original colour and crispness. 2 What are the three steps included in laundering? Ans Laundering consists of three steps: i) Regular washing of fabric to remove dirt. ii)finishing the fabric iii) Storing the fabric by ironing and folding it. 3 Name the basis on which clothes can be sorted? Ans Clothes can be sorted on the basis of: i)fibre or texture- cottons together, silks separately. ii)size- big articles like bed linen separated from smaller articles of personal use. iii)colour- coloured clothes separated from white ones. iv)degree of dirt- heavily soiled clothes separated from lightly soiled ones. 4 What is the benefit of using washing soda while soaking clothes? Ans Washing soda used while steeping heavily soiled clothes saves on time and labour and gives better results. 5 State the advantages of soaking clothes. Ans Soaking clothes helps to economise on time, labour and soap. Loose and soluble dirt is removed by action and impact of water particles. The clothes get thoroughly wet which helps in the removal of fixed dirt. Stains soluble in water are removed and the starch from previous laundering is removed. 6 Ironing and pressing are terms that are often used interchangeably. How are they different? Ans Ironing is by spreading the cloth that needs to be ironed on a flat and hard but lightly padded surface. Hot iron is moved back and forth over it along the length of the fabric with pressure. This method is used for cotton, linen, silk and synthetics. Pressing is done by placing a hot iron over a spread out fabric at one place, lifting it vertically up from the place after a few seconds and again placing it over another area. Pressing is done on clothes which have great elasticity like woolens, lace, net etc. 7 Synthetic garments need little or no maintenance. Give the benefits of using synthetic fabrics. Ans Synthetic fabrics are easy to wash. They need not be soaked if not very dirty. Tap water can be used to soak these fabrics. ( 1 )

2 These fabrics can be washed with any soap or detergent. Since, they are strong fabrics, methods of friction can be used to remove dirt. Synthetic fibres absorb very less quantity of water, hence they can be easily rinsed off. They dry quickly. Synthetic fabrics are wrinkle resistant and even less wrinkles appear if drip dried, they require little or no ironing. 8 Why should knitted woolens have their outlines traced before they are washed? Ans Wool has high elasticity which further increases when it is wet. so the knitted woolen fabrics within invariably lose their shape. Tracing helps to restore the garment to its original shape as they are put the outline and left to dry. 9 What should you keep in mind while blueing garments. Ans The blue is tied up in a muslin cloth and squeezed into the water till a required depth is obtained. Coloured clothes are not blued. Blues are advised for white cottons and linen only. Fabrics should not be dipped in blue water left standing for 5 minutes or more.the water containing the blue should be stirred well before the clothes are put in to prevent the blue from settling down as this may cause streaks and patches. Fabrics should not be left standing in the blue water as there will be patches of blue otherwise. The water should be sufficient to cover the garment fully. The garment should be squeezed well inside the water for the thorough penetration of blue into the garments. Blued fabrics should be dried in the sun for better results. 10 We need to use neutral soaps for woolens. Give reason. Ans Wool is a protein fibre and is highly sensitive to alkalies. Washing it with even mild soaps may harm it. Hence, only a neutral soap or reetha can be used for washing woolens. 11 Explain the process of laundering and ironing a silk garment. Ans Preparation: examine the garments for tears, holes, stains and treat accotdingly. Steeping: of silks is avoided due to its weak nature when it is wet. If the garments are much soiled, steeping can be done in lukewarm or water for a maximum of minutes. Use only a neutral soap for washing silks. Washing: silks should be washed with gentle handling, using kneading and squeezing method. For. much soiled areas like neckline, elbow and cuffs gentle rubbing with flat hand can be done. Extra soap water can be removed by gentle squeezing Rinsing:should be done in clear, soft tap water till all the soap is removed from the garments. Last rinse should be done by adding vinegar for increasing the luster of the garment. Stiffening: since silk is very soft and pliable, it requires atreatment of gum water to give it stiffness, proper shape, body and luster. Drying: coloured silks should be dried in the shade and white silks in the sunlight. Ironing: all the silk garments should be properly ironed before they are completely dried. Ironing temperature for silk is 100 F. Silk clothes should not be sprinklws with water for proper ironing as it leaves stains on the fabric. 12 Application of pressure is done in accordance with the type of fabric to be washed. Elaborate this statement. Ans The application of pressure can be done in 4 ways. i)the application of friction may be applied by hand rubbing or by equipments like brushes, sticks When friction is applied by hand there is less strain on the clothes. Application of friction by hand is possible only for small articles and lightly soaked clothes.scrubbing by brushes is possible only on ( 2 )

3 strong fabrics and for heavily soiled clothes. It is advisable to scrub the clothes in the direction away from the worker.friction may also be applied by lightly beating the clothes with a clothes stick or by beating the cloth against a hard floor or board. ii)the application of light pressure renders itself well in case of washing of fine textures, coloured and delicate clothes. The process consists of kneading and squeezing of the articles by hand in the soap solution.the pressure applied is light and hence it is a safe process. The kneading is continued till there is some lather left as the disappearance of lather indicates the presence of dirt. The heavily soiled portions can be brushed with a soft brush and clothes rinsed clean. iii)the suction method is suitable for all kinds of clothes. It is time and labour saving. The clothes are seeped in soap solution and then the suction washer is worked up and down to remove all the dirt. iv) The washing machine cleans clothes by agitating the clothes in a soap solution by revolving or moving by special arrangements. 13 Mention the points to be remembered while storing garments. Ans Some points to be remembered while storing garments: i)dirty clothes should never be stored. ii)clothes to be stored must be fully dry. Moisture left in clothes will promote mildew and moths. Just before storing, expose the clothes to strong sun. iii)closet or boxes where clothes are to be stored should be exposed to sun rays for some time. iv) Closet or boxes where clothes are to be stored should be moisture free. v) Some protective devices should be used to repel insects like a- use of newspapers b- use of dry neem leaves c- use of naphthalene balls 14. Explain the kneading and squeezing method of washing. In this method, light pressure is applied on the clothes by kneading and squeezing action of hands. This method is most suitable for cleaning weak and delicate fabrics like wool, silk, rayon, lace and net. The clothes washed by this method should be squeezed not wrung to remove the extra soap water and rinsed with enough quantity of water. After rinsing too, extra water should be removed by gentle squeezing. ( 3 )

4 Chapter 16 :Laundry Materials Answer the following questions. 1 Name the items required for laundering? Ans The items required for laundering are: a Water b Soap or detergents c Blues d Optical brightening agents e Stiffening agents f Bleaching agents g Laundry reagents 2 Why is water the only item without which no wet washing is possible? Ans i)water is a very good solvent, therefore much dirt and stains are cleaned in water while washing. ii)it dissolves and emulsifies soaps and detergents so that quick and easy cleaning is done. iii)there is a certain force of adhesion between clothes and water. Thus, the water enters deep into the fibres of the cloth and causes wetting. 3 How is a detergent different from a soap? Ans Detergents are cleaning agents made from chemicals. they are different from soaps in these ways: a They are readily soluble even in cold water. b They have lower surface tension. Therefore, they are more efficient than soaps. c They are easy to rinse out. d They are efficient even in cold wate,r unlike soaps. e They are cheaper than soaps. f Detergents do not combine with the salts of the water to form deposits on the fabric. 4 Why do we use blues? Ans White cellulosic fibres lose their bright whiteness with age and use. Blues are used in the last rinse to restore their whiteness. Blue being a complementary colour of yellow, it diminishes the yellow tinge of fabrics and makes them appear whiter. 5 What are the precautions you need to take while using bleaches? Ans Always use a bleach of known strength, never exceeding strength of 5 grains per gallon. Temperature at which bleach is used should never exceed 140 F. Always start by using bleach in the dilute form, then add more of it if required. Always use bleach for minimum time required for its action. A very thorough rinsing out of the bleach from the fabric is essential. 6 What are OBA S? What is their significance in the laundering process? Ans OBA S or FBA S are optical brightening agents or Fluorescent brightening agents. They are used for white fabrics that have lost their whiteness due to age and use. They are colourless dyes which attach themselves to the fabric and make them appear whiter or brighter by reflecting light. They absorb light from the UV region and reflect them back in the visible region. This reflected light counteracts the effect of yellowness, thus making them appear whiter and brighter than before. ( 4 )

5 7 Why do we need to use detergents to clean clothes? Ans Washing clothes in water alone- even with agitation provided by hand or by machine will remove some but not all stains, dirt and particulate soils Water alone cannot remove soils that are not water soluble, and water does not have the capability to keep removed soils suspended. Therefore, we opt to use laundry detergents when washing our clothes. 8 What are stiffening agents? What are the advantages of using them? Ans Stiffening agents are the materials that are used on fabrics to give them stiffness or crispness. The advantages of using starch: i It makes the fabrics appear smoother. ii Smooth surface of fabrics does not allow dirt particles to stick to them easily. iii Smooth surface of fabrics also makes them appear shining. iv It gives body and crispness to the fabrics. 9 What does the amount of starch to be applied upon fabrics depend on? Ans The amount of starch to be applied upon fabrics depends on: i Whether the fabric is thick or thin ii How much stiffness is required. iii Amount of stiffness desired by you. iv Heavier materials require less starch than light weight fabrics. 10 Write about the use of washing soda and borax as laundry reagents. Ans Washing soda available in crystalline form readily soluble in boiling water Increases cleaning action of soaps. Dissolves protein stains. Used to soften water. Helps in removing vegetable and scotch marks. Be careful as it gives yellow ring to white fabrics and fades colored ones if used frequently. Borax: White powder readily soluble in water. Can be used safely on any fabric. Used to neutralize acids in stain removal. Added to starch to prevent scorching or brewing of fabric because of high temperature. ( 5 )

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