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Karnataka KSEAB II PUC Apparel Made-Ups & Home Furnishing study materials
Karnataka KSEAB II PUC Apparel Made-Ups & Home Furnishing study resources

Karnataka KSEAB II PUC Apparel Made-Ups & Home Furnishing practice questions

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Question 1Introduction to Apparel and Home Furnishing Industry

Which fibre is classified as a natural cellulosic fibre obtained from the seed of a plant?

  1. Polyester
  2. Cotton Correct answer.
  3. Silk
  4. Wool

Explanation

Cotton grows as a protective covering around the seeds of the cotton plant, and its chemical composition is almost entirely cellulose. Wool and silk are protein fibres of animal origin, while polyester is a synthetic polymer made from petroleum-based chemicals.

Question 2Introduction to Apparel and Home Furnishing Industry

In the apparel production sequence, which stage immediately follows pattern making and grading before bulk fabric cutting begins?

  1. Garment finishing and pressing
  2. Retail display and merchandising
  3. Marker making and fabric spreading Correct answer.
  4. Yarn spinning and weaving

Explanation

After patterns are made and graded into sizes, markers are planned to place the pattern pieces economically on the fabric, and the fabric is spread in layers for cutting. Finishing and pressing come after stitching, while spinning and weaving belong to textile production upstream of garment making.

Question 3Introduction to Apparel and Home Furnishing Industry

A home furnishing unit needs a fabric for upholstery that must resist abrasion and repeated rubbing. Which performance property is being specified?

  1. Abrasion resistance Correct answer.
  2. Moisture regain
  3. Colour fastness to light
  4. Dimensional stability

Explanation

Abrasion resistance measures how well a fabric withstands rubbing and friction, which is the key durability requirement for upholstery that is sat on and rubbed daily. Light fastness concerns fading, dimensional stability concerns shrinkage, and moisture regain concerns water absorption.

Question 4Introduction to Apparel and Home Furnishing Industry

Which term describes the process of joining two pieces of fabric using a continuous interlooping stitch formed by needles and loopers rather than a bobbin thread?

  1. Knitting Correct answer.
  2. Bonding
  3. Weaving
  4. Felting

Explanation

Knitting builds fabric by interlooping yarns with needles and loopers, giving stretch and a looped structure. Weaving interlocks two sets of yarns at right angles, bonding uses adhesives, and felting entangles fibres by mechanical and moisture action without loops.

Question 5Introduction to Apparel and Home Furnishing Industry

In the Indian apparel export sector, which body is the primary government organisation responsible for promoting and regulating textile and apparel exports?

  1. Textile Committee under the Ministry of Textiles
  2. National Institute of Fashion Technology
  3. Apparel Export Promotion Council Correct answer.
  4. Bureau of Indian Standards

Explanation

The Apparel Export Promotion Council is the export promotion body for readymade garments, working with the Ministry of Textiles to support and regulate apparel exports. The Bureau of Indian Standards sets product standards, NIFT provides fashion education, and the Textile Committee handles quality testing and related services.

Question 6Introduction to Apparel and Home Furnishing Industry

A manufacturer wants to produce a low-cost, high-volume line of casual shirts with consistent quality. Which production system is most suitable?

  1. Single-piece custom tailoring
  2. Made-to-measure tailoring
  3. Couture hand-finishing
  4. Mass production in a progressive bundle system Correct answer.

Explanation

Mass production using a progressive bundle system moves bundles of cut parts through sequential operations, giving high output and consistent quality at low unit cost. Custom tailoring, made-to-measure, and couture methods are slower and labour-intensive, suited to individual garments rather than high-volume lines.

Question 7Introduction to Apparel and Home Furnishing Industry

Which of the following is a characteristic feature of a shuttle loom compared with a modern shuttleless loom?

  1. It uses a rapier to carry the weft yarn
  2. It inserts weft by means of compressed air
  3. It uses a projectile to carry the weft yarn
  4. It uses a shuttle to carry the weft yarn across the warp shed Correct answer.

Explanation

A shuttle loom carries the weft yarn across the shed inside a wooden or plastic shuttle that travels from one side to the other. Air-jet, rapier, and projectile looms are shuttleless types that insert weft by air, a carrier arm, or a projectile respectively.

Question 8Introduction to Apparel and Home Furnishing Industry

A home furnishing buyer wants curtains that drape softly and allow diffused light. Which fabric choice best meets this requirement?

  1. Heavy canvas upholstery fabric
  2. Bonded nonwoven felt
  3. Sheer voile made of fine cotton or polyester Correct answer.
  4. Coated blackout fabric

Explanation

Sheer voile is light, fine, and loosely constructed, so it hangs with soft folds and lets light filter through, which is exactly what draping curtains for diffused light require. Heavy canvas, coated blackout fabric, and bonded felt are dense, stiff, or opaque and block rather than diffuse light.

Question 9Introduction to Apparel and Home Furnishing Industry

Which of the following correctly states a key difference between natural and synthetic fibres in terms of moisture absorption?

  1. Synthetic fibres generally absorb more moisture than natural cellulosic fibres
  2. Both natural and synthetic fibres absorb equal amounts of moisture
  3. Synthetic fibres absorb moisture only when blended with wool
  4. Natural cellulosic fibres generally absorb more moisture than most synthetic fibres Correct answer.

Explanation

Cellulosic fibres such as cotton and viscose have many hydroxyl groups that attract water, giving them high moisture regain. Most synthetic fibres such as polyester are hydrophobic, with very low moisture absorption, which is why blends are often used for comfort.

Question 10Introduction to Apparel and Home Furnishing Industry

Which of these is a standard method of garment finishing applied to improve the smooth appearance of cotton shirts after washing?

  1. Sanforising
  2. Calendering with starch only
  3. Mercerising
  4. Resin finishing for durable press Correct answer.

Explanation

Resin finishing, also called durable press or wrinkle-free finishing, cross-links the cellulose so the garment resists wrinkling and holds a smooth appearance through washing. Mercerising improves lustre and strength, calendering gives temporary smoothness, and sanforising controls shrinkage.

Question 11Introduction to Apparel and Home Furnishing Industry

A pattern is graded from size 8 to size 12. What does grading mean in this context?

  1. Pressing the finished garment to shape
  2. Enlarging or reducing a base pattern systematically to produce other sizes Correct answer.
  3. Increasing the seam allowance on all edges
  4. Sorting cut pieces by shade and size

Explanation

Grading is the systematic enlargement or reduction of a base pattern to create a range of sizes while maintaining the fit and proportions of the design. It is not the same as adding seam allowance, sorting cut parts, or pressing the finished garment.

Question 12Introduction to Apparel and Home Furnishing Industry

Which of the following best explains why blends such as polyester-cotton are widely used in apparel?

  1. They eliminate the need for any dyeing or finishing
  2. They are always cheaper than either fibre used alone
  3. They make the fabric fully biodegradable
  4. They combine the strength and wrinkle resistance of polyester with the absorbency and comfort of cotton Correct answer.

Explanation

Blending lets the manufacturer combine complementary properties, so polyester contributes strength and crease recovery while cotton contributes absorbency and skin comfort. Blends do not automatically cost less, do not remove the need for dyeing or finishing, and do not make the fabric fully biodegradable.

Question 13Introduction to Apparel and Home Furnishing Industry

Which garment component is primarily used to give shape and support to a tailored jacket front?

  1. Lining
  2. Facing
  3. Seam binding
  4. Interlining Correct answer.

Explanation

Interlining is a supporting fabric attached between the outer fabric and the lining to give body and shape to areas such as the jacket front and collar. Facing finishes the raw edge of the front opening, lining covers the inside, and seam binding neatens seam allowances.

Question 14Introduction to Apparel and Home Furnishing Industry

In a cutting room, what is the main purpose of a marker?

  1. To indicate the thread tension setting on the machine
  2. To record the daily output of each sewing operator
  3. To mark the finished garment with the brand label
  4. To arrange pattern pieces economically on the fabric to minimise waste Correct answer.

Explanation

A marker is a plan that lays out the pattern pieces on the fabric in the most economical arrangement, taking into account grain, fabric width, and pattern matching, so that fabric waste is reduced. It is not an output record, a brand label, or a machine setting.

Question 15Introduction to Apparel and Home Furnishing Industry

A furnishing company wants to label a fabric as having good colour fastness to washing. Which test would most directly support this claim?

  1. Measuring the fabric's thickness with a micrometer
  2. Testing the fabric's flammability in a vertical flame test
  3. Washing a specimen with standard detergent under controlled conditions and assessing shade change Correct answer.
  4. Testing the fabric's tensile strength on a tensile tester

Explanation

Colour fastness to washing is assessed by washing a specimen with standard detergent under specified conditions and comparing any shade change or staining against a grey scale. Tensile strength, thickness, and flammability tests measure entirely different properties.

Question 16Introduction to Apparel and Home Furnishing Industry

Which statement best describes the role of the textile and apparel sector in the Indian economy?

  1. It depends entirely on imported raw materials with no domestic fibre production
  2. It is restricted to handloom production with no modern garment industry
  3. It contributes only a negligible share of employment and exports
  4. It is one of the largest employers, especially of women, and a major contributor to export earnings Correct answer.

Explanation

The textile and apparel sector is among India's largest employers, providing jobs across spinning, weaving, garmenting, and home furnishing, with a high share of women workers, and it is a leading source of export earnings. India also produces substantial domestic cotton and has a modern garment industry, so the other statements are incorrect.

Question 17Fibres, Yarns and Fabric Construction

Which natural fibre is obtained from the stem of a plant and is therefore classified as a bast fibre?

  1. Cotton
  2. Wool
  3. Jute Correct answer.
  4. Silk

Explanation

Bast fibres are sclerenchyma fibres taken from the phloem region of plant stems, and jute is the classic example used in apparel and home furnishing. Cotton is a seed hair, while wool and silk are animal fibres, so they cannot be bast fibres.

Question 18Fibres, Yarns and Fabric Construction

In a worsted yarn compared with a woollen yarn of the same fibre, which property is typical of the worsted yarn?

  1. Looser twist with trapped air pockets
  2. Higher lustre with fibres lying parallel Correct answer.
  3. Lower tensile strength
  4. More surface fuzz and bulk

Explanation

Worsted processing combs the fibres so that long fibres lie parallel before spinning with a higher twist, giving a smooth, lustrous, strong yarn. Woollen processing cards the fibres with less alignment, so the yarn is bulkier, fuzzier and weaker.

Question 19Fibres, Yarns and Fabric Construction

A plain weave fabric has 40 ends per inch and 36 picks per inch. What is its fabric count?

  1. 40
  2. 76 Correct answer.
  3. 4
  4. 1440

Explanation

Fabric count is the total number of yarns per inch, found by adding ends per inch and picks per inch. Here 40 plus 36 gives 76 yarns per inch.

Question 20Fibres, Yarns and Fabric Construction

Which weave produces a fabric with a smooth surface and high lustre because long floats of warp or weft cover the cloth?

  1. Pile weave
  2. Satin weave Correct answer.
  3. Plain weave
  4. Twill weave

Explanation

In a satin weave the binding points are spaced far apart, so long floats of warp or weft lie on the surface and reflect light, producing lustre and a smooth handle. Plain and twill weaves interlace more frequently and show a duller surface.

Question 21Fibres, Yarns and Fabric Construction

Which spinning system is used to convert short-staple cotton into a fine, even yarn by drafting a continuous ribbon of fibres?

  1. Wet spinning
  2. Melt spinning
  3. Film extrusion
  4. Ring spinning Correct answer.

Explanation

Ring spinning drafts a staple fibre roving and inserts twist with a traveller on a ring, which is the standard route for cotton and blends. Melt, wet and dry spinning are filament-extrusion methods used for manufactured fibres, not staple cotton.

Question 22Fibres, Yarns and Fabric Construction

A fabric is described as 2/2 twill. What does this designation indicate?

  1. Two warp yarns float over two weft yarns Correct answer.
  2. Two colours alternate in the weft
  3. Two yarns are plied in the warp
  4. The fabric has two layers

Explanation

In twill notation the first figure gives the number of yarns the warp or weft floats over and the second gives the number it floats under. A 2/2 twill therefore shows a float over two yarns and under two, producing the diagonal effect.

Question 23Fibres, Yarns and Fabric Construction

Which property of manufactured regenerated fibres such as viscose makes them behave like cotton in wet processing?

  1. They are completely hydrophobic
  2. They are thermoplastic
  3. They lose strength when wet Correct answer.
  4. They melt at ironing temperature

Explanation

Viscose is a regenerated cellulose with low wet strength, so it loses a large share of its tenacity when wet and must be handled gently during washing. Cotton also loses some strength when wet, while synthetic thermoplastic fibres behave differently.

Question 24Fibres, Yarns and Fabric Construction

Which yarn is made by twisting two or more already-spun single yarns together?

  1. Plied yarn Correct answer.
  2. Rotor yarn
  3. Slub yarn
  4. Boucle yarn

Explanation

A plied yarn is produced by twisting two or more single yarns together, which improves strength, evenness and balance. Slub and boucle are fancy yarns with deliberate irregularities, and rotor yarn is a single yarn made on open-end spinning.

Question 25Fibres, Yarns and Fabric Construction

A fabric made with a leno weave is best identified by which feature?

  1. Long warp floats on the surface
  2. Raised loops on one face
  3. A diagonal rib across the cloth
  4. Pairs of warp yarns crossing each other Correct answer.

Explanation

In leno weaving the doup harness makes adjacent warp yarns cross over each other around the weft, trapping it firmly. This open, stable structure is used for nettings, gauze and marquisette.

Question 26Fibres, Yarns and Fabric Construction

Which fibre length classification applies to cotton, whose individual fibres are measured in centimetres rather than metres?

  1. Monofilament
  2. Filament
  3. Tow
  4. Staple Correct answer.

Explanation

Natural fibres other than silk grow as short lengths called staple, and cotton staple length is stated in millimetres or centimetres and graded as short, medium or long. Filaments are continuous lengths, natural silk being the main natural filament.

Question 27Fibres, Yarns and Fabric Construction

Increasing the twist multiplier of a cotton yarn beyond the normal range will most directly cause which change?

  1. A yarn with no change in strength
  2. A harder, leaner yarn with reduced extensibility Correct answer.
  3. A yarn with lower twist liveliness
  4. A softer, bulkier hand

Explanation

Higher twist multiplier means more turns per inch for a given yarn count, so the yarn becomes compact and lean, with reduced extensibility and eventually lower strength as fibres are over-twisted. The hand becomes harder rather than softer.

Question 28Fibres, Yarns and Fabric Construction

Which weave would be chosen for a durable bed sheet that must be smooth, strong and inexpensive to produce?

  1. Jacquard weave
  2. Plain weave Correct answer.
  3. Double cloth
  4. Pique weave

Explanation

Plain weave gives the maximum number of interlacings per unit area, which yields a firm, strong, smooth and economical fabric, so it is standard for sheeting. Jacquard, double cloth and pique add complexity and cost without improving the basic requirement.

Question 29Fibres, Yarns and Fabric Construction

Which statement correctly describes the difference between carded and combed cotton yarns?

  1. Combed yarn contains more short fibres
  2. Combed yarn has fewer short fibres and higher strength Correct answer.
  3. Carded yarn is smoother and stronger
  4. Both contain identical fibre length distributions

Explanation

Combing removes short fibres and neps after carding, leaving a longer, more uniform fibre population that spins into a smoother, stronger and finer yarn. Carded yarn retains more short fibre and is therefore rougher and weaker.

Question 30Fibres, Yarns and Fabric Construction

Which fibre is produced by the wet spinning of a cellulose solution through a spinneret into a coagulating bath?

  1. Polyester
  2. Viscose rayon Correct answer.
  3. Polypropylene
  4. Nylon 6,6

Explanation

Viscose rayon is a regenerated cellulose fibre spun by forcing the alkaline cellulose xanthate solution through a spinneret into an acid coagulating bath. Polyester, nylon and polypropylene are melt-spun synthetic polymers.

Question 31Fibres, Yarns and Fabric Construction

A cloth shows fine diagonal lines running from bottom left to top right on the face. Which weave structure does this indicate?

  1. Twill Correct answer.
  2. Leno
  3. Plain
  4. Satin

Explanation

Twill weave steps the interlacing point by one end and one pick each time, producing a continuous diagonal line whose direction depends on the twill direction chosen. Plain weave shows a checkerboard, satin shows floats and leno shows crossed warps.

Question 32Fibres, Yarns and Fabric Construction

Which test result would most reliably confirm that a fabric sample is 100 percent cotton rather than a cotton-polyester blend?

  1. The sample shrinks sharply on heating
  2. The sample dissolves in acetone
  3. Burning gives a hard black bead
  4. Burning gives a soft ash with a paper smell Correct answer.

Explanation

Cotton is cellulose, so it burns quickly with a paper-like odour and leaves soft grey ash. A blend with polyester leaves a hard, dark bead because the thermoplastic component fuses, which is the diagnostic difference.

Question 33Fibres, Yarns and Fabric Construction

What is the main purpose of sizing applied to warp yarns before weaving?

  1. To add colour to the fabric
  2. To reduce abrasion and breakage during shedding Correct answer.
  3. To increase yarn lustre
  4. To reduce yarn moisture content

Explanation

Warp yarns endure repeated shedding, shedding friction and tension on the loom, so a size film is applied to bind protruding hairs and protect the yarn from abrasion and breakage. The size is later removed in desizing.

Question 34Fibres, Yarns and Fabric Construction

Which fabric construction gives stretch in both length and width without using elastomeric yarn?

  1. Weft-knitted single jersey Correct answer.
  2. Nonwoven felt
  3. Twill woven cloth
  4. Plain woven cloth

Explanation

Single jersey is a weft-knit structure of interlocking loops, so it extends in both directions as the loops deform, which is why knitwear is used for T-shirts and hosiery. Woven cloth stretches mainly on the bias and nonwoven felt has little stretch.

Question 35Fibres, Yarns and Fabric Construction

Which fibre property is measured by the term denier?

  1. Twist per inch
  2. Moisture regain
  3. Linear density of a filament yarn Correct answer.
  4. Fibre length

Explanation

Denier is the mass in grams of 9000 metres of yarn or filament, so it expresses linear density; a higher denier means a thicker yarn. Tex, based on 1000 metres, is the SI-preferred alternative.

Question 36Fibres, Yarns and Fabric Construction

In a given woven fabric, the crimp of warp yarns is found to be higher than that of weft yarns. What does this most likely indicate?

  1. The weft yarn is finer than the warp
  2. The warp was woven under lower tension Correct answer.
  3. The weft was inserted under higher tension
  4. The fabric has more weft than warp yarns

Explanation

Crimp is the waviness taken up by a yarn as it interlaces, and a yarn woven under lower tension is able to bend more around the crossing yarns, so it develops higher crimp. Higher tension in a set of yarns reduces their crimp.

Question 37Fibres, Yarns and Fabric Construction

Which weave is used to produce a figured design such as a floral motif on a furnishing fabric?

  1. Jacquard weave Correct answer.
  2. Mock leno weave
  3. Plain weave
  4. Rib weave

Explanation

A jacquard attachment controls individual warp yarns through punched cards or electronic selection, so any figured design can be woven into the cloth. Plain, rib and mock leno weaves produce small repeating effects rather than large figured motifs.

Question 38Fibres, Yarns and Fabric Construction

A student needs a fabric that is lightweight, quick drying and resistant to creasing for a rain jacket shell. Which fibre choice best meets all three needs?

  1. Wool
  2. Viscose rayon
  3. Cotton
  4. Polyester Correct answer.

Explanation

Polyester is a hydrophobic thermoplastic fibre with low moisture absorption, so it dries quickly, and its molecular structure gives good crease recovery and dimensional stability. It is also strong for its weight, which suits a lightweight shell fabric.

Question 39Fibres, Yarns and Fabric Construction

What distinguishes a nonwoven fabric from a woven or knitted fabric?

  1. It is made only from filament yarns
  2. It is made directly from a fibre web bonded by mechanical, thermal or chemical means Correct answer.
  3. It is made by interlooping a single set of yarns
  4. It is made by interlacing two sets of yarns at right angles

Explanation

Nonwovens are formed directly from a web of fibres or filaments that is bonded by needling, heat or adhesive, so no yarn formation or interlacing step occurs. Woven and knitted structures are built from yarns by interlacing or interlooping.

Question 40Fibres, Yarns and Fabric Construction

Two single cotton yarns of 40s count are plied together. How is the resulting yarn conventionally designated?

  1. 40s/2 ply twist
  2. 2/40s Correct answer.
  3. 80s
  4. 40/2s

Explanation

In the traditional cotton count notation the number of plies is written first and the single yarn count second, so two 40s singles become 2/40s. The plied yarn is approximately equivalent to 20s in linear density, not 80s.

Question 41Fibres, Yarns and Fabric Construction

Why is a crepe yarn given very high twist during spinning?

  1. To make the yarn more absorbent
  2. To make the yarn stronger for warp use
  3. To reduce the cost of production
  4. To create a lively yarn that gives a crinkled fabric surface Correct answer.

Explanation

Crepe yarns are twisted far above the normal level, sometimes in alternating directions, so the yarn is lively and contracts unevenly, producing a crinkled, pebbled fabric surface after wet finishing. The high twist is a design effect, not a strength or cost measure.

Question 42Fibres, Yarns and Fabric Construction

A yarn label states that a cotton yarn has a count of 60s (Ne). What does this indicate about the yarn?

  1. It contains 60 fibres in every cross-section of the yarn
  2. It is finer than a 40s yarn because a higher English cotton count means more hanks per pound Correct answer.
  3. It is coarser than a 40s yarn because a higher number means a heavier yarn
  4. It has 60 plies twisted together in the final yarn

Explanation

In the English cotton count (Ne), the number is the number of 840-yard hanks that weigh one pound, so a higher number means finer yarn. Therefore 60s cotton is finer than 40s cotton, and this indirect system runs opposite to denier and tex, where a larger number means a heavier yarn.

Question 43Fibres, Yarns and Fabric Construction

A mill needs a woven furnishing fabric in which the weft yarns float over several warp yarns to create a raised, lustrous surface with good abrasion resistance. Which weave structure should be selected?

  1. Satin weave Correct answer.
  2. Plain weave
  3. 2/2 matt weave
  4. Leno weave

Explanation

Satin weave uses long floats because each weft yarn passes over several warp yarns before interlacing, giving a smooth, lustrous face and good abrasion resistance, which suits furnishing fabrics. Plain and matt weaves interlace frequently and give a flatter, less lustrous surface, while leno twists the warp yarns around the weft and is used for open, stable structures.

Question 44Fibres, Yarns and Fabric Construction

A woven cotton fabric is found to have a higher warp crimp than weft crimp, with the warp yarns wavy and the weft yarns nearly straight. What does this indicate about the fabric's manufacture and behaviour?

  1. The warp yarns were sized with a heavier size recipe, which straightens them and lowers their crimp
  2. The fabric was woven with higher warp tension than weft tension, so the weft yarns wavy and the fabric extends more in the weft direction
  3. The fabric has been given a raised nap finish, which increases crimp only in the warp direction
  4. The fabric was woven with excessive weft tension, so the weft yarns lie straighter and take most of the load in the warp direction Correct answer.

Explanation

Crimp interchange depends on the balance of tensions during weaving: the yarn held under greater tension is woven straighter and has lower crimp. If weft yarns are nearly straight, the weft was under higher tension, and the wavy warp yarns will extend more readily when the fabric is pulled lengthwise.

Question 45Textile Finishing and Dyeing

Which chemical is most widely used as a desizing agent for starch-sized cotton fabric in the textile finishing industry?

  1. Amylase enzyme Correct answer.
  2. Sodium hydroxide
  3. Sodium chloride
  4. Dilute sulphuric acid

Explanation

Starch size is a natural polymer, so it is removed by enzymatic desizing using amylase, which hydrolyses starch into soluble sugars that wash out easily. Amylase works at mild temperature and near-neutral pH, protecting the cotton from fibre damage.

Question 46Textile Finishing and Dyeing

In the singeing process, the fabric is passed rapidly over a red-hot plate or flame mainly to:

  1. Improve the crease recovery of the fabric
  2. Remove protruding surface fibres Correct answer.
  3. Shrink the fabric permanently
  4. Increase the dye uptake uniformly

Explanation

Singeing burns off the loose projecting fibres on the fabric surface, giving a smooth, clean handle and reducing pilling. The fabric is passed quickly so that the body of the cloth is not damaged.

Question 47Textile Finishing and Dyeing

Mercerisation of cotton fabric is normally carried out using which treatment?

  1. Hot dilute acetic acid followed by drying
  2. Warm sodium carbonate solution followed by bleaching
  3. Cold water treatment under slack condition
  4. Cold concentrated sodium hydroxide followed by washing under tension Correct answer.

Explanation

Mercerisation uses cold concentrated sodium hydroxide (around 20-25 percent) applied while the fabric is held under tension, followed by thorough washing. This swells the fibre, increases lustre, strength and dye affinity.

Question 48Textile Finishing and Dyeing

Which dye class is applied to cotton from an alkaline bath containing a reducing agent such as sodium hydrosulphite?

  1. Reactive dyes
  2. Disperse dyes
  3. Acid dyes
  4. Vat dyes Correct answer.

Explanation

Vat dyes are insoluble pigments that are reduced in an alkaline bath with sodium hydrosulphite to a soluble leuco form, which penetrates the cotton and is later oxidised back to the insoluble pigment. This vatting step is characteristic of the class.

Question 49Textile Finishing and Dyeing

Calendering of fabric is best described as:

  1. A process that dyes the fabric from one side only
  2. A mechanical process that smooths the fabric surface by passing it through rollers Correct answer.
  3. A chemical treatment that imparts flame resistance
  4. A washing process that removes residual alkali

Explanation

Calendering is a mechanical finishing operation in which fabric passes between heated rollers under pressure to produce a smooth, glazed or embossed surface. It changes the appearance and handle without altering the chemical composition of the fibre.

Question 50Textile Finishing and Dyeing

Which finish is applied to cotton fabric to improve its crease recovery and dimensional stability?

  1. Resin finishing Correct answer.
  2. Water repellent finishing
  3. Softening
  4. Starching

Explanation

Resin finishing, typically using cross-linking agents such as dimethylol dihydroxy ethylene urea, forms cross-links between cellulose chains and gives durable crease recovery and dimensional stability. Softeners and starch give only temporary effects on handle.