Tamil Nadu HSE Second Year Textile Technology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Moisture regain

Percentage of moisture in a textile expressed as a fraction of its oven-dry weight: (moisture weight / oven-dry weight) x 100. Cotton is about 8.5% and wool about 16% under standard conditions.

Micronaire value

A measure of cotton fibre fineness and maturity obtained from an airflow instrument. Low micronaire indicates fine, immature fibres; high values indicate coarse, mature fibres affecting yarn strength.

Burning test

Identification test where a fibre is ignited and its flame, odour and ash observed. Cotton smells of burning paper, wool of burnt hair, and polyester melts into a hard black bead.

Regenerated fibre

Man-made fibre produced from a natural polymer, usually cellulose, that is dissolved and extruded. Viscose, modal and acetate are examples, unlike fully synthetic polyester or nylon.

Ginning percentage

Ratio of lint mass to seed cotton mass, expressed as a percentage. It indicates ginning outturn; roller ginning suits long staple cotton while saw gins handle shorter staples.

Carding action

Working between two wire-covered surfaces moving in opposite directions at the nip, opening fibre tufts into individual fibres and removing trash and neps to form a carded sliver.

Draft

Ratio of input linear density to output linear density in a drafting zone. It reduces sliver or roving thickness; doubling adds no draft but improves evenness by blending several ends.

Combing noil

Short fibres removed as waste during combing. Noil percentage measures combing intensity; higher noil removal gives a cleaner, more parallel and finer combed yarn.

Tex

Direct yarn numbering system giving mass in grams per 1000 metres of yarn. Higher tex means a coarser yarn; 1 tex equals 9 denier and is independent of material.

Ring spinning

Spinning method where a drafted roving receives twist from a traveller rotating on a ring and is wound onto a cop. It produces strong, versatile yarns but limits spindle speed.

Sizing

Application of a starch or size film to warp yarns before weaving to increase abrasion resistance and reduce breakage. Size pick-up percentage and add-on control weaving efficiency.

Primary loom motions

The three essential weaving motions: shedding separates warp threads, picking inserts the weft, and beat-up pushes the weft to the fell of the cloth. Weaving stops without any of them.

Plain weave

Simplest weave with 1/1 interlacing where each warp passes alternately over and under each weft. It gives maximum firmness and is used for cambric, poplin and voile.

Wale and course

In knitted fabric, a wale is a vertical column of interlocking loops and a course is a horizontal row. Their counts per inch describe knit density and fabric weight.

Needle punching

Non-woven bonding method in which barbed needles repeatedly penetrate a fibre web, entangling fibres mechanically. It produces felts for carpets, geotextiles and filters.

Singeing

Process of passing fabric over a gas flame or heated plate to burn off protruding fibres. It gives a smooth surface and reduces pilling before desizing and bleaching.

Desizing

Removal of size applied to warp yarns, usually by amylase enzymes that break down starch. Complete desizing is checked with an iodine test before scouring and bleaching.

Mercerising

Treatment of cotton with concentrated caustic soda under tension, producing a swollen, rounder fibre. It increases lustre, strength, dye affinity and dimensional stability.

Reactive dye

Dye that forms a covalent chemical bond with cellulose fibres in alkaline conditions. It gives excellent wash fastness on cotton and is applied by exhaust or pad-batch methods.

Discharge printing

Printing style where a chemical paste destroys the dye already present in the fabric to create a white or coloured pattern. It requires dyes that can be discharged.

Standard testing atmosphere

Controlled conditions of 20 plus or minus 2 degrees Celsius and 65 plus or minus 2 percent relative humidity used for conditioning and testing textiles so results are comparable.

CSP

Count strength product, calculated as lea strength in pounds multiplied by yarn count in Ne. It is a standard index of cotton yarn quality; higher CSP indicates better yarn.

Uster evenness

Instrument measurement of yarn mass variation along its length, reported as CV percent and imperfections such as thin places, thick places and neps per kilometre.

Crock fastness

Colour fastness to rubbing, assessed by rubbing a white cloth against the specimen under dry and wet conditions. Staining is rated against the grey scale.

Marker efficiency

Percentage of marker area actually covered by pattern pieces: (pattern area / marker area) x 100. Higher efficiency reduces fabric waste during cutting.

Overlock stitch

Stitch type 504 formed by two or more threads looping over the fabric edge. It sews and trims the edge in one operation, preventing fraying in knit and woven garments.

Grain line

Line marked on a pattern piece showing the direction of the warp or wale. It must be aligned with the fabric length during cutting to prevent garment distortion.

OEE

Overall equipment effectiveness, calculated as availability multiplied by performance multiplied by quality. It measures how effectively a machine is used in a textile mill.

Preventive maintenance

Scheduled servicing and inspection of machines before failure, such as wire replacement, lubrication and belt checks. It reduces breakdowns and extends machine life.

Prime cost

Sum of direct material, direct labour and direct expenses. Factory overheads are added to prime cost to obtain factory cost in textile costing.

Break-even quantity

Output at which total revenue equals total cost, calculated as fixed cost divided by contribution per unit. Contribution equals selling price minus variable cost.

Zero liquid discharge

Environmental approach in textile processing where effluent is treated and recycled so no liquid leaves the plant. It uses membrane and evaporation systems and reduces pollution.