Engineer Textile key terms

Mass in grams of 1000 metres of a fibre, yarn, or filament, used to express fineness. Decitex is one tenth of a tex; the older denier equals 9 tex.

Indirect yarn numbering system stating how many 840-yard hanks weigh one pound; a higher number means a finer yarn. Convert to tex with 590.5 divided by Ne.

Proportion of a fibre's polymer chains packed in ordered, repeating lattice regions. Higher crystallinity raises strength and stiffness but reduces moisture regain, dye accessibility, and elongation.

Degree to which polymer chains or crystallites lie parallel to the fibre axis, usually increased by drawing. Higher orientation raises tensile strength and modulus while lowering extension at break.

Equilibrium moisture content of a dry textile expressed as a percentage of its oven-dry mass at standard conditions. It governs comfort, static, dimensional change, and correct commercial weight invoicing.

Ratio of final to initial length applied during filament drawing. It aligns molecular chains, raising tenacity and reducing elongation; excessive drawing causes voids, fibrillation, or breaks.

Breaking force of a fibre or yarn divided by its linear density, typically reported in cN/tex or gf/denier. It allows fair strength comparison between materials of different fineness.

Cross-sectional thickness of a fibre, expressed as linear density or micrometre width. Finer fibres give softer, more drapeable fabrics, more fibres per yarn cross-section, and different spinning limits.

Airflow measure of cotton fibre fineness and maturity combined, reported in micrograms per inch. Low values suggest immature or fine cotton; high values suggest coarse or mature cotton.

Ratio of input to output linear density at a drafting zone, thinning the fibre assembly. Total draft equals the product of individual zone drafts and sets yarn count from sliver or roving.

Periodic thick and thin places in sliver or yarn caused by uncontrolled fibre movement in drafting, especially floating fibres. It produces count and strength variation that later processes rarely remove.

Closed-loop control that measures sliver mass and adjusts draft to reduce long-term count variation. It corrects slow drift but cannot remove very short-term irregularity within the measuring zone.

Twist per unit length divided by the square root of yarn count, expressing how hard a yarn is twisted independent of its size. It controls hand, strength, and hairiness.

Spinning method that drafts sliver, opens fibres into an air stream, and collects them in a rotating rotor to form a twisted yarn. Faster than ring spinning but gives lower strength and a different structure.

Ring spinning variant using pneumatic suction to condense the fibre strand after the front drafting rollers, removing the spinning triangle. It reduces hairiness and raises yarn strength and abrasion resistance.

The two yarn sets in woven fabric: warp runs lengthwise and is held under tension; weft is inserted across the width. Their interlacing pattern defines weave structure and fabric properties.

Redistribution of yarn crimp between warp and weft after weaving and relaxation, as yarns trade waviness to reach balance. It affects fabric width, shrinkage, and dimensional stability.

Measure of how completely yarns cover a fabric area, derived from yarn linear density and thread spacing. It predicts tightness, air permeability, and the risk of slippage or reed marks.

Number of knitted loops or stitches per unit area, usually wales and courses per centimetre. It determines fabric weight, extensibility, and dimensional stability after finishing.

Consolidation of a fibre web into fabric by thermal, chemical, or mechanical means such as calendering, resin, or needle punching. Bond type controls strength, softness, and drape.

Treatment of cotton with strong caustic soda under tension, swelling the fibre, improving lustre, strength, and dye uptake. Residual alkali must be neutralised and washed out thoroughly.

Removal of natural oils, waxes, pectins, and dirt from greige fabric using hot alkaline detergent liquor. Good scouring gives uniform absorbency essential for even dyeing and finishing.

Proportion of dye initially in the bath that transfers onto the fibre during dyeing. High exhaustion reduces colour in effluent and dye cost, but migration and levelling must still be controlled.

Resistance of a dyed or printed textile to colour change or staining under exposure such as washing, light, rubbing, or perspiration, graded against standard grey scales.

Objective colour measurement and recipe prediction using reflectance data and colour-space tolerances. It reduces metamerism risk and supports right-first-time dyeing and batch-to-batch consistency.

Bringing a specimen to equilibrium with a specified standard atmosphere before testing, so moisture content is stable. Without it, mass, strength, and dimensional results are unreliable.

Coefficient of variation of mass or thickness along a yarn or sliver, expressing irregularity as a percentage of the mean. It correlates with appearance, strength, and downstream breakage.

Mass of a fabric per square metre, determined on conditioned specimens. It links fabric specification, raw material consumption, and costing in production planning.

Statistical sampling standard defining the maximum percentage of defective units tolerated in a lot for a given inspection level. It underpins shipment acceptance and buyer-supplier contracts.

Fabric grading system assigning 1 to 4 penalty points per defect according to defect length, with points per 100 square metres compared against an agreed limit.

International standard specifying requirements for a quality management system covering process control, documentation, corrective action, and continual improvement. Certification is often a customer prerequisite.

Scheduled inspection, lubrication, and part replacement carried out before failure occurs. In textile plants it reduces unplanned stoppages, waste, and off-quality production on high-speed machinery.

Product of availability, performance, and quality rates, showing how much scheduled time produces good product. It identifies losses and prioritises improvement in spinning, weaving, or finishing lines.

Total elapsed time from order confirmation to delivery, including procurement, processing, and transit. Quoting realistic lead times protects customer service and capacity planning.

Material that has entered production but is not yet finished goods, held between processes. Excess WIP ties up cash, lengthens lead time, and hides quality and capacity problems.

Build-up of fibre, conversion, energy, labour, overhead, and wastage costs into a unit price. Accurate costing requires realistic yarn and fabric consumption and waste allowances.

Permeable technical fabric used in civil engineering for separation, filtration, drainage, or reinforcement of soil. Specification depends on tensile strength, permeability, and durability.

Textile product selected primarily for performance rather than aesthetics, serving medical, protective, automotive, agricultural, or industrial functions. Properties are specified by end-use standards and test methods.

Physical, chemical, and biological processes that remove dyes, salts, and organic load from textile wastewater before discharge or reuse, meeting permitted limits for colour, COD, and pH.

Production that reduces energy, water, chemicals, and waste per unit output while maintaining quality, often through heat recovery, water recycling, and cleaner dyeing routes.