Glossary

Terms used in textile finishing, with Turkish and English equivalents.

APEO / NPEO

The nonionic surfactant family used for decades as wetting agents, detergents and emulsifiers. In effluent it degrades to alkylphenol, which resists further breakdown, accumulates in water and disrupts hormone systems. EU legislation and every major brand list have banned it in textiles, and it sits among the priority substances in the ZDHC MRSL. Fatty alcohol ethoxylates and alkyl polyglucosides replaced it, and asking the supplier for an APEO-free declaration is standard practice.

Related terms: ZDHC MRSL, Wetting agent, Active content, TDS and SDS

Absorbency

How readily a fabric takes up water, and whether it does so at the same rate everywhere. The practical measurement is the drop test: a water drop is released onto the surface from a set height and the seconds to full absorption are recorded. It is the fastest indicator of scouring performance in pre-treatment, and if the drop time varies across the piece, unlevel dyeing follows. On the finishing side the softener choice can destroy absorbency, which is unacceptable on towelling and babywear.

Acetic acid

The weak organic acid used in dyehouses to bring pH down and neutralise alkali. Its buffering behaviour means it does not crash the pH, which makes it safer than mineral acids. Typical points of use are pH adjustment for enzyme steps, neutralisation after dyeing and setting the softener bath. Odour and its COD contribution in the effluent have pushed some plants towards formic acid or pH-sliding buffer systems.

Related terms: pH measurement, Soda ash, Caustic soda, Enzyme wash

Acid dye

The anionic class used on wool, silk and polyamide. Under acid conditions the fibre's amino end groups protonate and the dye binds ionically, so pH control is shade control here. On polyamide hosiery and swimwear the wash and perspiration fastness will not stand on its own, so a syntan-based nylon fixing agent is applied afterwards.

Acid wash

Tumbling dry denim with dry pumice stones that have been soaked in an oxidising solution. Sharp white marks appear where the stones touch and the ground stays dark between them, giving the mottled look the process is named for. Working dry makes the effect very harsh, and repeatability depends on how evenly the stones were charged. Without neutralisation and thorough rinsing at the end, oxidiser left on the cloth goes on damaging it.

Active content

The percentage of a product that actually does the work; the rest is water, solvent and auxiliaries. Comparing two suppliers on price per litre is misleading; the honest comparison is cost per unit of active content and the effect delivered on the cloth. High active content is not automatically better: a concentrate dosed into the bath without pre-dilution raises the risk of emulsion breakage and spotting. The TDS may quote solids and active matter separately, so it pays to check which figure is given.

Alpha-amylase

The enzyme that cuts starch chains at random points into short, water-soluble fragments. It is the standard tool for desizing and does nothing to non-starch sizes such as PVA, acrylate or CMC. Commercial grades are sorted by working temperature: medium-temperature types run at 60-80 °C, high-temperature types at 95-110 °C and suit saturated steam lines. Calcium stabilises most amylases, so a strong sequestering agent in the same bath can weaken the enzyme.

Amino silicone

Silicone carrying amino groups on the chain; those groups interact with the fibre, orient the polymer at the surface and deliver a very pronounced softness. The higher the amine value, the richer the handle and the greater the risk of yellowing and shade shift on whites. Low amine value or blocked amino types are used on whites and pastels. Its durability to washing makes it the choice where handle has to survive garment processing.

Anti-creasing agent

Lubricates the cloth in the dyebath so crease marks never set. Two families exist: oil and ester types give strong lubricity but can break and spot at high temperature, while polymeric types are more stable at HT and do not foam. Alkali and electrolyte stability is the real selection criterion, since the product also has to survive a bleach or reactive dyebath. It is no substitute for machine settings: without correcting load and ramp rate it will not carry the job alone.

Related terms: Crease mark, HT dyeing, Antifoam, Jet dyeing machine

Antibacterial finish

Treatment that holds back bacterial growth on the fabric and the odour that goes with it. Common actives are silver compounds, zinc pyrithione and silane quaternary ammonium structures, and whether the active leaches or stays bound to the surface decides wash durability. Effectiveness is measured numerically by AATCC 100 or ISO 20743 and re-tested after a stated number of washes. Biocidal product regulation (BPR in the EU) means the active has to be registered.

Related terms: Finishing, REACH, Wash fastness

Antifoam

Knocks foam down so the machine keeps transporting the cloth and circulating properly. On a jet the damage does not stop at overflowing. The air cushion makes fabric movement irregular, puts unlevelness and crease marks into the cloth, and starves the pump. Silicone types are the most effective but leave silicone spots if the emulsion breaks; oil-based types are safer with a shorter-lived effect. Knock-down and persistence are separate properties and rarely both strong in one product.

Antistatic finish

Bleeding off the static charge that builds up on synthetic fabric, so it stops attracting dust and clinging to the body. Most antistats are quaternary ammonium or polyether based and draw their conductivity from atmospheric moisture, so the effect fades in dry conditions. Polyester linings, carpet and technical textiles also need it during production, where static makes the selvedge curl on the stenter. Cationic types can yellow whites.

Related terms: Yellowing, Fibre types, Stenter, Ionic character

Back-staining

Dye released into the bath during washing reattaching itself to the white or light areas of the same goods. Denim shows it most clearly: indigo stripped in stone washing settles on the weft and the pockets, contrast is lost and a blue haze remains. Enzyme washing carries more risk, because cellulase frees dye along with the fibrils it cuts loose. Anti-back-staining dispersants prevent it by holding the dye in the liquor.

Bio-polishing

Cutting the protruding microfibrils on the fibre surface with cellulase. The fabric comes out smoother, the shade reads cleaner and the tendency to pill in wear drops. Acid cellulases work fast and aggressively at pH 4.5-5.5, neutral cellulases work more gently at pH 6-7 with less back-staining risk. The cost is weight loss: beyond 3-5 per cent, strength falls noticeably, so the enzyme has to be stopped on time and temperature.

Bleaching

Destroying the natural colouring matter in the fibre with an oxidising agent. On cotton the standard oxidiser is hydrogen peroxide, working under alkaline conditions. Uncontrolled peroxide decomposition causes pinholes and strength loss, which is why the bath carries a sequestering agent and a peroxide stabiliser.

Blended fabric

Two or more fibre types in the same fabric, most often cotton/polyester, cotton/elastane and viscose/polyamide. Each fibre wants its own dye class, so dyeing runs either in two separate baths or in one bath with two dye classes, and in a single bath the pH, temperature and auxiliary choice all have to be a compromise between two processes. The real risk is cross-staining: disperse dye soiling the cotton forces a clearing step on dark shades. Where elastane is present the temperature ceiling constrains the recipe from the start.

Carrier

An organic product that swells the amorphous regions of polyester so disperse dye can enter around 100 °C. It is used on machines that cannot hold pressure and on wool/polyester blends, since wool will not take 130 °C. The cost is real: odour, a drop in light fastness, effluent load and residue on the cloth. Carrier residue volatilises on the stenter and ends up fouling ducts and rollers, which is why HT dyeing has replaced it wherever a pressure machine exists.

Related terms: Disperse dye, HT dyeing, Light fastness, Stenter

Catalase

The enzyme that breaks hydrogen peroxide down into water and oxygen. Peroxide left on the cloth and in the bath after bleaching oxidises reactive dye, shifts the shade and causes unlevelness; catalase clears it in minutes at low temperature. Against the classic route of repeated hot rinses it saves a visible amount of water, steam and time. Working with the enzyme means holding pH and temperature in range and confirming zero residual peroxide with a test strip.

Caustic soda

The most heavily consumed alkali in a finishing plant. It saponifies wax and pectin in scouring, activates peroxide in bleaching, restructures the fibre in mercerising and acts as the fixation alkali in reactive dyeing. Concentration is followed in degrees Baumé on the mercerising range and in g/L in the bath. It is caustic and releases heat on dilution, so caustic always goes into water, never the other way round.

Related terms: Mercerising, Scouring, Soda ash, Dosage units

Cellulase

The enzyme group that hydrolyses the β-1,4 glycosidic bond in cellulose. Textiles use two main types: acid cellulase for bio-polishing and neutral cellulase for stone washing and neutral washing. It does not distinguish its target. The enzyme that cuts a protruding fibre end cuts cellulose wherever it makes contact, which is why the process is measured in weight and strength loss.

Chlorine fastness

Holding the specimen in an active chlorine solution that simulates pool water and grading the shade change. It is a standard clause in swimwear and pool product specifications. On elastane blends the test has two layers: beyond the shade change, the elastane itself degrades in chlorine and loses strength. Without chlorine-resistant elastane and the right dye selection, no finish will solve it on its own.

Colour deepening agent

A finish that lays a low refractive index film on the fibre so less light reflects off the surface and the shade reads deeper. The amount of dye on the fibre is unchanged; only the apparent depth rises, which is why black and navy polyester is its main home. Silicone resins and fluorinated polymers are the usual chemistries. Water repellency can rise and the handle can stiffen as a side effect, so it is balanced with a softener.

Continuous process

Processing the cloth metre by metre, without stopping, along a range. In pre-treatment this covers desize-wash-bleach lines, in dyeing the pad-steam and thermosol routes. Unit cost over long yardage sits well below batch processing, but a setting that drifts damages the whole lot: a small change in speed, pick-up or temperature means metres of faulty fabric. Head-to-tail and selvedge-to-centre differences are therefore checked continuously on these ranges.

Related terms: Padder, Exhaust dyeing, Pad-batch, Drying cylinder

Crease mark

A line set permanently into the cloth by it folding in the same place while running in rope form. After dyeing that line stays as a light or dark mark and ironing will not take it out. Viscose, elastane knits, satins and heavy wovens are the most exposed; fast temperature ramps, short liquor ratios and tension in the machine all trigger it. An anti-creasing agent works by lubricating the cloth so the fold never stays in one place.

Delta E (ΔE)

The total colour difference between a sample and its standard collapsed into a single number. The formula changes the answer: CMC(2:1) and CIEDE2000 are the ones in general textile use today, and the older CIELAB formula gives a different figure for the same pair. Customer tolerances are usually set around 1.0, but the number means nothing unless the formula and the illuminant are stated with it. When ΔE is low and the eye still sees a difference, metamerism is the thing to check.

Related terms: Spectrophotometer, Metamerism, Lab dip

Denim washing dispersant

The product that keeps stripped indigo dispersed in the liquor so it cannot redeposit on the weft and the pocketing. In enzyme washing it also has to leave the enzyme alone: some strong dispersants suppress cellulase activity and the effect never develops. Polycarboxylate and lignosulphonate types are the common chemistries, usually combined with a washing agent in the formulation. Hard water and high pH cut performance, so it is assessed together with the sequestering agent.

Desizing

Removing the warp size from the fabric. For starch size the standard route is alpha-amylase: the enzyme breaks starch into water-soluble short chains that rinse away. PVA and acrylate sizes are not enzyme-removable and come off with a hot alkaline wash. Success is checked against the TEGEWA scale.

Related terms: Size, Alpha-amylase, TEGEWA scale

Direct dye

The class that binds to cellulose by substantivity alone, with no chemical bond. Application is simple and cheap and the shade range is wide; wet fastness is the weak point. It still holds its place in lining, filler and price-driven work, where a cationic fixing agent lifts fastness part of the way. The same fixing agent also fixes residual direct dye alongside reactive shades.

Related terms: Dye fixing agent, Wash fastness, Reactive dye

Disperse dye

The practically water-insoluble class used on polyester and acetate. Dyeing runs on the small dissolved fraction diffusing into the fibre, which is why the bath has to go above polyester's glass transition, to 125-135 °C. Where a machine cannot reach that pressure, a carrier is used instead. Dye left on the fibre surface afterwards has to come off in reductive clearing, or rub and wash fastness will not hold.

Related terms: HT dyeing, Carrier, Oligomer, Reductive clearing

Dispersing agent

The surfactant that keeps water-insoluble dye particles suspended and separate in the liquor. Disperse and vat dyeing depend on it: once the dispersion breaks, particles agglomerate, drop onto the cloth as specks and spots, and build up inside the machine. Under HT conditions (130 °C) the dispersant itself has to stay stable, because one that breaks down releases the dye it was carrying.

Related terms: Disperse dye, Vat dye, HT dyeing, Oligomer

Dosage units

Dyehouse recipes use two units, and confusing them is an expensive mistake. Percentage owf is on the weight of fabric: 2% owf on 100 kg of cloth is 2 kg of product, and the quantity stays the same whatever the liquor ratio. g/L is on the volume of the bath: at 1:10 with 100 kg of cloth, 1 g/L is 1 kg of product, and at 1:5 the same g/L is half that. Dyes and auxiliaries that bind to the fibre are quoted owf; auxiliaries that work in the liquor (wetting agent, sequestrant, antifoam) are quoted in g/L.

Related terms: Liquor ratio, Recipe, Active content

Drying cylinder

Drying the cloth by contact with steam-heated metal cylinders. It is faster and cheaper than hot air, but the fabric is pressed against the cylinder, so the handle stiffens and the surface glazes. In padded finishes, migration of the chemical to the surface is more pronounced on cylinders than in a stenter. It is the usual choice on pre-treatment ranges and woven goods, and avoided on delicate knits.

Related terms: Stenter, Padder, Continuous process, Handle

Dye fixing agent

An after-treatment that raises wet fastness by binding anionic dye on the fibre with its cationic structure. Polycationic resins are used for direct and reactive dyes on cellulose, syntan-based products on polyamide. A fixing agent is not a substitute for proper washing off: over a surface still loaded with hydrolysed dye it only masks the problem until the first home wash. Overdosing stiffens the handle and shifts light fastness and some shades.

Easy-care finish

Cross-linking the cellulose chains to each other so the cloth creases less. The standard cross-linker today is DMDHEU and its low-formaldehyde modifications, cured on the stenter with a catalyst such as magnesium chloride. The price is strength: as cross-linking rises, tensile and tear strength fall, which is why softener and polyethylene usually go into the same recipe. Formaldehyde release is the parameter to watch, because of OEKO-TEX and brand limits.

Elastomeric silicone

A silicone that cross-links on the fibre as it dries and builds an elastic film. It gives body, recovery and bulk, and is used in knitwear for dimensional stability and shape retention after make-up. On elastane blends it supports the stretch, and on wovens such as denim and gabardine it gives a warm handle. Because it cross-links, standing liquor is a risk and it can gel in the pad trough.

Related terms: Micro silicone emulsion, Handle, Fibre types, Padder

Enzyme deactivation

Stopping the enzyme irreversibly with heat or pH once its work is done. For cellulase the practical routes are going above 80 °C or taking the pH over 10; draining the bath is not enough, because enzyme left on the fibre keeps cutting. Skipping it gives a soft but weakened fabric that loses strength in storage. The damage is usually discovered in make-up or in the customer's test lab.

Enzyme wash

Breaking down surface fibre ends on denim with cellulase and stripping indigo in a controlled way. It is kinder to the machine and the cloth than stone, puts less load on the effluent and repeats better. The two critical parameters are pH and temperature: outside the window the effect either fails to develop or strength collapses. If the enzyme is not deactivated at the end, abrasion carries on even in storage.

Exhaust dyeing

The batch method, where the goods sit in one bath and dye transfers from the water phase into the fibre over time. Salt, temperature and alkali shift the equilibrium; what is left in the bath at the end measures exhaustion. Most knit dyehouses in Turkey run this way on jet and overflow machines. Because every batch makes its own bath, reproducibility comes down to recipe discipline.

Fastness

How well a dyed fabric holds its colour against outside influences. Each influence has its own test and standard: washing, rubbing, perspiration, light, chlorine, ironing, water. Results are normally graded 1-5 (1-8 for light) and the customer specification states which test at what level. Fastness depends as much on the wash-off and after-treatment as on the dye itself; the same dye under a different washing regime grades differently.

Fibre types

The first thing a finishing recipe depends on is which fibre is in front of you. Cellulosics (cotton, viscose, linen) tolerate alkali and dye with reactive, direct or vat dyes, while viscose loses most of its strength when wet and is sensitive to tension and crease marks. Polyester needs disperse dye at 130 °C, polyamide and wool run with acid dyes under acidic conditions, and acrylic takes cationic dyes and is very sensitive around its glass transition. Elastane is not dyed at all but limits everything: it degrades above 120 °C and will not take chlorine or high alkali.

Related terms: Blended fabric, Disperse dye, Acid dye, Reactive dye

Finishing

The last treatments, applied after dyeing and washing, that give the cloth its handle, appearance or a functional property. Chemical finishes go on by pad or exhaust, mechanical finishes come from the stenter, the emerising machine or the calender. Because it sets what the customer actually feels, complaints tend to land here even when the root cause is uneven absorbency from pre-treatment. The same recipe gives a different handle at a different stenter speed.

Related terms: Handle, Softener, Stenter, Padder

Flame retardant finish

Treatment that delays ignition and limits how far flame spreads once the fabric is exposed. On cotton the durable route is a cured phosphorus-based system of the Pyrovatex or Proban type; on polyester, phosphorus/halogen products and types applied during dyeing are used. Non-durable ammonium salt finishes are cheap but wash out at once, so they only make sense on single-use or non-laundered goods. Which standard the article has to pass (bedding, curtains, workwear) decides the recipe.

Related terms: Finishing, Padder, Stenter, Fibre types

Foam

The layer that forms when surfactants in the bath stabilise air bubbles. In jets and overflows it makes the fabric float, causes pump cavitation and puts dosing out of control; on the padder, trapped bubbles sit on the cloth and produce spotty pick-up. An antifoam knocks the foam down, but the source is usually a wetting or washing agent already in the recipe.

Related terms: Antifoam, Wetting agent, Padder

Formaldehyde

A chemical released from certain resin finishes, fixing agents and print binders, measured as an emission from the cloth. ISO 14184-1 determines it in ppm by water extraction; for babywear the limit is held near zero at 16 ppm, and for skin-contact articles around 75 ppm. The source is rarely a single product but the sum of several recipe components. Buying brands track it separately in their restricted substance lists.

Formaldehyde-free fixing

Part of the traditional fixing agent range is based on dicyandiamide-formaldehyde condensates, which leave free formaldehyde on the cloth. Brand restricted substance lists and OEKO-TEX limits have ruled those types out for children's and babywear. Formaldehyde-free alternatives are built on polyamines, polyquaternary ammonium or polyurethane chemistry; they usually give slightly less fastness gain and a softer handle penalty. When selecting, ask for the test result on fabric alongside the formaldehyde statement in the TDS.

GOTS

The standard that certifies textiles made from organic fibre from the field through to the finished article. On the chemical side it maintains its own positive list: auxiliaries are assessed for biodegradability, toxicity and composition before they are approved. For a dyehouse that means an organic cotton lot may only be run with products that appear on that list. The standard also carries social criteria and a wastewater treatment requirement.

Related terms: OEKO-TEX ECO PASSPORT, bluesign, ZDHC MRSL

Greige fabric

Fabric straight off the loom or the knitting machine, with no finishing treatment on it. It carries size, spin finish, cotton's natural wax and field trash, and its colour is a dirty cream. Every lot arriving at the finishing plant can differ in yarn count, blend and construction, so when the greige lot changes the pre-treatment recipe should be re-validated before production runs. A good share of the surprises in dyeing start here.

Related terms: Size, Pre-treatment, Spin finish, Fibre types

Grey scale

The pair of grey cards used to grade shade change and staining visually in fastness testing. There are two scales: ISO 105-A02 for change in colour and ISO 105-A03 for staining, both graded 1 (very poor) to 5 (no change) in half steps. Assessment has to be made under D65 against a neutral grey background, or two laboratories will report different grades. Instrumental grading is spreading, but acceptance in the trade still runs largely on the scale.

HT dyeing

Dyeing above 100 °C, typically at 130 °C, in a closed pressurised machine. It is the standard route for polyester and gives enough diffusion without a carrier. Every auxiliary in the bath is stressed at that temperature, so antifoam, levelling agent and dispersant all have to be HT-stable types. Steep heating and cooling ramps show up as crease marks on elastane blends and as unlevelness on polyester.

Related terms: Disperse dye, Carrier, Oligomer, HT dyeing machine

HT dyeing machine

A closed, pressure-rated dyeing machine that can run up to 130-140 °C. It is what makes dyeing polyester and its blends possible without a carrier. Versions exist for rope form (jet and overflow), open width and package or yarn dyeing. Heating and cooling ramps, pump speed and drain temperature decide oligomer build-up and crease formation, and the oligomer crust left in the vessel shows up as spots on the next pale batch.

Handle

What the cloth feels like in the hand: softness, slip, fullness, elasticity and surface roughness. It resists measurement, so most mills work against an approved reference swatch. Softener selection starts from the handle target: macro silicone gives surface slip, micro silicone gives internal softness, elastomeric silicone gives recovery and body. When a customer says "make it softer", the recipe should not be written until it is clear which of these they mean.

Heat setting

Heating synthetic fabric under tension on the stenter at around 180-200 °C to relax internal stresses and lock in the dimensions. Shrinkage and spirality on polyester, polyamide and elastane knits can only be brought under control this way. Temperature and dwell also change how the fabric takes dye, so for goods set before dyeing the setting parameters belong in the dye recipe. Spin finish left on the cloth before setting bakes in as yellow marks and stains.

Related terms: Stenter, Spin finish, Yellowing, Fibre types

Hydrogen peroxide

The standard oxidiser for cotton bleaching, working through the perhydroxyl ion under alkaline conditions. Its performance is managed through the triangle of temperature, pH and stability: controlled decomposition means whiteness, uncontrolled decomposition means pinholes and lost strength. Heavy metal ions, iron above all, accelerate the breakdown instantly, which is why the bath carries a sequestering agent and a stabiliser. Whatever is left on the cloth afterwards has to be taken to zero before dyeing.

Hydrolysed dye

The fraction of reactive dye that has reacted with water instead of cellulose and can no longer bond. It sits on the fibre physically and still gives colour, so the shade can look right at the end of dyeing while the fastness is not there. Depending on alkali dose, temperature and dye class, 10 to 40 per cent of the dye can end up this way. It is the only thing soaping is aimed at.

Hydrophilic silicone

A silicone type carrying polyether groups that softens without destroying the fabric's water absorbency. Classic amino silicones leave a hydrophobic film and are therefore out of the question on towelling, robes, activewear and medical textiles, which is the gap these types fill. The handle is usually less rich than an amino silicone, but the drop test passes and the yellowing risk is low. Any product claiming moisture management starts its finishing recipe here.

Related terms: Absorbency, Amino silicone, Softener, Handle

Hydrosulphite

The strong reducing agent used to reduce vat and sulphur dyes, to clear polyester reductively and to strip colour. It works fast hot and under alkali, and it decomposes on its own in contact with air, so it has to go into the bath fresh. In storage it reacts with moisture and can self-heat, which is why it is kept dry and sealed. Because it loads the effluent with sulphite, enzymatic and organic reducing alternatives are being looked at.

Related terms: Vat dye, Reductive clearing, Indigo, Caustic soda

Hypochlorite bleaching

Fading denim quickly and cheaply with sodium hypochlorite. The effect is strong but hard to hold: a few minutes' difference moves the cast visibly. An antichlor step with bisulphite or peroxide is mandatory at the end, or the fabric yellows in storage, the elastane degrades and strength falls. AOX load and brand restrictions are pushing many plants towards ozone and laccase instead.

Indigo

The vat dye behind denim blue. Warp yarn passes through a series of vat baths on the slasher line, each dip oxidising a thin layer so the dye never fully penetrates the yarn and stays in an outer shell. That ring-dyed structure is the only reason denim can later be washed down and aged. Indigo has poor rub fastness, which is a characteristic of the product rather than a fault.

Related terms: Vat dye, Indigo fading, Stone wash, Back-staining

Indigo fading

Taking denim down to a target lightness by partly stripping the indigo or destroying it by oxidation. The route decides the cast: mechanical abrasion and enzymes keep contrast, hypochlorite and permanganate give a flatter, yellower ground, ozone and laccase sit in between. The same lightness reached by different routes does not read the same on a colour measurement. Skipping the neutralisation afterwards leaves cloth that yellows and loses strength in storage.

Related terms: Hypochlorite bleaching, Ozone washing, Laccase, Indigo

Ionic character

The electrical charge a surfactant carries in water: anionic (negative), cationic (positive), nonionic (neutral) and amphoteric (depending on pH). The first rule of building a recipe follows from it, since an anionic and a cationic product in the same bath neutralise each other and form a precipitate. Cellulose and most dyes are anionic, so cationic products such as fixing agents and some softeners exhaust fast onto the fibre and carry a risk of uneven distribution. That single line in the TDS heads off most compatibility problems.

Jet dyeing machine

An exhaust machine that runs the cloth in rope form through a nozzle and circulates it with the liquor. In a classic jet the liquor pressure carries the fabric; in an overflow the fabric falls under its own weight at lower tension, and soft-flow types work on an air and water mix. Short liquor ratios and fast circulation generate foam, which is why antifoam and anti-creasing agent are fixed parts of the recipe on these machines. Nozzle setting, load and fabric speed relate directly to crease marks and unlevelness.

Related terms: Exhaust dyeing, Crease mark, Antifoam, Liquor ratio

Lab dip

Dyeing small samples on a laboratory machine to hit the customer's colour reference. The approved dip becomes the basis of the bulk recipe, but laboratory liquor ratio and agitation never match the production machine, so the transfer is not automatic. Mills close the gap by keeping their own lab-to-bulk correction factors. Acceptance is judged on a spectrophotometer against a ΔE tolerance.

Related terms: Recipe, Spectrophotometer, Delta E (ΔE), Liquor ratio

Laccase

A copper-containing enzyme that oxidises phenolic structures using atmospheric oxygen. On denim it breaks down indigo enzymatically and fades it without hypochlorite, usually giving a greyer, flatter cast. Compared with conventional bleaching the fibre is not damaged and the effluent load is lower, though the effect is less aggressive than hypochlorite. The mediator and pH window depend on the product, and the enzyme has to be deactivated at the end.

Levelling agent

An auxiliary that slows dye uptake so the shade spreads evenly. Two mechanisms are in use: products with dye affinity, which hold the dye back in the liquor as a weak complex, and products with fibre affinity, which occupy the fibre first and are then displaced by the dye. Overdosing lightens the shade and wrecks reproducibility, so the dose belongs to the dye class and the machine, not to a fixed house recipe.

Related terms: Levelness, Unlevelness, Dispersing agent, HT dyeing

Levelness

The same shade at every point on the cloth. Levelness is built two ways: by letting dye transfer onto the fibre slowly and controllably so it can still migrate, or by getting it distributed evenly from the start. For most dye classes the critical window is 60-80 °C; a heating programme that races through it leaves a difference nothing downstream will correct.

Related terms: Unlevelness, Levelling agent, Exhaust dyeing, Recipe

Light fastness

Exposing the specimen to controlled light in a xenon arc cabinet and grading it 1-8 against the blue wool scale. Unlike the other fastness scales it runs to 8, and each step means roughly double the resistance of the one below. Pale and bright shades grade lower than dark ones, because the same light dose falls on less dye. It is the deciding test for curtains, upholstery, automotive and outerwear, and carrier residues or certain UV absorbers move the result directly.

Related terms: Fastness, Carrier, Disperse dye, Vat dye

Lime spot

Calcium and magnesium from hard water combining with fatty acids, dye or softener and depositing on the cloth. It reads as a whitish bloom in reflected light, or as a light ring on a dyed ground, and it does not wash out easily. The usual points of failure are the scouring bath, the first rinse and the softener bath. The answer is not stain removal but the right sequestering agent at the right dose.

Liquor ratio

The ratio of goods weight to bath volume, written as 1:8, meaning eight litres of water per kilo of fabric. Water, steam, salt and chemical consumption all follow it, which makes it the economic centre of machine selection. The shorter the ratio, the harder levelling becomes and the worse foam gets: circulation speeds up, air is drawn in and antifoam stops being optional. Dosages quoted in g/L have to be recalculated whenever the ratio changes.

Machine cleaning

Stripping the dye, oligomer, silicone and lime deposits that build up in the vessel, pipework and filter of a dyeing machine. It is normally run as a hot caustic cycle with a strong washing agent, followed by an acid neutralisation. Skipping it when moving from dark to pale shades comes back as spotting and shade drift on the next batch. Once the deposit has hardened, chemical cleaning alone will not shift it and mechanical work is needed.

Related terms: Oligomer, Lime spot, Jet dyeing machine, Caustic soda

Macro silicone emulsion

Silicone emulsified to particle sizes in the micron range, milky white in the drum. The particles stay on the fibre surface and give slip and a silky drape, which is what is wanted when sewability and a slick handle matter. Emulsion stability is lower than for micro types, and shear or hard water can break it. Pad application is safer than exhaust for this family.

Related terms: Micro silicone emulsion, Handle, Padder, Silicone spot

Mercerising

Passing cotton under tension through concentrated sodium hydroxide. The fibre cross-section rounds out, lustre and dye uptake increase and strength rises. It needs a dedicated wetting agent that wets fast without foaming at high caustic concentration. Ordinary wetting agents salt out.

Related terms: Pre-treatment, Wetting agent, Caustic soda

Metamerism

Two samples matching under one light source and differing under another. The cause is different reflectance curves, which becomes unavoidable when the same shade is hit with different dye combinations. That gap between store lighting and daylight is the classic reason for panel-to-panel complaints in garments. The defence is to choose a recipe close to the standard's own dye combination and to approve under at least two illuminants, D65 with TL84 or A.

Related terms: Spectrophotometer, Delta E (ΔE), Lab dip

Micro silicone emulsion

A silicone emulsion with particle size taken below about 100 nm, clear or opalescent in appearance. The small particles penetrate between and into the fibres, so instead of sitting on the surface they give softness and fullness from the inside. Emulsion stability is high, which makes it safer in exhaust application and on hard water. The trade-offs are a higher price per unit of active content and less surface slip than macro types.

Neutral cellulase

Cellulase that works in the pH 6-7 range. It abrades more slowly than acid cellulase, but back-staining is far lower, so the weft and the pocketing stay whiter and contrast holds. Working at neutral pH removes the acid adjustment and the neutralisation that follows it, which shortens the cycle. It is the standard choice for light washes where high contrast is wanted.

Neutralisation

Bringing residual alkali on the cloth and in the bath down to neutral with acetic or formic acid. After bleaching and reactive dyeing it cannot be skipped: carried-over alkali raises soaping agent consumption, stops the enzyme or softener in the next step from working and yellows the goods in storage. The check is simple: the extract pH is expected to land between 6 and 7. Diluting and metering the acid rather than tipping it in avoids the spots that come from a local pH shock.

Related terms: Acetic acid, pH measurement, Soaping, Yellowing

OEKO-TEX ECO PASSPORT

The certification system for textile chemicals and auxiliaries; where STANDARD 100 looks at the finished article, ECO PASSPORT looks at the chemical itself. It runs in two stages: every component of the formulation is screened against restricted substance lists, then analytical verification follows. A certified auxiliary is accepted in a customer's STANDARD 100 application and cuts the documentation burden down the supply chain. It is also one of the recognised routes to ZDHC MRSL conformance.

Related terms: ZDHC MRSL, Formaldehyde, GOTS, TDS and SDS

Oil stain remover

Dissolves and emulsifies the machine oil, silicone oil and grease the cloth picks up in knitting and weaving. Three families exist: solvent-based (strongest, with odour and VOC issues), solvent-free surfactant blends, and natural or aromatic solvent types such as d-limonene. Stains have to come off before dyeing; spot treatment on dyed cloth almost always leaves a halo. The type of oil decides the product, since mineral oil and silicone oil do not come out with the same chemistry.

Oligomer

Short cyclic chains inside polyester itself, which migrate out of the fibre above 120 °C. As the bath cools they recrystallise, leaving white dust on the cloth and a hard crust in the machine body and pipework. On dark shades it shows as white specks, on pale shades as a harsh handle. Draining hot, running an oligomer-active dispersant and dropping the bath around 110 °C are the practical countermeasures.

Ozone washing

Fading indigo by oxidising it with ozone gas generated in a closed cabinet or drum. It uses almost no water, leaves no chemical residue and takes minutes, which is why mills chasing water and chemical savings adopted it quickly. Dry ozone gives a light, flat fade; on damp fabric the effect is stronger. Ozone is toxic, so cabinet sealing and a residual ozone destruct unit are the operator's responsibility.

Pad-batch

Padding reactive dye and alkali onto the cloth, then batching it on a roll and rotating it at room temperature for 4 to 24 hours. With no steam and no salt it costs clearly less than exhaust dyeing in both chemicals and energy. It demands discipline in return: a roll that stops turning runs at the bottom, an uncovered roll dries at the selvedges, and a dye/alkali mix left standing hydrolyses. Cold and hot rinsing followed by soaping are not optional at the end.

Related terms: Reactive dye, Padder, Soaping, Hydrolysed dye

Padder

Draws the cloth through a trough of chemical solution, then squeezes it between two rollers so a fixed amount of liquor stays on it. The percentage left behind, the pick-up, is the most critical variable in a pad recipe: change the nip pressure and the amount of chemical on the cloth changes with it. The trough volume has to be small and the liquor continuously replenished, because the fabric takes components selectively and the composition drifts (tailing). The padder is the entry point for pad-batch and continuous ranges.

Related terms: Pad-batch, Continuous process, Stenter, Finishing

Peroxide stabiliser

The product that keeps hydrogen peroxide decomposing at a controlled rate in the bleach bath. Heavy metal ions carried in by the water and the cloth (iron, copper, manganese) crash the peroxide all at once; the stabiliser spreads the decomposition out by binding those ions or buffering the perhydroxyl ion. Most commercial products combine sequestering and stabilising in one.

Perspiration fastness

Wetting the specimen with artificial perspiration solution, holding it under pressure against the adjacent fabric at 37 °C, then grading on the grey scales. Two solutions are used, acid and alkaline, and alkaline perspiration is the harder one for polyamide and wool. Activewear and underwear specifications often add combined perspiration-light fastness, which is a much more severe test. When the grade is low, dye selection and the fixing step are the first things to review.

Related terms: Fastness, Dye fixing agent, Acid dye, Grey scale

Pigment printing

Fixing a pigment, which has no affinity for the fibre, onto the surface inside a binder film. It is the most widely used print route because it needs no washing off, works on any fibre and is cheap. Rub fastness and handle are the weak points: the binder film stiffens the cloth and heavy pigment loads crock in dry rubbing. A silicone or polyethylene softener applied afterwards brings the handle back.

Related terms: Rubbing fastness, Handle, Heat setting, Softener

Pilling

Fibre ends working out of the fabric surface in wear and washing, then tangling into small balls. It shows up most on short-staple yarns and cotton/polyester blends; polyester fibre does not break, so the pill stays attached and that is where the complaint comes from. A cellulase treatment removes the ends present on the surface and delays the onset, but does not prevent pilling.

Related terms: Pilling test, Bio-polishing, Cellulase

Pilling test

Generating pills on the fabric surface with controlled abrasion and grading them 1-5. The most common instrument is the Martindale, where the specimen is rubbed in a Lissajous figure under a set load and assessed after 125, 500, 1000 and 2000 rubs. Polyester and its blends grade poorly because the anchoring polyester fibres do not break, so the pill stays on the surface. On cotton, cellulase bio-polishing lifts the grade; on synthetics the answer lies in the fibre and yarn construction.

Related terms: Bio-polishing, Tensile strength, Fibre types

Polyethylene emulsion

An aqueous emulsion of polyethylene wax that gives surface slip and cools the sewing needle. Its real job is not handle but reducing needle damage and tear strength loss in garment make-up. Used alongside silicone it complements the slip and brings the cost of the recipe down. Oxidised grades are anionic and more stable; non-oxidised grades are nonionic.

Related terms: Softener, Handle, Tensile strength, Ionic character

Potassium permanganate spray

An oxidising solution sprayed locally onto jeans mounted on a dummy, destroying indigo where the spray lands to create knee and thigh highlights. The brown manganese dioxide left behind after oxidation is neutralised with metabisulphite. It is one of the worst steps in the industry for worker health: respiratory protection and an enclosed booth are mandatory, and many brands have banned it outright. Laser abrasion and ozone are taking its place.

Pre-treatment

The chain of steps that prepares greige cloth for dyeing: desizing, singeing, scouring, bleaching and, where required, mercerising. It has one goal: the same absorbency and the same whiteness everywhere on the piece. Most unlevelness complaints in dyeing trace back to pre-treatment.

Related terms: Bleaching, Scouring, Mercerising, Unlevelness

Pumice stone

The porous volcanic rock used in stone washing. Its low density lets it abrade without crushing the cloth, but it crumbles as it works and leaves sludge in the machine. The stone-to-fabric ratio and drum loading set the strength of the effect: too much stone tears the fabric, too little and the effect does not develop. Synthetic stones used in its place last longer and leave less residue.

Related terms: Stone wash, Enzyme wash, Neutral cellulase

REACH

The European Union regulation on the registration, evaluation, authorisation and restriction of chemicals. Three parts of it bear on textile auxiliaries: registration of substances imported into the EU above one tonne a year, the Annex XVII restrictions, and the candidate list of substances of very high concern (SVHC). For a dyehouse exporting to the EU the practical consequence is that the SDS must carry the REACH registration number and an SVHC statement. The candidate list is updated twice a year, so the date on a supplier declaration matters.

Related terms: TDS and SDS, ZDHC MRSL, APEO / NPEO

Reactive dye

The dye class that forms a covalent bond with cellulose, and the main route for cotton, viscose and linen. The dye is first exhausted onto the fibre with salt, then fixed under alkali from soda ash or caustic. Fixation is never complete: whatever fails to bond reacts with water instead, hydrolyses and simply sits on the fibre. If that residue is not soaped off, wash and rub fastness drop.

Related terms: Hydrolysed dye, Soaping, Dye fixing agent, Soda ash

Reactive washing-off agent

The product that lifts hydrolysed dye off the fibre and keeps it dispersed in the bath so it cannot redeposit. A good washing-off agent behaves as a dispersant at the same time; removing the dye is only half the job, holding it in the water is the other half. On hard water, types with sequestering activity are preferred, because calcium drives the dye straight back onto the cloth. Low-foaming grades also cut the antifoam demand on jet machines.

Related terms: Soaping, Hydrolysed dye, Sequestering agent, Antifoam

Recipe

The step-by-step instruction that sets out the chemicals, dosage, temperature, time and pH for a process. A good recipe never quotes a dose on its own: it states the unit (% owf or g/L), the liquor ratio it applies at and the machine it was written for. Reproducibility comes less from the recipe than from sticking to it, since shortening a ramp or a dosing time gives a different shade from the same figures. It has to be re-validated whenever the water hardness or the fabric lot changes.

Related terms: Dosage units, Liquor ratio, Lab dip, Water hardness

Reductive clearing

Breaking down the disperse dye left on the polyester surface after dyeing by reducing it with hydrosulphite and caustic so it becomes water-soluble. On dark shades it cannot be skipped: without it rub and perspiration fastness fail and dye transfers onto white panels in elastane blends. The classic route is hydrosulphite and caustic at 70-80 °C; odour and effluent load are pushing mills towards alkali-stable reductive clearing agents. An acid rinse afterwards is needed to take all the alkali out.

Rubbing fastness

Rubbing the fabric surface with a standard white cloth under defined pressure on a crockmeter and grading the transfer on the grey scale. Two grades are given, dry and wet, and the wet grade is always the lower one. Dark shades, pigment prints and indigo all struggle with this test by nature. A low grade usually means loose dye on the surface, so the answer is better washing off, a reductive clear, or a fixing agent.

Scouring

Removing cotton's natural wax, pectin, oil and protein residues in a hot alkaline bath. At the end the fabric is hydrophilic, checked with a drop test. Wetting agent choice matters here: it has to work without foaming and stay stable at high pH.

Related terms: Pre-treatment, Absorbency, Wetting agent

Sequestering agent

A product that complexes calcium, magnesium and heavy metal ions in the bath. In a mill on hard water, without one, peroxide decomposes uncontrollably in bleaching, lime spots and shade shifts appear in dyeing, and softener drops out. Acrylate, phosphonate and polyacrylate types differ in which ions they bind best.

Related terms: Water hardness, Peroxide stabiliser, Bleaching

Silicone spot

The dark, greasy-looking mark left when a silicone emulsion breaks and the oil phase collects on the cloth. What breaks emulsions is well known: high shear, hard water, the wrong pH, mixing cationic and anionic products, and pouring concentrate straight into the bath. Once it is there, removal is hard, needing a solvent-based remover and a hot wash, with a risk to the shade. Silicone should always be pre-diluted with water and metered in through a dosing pump.

Size

The film applied to warp yarn so it survives weaving. It can be starch, modified starch, PVA or acrylate based. Once the cloth is off the loom the size has no further purpose and is removed in the first step of pre-treatment; if it stays, dye and finishing agents cannot reach the fibre.

Related terms: Desizing, Pre-treatment

Soaping

Removing unbound dye from the fibre surface in near-boiling water with a washing-off agent after reactive dyeing. Success is measured when the rinse water runs clear, not when the bath looks exhausted. Dark shades that are under-soaped bleed in the first home wash, lose rub fastness and stain white panels in garment make-up. An acid rinse beforehand stops alkali carry-over and makes the soaping step work harder.

Soda ash

The most widely used fixation alkali in reactive dyeing. It works more gently than caustic and buffers the bath around pH 10.5-11, which keeps the dye-fibre reaction controlled. It is normally dosed in stages during dyeing; adding it in one shot fixes dye on the surface and causes unlevelness. Its solubility in a hot bath is limited, so if it is not properly dissolved in the make-up tank it reaches the cloth as powder and leaves specks.

Softener

Anything that lays a thin oil or polymer film on the fibre surface and cuts fibre-to-fibre friction. Four groups are in use: cationic (softest handle, with yellowing and fastness risks), nonionic (shade-friendly, moderate effect), anionic (hydrophilic, safe on whites) and silicone. Mismatched ionic character is the most common mistake: a cationic softener and an anionic product in the same bath will drop out. End use decides too, since loss of absorbency is unacceptable on towelling and babywear.

Spectrophotometer

An instrument that measures reflected light by wavelength and describes colour numerically. Its outputs are the reflectance curve and the L*a*b* values calculated from it, which underpin recipe prediction, shade acceptance and colour transfer between plants. Measuring conditions change the answer: number of folds, aperture size, specular included or excluded, and calibration standard all belong in the report. Where instrumental and visual judgements disagree, the contract has to say which one decides.

Related terms: Delta E (ΔE), Metamerism, Lab dip, Grey scale

Spin finish

The oil and emulsifier blend applied to fibre surfaces to cut friction in spinning and knitting. The amount is small but unevenly distributed, so cloth dyed without a scour shows absorbency differences and spots. On synthetics it becomes much harder to remove after heat setting, because the oil polymerises and leaves a yellow mark. That is why polyester and polyamide knits are pre-scoured before setting.

Related terms: Oil stain remover, Heat setting, Yellowing, Absorbency

Stenter

The machine that holds the cloth on pin or clip chains at both selvedges and carries it under tension through hot air chambers. Drying, finish curing, heat setting and width setting all happen here. The critical parameters are chamber temperature, fabric speed, overfeed and air circulation, and the same finish recipe gives a different result at a different speed. Oil and oligomer building up in the chambers drips onto the cloth as stains, so the cleaning interval is part of production planning.

Related terms: Heat setting, Finishing, Padder, Drying cylinder

Stone wash

Ageing denim by tumbling it with pumice stone. The stone abrades indigo from the surface, brings out contrast on seams and edges and softens the cloth. The downsides are machine wear, tears in the fabric, stone grit left in pockets and a heavy sludge load in the effluent. That is why most of the work moved to cellulase abrasion; stone today is usually run alongside enzyme, in smaller quantities.

Strength loss

A process reducing the tensile or tear strength of the cloth. It turns up in cellulase treatments, in uncontrolled peroxide decomposition during bleaching, and in over-mercerising. Weight loss is used in the lab as a proxy: it is quick to measure and moves in the same direction, but the ratio between the two depends on fabric construction and has to be established once per quality.

TDS and SDS

The two documents that come with every chemical. The TDS says what the product is and how to run it: ionic character, active content, pH, density, working temperature, recommended dosage and compatibility. The SDS is the legally required safety document in sixteen standard sections: hazard classification, first aid, storage, personal protective equipment, transport and regulatory information. Recipes are built from the TDS, while the store and the safety officer work from the SDS; neither replaces the other.

Related terms: Active content, Ionic character, REACH, Dosage units

TEGEWA scale

The violet comparison scale used to grade desizing. A drop of iodine / potassium iodide solution is placed on the fabric and the resulting colour compared against a 1-to-9 scale. Nine means the size is fully removed, one means untouched. A rating of 7-8 or better is normally required before dyeing.

Related terms: Desizing, Alpha-amylase

Tensile strength

The force a fabric withstands before it breaks, measured by the strip or grab method, with tear strength reported separately by a test such as Elmendorf. In a finishing plant a strength loss is usually the clearest evidence of a chemical error: uncontrolled peroxide, over-dosed cellulase, high caustic, residual chlorine and an over-hot stenter all show up here. In enzyme processes, weight loss and strength loss have to be tracked together. An easy-care finish reduces strength by definition.

Unlevelness

Dye taken up unevenly across the piece, light in one place and dark in another. The cause usually sits upstream of the dyebath: cloth with size still on it, patchy absorbency or residual peroxide will not dye level. On the machine side, heating rate, liquor circulation and the salt/alkali dosing profile produce the same defect. A levelling agent is insurance on well-prepared cloth, not a cover for bad preparation.

Related terms: Levelness, Levelling agent, Pre-treatment, Catalase

Vat dye

A water-insoluble class that is reduced to a soluble leuco form, taken into the fibre and re-oxidised there so it is trapped. Reduction is classically done with hydrosulphite and caustic. Light and wash fastness are very high, which is why workwear and curtain fabrics use it; the trade-off is a long, expensive process with a heavy effluent load. Indigo belongs to this class.

Related terms: Indigo, Hydrosulphite, Caustic soda, Dispersing agent

Wash fastness

Washing the specimen at a defined temperature, detergent and time under a standard such as ISO 105-C06, then grading both the shade change and the staining of the multifibre adjacent fabric on the grey scales. In practice the staining grade matters more than the change, because dye transferring onto a white panel in make-up is a straight rejection. On reactive shades a low grade almost always means incomplete soaping. A fixing agent can lift the grade by a step but will not cover for a bad wash-off.

Related terms: Fastness, Grey scale, Soaping, Dye fixing agent

Water hardness

The total calcium and magnesium content of the water, usually quoted in French (°fH) or German (°dH) degrees. It is the invisible variable in a dyehouse recipe: the same recipe gives different results in two plants on different water. Sequestering agent dosage is set from the water analysis.

Related terms: Sequestering agent, Lime spot

Water repellent finish

Lowering the surface energy of the fibre so a water droplet rolls off instead of spreading into it. C6 fluorocarbon types give both water and oil repellency; fluorine-free alternatives (dendrimer, paraffin/silicone, polyurethane) cannot deliver oil repellency and are currently less durable. It is padded and must be cured at 150-170 °C, since an uncured finish is gone after the first wash. Residual ionic softener, wetting agent or soap on the cloth cancels the effect, so the fabric has to be clean and neutral beforehand.

Related terms: Padder, Stenter, Absorbency, ZDHC MRSL

Wetting agent

The surfactant that lowers the surface tension of water so the fabric wets out fast and evenly. Raw cotton repels water because of its natural wax, and without a wetting agent the scouring and bleaching liquors never reach the fibre. Selection follows the bath: mercerising needs stability in concentrated caustic, bleaching needs high pH and peroxide tolerance, a jet needs low foam. Wetting speed and foam always pull against each other.

Related terms: Scouring, Absorbency, Mercerising, Antifoam

Yellowing

Whites and pale shades drifting towards yellow during storage or under heat and light. Textiles have three main sources: cationic softeners and high amine value silicones oxidising under heat, BHT in packaging and cartons reacting with nitrogen oxides (phenolic yellowing), and residual alkali. Pushing the stenter above 150 °C multiplies the risk quickly. On whites the finish recipe and the storage packaging have to be judged together.

Related terms: Amino silicone, Softener, Stenter, Heat setting

ZDHC MRSL

The list published by the ZDHC (Zero Discharge of Hazardous Chemicals) programme that restricts what may be present in chemicals used in textile manufacturing. It differs from an RSL in focus: an RSL looks at residues in the finished article, the MRSL at the chemical itself, so a substance is off-limits even if none of it survives into the product. Chemical suppliers certify products against conformance levels 1, 2 and 3 and publish them on the ZDHC Gateway. It is the document most often asked for in brand supplier audits.

bluesign

A chemical and production management system built on an input stream approach. Its logic is to keep hazardous substances out of the process rather than measure them at the end; approved chemicals appear on the bluesign APPROVED list and bluesign SYSTEM PARTNER plants work from it. Resource efficiency, occupational safety and emissions are part of the audit as well. Outdoor and technical apparel brands ask for it most often.

Related terms: ZDHC MRSL, GOTS, OEKO-TEX ECO PASSPORT

pH measurement

Measuring how acid or alkaline the bath and the finished fabric are. In the bath, pH defines the working window of every step from enzyme activity to dye fixation, and a strip reading is not good enough for enzyme work; a calibrated meter is. On finished goods pH is measured on an aqueous extract, and specifications typically ask for 4.5 to 7.5; residual alkali above that irritates skin, yellows the goods in storage and degrades finish performance. Buffer systems are used to stop the pH drifting as the temperature changes.