Brio Cleaners Glossary

Common Terms from the Dry Cleaning Industry

We have defined several industry terms that explain how dry cleaning works. See our FAQs for more answers, Advice & Tips for quick links, and Knowledge & Advice for detailed articles.

For information on Brio’s dry cleaning services, see our pages on Professional Garment Care, Formal & Designer Wear, Specialty Items, and Wholesale Commercial.

Amyl Acetate

A dry-side spotting agent that fights plastic and oil stains.

Anti-foaming Agents

Chemicals used to reduce foaming in the still caused by solvent contaminants such as filter powder, pigments, acids, detergents, retexturing agents and water repellents.


The final dry cleaning step after cleaning and finishing processes: sorting, bagging, and racking clothes on a conveyor.

Atmospheric Still

A still that distills without using internal pressure or vacuum, standard in dry cleaning operations that use chlorinated solvents such as perchloroethylene.


The washing of spent diatomite from tubular filters by reversing solvent flow, as opposed to bumping.

Bactericides (Biocides)

Solution used in dry cleaning detergents, particularly for petroleum dry cleaning solvents, to counter bio-contamination.

Base Tank

Tanks at a dry cleaning machine’s base in one to three units, holding both dirty solvent for distillation and clean solvent.

Belly Washer

A washer from now-obsolete transfer machine procedures. A belly washer’s rotating cylinder holds textiles and receives solvent from the outer metal shell. The machine would extract solvent before moving textiles to the tumbler.


A stain-fighting chemical used in laundering and spotting operations. Oxidizing bleaches and reducing bleaches use different chemical processes to combat different kinds of stains.

Boil Down

The final distillation step of heating solvent in the still to recover it before cleaning the still.


The insulated machine that heats water into hot water and steam for use in distillation, finishing, spotting, and cleaning operations. Boiler blowdown water and boiler feed water treatment prevent internal scale buildup in boilers.

Boiler Feed Water Treatment

The prevention of scale buildup in boilers through chemical agents, as opposed to boiler blowdown water.


The release of muck from a muck cooker or still, resulting from overfilling or overheating.

Bound Moisture

Water that a detergent in a dry cleaning solvent binds and releases.


A plate at the base of a steam press, holding textiles for pressing.

Bumping (Air Bumping)

The separation of spent diatomite from tubular filters using compressed air or agitation, as opposed to backwashing.

Button Trap

A dry cleaning machine component that blocks objects (e.g. buttons, coins, lint) from entering the solvent pump behind it.

Carbon Adsorber

A dry cleaning machine component that adsorbs vaporized solvent on a bed of activated carbon attached to the air outlet.

Cartridge Filter

A common replaceable filter made of filter paper, clay, and carbon in a metal shell.


The sorting of textiles into appropriate groups for high-volume treatment, based on color, material, finish, trim, and weight.

Coin-Operated Dry Cleaning Machine

A self-service dry cleaning machine that launderettes provide for customer use. Most coin-operated dry cleaning machines use cartridge filters as opposed to powder filtration systems, and they provide pre-charged solvent for 8-10 lbs of textiles.

Cold Spotting Board

A spotting board that does not use steam.

Combination Machine

A transfer machine that washes textiles and extracts solvent before the process moves on to the tumbler.

Commercial Drycleaners

Drycleaners that primarily clean apparel, uniforms, and flatwork, as opposed to industrial cleaners.

Condensate Water

In dry cleaning, wastewater condensed from solvent vapors and steam.


A dry cleaning machine component that cools solvent vapors, converting them back into liquid. It connects to the still, vapor recovery unit, and muck cooker.

Constant Pressure Filter

A powder filtration system that retains its diatomite coating by applying constant pressure, as opposed to regenerative filters.

Contact Water

Wastewater that contains dry cleaning solvent after contacting it inside a dry cleaning machine.

Cooked Powder Residue

Hazardous waste containing solvent, carbon, diatomite, grease, lint, dyes, soils and water as a result of distilling and cooking muck.


(See: Muck Cooker)


The final drying step of cooling textiles in the drum via the refrigerated condenser to reduce creases and solvent concentration.


(See: Drum)

Deodorizing Cycle

The reclaimer’s final step, where outer air through the air inlet and exhaust valves removes solvent vapors to leave textiles dry and odorless.


A solution that regularly supplements dry cleaning solvent with strengthened removal of water-soluble soils.


An abbreviation of diatomaceous earth, the powder used to line constant pressure filters and regenerative filters in powder filtration systems. Spent diatomite is a component of muck.

Digestive Agent

A spotting solution made of digestive enzymes to fight organic stains (e.g. from food).


The boiling and vaporization of solvent in the dry cleaning machine’s still to purify it for a reusable water-solvent condensation headed for the water separator, leaving still bottoms behind as waste.

Diverter Valve

A valve that blocks outer air from entering a refrigerated condenser.


Container for textiles in a dry cleaning machine’s washer-extractor.

Dry Cleaning

The cleaning of textiles with dry cleaning solvent, as opposed to laundering or wetcleaning with water. Tags read “dry clean only” whenever textiles can only be drycleaned rather than laundered, but wetcleaning allows for the same textiles to be cleaned with specially-distributed water and none of the hazardous solvents. Dry cleaning operations move from marking to classification to cleaning, drying, and finishing in dry cleaning machines to assembly, and may involve commercial drycleaners, industrial cleaners, coin-operated dry cleaning machines, and/or dry drop-off facilities.

Dry Cleaning Solvent

A substance that dissolves soil, grease, and other stains on textiles without using water (i.e. by dry cleaning). Petroleum-based dry cleaning solvents and chlorinated solvents such as perchloroethylene present environmental and health risks, so eco-friendly wetcleaning operations are designed to avoid them.

Dry Drop-off Facility

A commercial storefront that transfers customers’ textiles to and from dry cleaning facilities elsewhere instead of operating on-site.

Dry-Side Spotting Agent

A spotting agent that fights non-water soluble stains from oil and grease, as opposed to wet-side spotting agents. They include perchloroethylene, amyl acetate, and petroleum dry cleaning solvents.

Dry-to-Dry Machine

A dry cleaning machine whose drum executes both the cleaning and drying cycles, releasing textiles dry and extracted while preventing solvent vapors’ escape.


(See: Reclaimer)

Drying Cycle

The removal of solvent from washed and extracted textiles by activating heating coils for as long as the drum’s rotation lasts.


The increased rotation of the washer-extractor drum after the wash cycle to separate solvent from textiles.


A centrifuge in a washer-extractor that extracts dry cleaning solvent from textiles after the washer has run its course.

Fifth Generation Dry Cleaning Machine
Filter Cake

(See: Muck)

Filter Powder

(See: Diatomite)

Fugitive Vapors

Vapors that dry cleaning machines and other equipment release into air outside. Inductive fans offset the releases of fugitive vapors.

Full-size Carbon Unit

An adsorptive carbon unit that holds solvent during the drying cycle, when vapors recirculate from the drum.


A gray tinge to textiles resulting from soil particles in solvent. Polishing filters are designed to offset graying.

Grid-Head Press

A stream press whose perforations vent steam and air on woolen textiles.

Halogenated-Hydrocarbon Detector

A detector that identifies and signals changes in perchloroethylene vapor concentrations.

Heating Coil

A dry cleaning machine component that heats air removed from the drum after perchloroethylene condensation so that the heated air can recirculate into the drum.

Hot Plate Evaporator

A dry cleaning machine component whose heating coil vaporizes wastewater from water separators and vacuum presses.

Hot-Head Press

A steam press whose solid stainless steel heats steam up to 300° F on silken textiles.

Hydrogen Peroxide

A form of oxidizing bleach commonly used against organic stains in spotting.

Inductive Fan

A dry cleaning machine component that fans air into the machine upon opening of the door to reduce releases of fugitive vapors.

Industrial Cleaners

Drycleaners that clean dust control items, work uniforms, and wiping towels, as opposed to commercial drycleaners.

Insoluble Soil

Common soils that water and dry cleaning solvent cannot dissolve, such as non-volatile residues, lint, earth, sand, hair, carbon, and cosmetics; dry cleaning machines’ lubrication separates insoluble soils from textiles when solvents cannot.

Loading Factor

The ideal weight of a textile load per machine, based on wheel or tumbler sizes, cleaning processes, and solvents.


The first step of dry cleaning: tagging or stamping numbers onto textiles for identification.


A device that disposes of wastewater into the air upon the water’s filtration through activated carbon or polymer filter.


Waste from powder filtration systems, comprised of diatomite, lint, water, grease, spent solvent, soil, carbon, and non-volatile residues.

Muck Cooker

A device that distills muck, evaporating it and recovering solvent.

Non-volatile Residue (NVR)

A waste product of solvent distillation, composed of fats, oils, gums, and insoluble soils.

Optical Brighteners

Chemicals added to detergents to brighten textiles’ color.

Oxidizing Bleach

A bleach that fights stains through oxidation, as opposed to reducing bleach; examples include sodium perborate, hydrogen peroxide, and sodium hypochlorite.

Percent Detergent

The detergent-to-solvent ratio in the dry cleaning cycle; most charged solvents are 0.5%-1.5% detergent.


The most common dry cleaning solvent due to its effective removal of non-water soluble soils, commonly abbreviated as “Perc”. Due to the solvent’s status as a known carcinogen and air and groundwater pollutant, eco-friendly alternatives to dry cleaning such as wetcleaning avoid the use of perchloroethylene .

Petroleum Dry Cleaning Solvent

A petroleum-based form of dry cleaning solvent, as opposed to chlorinated solvents such as perchloroethylene.

Polishing Filter

A filter under the main filtration system that reduces graying from small soil particles via miniscule pores between spiral cotton or resin-bonded fibers.

Powder Filtration System

Dry cleaning filtration systems that filter substances through surfaces lined with diatomite and activated carbon. Constant pressure filters and regenerative filters are the two forms of powder filtration systems, whose waste in the form of muck must be processed in the muck cooker.

Pre-charged Solvent

Dry cleaning solvent whose manufacturer added detergent beforehand, typically for use in coin-operated dry cleaning machines.


Layering diatomite onto a filter before contact with impure solvent to avoid clogging the filter when impurities emerge.

Protein Formula Detergent

A wet-side spotting agent utilizing digestive enzymes such as Lipase, Cellulase, Amylase, or Protease against cellulose, fats, proteins, starch, and oils.

Pump Strainer

A dry cleaning machine component that blocks lint and other particles from the solvent pump.

Rag Filter

A terry cloth filter that separates water and waste from distilled solvent transferred to the water separator, used mostly in petroleum dry cleaning solvent operations.


A machine that tumbles textiles in heated air to separate solvent from them. It condenses solvents and transfers them to the water separator.

Reclaiming Cycle

The first step of reclaiming, where hot air vaporizes solvent from textiles. Afterward, the reclaimer condenses vapors into reusable liquid solvent.


The routine re-use of solvents after vaporization, condensation, filtration and distillation.

Reducing Bleach

A bleach that fights stains through reducing, as opposed to oxidizing bleach; examples include sodium bisulfite, titanium stripper, and sodium hydrosulfite.

Refrigerated Condenser

A dry cleaning machine component that condenses solvent by chilling the vapors.

Refrigerated Condenser Coil

The refrigerated condenser’s coil, which condenses solvent by cooling.

Regenerative Filters

The most common powder filtration system that retains its diatomite coating in flexible tubes that require bumping to remove the spent powder, as opposed to constant pressure filters.

Room Enclosure

The enclosure of a transfer machine system, which holds solvent vapors before transferring them to carbon adsorbers.

Separator Water

A form of contact water that water separators produce during the solvent-water separation process.

Slide Board

A metal-lined board that transfers textiles from washers to extractors in transfer machine operations.

Sodium Bisulfite

A form of reducing bleach commonly used to remove chlorine bleach in spotting.

Sodium Hydrosulfite

A form of reducing bleach commonly used in spotting.

Sodium Hypochlorite

A form of oxidizing bleach most commonly used in spotting as a 1% solution.

Sodium Perborate

A form of oxidizing bleach commonly used in spotting, with acetic acid to lower its alkalinity.

Solvation Process

The circulation of air from the condenser to the water bath to the tumbler in order to recover solvent from the heated textiles.

Solvent Pump

A dry cleaning machine component that pumps solvent into the machine.

Solvent Relative Humidity

The percentage of water a solvent’s detergent holds per the detergent’s maximum holding capacity; a measure of a solvent’s moisture upon adding detergent.

Solvent Relative Humidity Instrument

An instrument that gathers solvent, air, and water vapors and measures their solvent relative humidity, adding water to the machine when levels drop below standard.

Solvent Turnover

The measurement of distilled solvent (in gallons) to be replaced for each 100 pounds of textiles drycleaned.


The selective use of water, detergent, steam, or chemicals as spotting agents to clean particular spots on textiles.

Spotting Agent

A chemical used in spotting operations, ranging from dry-side spotting agents to wet-side spotting agents to bleach.

Spotting Board

The steam-supplied space for spotting operations.

Steam Press

A finishing device that presses drycleaned textiles with steam. The steam press connects to the boiler and vacuum unit, the latter supplying steam while the former holds textiles in place via vacuum and collects condensed steam.

Steam Stripping

The recovery of solvent from still bottoms by releasing steam directly into them, lowering the boiling point and raising the distillation rate, as opposed to steam sweeping.

Steam Sweeping

The recovery of solvent from still bottoms by steaming them above the liquid surface, raising the temperature, as opposed to steam stripping.


A dry cleaning machine component that vaporizes, purifies, and recovers dry cleaning solvent.

Still Bottoms

The waste stills produce in distillation, containing water, soil, solvent, carbon, and other non-volatile residues; still bottoms resulting from chlorinated dry cleaning solvent are hazardous. Steam stripping and steam sweeping are two means of recovering solvent from still bottoms.


A surface active agent, or a chemical that reduces surface tension of water and oil molecules to maintain an otherwise unstable mixture between them.


A finishing device that reduces creases in textiles by blowing air and steam through them.

Sweetener Powder

A filter powder made of activated clay, which adsorbs dyes, detergents, fatty acids, and other impurities from solvent and prevents filter clogging alongside diatomite.

Synthetic Detergents

A solid or liquid detergent that can dissolve oils in water.

Tetrachloroethylene or Tetrachloroethene
Third Generation Dry Cleaning Machine
Titanium Stripper

A reducing bleach frequently used in spotting to whiten textiles and reduce dye stains via 10 – 15% titanous sulfate and 1- 4% sulfuric acid.

Transfer Machine

A dry cleaning machine with separate washing and drying units, typically a washer, extractor, and tumbler or reclaimer. The modern alternative is a dry-to-dry machine.

Tubular Filter

A cylindrical powder filtration system subject to precoating to avoid clogging.

Vacuum Still

A still specialized for distilling petroleum dry cleaning solvents through an internal vacuum.

Vacuum Unit

A dry cleaning machine component that gathers condensate from steam presses and spotting boards though a small vacuum pump and into a tank at the unit’s base.

Vacuum Water
Vapor Adsorber
Vapor Recovery Unit

An instrument that collects solvent vapors from dry-to-dry machines’ vents, transfer machines’ dryers, and ventilation outside of machines.


In dry cleaning, a machine that washes and agitates textiles in solvent (as in a washer-extractor).


In dry cleaning, a dry cleaning machine component that holds and rotates textiles in its drum contained in the outer shell that holds and distributes dry cleaning solvent. The machine serves the purposes of washer, extractor and, in the case of dry-to-dry machines, reclaimer.

Water Separator

A dry cleaning machine component that separates water from solvent via gravity. Water separators mediate solvent’s movement into storage tanks from muck cookers, vapor recovery units, stills, and dryers.

Water Soluble Soil

Soil that water dissolves, such as sugar, starch, syrups, salt, gums, and other food-related organic substances.

Wet-side Spotting Agent

A spotting agent that fights water-soluble soils, as opposed to wet-side spotting agents. They include water, alkalis, acids, ammonia, and synthetic detergents.


(See: Drum)

Wholesale Supply Facility

A commercial facility that supplies dry cleaning equipment or solvents to dry cleaning facilities.