laundering by hand on scrub boardTechnology has had a tremendous impact on our lives, including the way our clothes are cleaned.  The first washing machine was invented by Sir John Hoskins in 1677; it used a wheel and cylinder to squeeze water through bags of linens.  Rollers, stirring sticks, washboards   and hot irons used for pressing all led the way for the commercial laundry industry, which started in 1837.

vintage iron heated on stove for pressingIn 1848 dry cleaning was discovered by an owner of a textile dyeworks when he found that the liquid from an oil lamp dissolved fat and eliminated the shrinking, fading and discoloration caused by water washing.  By 1900, commercial laundries offered “wet wash services”, where they would clean the clothes and return them to be dried and pressed.  Over time, they did laundering, drying and starching, leaving only the pressing for the customer.

After WWII, the first synthetic cleaning fluids were developed, and eventually, a fast evaporating, non-flammable, colourless liquid was developed.  This liquid is called perchloroethylene, often referred to as perc.  Over 90% of the dry cleaning industry uses perc, and the development of this liquid has revolutionized the way clothes are cleaned.

Dry Cleaning – The Process

drycleaning machineSo, you’ve gone to your local dry cleaning store and dropped off your clothes, a few days later, you will pick up those items continuing with your day without thinking about what happens to your clothes when they are left.  To help you better understand the process, we’re going to run through what happens to your clothing once the items are dropped off.

In spite of the name, dry cleaning is not completely dry; fluids are used during dry cleaning.  In the early days of dry cleaning dry cleaning solvents such as benzene, kerosene, camphene and gasoline were used, all are very flammable substances, making dry cleaning a very hazardous business – at least until safer solvents were developed.  When perc was introduced, it quickly became the solvent of choice as it is a nonflammable synthetic solvent.  Other cleaning solvents have been added and others are still currently being tested.

Dry cleaning is not the answer to all oil and stain removal problems.  Sometimes, stains can become permanently embedded in fiber, or fabrics cannot withstand normal cleaning or stain removal procedures.  It is important for everyone, including drycleaners to read and follow the instructions on all the care labels attached to the item.

Although there are many various makes and models of dry cleaning machines, they all work on the same principle.  All machines consist of four basic components:

  • The holding or base tank
  • The pump
  • The filter
  • A cylinder or wheel

The holding (or base) tank houses the dry cleaning solvent.  The pump is used to circulate the solvent through the machine during the cleaning process.  The filters are used to trap impurities and the cylinder (or wheel) is where the garments are placed for cleaning.  The cylinder contains ribs to help lift and drop the garments.

Basic operation of the machine is easy to understand.  Solvent is drawn from the tank by the pump, the pump then sends the solvent through filters to trap any impurities.  The filtered solvent leaves the cylinder button trap and goes back into the holding tank.  This process is repeated throughout the cleaning cycle, ensure the solvent is maintained for effective cleaning at all times.

Once the cleaning cycle is complete, the solvent is drained and an extract cycle is run to remove any excess solvent from the garments.  This solvent is then drained back to the bare tank.  The rotation of the cylinder is increased during the extraction process creating centrifugal force to remove the solvent from the garments.

Once the items have finished being extracted of solvents, the cylinder stops and the drying process begins.  Warm air is circulated through the cylinder and helps to vaporize the solvent left on the clothing.  Solvent is purified with heat in a still and the vapors are then condensed back into a liquid, leaving behind all impurities in the still.  The clean solvent is then pumped back into the holding tank, ready for the process to begin again.

Before cleaning, all garments are inspected and separated by color, fabric, soilage levels, etc as the length of the cleaning cycle depends upon the type of garment and level of soiling.
Heavily stained garments may go through an additional stain removal process prior to cleaning.  Stains will be treated to their specific needs just prior to cleaning.

Much time and effort goes into the process of caring for your garments.

Wet Cleaning

Depending on the care label and the knowledge of your professional dry cleaner, wet cleaning may be the most suitable cleaning method for some garments.  According to rules established in 1972, clothing manufacturers only need to list one method of proper care, regardless of how many other safe methods can be used.  If a label states that the garment is “Washable”, it may or may not dry clean well.
The process of wet cleaning is similar to dry cleaning, in that it begins with pretreatment of spots and stains with the usage of special cleaning agents.  The biggest difference between the two methods is that additives and water are used in wet cleaning.  Extra precautions are taken to prevent loss of colour, shrinkage and fabric distortion.


Shirts and other items that say “Washable” on the label can be laundered.  Unlike home laundering, this process uses special detergents, additives and finished that help achieve cleaner cuffs and collars.  The end of the laundering process also includes professional pressing for a crisp clean finish.
If you request a method of cleaning that is not listed on your garment care label, your dry cleaner may ask you to sign a consent form as a way of verifying you accept the potential risk of cleaning the garment.