The use of Moisture in Drycleaning Systems
Almost since time began drycleaners have been afraid to use a controlled amount of moisture in the drycleaning system. I have always been curious as to the origination of this paranoia. About as close as I can come is the story that many years ago the cleaner had a bit of shrinkage in a load of clothes and the culprit was moisture getting into the solvent. The mositure frequently came from the still when it boiled over due to a steam or water leak in one of the coils. Another was that loads of water could get into the system was many, many years ago while using petroleum solvent there would be condensation in the huge storage tanks and the failure of the cleaner to drain the water from the coned bottoms of the storage tanks before allowing news solvent into the cleaning system. Without proper draining of the bottom of the cone shaped tank eventually a couple of gallons of raw water would get into the cleaning solvent and, raise filter pressure and ruin garments.
Yet a cleaner will go through several gallons of prespotter mixture a day (which is about 80% water) and think nothing of it. Yet they are afraid to put the moisture in the system when and while it will do the most good.
The reason for using moisture in the drycleaning machine is very simply when you understand that the soil on clothing is of three types; solvent soluble, water soluble and insoluble. Solvent soluble soil is composed of oils and greases and is a small amount of total soil on the garments that are being cleaned. Water soluble soil is the largest amount of soil a garment has picked up during wear and is called water soluble because it was wet when it got on the garment usually from perspiration, food, drinks, etc. The third type of soil is insoluble and is more or less, debris that is not readily broken down due to its hard nature. Think of insoluble soil as sand, dust particles, and other solid materials.
In order to remove oil and greased based stains an oil or grease needs to be put back into the stain, especially if it has dried. Water soluble soil needs to have water re-introduced back into the stain in order to help get it back into suspension so it can be flushed away.
Both of these types of soil, during the cleaning process get into the solvent through detergent (by lubrication, penetration and suspension) then must be removed either through distillation or the use of a filter powder which has an affinity for cleaning the solvent of odors, moisture, dyes and oils and greases, can be removed from the solvent by filter aids designed to remove moisture, oils, greases, dyes and odors by Tonsil Filter Aid or Krystal Klean. If contaminants are allowed to remain in the solvent they will discolor the solvent thus preventing sharp and crisp whites, pastels and even colored garments. If not removed from the solvent the contaminants build up and will allow bacteria to grow in a lighter than water solvent and produce odors as the substances breakdown. IF spotting chemicals such as ammonia, acetic acid, protein spotter and tannin stain remover are not flushed out prior to cleaning they will decompose and cause odors and contamination of the solvent also.
Insoluble soil needs to be removed through the filter as it is not soluble in the solvent. If not using Tonsil or Krystal Klean a carbon must also be introduced to remove the dyes that are released into the solvent. It is almost impossible to remove large amounts of dyestuffs from solvent through distillation due to its extremely fine nature.
In order to use a very slight amount of moisture in your drycleaning system you may use a prespotter and mix it 7 parts of water to 1 part of prespotter. After this is mixed add two ounces of the mixture for each ten pounds to be cleaned and put it into the wash basket before adding any clothing. To be on the safe side you should wipe the wet spot of the basket with a cloth towel before adding white or light colored garments. If the load is to be dark there is no need to dry the drum before putting the clothes in.
To help ease your minds about moisture synthetic fibers will hold a very small amount of moisture and in the range of two percent of their total weight. Specialty wool can hold up to 32% of their total weight in water and not even feel wet. Other garments will hold less but probably in the area of 8 to 15 % moisture without feeling wet. If the moisture is not there, the water soluble stain removal will be very low which increases spotting and re-runs. A lack of moisture will also allow static electricity to build up resulting in some surprising shocks while unloading the machine and attracting lint.
The choice is yours. You can either continue what you are doing or give the suggestion above a try and notice amazing results in the first load.
For additional information on solvents, detergents, spotting chemicals, solvent flow, and proper cleaning procedures please consult the Master Drycleaners Notebook available under “Books” or available from Cleaners Supply in either Spanish or English.
Questions? Let me hear them at firstname.lastname@example.org (Everett Childers)