Proper and safe use of dry solvents in cleaningby Jeff Cross
One of the most common spotters used in carpet (and furniture) cleaning is the dry solvent.
When cleaning a room of carpet or a piece of furniture, most spots are easily removed with regular cleaning.
This is because proper preconditioning, agitation and rinse remove nearly all soils and spots.
Remaining spots are often oily and need more attention: The attention of a dry solvent spotter.
Which type of dry solvent spotter is best?
Safe solvents that work
Walk into any distributor of carpet cleaning products or open any catalog, and you will see several types of dry solvent spotters you can use in your cleaning (spot removal) process.
Remember, a "dry" solvent is any type of chemical that has no water content, and thus has no pH reading.
The word "solvent" describes anything that dissolves something else. That's why water is called the universal solvent.
Cleaning performance is definitely important, but even more important is safety.
The solvent you choose must be safe for the user and customer/facility.
Nearly all solvents on the market today are not only safe do to the due diligence of distributors and manufacturers, but also work well due to improvements in formulation.
What they remove
Remember that liquids like liquids in the same family. In other words, solvent spotters like or are attracted to oily-based spots, which include but are not limited to:
Many cosmetics (lip stick, etc)
How to address the proper use of removing these spots can be found by clicking here. The information in this link discusses removing the various classes of spots.
Types of dry solvents
Here we will discuss the most popular types of solvents, and then you can choose which type is best for your own company or facility. Factors to consider when choosing a solvent include the KB value (solvency), toxicity, flammability and residues.
The most popular dry solvent over the years is the volatile dry solvent.
Volatile, in the cleaning industry, does not refer to the explosive powers of the chemical, but instead refers to its ability to evaporate or dissipate rapidly.
1,1,1-trichloroethene was a hugely popular dry volatile solvent (KB value of 120, high solvency) until it was removed due to environmental concerns. Because it was very effective in removing nearly all types of oil-based spots, many tears were spilled when it was no longer available.
The best substitutes today are still chlorinated hydrocarbons, either trichloroethylene (KB 100) or perchloroethylene (KB 90). As with 1,1,1, there is slight toxicity but no flammability. These will no doubt leave the industry and it may be worth stockpiling them. They are available from dry cleaning suppliers and some cleaning suppliers.
Flammability becomes an issue with many other substitutes. This is measured as "flash point" and should be of great concern if it is less than 98 degrees Fahrenheit. This includes petroleum solvents like odorless mineral spirits (KB 30, flash point 134 F) Stoddard solvent (KB 30, flash point 98 F) and mineral spirits/paint thinner (KB 30, flash point room temperature).
Turpentine, xylene and other hardware store products are generally not used due to flammability and toxicity issues.
Acetone is another type of volatile dry solvent, but do not use it on furniture as it dissolves acetate fibers.
Isopropyl alcohol may be effective on some inks, but it is also highly flammable.
Your distributor will have a good selection of dry, volatile spotters to choose from.
The second class of dry solvents is the "non-volatile" variety. This means the solvent must be rinsed with either very hot water and detergent or by a volatile dry solvent.
Non-volatile dry solvents (NVDS) are simply petroleum-based or citrus-based spotters that do not evaporate or evaporate very slowly and can leave behind residues that will cause resoiling. Most of the early paint, oil and grease (POG) removers were coupled solvents and detergents with slow evaporation to allow working time on difficult to dissolve substances.
No doubt the most popular non-volatile dry solvent used today is based off the citrus product d-Limonene. It's a natural substance that still evaporates (but leaves a 2-5% sticky residue) and is a good choice for spot removal and as an additive to certain cleaning solutions (as a booster).
Because of the residue, it is very important to thoroughly rinse d-Limonene based products.
Gel solvents are popular in the NVDS category. They have a solvent-base of several types of chemicals, the most popular cited as d-Limonene. That's why most gel solvent spotters smell like citrus.
The benefit of gel solvent spotters is the solvent doesn't go into the backing of the fabric you are cleaning, and thus doesn't cause a delamination problem.
It also rinses fair to excellent with hot water and detergent, which means you don't need a volatile dry solvent for rinsing purposes.
Gel solvents can be blended with solvent compatible-based detergents, which give the gel a dual-capability: It can remove both water and oil-based spots. These gels often have a white or milky look and some require shaking before use, but most rinse far more easily than the straight gels because of the detergent component.
When faced with an unknown spot, try your dry solvent first.
Water on a textile creates a barrier, and the dry solvent will not want to penetrate.
If you have wetted a fabric, and determine you need to use a dry solvent spotter, remove as much moisture as possible before applying the dry solvent.
Some oil-based spots, when removed with your dry spotter, will still leave a dye stain behind. When this happens, use the appropriate bleaching action.
Never forget to use plenty of ventilation when using dry solvents.
Although most dry solvents are safe, avoid skin contact.
Never give samples to your customers or people in your facilities, unless they are specifically made for this purpose and properly labeled.