Rug Cleaning 101: Products to Successfully Clean Area Rugs

This month we will look at the parameters of cleaning products to successfully clean area rugs – the fifth and last in the series Rug Cleaning 101. 

2011-12-12-1We have discussed why attending a rug-cleaning training course is important (education is inexpensive, while rugs are expensive); how our new industry standard states rugs should be cleaned off-site (the S100 Standard and Reference Guide for Professional Cleaning of Textile Floor Coverings is out now); the importance of a rug pre-cleaning inspection; and state-of-the-art rug cleaning equipment that is now on the market.  


Pre-Cleaning Inspection of Specialty Rugs


2005-07-12-1The most important step in rug cleaning occurs before the cleaning process begins. This process is the pre-cleaning inspection of the rug. 

 2005-07-12-2We can't always catch every problem in advance - we will have "surprises" - but be detailed in your documentation. Establish the condition of the rug prior to cleaning and record it.

The recording will require an inspection report. This is similar to what is done when cleaning upholstery and wall-to-wall carpet. All pre-existing problems with the rug need to be documented, with a copy provided to the customer. We want to explain to the customer their problems before cleaning - not give them excuses after cleaning. 


To begin, establish an approximate value and record it on the client's receipt. As a general rule, machine-made rugs will decrease in value, similar to an automobile. If the condition is not good, often the value will be approximately equal to the cost of cleaning. If you are new to rug cleaning and do not have a sense of rug value, ask the customer to establish a value. This may help to limit potential liability if a customer would claim you damaged her rug.

The next step is to establish the condition of the rug prior to cleaning on your inspection document. It is necessary for the rug specialist to know possible problems that can arise during cleaning. The new IICRC Rug Cleaning Technician class covers more than 50 items to look for, as does the ASCR three-day Rug School. The following are a few key items.

Rug identification is where the process begins. This comes from experience. It won't matter if I tell you to watch out for Pakistani Bokhara rugs because they often bleed or for Chinese needlepoint rugs as they may have cartoon markings if you do not know what these rugs look like. Attending a rug training course will help in this area. Advanced rug identification is covered in the ASCR Certified Rug Specialists course.

The first step is to determine if the rug is machine-made or hand-made. We will discuss certain problems of machine-made rugs in this article, and cover hand-knotted rugs next time. 


The key to determining machine-made vs. hand-knotted is to look at the back of the rug for the thin white warp yarns that run the length of the rug(Image 1). Machine-woven rugs can be manufactured on a Wilton or Axminster loom. Both will show the warp yarns. Often, a machine-made rug will have a label that will give country of origin and other information.

Just because a rug is machine-woven does not tell you it is inexpensive. Wilton-woven border rugs from Stark Carpet (Image 2) or Edward Fields can be very expensive.

When Wilton-woven border rugs are wet-cleaned, they may shrink. Even the slightest shrinkage will cause buckling. This is because the warps of the rug field are at a right angle to the attached borders. Once shrinkage has occurred, the only way to correct the problem is to take the rug apart and re-assemble it or try to block the rug. If you do not have repair capabilities in your company, limit your cleaning method to absorbent compound (Image 3). 


Image 5

Manufacturer or stencil marks can result in a real "surprise." Rugs from China or India that are tufted or stitched into a backing material may have the design drawn or stenciled on this foundation material. Careful inspection will not always reveal this hidden problem. Once cleaning has resulted in revealing this problem it is often too late to correct it (Image 4). When you see rugs with this type of foundation material (Image 5), the rug should be dried flat and face down, so any wicking dye bleed will go to the rug back and not be visible when the rug is returned to your customer's home. 

This type of rug construction can include rugs with a backing material glued to the rug, as in Image 5. The latex used often is full of marble dust (calcium carbonate), which is filler much like gravel is used in concrete. As the filler breaks down, you will see "sand" under the rug. This is a sign the rug is delaminating. The wool face yarns can outlive the cheap latex used in these rugs. Even if you do not see delamination, write it down, as you will often find it after cleaning.

Another persistent problem with these hand-tufted or hand-gunned rugs is the latex, which is not properly cured during the manufacturing process. As a result, the rugs have a peculiar smell. This odor may be noticed when the rug is new, after it has been in the home for a period of time, or after cleaning. I do not know of a process to correct this odor issue that is consistently successful.

Next time we will look at and knotted-rugs and some key problems to look for.



Fugitive Dye Removal


As promised in a past Rug Cleaning Specialist column, I will address the topic of removing fugitive dyes from areas rugs. The principles can be applied to any textile, but we will focus on wool rugs.

Despite the fact you test every color in the rug before wet cleaning, sooner or later you will have a surprise. Then what do you do? As all of you have sworn off cleaning specialty rugs on location, you can correct the problem and return the rug to the owner with out a claim.

bleaches-and-strippers-800The chart to the left shows the most common bleaches and strippers used to correct stains. Using these chemicals should always be considered a “last resort” solution— and we’re talking fix it or buy it time.

Oxidizing bleaches are unstable solutions that contain extra oxygen molecules. These extra molecules are continuously released and seek out and attach to the molecular structure of dyes. By doing so, the dyes are oxidized and chemically changed and can be rendered colorless. Reducing agents (also called strippers) work the opposite of oxidizing bleaches. Oxygen molecules from dye molecular structures are absorbed by reducing agents, causing them to be changed. So, oxidizing bleaches add oxygen to the dye, while strippers take away the oxygen. The result is the same from both chemicals—unwanted color is removed. First, let’s take a look at the bleach part of the list.

Hydrogen Peroxide at a 3% solution (the kind you buy for first aid) is a fairly safe agent and can be used for removing many spots that are not always “last resort” situations. Multiple applications are often necessary for complete spot removal. The chemical formula is H2O2; it gives up one oxygen molecule and returns to water leaving no residual. Hydrogen Peroxide can be accelerated by heat and ammonia. Several manufacturers sell a two-part kit of these chemicals for spotting (with the hydrogen peroxide a minimum 10% solution).

As you will recall from past columns, anionic acid dyes are used on wool. The high pH of the ammonia plus the peroxide will permanently damage these acid dyes. This type product is best suited for synthetic fibers where is has good results.

Chlorine bleach will yellow, weaken and can even dissolve protein fibers (silk and wool) so this material should not be used. I know a few plant cleaners have some for “special” problems, but it is best to never use it on wool rugs. Safer alternatives are discussed below.

Of the reducing agents, Sodium Bisulphate is the most commonly used. It has somewhat limited success in removing dye bleed, but is used in coffee stain removers, Haitian cotton cleaners and browning treatment. It is also used to neutralize chlorine bleach.

Sodium Hydrosulphite has been the standard fugitive dye remover for years. It is accelerated by heat and seems to work best at 160°F to 170°F and should be kept at this temperature while being used. This can be done by keeping the solution on a hot plate and monitoring the temperature with a thermometer. The product can be applied to the dye bleed area with a Q-Tip or a small paintbrush. Sometime ammonia is added to the solution to loosen the color, which is then stripped by the “hydros.” This process is more an art than science. Anyone who would like to attempt this process should practice on scraps of old carpet before working on a customer’s rug. It is an effective product, but go slowly and take your time. Be certain to rinse all chemical from the rug after dye removal. Then dry the rug flat with an air mover to speed drying.

If using Hydrosulphite, be certain the container is airtight and stored in a dry cool place and only dry scoops are used in the product. Damp Hydrosulphite can generate heat to the point of spontaneous ignition creating a fire if not immediately controlled.

Titanium Stripper is supplied as a dark violet liquid. This product works best on dye bleed from dark colors and stains from berries. It does not cause white fabrics to improve in whiteness. Heat is used to accelerate its action when necessary. You should not use an alkaline material with titanium strippers, as the combination will cause a black stain. Flush the rug thoroughly after dye stain removal and dry the rug flat with an air mover.

Strippers, which are blended products, are available under various brand names. A manufacturer may add citric acid or other materials to stabilize the strippers and then sell that product under their house name.

Illustration II-IV show how one of these products work. This powdered stripper is mixed in water with glacial acidic acid added. The material is painted on the dye bleed area of the Oriental rug as seen in Illustration II. Heat is used to accelerate the product. Illustration III shows a Jiffy Steamer in use and Illustration IV a Wagner wallpaper steamer being used. Both steamers seem to work well to provide controlled heat to accelerate the stripper.

Painting the product on the dye bleed area then applying steam allows the rug specialist to control the process. As this product works in an acid pH environment, there is less likelihood of damage to the wool fibers and removal of the “friendly” dyes. Before attempting to remove dye bleed or other difficult stains, practice on a scrap of carpet. This method seems to be the least demanding of the dye removal processes and produces good, consistent results. 

Pre-Cleaning Inspection of Hand-Knotted Rugs

In a previous article we discussed the pre-cleaning inspection of specialty rugs. This time we will look at potential problems with hand-knotted rugs.

Our industry standard is to avoid cleaning area rugs on-location. Hopefully all rug specialists are aware of this - but it bears repeating. We can, however, do our initial pre-cleaning inspection in the home. Be certain to inspect the rug front and back. If additional problems come to light back in the shop be certain to call the customer and inform them of what was found and document that information. 


Cleaning Wool Fiber Rugs


In several of the calls I have recently received from novice rug cleaners, they describe a rug only as “wool” or “silk.”

True, this is the starting point in determining what you are about to clean. However, as you develop your rug-cleaning skills, you should go beyond fiber identification and develop product knowledge, be it through training, attending seminars or reading rug-cleaning books.

Because fiber identification is the best place to start in the rug cleaning process, let’s look at the main fiber you will encounter: wool. 


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