In many hand woven rugs we see what is known as a Lustre or Luster Wash. Newcomers to hand woven rugs love the silky soft handle of the wool. The problem is that the Luster Wash is sever oxidation by powerful bleach. The rug will not last as long or wear as well and it is very risky to wash. I am not suggesting anyone Luster Wash a rug but I offer this technical bullitin to show the issues involved and also what the cleaners almost 60 years ago had to deal with.
You will see a number of outdated or dangerous chemicals described. I am not sure if it is wise to share outdated information but I decided to go with this as a historical snapshot of how things were done in yesteryear. Please do not be stupid, risky, or foolish:
NIRC technical bulletin T-73 from June 1956
Richard N. Hopper, Technical Director, National Institute of Rug Cleaning, Inc.,
How is the Chemically Washed Sheen Produced? Rough surfaced wool fiber, as pictured in Bulletin T-42, The Case of the Missing, Knots, can be made smoother, if a portion of its outer skin is dissolved away. This partial removal requires a very powerful chemical. Chlorine bleaches are just such powerful substances and are those most used in this connection. These bleaching agents are known to chemists and to trained professional cleaners as hypochlorites. There are three commonly used hypochlorites;
1. Chloride of lime or ordinary bleaching powder, about 35% active;
2. Calcium hypochlorite such as can be purchased under trade names such as H.T. H. or Perchloron, about 65 to 70% active ingredient.
3. Sodium hypochlorite, (Clorox or similar ordinary liquid laundry bleach) usually about five to fifteen percent active.
The first two are cheaper and easier to keep. These are not very soluble and must be converted to the sodium type (No.3) by addition of soda ash or modified soda before they are used. In any event, the bleaches described must be diluted to an exact concentration of below 0.8 percent available chlorine
Should This Treatment Be Applied in the Conventional Rug Cleaning Plant?
In the chemical wash treatment, the concentration of the bleach liquor and the action must be carefully and accurately controlled. If not, much damage to the fiber and the dyes can occur. Hence it should not be attempted in the usual rug cleaning plant unless special equipment and thoroughly trained and experienced personnel are available.
What Happens to the Dyes When the Rugs Are Treated?
After the "chemical wash", the rugs usually have a shiny surface appearance but some the dyes may be faded. These colors are often replaced by hand painting with special bright dyes. The re-dye job is not always .complete and the colors may bleed profusely afterwards unless great, care is taken when the rugs are cleaned.
What Causes the Loss of Sheen in Cleaning?
Loss of sheen after cleaning may be attributed to either one of two causes. In the first place, imperfect soil removal and poor rinsing may cause redeposit of soil and consequential graying. Secondly, if a true soap product is used as a cleaning agent, the calcium or lime deposited on the wool during the "chemical wash" will convert this soap to sticky dull lime soap curds like a bathtub ring. These are the "tattletale gray" deposits so widely publicize4 by detergent advertisements. Since these absorb rather than reflect the light, the sheen so highly prized disappears. Often these "lime soaps" remain on the rug from previous cleanings. This "sheen" can also be dulled by wear because the "chemical wash" probably weakens the wool perceptibly. The smooth fibers are then apt to become shorter as the smooth ends break off. This in turn produces a less glossy general appearance.
Regardless of the cause of the loss of sheen, further chemical washing in our opinion is not the safest answer. We believe that careful and thorough washing and rinsing produces the most beautiful restoration of all. One method of accomplishing this follows:
A Recommended Cleaning Procedure:
1. Inspect your Orientals carefully on receipt. Dont guess. Test each color, especially in the brighter figures for bleeding to:
a. your detergent solution,
b. plain water,
c. water containing a little "Calgon” or "Sequestrene",
d. water containing acetic acid (about one ounce of 56% to a gallon of water) and finally,
e. a mixture of the acetic acid and your detergent solution. This last is necessary in case you have bleeding to the detergent solution and you must keep the dye "set" while the rug is wet.
2. The washing detergent is an important factor. Avoid true soaps. Instead of soaps, make use a syndet solution as follows:
- A fatty alcohol sulfate anionic detergent * 3 lbs.
- A nonionic detergent ** 1 lb.
- A water softening agent (Sequestrant) *** 1 lb.
- Water 100 gallons
- See mimeographed supplement to this Bulletin for further information. (N.B. I skipped the supplement since I see no point in dredging up old products which are best left in the past.)
3. Dust each rug carefully. Ten percent or more of the weight of the rug may be air removable dirt, so get that out first even if you have to run the rugs twice through the dusting machine.
4. Clean the rug by the methods you customarily employ. Any conventional plant equipment such as the rotary brush, the automatic reciprocating brush machine or the pressure jet machine, if carefully and correctly operated, will do a satisfactory job. Some of our members also wash these rugs successfully by modified laundry wheel methods. In this case, alkaline soaps or syndets should be shunned and the washing should be done in cool or cold water at a high level. The rug should be removed from the wheel and extracted as soon as possible and while still draining.
The main thing to avoid is prolonged exposure to the wetting where one part of the carpet can be in contact with another or where concentrated drainings may flow to another part of the fabric. Never let a chemically washed oriental lie around wet on the wash floor. Handle it fast!!!
If in your inspection tests you find a tendency for a dye to bleed to your detergent or plain water, but not to the acetic acid, you should saturate the rug with a solution of about one to one-and-one-half quarts of 56%acetic acid to ten gallons of water.
Apply the detergent solution recommended and brush or jet scrub. Rinse and rescrub. Again rinse at least three times rapidly. For floor cleaning, a wooden or rubber bladed squeegee should be used for removal of the spent suds and rinse water between sudsings and rinsings. These rinses are important and unless you flush the rugs carefully and enough times, they will still come out dull. Where dye bleeding is likely use the acetic acid solution for each sudsing and for each rinse.
5. If necessary scrub the fringes with an extra application of detergent. In this case, don’t use the acid but take care that the suds do not contact the main part of the rug. Rinse the fringes well.
6. Squeeze roll wring the rug as tightly as possible without harming the fabric. If a vacuum is used instead, pull out as much water as you can, even if you must go over it twice. Don't delay handling; however. After the extraction, avoid rolling these rugs unless precautions are taken to prevent transfer stains. See our Bulletin T-1 "Handling Wet Rugs" for tips as to how to do this.
7. In some rug cleaning plants “high lights" are produced by changing the direction of the pile lay while the rug is still wet. Two ways of doing this are:
a. If a large centrifugal extractor is available, the wringing action alone will produce a random crushing effect that will show directional highlights.
b. If a squeeze roll type wringer is used ‘highlight’s" may be produced by folding the rug while still damp and letting it set for about a half hour. In this case, be sure to place heavy clean white paper between the folds so that bleeding between different colored' figures may be avoided.
8. If your poles are wide enough hang the rugs so that the fringes are at the sides instead of at the top and bottom. This will prevent much fringe discoloration.
9. If you extract water by vacuum and your rugs are quite wet, it may be necessary in case of bleeders, to dry them flat.
10. Before delivery, inspect for excellence in workmanship and for condition. You should be proud of the job.
Special thanks to Thea Sand for sharing NIRC technical bulletin T-73 from June 1956 with me.