T Monahan
Supportive Member
Over the years, I have had the privilege to engage in discussions with many authentic and serious rug washers about the use of chlorine compounds in Oriental rug cleaning. One such recent discussion prompted Robert Mann of Robert Mann Oriental Rugs to email me his observations. His response to me was the result of reading another test result that was conducted on di-chlor and its use in the Centrum Force Starr Wash Tub. With Robert's permission, please find copied below his remarks on the subject line of this posted thread:
Email dated 10/9/13
Dear Tom,
Thanks for the testing info. It's interesting stuff, and I'm happy to see it.
There are people worried about the use of chlorine compounds in Oriental rug cleaning, but I am not one of them. Various procedures using chlorine have been employed safely in the laundry and rug cleaning industry for a long time. New applications for different chlorine compounds (sodium chlorite and hypochlorous acid) are being developed and tested by rug cleaners today with promising and useful results. Sharing and discussing these results openly may lead to advances in our industry.
Current talk regarding the alleged dangers and 'recklessness' of the use of chlorine compounds in rug cleaning seems a partisan attack whose goals are obscure. Certainly one can damage rugs or wool with chlorine compounds, but the contention that the use of this chemical is somehow absolutely 'wrong' falls in the same category as arguments suggesting that 'cars kill people'. Everyone's tool box contains implements which, when inappropriately used, can cause damage. We live with realities of this sort everyday; skill, training, and well developed procedures make this possible.
Historically chlorine compounds have been employed for many years to 'finish wash' rugs. This practice is still common today and has been used on the majority of handmade wool rugs we see as cleaners.
What am I talking about? The finishing of wool rugs, wool yarns, and other wool goods often involves the use of acids and chlorine compounds employed together to alter the structural properties of wool at the fiber level. Traditionally this was known as 'chlorination of wool'; today industry often refers to these wools as having been 'super washed'. These common processes are used to control shrinkage and felting, make wools easier to dye, to increase sheen and improve the 'hand' of the fiber.
In the finish washing of new rugs this process is also used to reduce color intensity, creating a softened 'antique' look. The Oriental rug trade calls this 'luster washing' or 'antique washing' and in fact a majority of wool hand knotted rugs produced during the last 100 years or so have been washed this way to varying degrees. These are often very strong washes with surprisingly high concentrations of chlorine, sometimes applied at temperatures that dramatically accelerate their action.
A. Cecil Edwards, in his book "The Persian Carpet", suggests that chlorination and other 'antique washing' processes began around 1900 and evolved out of a need to supply the market with 'old looking' rugs when existing stocks were depleted by increased demand from the US and Europe. Fashion being what it is, the use of luster washing persists today because 'shiny' sells.
Whether this is a good thing or not is a matter of opinion. Certainly there are whole categories of rugs that may have been 'over washed'. Af-Pak Choobi rugs come to mind, as do 90-line Chinese. Taste and fashion have dictated the use of these washes to a large degree and as we all know, tastes change over time.
Most antique Iranian rugs we see have been chlorine washed, often very heavily. Nearly all Sarouks, Kashans, Kermans, etc. were luster washed when they passed through European traders hands, or after they landed in the US. Modern Iranian rugs are heavily washed too. The highly regarded Zollanvari Gabbe productions that have been popular in the US for twenty years now have a very strong wash used on them. In fact the use of these washes is so pervasive that when we see the occasional rug that was not chlorine washed it looks so different that we are surprised by it's appearance.
I personally had the opportunity at the Woven Legends company to write the formulations for their washes for over twenty years. We did extensive testing on new production lines. Weaker washes, stronger washes, continually monitoring the results. Pretty much everybody else in modern production did the same; India, Iran, China, Pakistan, Romania, Turkey. I observed this personally. Nepal is an exception to the rule; producers there did not luster wash themselves, but rather sent goods to Knecht AG, a large washing company in Switzerland, a practice now discontinued because of cost and changes in fashion.
The washes used at Woven Legends were average in strength by industry standard. '150ml available chlorine' liquid bleach would be added to the wash tub at a rate of 3.5% of water weight and then boosted with .3% caustic soda by weight. That is about 245 liters of liquid bleach, about 30 gallons, in 7000 liters of water. The wash tub was fitted with a steam jet that brought run temperatures to 40 degrees Celsius, about 104 F. The rugs were run at this temperature for twenty minutes, the tank drained, and run again for twenty minutes with fresh solution if a stronger effect was desired. Keep in mind that chlorine action doubles in strength for every 10 degrees Celsius rise in temperature.
It is worth noting that Woven Legends rugs were highly regarded and one of the hottest selling products in the high end hand knotted market for many years. Whatever they were doing, the public really liked it.
I have participated in the luster washing of rugs in India, Pakistan, and China as well. In all cases the wash formulations were stronger and more active than the washes used in Turkey.
Wash procedures of this sort have only a passing resemblance to the use of di-chlor in a wash tank. It is hard to compare the two but I would guess that luster washing formulations are easily ten to twenty times stronger than any effect di-chlor might have in a wash tank.
Getting back to the rancorous politics of the moment, the question one might ask is why would someone be so worried about the use of a mild water purifier when nearly every rug they handle has been treated with a range of very powerful chlorine based luster washing procedures already? Who benefits from the continual attacks on the testing and development of safe procedures using chlorine compounds? Are people reticent to speak openly for fear of attack? One once had to drag a soap box to a corner and shout to however many might assemble. The internet has changed all that, but it has not necessarily improved the content of what is being said. Since it is nearly impossible to ignore the objections of the few, I believe it makes sense to present other views for people to consider.
Best wishes,
Robert
Email dated 10/9/13
Dear Tom,
Thanks for the testing info. It's interesting stuff, and I'm happy to see it.
There are people worried about the use of chlorine compounds in Oriental rug cleaning, but I am not one of them. Various procedures using chlorine have been employed safely in the laundry and rug cleaning industry for a long time. New applications for different chlorine compounds (sodium chlorite and hypochlorous acid) are being developed and tested by rug cleaners today with promising and useful results. Sharing and discussing these results openly may lead to advances in our industry.
Current talk regarding the alleged dangers and 'recklessness' of the use of chlorine compounds in rug cleaning seems a partisan attack whose goals are obscure. Certainly one can damage rugs or wool with chlorine compounds, but the contention that the use of this chemical is somehow absolutely 'wrong' falls in the same category as arguments suggesting that 'cars kill people'. Everyone's tool box contains implements which, when inappropriately used, can cause damage. We live with realities of this sort everyday; skill, training, and well developed procedures make this possible.
Historically chlorine compounds have been employed for many years to 'finish wash' rugs. This practice is still common today and has been used on the majority of handmade wool rugs we see as cleaners.
What am I talking about? The finishing of wool rugs, wool yarns, and other wool goods often involves the use of acids and chlorine compounds employed together to alter the structural properties of wool at the fiber level. Traditionally this was known as 'chlorination of wool'; today industry often refers to these wools as having been 'super washed'. These common processes are used to control shrinkage and felting, make wools easier to dye, to increase sheen and improve the 'hand' of the fiber.
In the finish washing of new rugs this process is also used to reduce color intensity, creating a softened 'antique' look. The Oriental rug trade calls this 'luster washing' or 'antique washing' and in fact a majority of wool hand knotted rugs produced during the last 100 years or so have been washed this way to varying degrees. These are often very strong washes with surprisingly high concentrations of chlorine, sometimes applied at temperatures that dramatically accelerate their action.
A. Cecil Edwards, in his book "The Persian Carpet", suggests that chlorination and other 'antique washing' processes began around 1900 and evolved out of a need to supply the market with 'old looking' rugs when existing stocks were depleted by increased demand from the US and Europe. Fashion being what it is, the use of luster washing persists today because 'shiny' sells.
Whether this is a good thing or not is a matter of opinion. Certainly there are whole categories of rugs that may have been 'over washed'. Af-Pak Choobi rugs come to mind, as do 90-line Chinese. Taste and fashion have dictated the use of these washes to a large degree and as we all know, tastes change over time.
Most antique Iranian rugs we see have been chlorine washed, often very heavily. Nearly all Sarouks, Kashans, Kermans, etc. were luster washed when they passed through European traders hands, or after they landed in the US. Modern Iranian rugs are heavily washed too. The highly regarded Zollanvari Gabbe productions that have been popular in the US for twenty years now have a very strong wash used on them. In fact the use of these washes is so pervasive that when we see the occasional rug that was not chlorine washed it looks so different that we are surprised by it's appearance.
I personally had the opportunity at the Woven Legends company to write the formulations for their washes for over twenty years. We did extensive testing on new production lines. Weaker washes, stronger washes, continually monitoring the results. Pretty much everybody else in modern production did the same; India, Iran, China, Pakistan, Romania, Turkey. I observed this personally. Nepal is an exception to the rule; producers there did not luster wash themselves, but rather sent goods to Knecht AG, a large washing company in Switzerland, a practice now discontinued because of cost and changes in fashion.
The washes used at Woven Legends were average in strength by industry standard. '150ml available chlorine' liquid bleach would be added to the wash tub at a rate of 3.5% of water weight and then boosted with .3% caustic soda by weight. That is about 245 liters of liquid bleach, about 30 gallons, in 7000 liters of water. The wash tub was fitted with a steam jet that brought run temperatures to 40 degrees Celsius, about 104 F. The rugs were run at this temperature for twenty minutes, the tank drained, and run again for twenty minutes with fresh solution if a stronger effect was desired. Keep in mind that chlorine action doubles in strength for every 10 degrees Celsius rise in temperature.
It is worth noting that Woven Legends rugs were highly regarded and one of the hottest selling products in the high end hand knotted market for many years. Whatever they were doing, the public really liked it.
I have participated in the luster washing of rugs in India, Pakistan, and China as well. In all cases the wash formulations were stronger and more active than the washes used in Turkey.
Wash procedures of this sort have only a passing resemblance to the use of di-chlor in a wash tank. It is hard to compare the two but I would guess that luster washing formulations are easily ten to twenty times stronger than any effect di-chlor might have in a wash tank.
Getting back to the rancorous politics of the moment, the question one might ask is why would someone be so worried about the use of a mild water purifier when nearly every rug they handle has been treated with a range of very powerful chlorine based luster washing procedures already? Who benefits from the continual attacks on the testing and development of safe procedures using chlorine compounds? Are people reticent to speak openly for fear of attack? One once had to drag a soap box to a corner and shout to however many might assemble. The internet has changed all that, but it has not necessarily improved the content of what is being said. Since it is nearly impossible to ignore the objections of the few, I believe it makes sense to present other views for people to consider.
Best wishes,
Robert
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