sweendogg said:
Speaking of chemistry fun.... I had a fun little stain caused by some moisture... O2 cleaned, but the orange/ yellow remained, tried some small spotters but knew I had to work a little advance spotting. Got the oxidizer out first.. turned it RED! Acid side spotter, back to yellow, reduced it and turned it brighter yellow.. ok acid rinse again, then quick dried it... Gone... I felt a little like a mad scientist. All I can figure is that the water stain was a result of the moisture interacting with a rubber exercise mat and as a result of the time and lord only knows how many voc's/ chemical reactions took place, it reacted with the indicator dyes in the carpet.
Scott or Shawn... or anyone who may have a lead, manufactures always say that certain carpets have pH indicator Dyes. Yet we as a retailer have never seen any product info indicating whether a carpet does or does not. It would seem like there is not a whole lot of information readily available to talk about these specific dyes from a chemistry standpoint. Yet it seems like these problems occur regularly and always seems to result in carpet mystery's. While alot of us know about and understand enough to correct the problems. It still seems to be a weak link in the industry knowledge base.
While carpet cleaners have long used the term "indicator dye" the manufacturing industry and the chemists who make carpet dyes don't care for the term. It is technically inaccurate.
The majority of dyes used for nylon carpet are acid dyes. They are applied under acid conditions and are most stable in an acidic or neutral environment.
Manufacturers or dye chemists would never intentionally select a dye that they knew would change colors. (Designers on the other hand... J/K) But every once in a while a dye would show up that became unstable when the pH moved away from its normal slightly acidic state. Because the result was similar to true indicator dyes used to coat pH paper strips.
This actually happened to a lot of carpet back in the 1960s and '70s. It is not nearly as common with newer carpet. The mills learned to test for this before using a dye on a lot of carpet. Since they feel they address the problem before the carpet gets into the retail store or someone's home, the mills don't see much reason to discuss it publicly.
So, the problem is rare on new carpet, sometimes seen on older carpet. Upholstery fabric manufacturers do not seem to be so thorough in testing for this phenomenon as carpet manufacturers. So, you may see it more often on upholstery.
Also rather rare, but sometimes is the result of a chemical reaction from various cleaning agent being used one after the other without rinsing in between. So you can see it if Mrs. Jones has used everything under the kitchen sink on it before you got there.
