Most discoloration in carpet is from contaminant residue, reaction with something coming in contact with the carpet, a weakening of the dye from a change in ph or from an atmospheric influencer such as ultraviolet light (the sun) ozone or nitrogen dioxide. The atmospheric influences are common everywhere but higher concentrations exist in certain geographic locations. A question posed the other day by a very good friend of mine who happens to be a carpet inspector was: “will indicator dye in carpet cause a discoloration which would be the color of the indicator dye?” He had recently inspected a very light, almost white, carpet where there was a rusty color tint evident after the carpet got wet from a water leak that ran down the edge of the fireplace and chimney. He thought that maybe indicator dye used in the carpet might be the reason for the discoloration. First let me explain what indicator dye is so you’ll understand the nature of his question.

Indicator dye is a light tint that’s put on carpet fiber to identify it during the manufacturing process. It is completely washed out during the initial rinse and preparation of the carpet in the dyeing process. Only white yarn is marked with an indicator dye. Once this very light tint is rinsed from the carpet it’s gone - it has no further influence in the coloration of the carpet. In fact, the indicator dye is very light and sparse - only random puffs of color are applied. Indicator dye is only used on white, undyed fiber for carpets that are to be dyed in the batch or beck dyeing process, the continuous dyeing process or on white yarn that is to be pre-dyed. Carpet being constructed with pre-colored yarn has no indicator dyes on it.

It is impossible for indicator dye to discolor the carpet after it has been manufactured because there isn’t any of it left in the carpet. As I mentioned, it is only applied very randomly and very lightly. It is not something that covers the entire yarn or carpet so there is no chance of ever seeing it in finished goods. Any discoloration of carpet is going to be caused by the addition of a foreign substance that imparts color onto the carpet or by something that strips color from the carpet such as an oxidizer (bleaching agent). Certainly a water leak in the home that runs down a fireplace and chimney is going to carry with it a multitude of materials that can and will discolor a light colored carpet. If the carpet is a light colored nylon the chances of the discolorant permanently affecting the carpet are high. If these materials are left to sit on the carpet for any length of time their affect can be irreversible. As I’ve stated before, you can’t be oblivious to the obvious. If there was no discoloration in the carpet prior to an event taking place that caused foreign materials to infiltrate the carpet such as a water leak, it’s the foreign materials that caused the discoloration, not anything in the carpet. There is nothing in carpet that will react or be activated that will cause discoloration.

You have to understand that the easiest fiber to color or discolor is nylon. Nylon is used in approximately 67% of all the carpet manufactured. The other two dominant fibers used are polypropylene (olefin) and polyester. Polyproplylene is virtually impossible to discolor. It is solution dyed and it hates water so nothing with a water base coming in contact with it is going to have any affect on it whatsoever. Polyester is extremely difficult to dye - color has to be forced into it. It too, is very unlikely to discolor from a foreign influence. The greatest influence to discoloration is the sun and it will fade anything, whether it’s carpet or your car. The darker the color the more sunlight it will absorb and the greater the likelihood of fading, unless sunlight is blocked or inhibited in some way.

Indicator dye is not something any dealer or consumer would ever know about unless they saw carpet going through all of the manufacturing processes. It is not something that ever makes it into the field and it certainly is nothing anyone should ever be concerned about relative to having any affect on a color change in carpet. The most important influence in a carpet’s purchase is its color. The carpet industry is very conscious of maintaining the integrity of that color and they use nothing in the manufacturing process that will compromise that integrity. Sometimes the colorfastness of the product may be an issue if the dye house messes up and this is easy enough to determine with testing. Indicator dye wouldn’t be something that would ever affect a carpets color.

We have had requests to hold another LGM Carpet Seminar but we need 25 attendees to conduct the course, which would be in November. If you’re interested in attending this educational opportunity contact us by phone, fax or E-mail and we’ll give you the details. You won’t be disappointed in your investment.