Bleaching fringes or frons at the edges of carpets, carpet cleaning is one of the services, even though theysubsequently washed after washing the carpet, and treated in a completely different way.
If they are in good condition and not damaged, they can whiten in order to get the white color, of course,if they were white. Otherwise, if you have colored or damaged they are just washed with mild detergent and rinse,and sometimes just vacuum cleaned.
Can I Whiten my Rug's Fringe? Losing Fringe!
The answer is yes, but with a possible downside. Whitening fringe is a fairly inexpensive process but could have long term consequences to the value of your rug. Often after washing a carpet, the fringe is bleached to accent the overall wash and by producing a fresh look to the fringe itself.
Although cotton fringe has been used in carpets for many years, nothing has changed about the fiber itself. As organic matter, cotton fibers degrade under the use of harsh chemicals such as bleach. While bleach won't necessarily disintegrate your fringe, the use is not recommended as final results are fairly inconsistent. If fringe is over-bleached, or the bleach had not been neutralized/properly washed out, it will cause fringe deterioration. Remember, on an oriental rug, the fringe is not just decoration, it is a continuation of the rug's structure. Should excess bleach be absorbed past the visible fringe, the structural integrity of your rug may be compromised. Unnecessary loss of fringe as described can decrease the value of your rug. If the fringe is worn, the rug looses its buffer, and knots towards the ends can easily be lost.
To test the fringe yourself, take one single tassel in an inconspicuous area. Don't yank hard, simply apply slow and steady pressure. If your fringe is in good shape, it will not release even if strong force is applied. Conversely, if the tassel releases with little to slight effort, the fringe is not in good shape. This single tassel popped off a split second after the photograph was taken.