The importance of fiber identification in fabric and carpet cleaning may be reflected in the fact that it usually one of the first topics in entry level classes like CCT or UFT.
Different fibers react differently to bleach, sunshine, soils, pH, and even oxygen, so the type of fiber you are cleaning will be a major factor in the process you choose and the cleaning agent you select. A substance that has no effect on one fiber type may destroy another.
Fiber identification is certainly not rocket science, and in some cases it even has a "Duh!" factor. Proper identification may require burn testing or chemical testing. Chemical testing is quite limited but very easy, requiring only the use of our sense of sight. The two most common chemical tests involve water and/or nylon.
Nylon will melt in formic acid at room temperature, while all other fiber types will not be affected. Olefin will float in water, while most other fiber types will sink in water. However, the presence of any surfactant in the materials used for the float test may skew the results, and can cause even olefin to sink. This uncertainty may cause you to use both formic acid and water for burn testing.
Burn testing is a bit more complicated, but a bit more certain. Burn testing makes use of your sense of sight as well as smell. Burn testing may be best performed with a complete burn test chart close at hand, but suffice it to say that you will be looking at the color of the flame as well as the color of the ash.
The action of the flame and the color of the smoke from the burning fiber are considered in the determination of the fiber type being tested. The smell given off by the burning fiber is also an indicator of the fiber type. For someone such as myself with no sense of smell, odor will not be a factor. There should have been a complete burn test chart in the textbook provided for your IICRC-approved class; make a copy of it for your brag book and use it to burn test fibers in the presence of your customer. Customers with degrees in fiber- or fabric-related fields like interior design are especially impressed by the cleaner who understands the burn test.
Unplanned losses of color, change of color and carpet shrinkage are some of the major types of damage that can be the result of improper or a total lack of fiber identification. Since the primary fiber used in Berbers is olefin, which is colorfast to bleach and UV light, the cleaner that cannot identify the type of fiber being serviced may be at a disadvantage in selecting the proper cleaning agents for the job.
Blends can be a tough call when trying to identify fibers. Being able to differentiate between natural fibers and synthetics will prevent most of the problems mentioned here, such as browning or shrinkage. There are fewer factors to consider in the natural vs. synthetic decision. A natural fiber such as jute or cotton will not melt, but will usually smolder somewhat and you will be left with just a dry crumbly, while a synthetic yarn will shrink from the flame, leaving you with a melted ball of plastic. The presence of a cellulose fiber such as jute, cotton or linen in a carpet or fabric which experiences slow drying may result in the development of cellulose browning, or it may cause the carpet to shrink. Synthetic fibers will not develop cellulose browning or shrinkage from slow drying, but they may develop soil wicking, ripples, buckles, or bulges.
The ability to correctly identify fiber types will not totally eliminate all of your headaches, but it will go a long ways towards reducing many of them. Maybe a little competition among crews or between boss and technician will motivate all involved to polish their skills. It may also reduce the number of "surprises" encountered in the field. Fiber identification may not be a skill you will use daily, but it will be of value in many situations. Think of it as another great tool in your toolbox.