These are fibers that originate from plants, animals and insects.
Most natural fabrics are very absorbent and require special care and skill, especially with the chemistry used in your cleaning process.
Protein fibers come from animal or their by-products (wool and silk). Sodium hypochlorite, also known as common household (chlorine) bleach, will soften and even completely dissolve protein fibers, causing permanent damage.
Protein fibers are naturally flame resistant, and normally will hide dirt and give fabrics a “warm” look and feel. For commercial applications, this is a consideration, as more architects and building maintenance managers are concerned with safety (flammability).
The fleece of a sheep or lamb; the most common natural fiber.
This three-part fiber (epidermis – the outer layer of the fiber – cortex and medulla) dates back to 2,000 BC. Wool has a natural crimp which makes it resilient (bounces back when crushed).
Use care with alkalinity. Most cleaning chemicals are alkaline. Damage to wool fibers can be caused by strong alkalinity and, in some cases, acidity. Detergents chosen for cleaning wool should be approved for wool fibers. Dye migration can occur with high pH.
When agitating wool fibers, be cautious. You can “felt” the fabric. Felting is the interlocking of the scales of the wool fiber and can make the carpet appear “slimy” during cleaning. Felting is also caused by high alkalinity.
Only use fluorochemicals (which lower surface energy of fibers, resisting water, oil and dry soils) as fabric protectors (Teflon, Scotchgard, various brands). Silicones block the pores of wool fibers, causing degradation (and rapid resoiling on any fiber).
Wool can be damaged and degrade and lose strength if left for prolonged time periods in direct sunlight.
Lamb wool is the first fleece that is sheered from a sheep that is eight months or younger. It is soft and fine compared to subsequent sheering.
Virgin wool is wool spun for the first time. Pulled wool is taken from slaughtered animals.
Wool hides dirt, so the carpet may have much more soil than first estimated.
Wool can sustain insect growth.
Bleeds (with moisture), crocks (with or without moisture, but with agitation).
Produced by the silkworm, it is the strongest of all natural fibers.
Silk fibers will easily watermark, so be sure to clean them evenly.
Texture distorts easily. Yellows with age. Spots easily. Damaged by alkaline and perspiration.
These come from plants or vegetation. Examples are cotton and jute. Rayon is regenerated cotton product (cheap and weak).
Only these fibers can have “cellulosic browning” from “lignin”, the substance in plant matter. Alkaline agents (see section on “chemistry” later in this manual) intensify this, and are not effective in removing browning. If you need alkalinity (such as ammonia), always neutralize with an acid (such as citric or acetic – vinegar).
Using too much water or not drying a fabric fast enough contributes to browning.
Cotton is highly absorbent which means longer drying times. These fibers are taken from the seed hairs of the cotton plant via ginning.
Jute is made from the stalks of the jute plant. It is used mostly as a secondary backing on tufted carpet and warp and fill yarns for woven carpet, and blended with sisal for mats. It has good dimensional stability and resistance to dry heat. But it may shrink and rot or brown with over wetting and improper drying. Natural fibers may take longer to dry because they are more absorbent then synthetic fibers.
Other natural fibers found in carpet and rugs include coir (coconut husk), seagrass and sisal (agave plant) – use low moisture cleaning with these fibers and wet the surface evenly.