You might be thinking; "why do I need to know anything about fibers, and yarns, and spinning, and all that technical jargon". However, it's not a bad idea to have at least a basic understanding of the difference between a staple fiber and a BCF fiber before you go shopping for your new area rug. Then you will also have a better understanding of such things as: why your new wool rug has the potential to shed for a while after its first installed. Or what the difference is between a natural fiber and a synthetic fiber, and does that difference play a role in how you care for your rug, or where you install it in your home.
A Staple Yarn:
Staple yarns are yarns that are produced through a process of gathering together a series of short fibers by spinning and twisting. Often wool is the first fiber that comes to mind when we think of a staple fiber, but there are several other natural fibers that fall into this category. In fact, all natural fibers, with the exception of silk, are staple fibers.
When a staple fiber is used to produce an area rug that has a cut pile finish, naturally some loose fibers will be released, as the cutting of the tuft may sever the end of the staple that is not anchored. This is often referred to as shedding, or pilling, and will often result in the accumulation of these fibers on the surface of your rug. You may also notice your vacuum cleaner bag is filled with these short staples. Better quality staple fibers shed much less because the fibers are longer.
You should be aware that this shedding does not affect rug performance, or long-term appearance, and that it will eventually stop with time depending on the frequency of vacuuming and the amount of traffic. Some manufacturers will tell you that this will dissipate within a few weeks, but my experience tells me that it can often last for a few months. If your rug is still shedding significantly after 5 or 6 months, then there is likely something wrong. Poor anchoring of the yarn to the rug backing may have occurred and your retailer should be contacted. This is very rare but should be noted.
The other type of area rugs that utilize staple fibers are flat-weaves and loop piles.The issue of shedding with these rugs is significantly less as the yarn is not cut, so the fibers remain intact.
Bulked Continuous Filament Yarn (BCF Yarn) :
Bulked Continuous Filament is different than a staple fiber. BCF yarns are synthetic man-made yarns (again silk being the exception), that are often very long filaments of fiber that are plied together to form continuous bundles of fiber. Instead of creating yarn from many short fibers like a staple yarn, BCF yarns are formed when a continuous filament is extruded as one long string. These strings are then twisted and heat-set together to form strands of yarn.
The long filaments are made by first loading a machine with polymer chips, which are then melted and extruded through a "spinneret" to form a filament(s), which are then cooled and conditioned, and finally wound.
Because BCF fiber is one continuous strand of fiber, it will not shed loose fibers like a staple fiber, and it is also less expensive than many of the staple fibers, making it an excellent option particularly for entry level rugs. BCF area rugs are often machine made and generally easy to care for and maintain.
Below is an excellent video which demonstrates the effect of fire on a variety of both natural and synthetic fibers.