Nylon was at one time the king of carpet fibers (of course before that wool was the king but times change, eh?). Now you are seeing more and more polyester yarn being used in the manufacturing process. Why?
Well, price of course, silly! Polyester yarn is cheaper than nylon. So you will get a thicker feeling carpet, more luxurious, for less money than it's nylon counterpart. Of course you do lose performance with polyester but let's not confuse things with facts.
Nylon carpet will hold up better to wear! Period! Nylon is more resilient than polyester so it stands up better to higher wear. Most carpets don't wear out. They ugly out! People think because carpet is matting down that it is wearing out but that simply is not true. All carpet will mat down but nylon carpet will resist matting better and will recover and stand up with a good vacuuming.
Polyester on the other hand will mat faster and will not recover as easily. So potentially polyester carpet will "look" worn out faster than a nylon carpet will (all other things being equal such as construction, pile height, pile density, brand of nylon used etc).
Polyester yarn also can't heatset as well as nylon carpet. What is heatset? That's the process of heating up the yarn so it will retain it's shape. When a carpet fiber is made it will be twisted together with a number of yarns (like a rope is made by twisting together its fibers thereby creating strength). When the required amount of fibers are twisted together to make the carpet yarn, they are set with high heat to "set in" it's shape. This creates it's strength.
Unfortunately, polyester yarn cannot be heated with as high a temperature as nylon yarn can (because if it was it would melt). Because of this fact, the lower temperature used in the heatset of polyester yarn will cause it to be "not as strong" as nylon which can take a higher heatset level. Hence, nylon yarn is "stronger" than polyester yarn and will not unwind with repeated use as polyester can. This is the main factor in nylon's superiority when it pertains to wear and matting.
Remember when I said that carpets don't wear out as much as they ugly out? Because nylon doesn't unwind as much in the pivot points of the wear patterns it will perform better from an appearance standpoint.
So, nylon carpet yarn wins out on the performance scale when it comes to wearability, appearance retention and matting resistance.
To be fair, polyester does have stainability attributes that we will discuss on our next blog. Stay tuned!
Jeff Dean
Dover Floor Covering
http://doverfloorcovering.com
