Hey, one time I can respectfully disagree with Shawn! If the two are indistinguishable to the cleaner he can't possibly know why two seemingly identical nylon carpets will clean up differently. Say he's the type of cleaner that buys into current marketing hype and uses oxidizers on everything but wool, that ignorance might make him look pretty silly when he has to talk with a mill rep.

Chemical producers always guarantee that if you use their product as advertised, they'll buy any carpet you screw up, right? :roll:
Compared to type 6.6, type six:
- More readily accepts dyes.
For this reason it works well for post-production dying, whether with a pattern or a solid color. In addition to being a cheaper to produce fiber, this makes for carpet that can be sold at a lower price point than the harder to dye 6.6. "Builder's spec" nylon is always type 6.
- More readily accepts stains.
Lots of "stains" that can be removed from type 6.6 quickly become part of type 6. If you can't a get a coffee stain out of nylon carpet you can be reasonably sure that's a type 6. Keeping the Teflon "refreshed" makes a bigger difference in keeping up the appearance of type 6 nylon.
- More readily loses dyes. Ever have a leaky fitting or a usually dependable spotting procedure take the color out of a nylon carpet? That's type 6. Ever have seen oxydizer fading on a nylon carpet? Type 6 again. (Of course, no one here will admit to having ever seen this. :wink: )
- Is a softer fiber, so even if dyed in-solution is more easily permanently discolored by grit in traffic areas. Again, re-applying a fluorochemcial protectant will make a bigger difference over the life of this carpet.
Commercial carpet specifiers use type 6 if the customer is driven by price, or if the carpet is going into an upmarket retail location that will tear it out in three to five years just to keep the look "fresh." They will use type 6.6 in installations that get heavy use or the client wants the carpet to last as long as possible and aren't inclined to buy wool.