I have learned a lot in my research of artificial turf.  Polypropylene is the primary ingredient in artificial turf.  Nylon is not the way to go with artificial turf.  Polypropylene is soft and resilient and nylon is rough and hard.  Nylon has a lower melting point than Polypropylene, but neither melting point is of any concern.  Polypropylene fibers can be manufactured in many different shapes, designs and colors than nylon. The color selection is much greater than nylon synthetic grass offering realistic colors such as lime, field green, olive, emerald green, beige and bi-color green that aren't offered in nylon turf.  Don't fall for the lure of nylon synthetic grass as it is not nearly realistic, soft and durable as Polypropylene.