I have looked at all of those vendors, Alibaba etc. and I am not finding the polyester that is being used by Patagonia, Nau, Osprey, etc. It is made from recycled PET and likewise can be melted back down chemically and spun into new fiber. I like durability and feel of the materialfrom the bags I have, but cannot find this material in small quantities.
I know that the nylon based cordura and ballistic cloth can get me close to the same ends, but I am working through the design exercise of making the whole bag one recycled and recyclable material.