Tricot is a common term for a knitted fabric. Usually fairly tough because its stretchy as a result of the knit pattern used to weave it.
If its a NorthFace bag I'd not worry about it being tough enough to wash. I'd never heard of noseeum dividers until I got into DIY sites... Commercial bags I've had have always been washed in large commercial washing machines and tumbled dry in commercial dryers... (Think large front loaders like at the local laundromat.) Take a very clean shoe or similar dryer ball to fluff the down as it dries...