Treated pipe and elutration are acceptable starts. I would suggest that you also look at blower speed, air volume and line size. If you do not have a cooler and you are running at high velocitys, you will continue to have fines and streamer problems even after you treat the pipe.

If the product is virgin, treating the pipe will help. If the product has additives that will destroy the treatment. Some compounded Polymers will not cause streamers because they are self cleaning the line. If you are conveying with 50c-65c air (120f to 200f) you will possibly coat even treated pipe. Also look at velocity and try to stay below 6000 fpm terminal. It migh help to step the pipe at the end.

There are other variables based on copolymer and homopolymer materials.

You should have a study done to identfy all the problems so when you do spend capitol, you do so wisely.