How to wash my large 100% Polyester Fiber blanket?

Answer:

How To Wash Polyester Blankets

Is the white fleece part of it? Oh boy, I wonder if the red will run into the white? If a twin size you can use a washing machine. Double and larger you'll need to use a laundromat machine. Make sure it has a cold water wash cycle. Get the color grabbing cloths by Carbona, they would help grab any loose color in the wash. Use Woolite or really any laundry detergent would be fine as long as there is not bleach or color brighteners in it. Dry carefully in a machine for a bit and then hang up to finish drying. Air dying will stiffen fabric, but if heated first in the dryer, it won't happen.

Polyester is fine to toss in the washer. Regular everyday detergent is fine. Whatever you use on your normal clothes will work. Wash it in warm water and toss it in the dryer at low temperature. It's a tough fabric really so it's not too hard to clean.