No, the flour contains all parts of the hulled seeds, and there are no skins or other parts that need to be removed. If you use a high-speed blender to process the seeds, you'll end up with a very uniformly fine flour. However, other equipment may not produce such uniform results. Straining the flour is difficult, because a fine mesh sieve is too small for the flour to easily pass through. So if you use a coffee grinder, standard blender, or food processor to make sunflower flour, you may have to sort through the batch, removing larger, unblended pieces.