Thus, under the mechanical stress at which the quill breaks, the fiber just bends. First, the feathers are cleaned. We use a water-soluble solvent like ethanol, which removes the soluble protein, dissolves the fat, and dries the feathers. The removal of the soluble protein and fats eliminates the food source upon which bacteria can grow. The smell associated with dirty feathers is from the soluble protein on the feather, and not from the feather itself.
Feathers have no more smell than down feathers.
When the feathers are dry, a high-precision shredder cuts the fiber from the feather, forming a mixture of fiber quill chunks. An airflow system then passes the mixture down a smaller cylindrical tube with air flowing up the inside of a larger tube. This produces turbulent flow at the exit of the inner tube. The chunks of quill under turbulent flow keep going down where they are collected and removed. The fiber under turbulent flow stops and changes direction, capturing the upward flow out of the cylinder.