The development direction of down filling machine is specifically reflected in the quality indicators and falling objects of the semi-products (all kinds of down) after opening. This includes: the type and quantity of impurities and defects in the semi-product; the structure and uniformity of the semi-product; the content of short fibers in the semi-product; the openness of the down fiber block, based on the average weight of the down fiber block, unit volume weight or The final speed of the free settlement of the down fiber block in the air is expressed; the falling matter contains the number of spinnable fibers.