PURPOSE: To pack a commodity by a full automatic mechanical process from filling to packaging by a method wherein on a tray which travels in a loop is put a sack in such a manner as to have the free end of the tray inserted into the open end of the sack when the tray has traveled a certain distance from the point of loading the tray and the sack packed with the commodity is withdrawn from the tray.

CONSTITUTION: From vibrating hoppers 25 is discharged a commodity 5 comprising rows of slender objects onto each of trays; on each of these trays 36. When it has traveled by a certain pitch, is put manually or by a suitable mounting device a sack 6 of polyethylene or the like in such a manner as to have the tray inserted into the sack through the open end. The tray 36 holding a load of commodity 5, that is, rows of slender object, and the sack 6 by insertion is made to travel along a looped course by a driving sprocket 59 and a driven sprocket 60 engaging with a chain 53 and driven by a drive motor 8; at the opposite side the commodity together with the sack is raked out and drawn off the tray manually or by a special raking device. Kidney beans 3 as a commodity can be packed in rows of slender objects in an orderly manner. Heat-sealing of the sack at the opening completes the packaging. This packing process enables packing a specified sack, for example, of polyethylene with slender objects as a commodity each pack by the prescribed weight and neatly and assuredly.