Integrally serially connected top fillable bags have closed bottoms and sides and reclosable zippers from which pull flanges extend upwardly. The bags are separated along their sides including the pull flanges and continuous connecting strips connect the tops of the pull flanges and have guide ribs extending continuously therealong for engagement by supporting jaws which serve to open the serially connected bags one at a time at a filling station for filling. After the filling station, the filled bag is separated from the connected bags by removing the connecting strip from the tops of the pull flanges of the filled bags in line with or below the top ends of the separations between bags. The zipper of the filled bag is closed by a closing device such as pinch rolls through which the bag is pulled and the connecting strips removed.