Abstract: Bags containing a particle, powder or granule product are packed inside a wrapper formed from an elongated laminar wrapping of thermo-bonding plastic. The wrapping is sealed along longitudinal seams to form a sleeve. The bags of product are advanced on a transporter and pressed to a compact and even shape. A first bag is placed on a temporary support and the wrapping formed into a sleeve about the bag. The first bag is allowed to fall into the sleeve. The sleeve and bag are caused to ascend at the same time, and the sleeve is closed with seams during its descent. The process is then repeated for successive bags until the sleeve contains a set number of bags. The sleeve is then closed into a welded wrapping about the bags.