Abstract: Apparatus and process for continuously and repetitively producing grocery sacks from a thermoplastic web at high speed, including particularly a folding operation involving applying grasping action to bag blanks formed from a heat sealed gusseted flattened tubular web of, e.g., high density polyethylene at the upper and lower portions thereof, respectively, causing said portions to be forwarded at differential longitudinal speeds whereby a rough folded bag bottom is formed. Preferably, the web is flexed as by introduction of air to the bag blank or sack to release the respective web faces and facilitate folding. A complete apparatus includes sealing, cutting, folding and pressing means and may incorporate printing and like ancillary features.

Abstract: An olefin polymerization process for the preparation of polyolefins having relatively low molecular weights and high melt indexes without loss of catalyst activity, utilizing a catalyst comprising a silica xerogel support having a pore volume greater than about 2.0 cc/g, the major portion of which volume is provided by pores having pore diameters ranging from 300 to 600 A and a surface area ranging from 200 to 500 m.sup.2 /g, and having deposited thereon a metal-containing catalytic material, such as chromium oxide, or other metal oxide. The process is designed for the preparation of polymers and copolymers of 1-olefins having a maximum of 8 carbon atoms in the chain and having no branching nearer the double bond than the 4-position, e.g., ethylene polymers.