Stretch hoods from LyondellBasell are used to unitize products stacked on pallets. Stretch hood equipment encases palletized goods in film tubing. The process begins when the film tube is cut and top-sealed (or not for some applications) from a roll feed, then stretched with four grippers to assist the film in fitting over the stack. The tube is then pulled over the stack and around the pallet. Once released, horizontal and vertical tension produces the necessary holding force.