US8801285B2: BULK BAG LIFTING LOOP ATTACHMENT SYSTEM
An improved bulkbag and method of making same,ofthe type having four sidewalls,a floorandtop portion,allportions stitched together to define the enclosure for the bulk bag housing material. The bag comprises a plurality offour wall panels,which each panel having a first and second vertical edge for sewing into the next adjacent panel along each edge. Prior to sewing thepanelstogether,to eachupper edge ofeach panel there is provided a first and second leg ofa lifting loop, so that each loop spans from the first edge to the second edge ofeach panel. The panels are then sewn together along their edges,and there is defined the bulk bag,with the endsofeach ofthe four lifting loops terminating at the stitch line between panels,which define the middle ofeach sidewall ofthe bag. There would then be provided a reinforcement ring at each point where a pair of legs of lifting loops are stitched to strengthen the attachment point. Further there would be pro vided at each lifting loop attachment points a dart,or stacker seam to define the bottleneck feature ofthe bag. The lifting loop attachment points would define a vertical seam along the surface ofthe dart defined by the stacker seam. Further there is provided a back tack stitching feature to prevent spread forces in the filled bag,and reinforcing strapping in the loops to provide a stiffening feature to the loops