U-panel bulk bags

One long strip and two sides

Picture a strip of woven fabric as wide as the bag and long enough to run up one wall, across the floor and up the opposite wall. Fold it into a U. Sew a separate panel into each open side and you have the body. A top panel or skirt goes on the rim, loops go at the corners, and the bottom gets a spout if you want one.

Because the floor and two of the walls are one piece, two of the four bottom edges have no seam at all. The weight on the floor is carried straight up into those two walls through the weave, and only the other two edges rely on stitching.

Corner loops on this build are usually sewn where a side panel meets the U, so each loop picks up two walls. Cross-corner loops wrap the corner itself and give a fork driver a wider opening to slide tines through. Either way, lift with all four.

Filling it square and emptying it clean

Hung from a fill frame by its four loops, a U-panel bag opens out close to square. Light vibration during the fill helps the product settle into the corners. With a duffle top, the skirt is gathered over the fill chute, then tied once the scale reads the target weight.

A discharge spout sewn into the center of the floor drains the product toward the middle. Lift by all four loops, lower the bag onto the unloader frame, and untie the spout inside the hopper's box. The continuous floor tends to hang evenly, which helps the spout sit centered.

Watch the first few fills on a new size. If product mounds high in the middle while the corners stay slack, the bag may be too tall for your density, or the frame's hooks may sit too close together. Small adjustments here pay off later in how upright the bags stand on the warehouse floor.

Folded and baled like the rest

Empty U-panel bags fold flat along their seams, go into strapped bales, and stack on wrapped pallets. The duffle skirt folds in on top. We confirm the bags per bale and bales per pallet with each order, since fabric weight and height change the count. One pallet travels LTL; regular volume to the same dock often justifies a full trailer.

Filled, these bags sit snugly side by side, and their flat walls let a forklift driver set them close on a trailer floor or in a bay. How an outbound load is secured, with straps, airbags or load bars, is the carrier's call rather than part of the bag spec.

Receiving crews can often tell a U-panel bale on sight: the flattened bags show two long folds where the U turns up into the walls. Count bales against the packing list, check the label on one bag per bale, and keep them flat and dry until the line calls for them.

Set against four-panel, circular and baffle

Four-panel bags sew four walls to a separate floor panel, so every bottom edge is a seam. They hold a square shape well. Circular woven bags have no vertical seams at all but round out when full and take more floor space. Baffle bags add internal panels across the corners so the filled bag stays truly square, which fits more product on a trailer or in a rack.

Most makers settle on a standard construction for each size. If four-panel bags have served you well, there's no reason to change. If seams along the floor have been splitting under heavy fills of barite, ground limestone or metal powder, a U-panel trial is worth running.

Telling us what you need

Most buyers don't specify the body build at all, and that's fine: give us the product, its weight per cubic foot, the fill weight, the top and bottom, and the stacking plan, and we'll quote a U-panel where it suits. Include the ZIP of the plant and how often you fill. We plan the load and confirm the day with the carrier before we give it to you.

Bring a photo of the bag you use now, its label, and a note of whatever annoys your operators: loops that twist, spouts that sit off center, walls that lean. Those details tell us more than a dimension sheet, and they help match a replacement that drops straight into your routine.