Circular woven bulk bags

Woven as a tube, not sewn into one

A circular loom weaves polypropylene tapes into a continuous sleeve. The maker cuts the sleeve to the bag's height, sews a top panel or skirt to one end and a floor to the other, and attaches the loops. The walls never had a seam in them; the fabric simply goes all the way round.

Weaving the sleeve is continuous: one loom turns out long lengths that are later cut, printed and converted. Heavier tapes make a stiffer, tougher sleeve, finer tapes a softer, lighter one. Either way the wall is uniform without a lapped edge or selvedge to catch.

That leaves two sewn joints instead of six or more. Every stitch line is a row of needle holes and a place where powder can work out or contamination can work in, so fewer of them is the main reason to choose this build.

Tube width is fixed by the loom, so circular bags come in the footprints a maker weaves. That's rarely a limit for ordinary 35 in or 41 in bags, but an odd footprint for a special rack or a narrow container may be easier to build from panels.

Shape on the frame and in the stack

With no corners built in, a circular bag hangs on the fill frame like a sleeve and swells toward a cylinder as it fills. It is perfectly serviceable, but it takes more floor than a square bag of the same capacity and doesn't pack as tightly against its neighbours on a trailer.

For single-height storage and direct-to-unloader use, that hardly matters. For stacked warehouses, or freight where every inch of trailer counts, compare it with a U-panel or baffle bag before you decide.

Pallet overhang is the practical test. Set one filled circular bag on the pallet you actually use and look at its edges. A round body bulging past the deck snags on racking uprights and trailer walls; a slightly smaller diameter or a shorter fill usually cures it.

Fill, discharge and the liner question

Circular bags fill the same way as any spout top: neck over the head, clamp, fill to weight, tie. At discharge, the spout empties to the center. The smooth tube without inner seam allowances is a good host for a liner, and fitted liners that follow the bag's shape are a common pairing on food and chemical lines.

For a moisture-sensitive or very fine product, the full build might read: circular woven, coated, sift-proof top and bottom seams, fitted liner, spout top and spout bottom. Each item answers a different leak.

• Coating seals the weave
• Circular body removes the side seams
• Sift-proof stitching closes the remaining seams
• A liner keeps moisture out

How circular bags travel

Empty, a circular bag lays flat like a pillowcase and folds into bales as easily as any other. Bales ride on stretch-wrapped pallets, LTL for a pallet or two and a full trailer when the volume and your storage allow. Fitted liners can come installed or packed separately; tell us which your line prefers.

On delivery, check that loose liners match the bag size on the label, and keep each lot together. A liner cut for one tube diameter won't sit properly in another, and a mismatched pair usually shows up as wrinkles, trapped air and a slow, messy discharge.

Circular bodies also suit converters who print the outside, since no seam interrupts a logo, a lot box or a handling panel.

Writing the request for a circular bag

Say why you want it, usually sifting or hygiene, because that tells us which other parts to match. Add the product, spout sizes, liner, static type, whether it's a food line, the fill weight, how you stack, the monthly count and the delivery ZIP. We quote the bags and the freight as one load and confirm the date with the carrier.

Switching from panel bags? Run a trial pallet first. Operators notice how a round bag hangs on the frame, and warehouse crews notice how it stacks.