Circular Woven Bags: Seamless Strength for Heavy Loads

2026-11-06 10:25:00

When a bag has to carry maximum weight with the fewest weak points, circular woven bags are the answer. Zhejiang Saiqiang Plastic Co., Ltd. weaves them on circular looms as one continuous tube — no side seam, no stitched joint, just uniform strength all round.

Seamless construction, superior strength

Unlike flat woven sacks, circular woven sacks have no side seam that can split under load. Because the tube is woven in a single pass, the stress of filling, stacking and handling spreads evenly around the circumference instead of concentrating on a stitch line. That suits fertilizer, cement, feed, grain and construction materials.

Fabric weight decides the load

The most useful number when you specify a woven bag is the pp woven bag gsm, because fabric weight sets the woven bag load capacity. Our circular fabric runs 40 to 120 gsm, covering 5 kg to 100 kg packs.

Treat the table as a starting point: a dense or sharp-edged powder needs more fabric than a fluffy one at the same weight. An 80gsm woven bag suits 25 kg retail rice and sugar, while 100gsm pp woven fabric is the usual answer above 30 kg.

Versatile and customizable

As a circular woven bags manufacturer we offer custom sizes, fabric weight, lamination, inner liners and print. Add a PP coating and the weave closes into a moisture barrier with a smooth surface for up to eight colours; leave it off and you keep the lowest cost per bag with six-colour direct print. See our 40–120 gsm custom-printed tubular sacks for the full style list — back-sewn, side-gusseted, circular tube or valve.

Common mistakes when specifying circular bags

Three issues recur on first orders. Buyers choose grammage by price instead of fill weight, and find the limit only when pallets split in transit. Others forget UV stabilisation for bags stored outdoors. Some measure a bag flat, ignore gusset depth, then find a 50 kg fill no longer fits. Send fill weight, density, stacking height and storage conditions before we quote.

Quality you can measure

Every batch is checked for weave density, fabric weight, tensile strength, burst resistance and seam integrity, with drop tests from 1.2 metres. Optional UV stabilisation and moisture protection extend performance in demanding environments.

Global supply, reliable delivery

With more than 15 years of export experience and over 10 million bags per month, we supply heavy duty woven sacks and circular bags to buyers worldwide. Send your fill weight and target quantity and we will confirm fabric weight, closure and print.

Frequently asked questions

What is the difference between a circular woven bag and a flat woven sack?

A circular bag is woven as one continuous tube, so it has no side seam at all and the load is carried evenly around the circumference. A flat woven sack is woven as a sheet, cut open and stitched down the side, which creates a seam that becomes the weakest point under heavy loads. Circular construction uses slightly more fabric but removes that failure mode.

Which grammage do I need for a 50 kg fill?

For a 50 kg fill in a plain circular tube we normally start at 100 to 110 gsm, and move up to 120 gsm for dense or sharp-edged products such as cement, mortar or minerals. Lighter 80 gsm fabric suits 25 kg retail rice, sugar and feed. Confirm the rating with a sample drop test before you commit to a full production run.

Can circular woven bags include an inner liner?

Yes. A loose or attached PE liner turns the bag into a moisture and contamination barrier for hygroscopic powders, sugar and chemicals, and the liner can be food-grade where the application requires it. The liner adds a small cost per bag and is fitted before the top is sewn, so specify it together with the fabric weight at quotation stage.

What is the minimum order and lead time?

Our minimum order starts from 500 pieces per size and print design. Lead time depends on whether the bag is plain, laminated or lined, and on the number of print colours: plain bags ship fastest, while new print cylinders add preparation time. Share your target quantity and delivery port and we will confirm a schedule.