Valve bags vs. open-mouth bags: which to use

Both carry the same products, but they fill and seal very differently.

Open-mouth bags

Filled from a wide top opening and then stitched or heat-sealed. Flexible for many products, but filling is slower and needs a sealing step.

Valve bags

Filled through a small valve in one corner; the valve self-seals under the product’s own pressure. No top sewing, faster automated filling, and a clean, square, stackable result.

The rule of thumb

For free-flowing powders and granules at volume — cement, gypsum, flour, additives — valve bags win on speed and tidiness. For lumpy, sticky or low-volume goods, open-mouth bags stay more flexible. Many plants run both.