A valve bag fills through a small opening (the valve) instead of an open top, which makes filling faster and cleaner on automatic spouts. The valve is the part your filling spout enters, and its construction decides how well the bag seals, how much dust escapes, and how it holds up during transport.
An outer valve is formed by folding the paper wall outward at the mouth. A finger-grip notch (a small cutout at the valve mouth) lets the operator pull the valve open easily before filling. It is the most common choice for cement, mortar and tile adhesive, where a simple, low-cost, dust-controlled valve is enough.
An ultrasonic valve is sealed by ultrasonic welding, so the valve paper is heat-bonded rather than merely folded. This gives a tighter, self-closing seal that resists reopening during handling — a good fit for fine, dusty powders and for bags that travel long distances.
A ring valve (or inner valve) adds a paper ring inside the mouth for a firmer, more stable opening that fills consistently and resists collapse. It is often chosen for higher-speed lines and for heavier contents.
We make all three with a standard 10.5 cm valve and can tailor width (35–48 cm), length and film liner to your product. Send us your filling line details and we will recommend the right construction.
Tell us your product and filling line — we reply within 24 hours.
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