Internal Valve Woven Bag
Internal valve woven bags are a type of valve bag made from polypropylene (PP) or polyethylene (PE) woven fabric. The top and bottom are fully stitched, leaving only one filling inlet for machine filling, known as the internal valve. The internal valve is hidden inside the bag body, usually located at the top or side of the bag.
After filling, the internal valve closes automatically. The sealing principle is that the packed material presses the valve closed from the inside, achieving an effective seal without additional operations. However, a small amount of powder leakage may occur during the filling process, which is a normal characteristic of this bag type.
Internal valve woven bags are mainly used for packaging powdered or granular solid materials, such as chemical powders and construction materials including cement, tile adhesive, and waterproof mortar.
Key Advantages
Good Sealing Performance
With the valve located inside the bag, the material is well protected from external contamination and moisture, reducing product loss during storage and transportation.
Neat and Stable Palletizing
After filling, the bags usually form a square, block-shaped structure, allowing neat stacking and stable palletizing. This helps maximize warehouse space utilization and minimizes the risk of stack slippage.
High Packing Efficiency
These bags are suitable for dedicated filling machines. There is no need to open the entire bag mouth, and materials are quickly filled through the valve under pneumatic or mechanical force, significantly improving packing efficiency.
Improved Environmental Performance
Some internal valve woven bags are made from recyclable materials, helping reduce environmental impact and meeting sustainable development requirements.
