The Valve-Type Paper Poly Woven Bag is a premium paper-plastic compound sack designed specifically for high-speed automated filling operations. The bag is fitted with a precision valve either at the top or bottom through which the product is filled using an impeller or air-packer filling machine. Once the bag is released from the filling spout, the internal pressure of the enclosed product causes the valve to automatically seal shut creating a clean, dust-free, tamper-evident closure without any additional sealing equipment.