Abstract: A container bag i.e. a flexible intermediate bulk container or FIBC (10) comprising a body of flexible material having lifting loops (18) across the corners thereof and baffles (22) to maintain a square configuration is characterized in that a liner (28) is provided sealed to the baffles (22). In accordance with the present invention baffles (22) are positioned within the liner (28) and are sealed to it before the liner (28) is affixed to the FIBC. In this manner, an FIBC can be produced which has both baffles giving it a square configuration and a liner to prevent ingress of moisture and air. The liner taking on the "square" configuration imparts it to the FIBC as a whole. The baffles may protrude from the liner and be attached to the FIBC walls, or they may be wholly within the liner. In either case, the liner (28) will preferably be impervious to air and moisture and may be formed from a polyolefin sheet material.

Abstract: A container bag (10 designed to be inflated before or during filling characterized in that a pressure relief valve (22) is incorporated or incorporatable into the bag body, the valve being connectible to a receiver for exhausted powder or pulverulent matter. The pressure relief valve can be set to give a desired inflation pressure in the FIBC but will permit air to escape above this pressure thereby ensuring that the stitching and seams of the FIBC are not over-stressed to the point of leakage. The valve is connectible to, and preferably is connected to, a receiver for any vented gases and entrained powder. Preferably the receiver is the filling silo (28) so that any expelled powder is returned for refilling.