Bag with membrane

Abstract

Bag for receiving bulk material and in particular cement, having a bottom seam and an opposite filling end wherein a receiving space is provided between the bottom seam and the filling end provided to receive the bulk material and formed by the bag wall. A de-aeration device is disposed in the bag wall between the bottom seam and the filling end for de-aerating the bag interior after filling. The de-aeration device comprises a semi-permeable membrane inserted in the bag wall. The membrane is air-permeable and water-impermeable.

1 . Bag for receiving bulk material and in particular cement, having a bottom seam and a filling end opposite, wherein a receiving space is provided between the bottom seam and the filling end for receiving the bulk material and formed by the bag wall wherein at least one de-aeration device is disposed between the bottom seam and the filling end in the bag wall to de-aerate the bag interior after filling, characterized in that the de-aeration device comprises at least one semipermeable membrane inserted in the bag wall and which is air-permeable but water-impermeable. 
     
     
         2 . The bag according to  claim 1  wherein the bag is provided with a head seam near the filling end. 
     
     
         3 . The bag according to  claim 2 , wherein the cross-section of the filled bag is nearly rectangular near the bottom seam and near the head seam. 
     
     
         4 . The bag according to  claim 1  wherein the bottom seam and/or a head seam comprise at least one weld seam and/or glued seam. 
     
     
         5 . The bag according to  claim 1  wherein the de-aeration device comprises at least one de-aeration component with the at least one membrane. 
     
     
         6 . The bag according to  claim 5  wherein the de-aeration component is disposed at the inner bag wall. 
     
     
         7 . The bag according to  claim 5  wherein the membrane consists of polytetrafluoroethylene at least in part. 
     
     
         8 . The bag according to  claim 1  wherein the bag wall consists of a plastic material at least in part. 
     
     
         9 . The bag according to  claim 1  wherein the bag wall is provided with gussets. 
     
     
         10 . The bag according to  claim 1  wherein the bag wall is provided with corner welds at the ends to allow a rectangular shape. 
     
     
         11 . The bag according to  claim 1  wherein the de-aeration device is disposed in the top wall. 
     
     
         12 . The bag according to  claim 1  wherein the de-aeration device is disposed in one of the narrow side walls. 
     
     
         13 . The bag according to  claim 1  wherein a de-aeration component is inserted into the bag wall by means of a seam wherein at least one opening is provided in the bag wall within the seam contour and wherein the seam is preferably configured as a welded seam or a glued seam or an adhesive area. 
     
     
         14 . The bag according to  claim 1  wherein a surface of a de-aeration component is less than 1% and in particular less than 0.5% of the bag wall surface, and/or wherein the de-aeration performance is higher than 0.01 liters/minute and in particular higher than 0.25 liters/minute. 
     
     
         15 . The bag according to  claim 1  wherein a de-aeration component comprises a holder frame surrounding the membrane.