| 摘要 |
<p>The invention relates to paper sacks and applies to the closing of a valve sack mouth. The valve has a valve tube (12) which can be closed by heatsealing after the filling of the sack, and/or the valve has a closing flap (14) which after the filling of the sack can be folded over the valve mouth and attached to the bottom by heatsealing. Both the valve tube and the closing flap are of material suitable for defibration. The sack is thus made completely tight and can therefore be used for storing both material that must be protected from the outside environment and material that is harmful to the environment. The sack can also be made to be refiberable.</p> |
