| 摘要 |
<p>A block bottom valve bag comprises an elongated bag tube having opposite ends. One end of the bag is folded to form a block bottom closure comprising first and second side flaps folded toward one another in overlapping relationship and adhered to one another, and a pair of end flaps extending inwardly beneath the side flaps at the opposite ends thereof. An elongated valve member extends between one of the end flap and overlapped side flaps. The valve member comprises an elongated flexible valve tube collapsed into a flat configuration having upper and lower walls in facing relation. The upper wall is operatively secured to the interior surfaces of the side flap and the lower wall of the valve tube is operatively secured adjacent one end thereof to the end flap and is detachably secured adjacent the other end thereof to the end flap. A reinforcing sheet member may be interposed between and adhered to the under surface of the side flaps and the upper surface of the valve tube.</p> |
