| 摘要 |
<p>The corrugated medium (11) and liners (13, 14) of a water-resistant containerboard (10) are each essentially completely impregnated by a liquid water-resistant agent such as wax which also uniformly coats the surfaces of the medium (11) and liners (13,14) with a layer (16A) sufficiently thick to cover the outer extremities of fibres protruding from such surfaces. The coating and impregnation is accomplished by feeding a flat untreated corrugated containerboard (10) in the direction of its open flutes (9) and in a continuous movement into and out of a hot melt bath (16) of the water-resistant agent at a controlled speed sufficient to force the liquid agent through the flutes (9) of the containerboard (10), so as to ensure exposure of all surface portions of the board (10) to the hot melt (16) for the same amount of time at the same temperature conditions. Upon removal of the board (10) from the hot bath (16), the board (10) is moved to a position with its leading edge uppermost to drain excess liquid agent from the board (10), which is then moved to a horizontal position (20A) to stabilize the depth of the liquid surface coating by the agent and thence to a vertical position (22,23) with the trailing edge uppermost to reverse the direction of final drainage while the board (10) is cooled to solidify the agent.</p> |
