| 摘要 |
A web-forming machine having first and second endless web-forming bands (12, 14) to receive stock in dewatering web-forming relationship therebetween, a source (18) for depositing stock on at least one said band (12), a first web-forming roll (22) located within the loop of the first band (12 or 14), the first and second bands (12, 14) passing over an arcuate portion of substantially 30 DEG to 60 DEG of the first web-forming roll (22) in convergent wrapping relationship therewith, there being a second web-forming roll (24) which is adjacent the first web-forming roll (22) and is located within the loop of the second band (14 or 12) so that the first and second bands (12, 14) pass over the second web-forming roll (24) in reverse wrapping relationship thereabout, and means for dewatering the stock characterized in that the first web-forming roll (22) is an open, non-suction roll and said bands (12, 14) wrap the first web-forming roll (22) so that the web is only partially formed in a first web-forming zone (31) adjacent the first web-forming roll (22), there being bi-directional dewatering of the stock at the first web-forming roll (22) to form the outer faces of the web while leaving at least an interior portion of the web unformed, and there being reversal of internal water flow through a portion of the thickness of the web at a further web-forming zone (32) adjacent the second web-forming roll (24), whereby to complete the formation of the internal unformed portion of the web. |
