| 摘要 |
<p>In order to meet higher demands for the properties of paperboard products an improved method and machine for the manufacture of paperboard are proposed according to the present invention in which a core (3) of a paperboard web is formed in a second forming unit (24) from a stock with a consistency of 1.5-6.0 % being supplied to the fourdrinier wire (6) of a fourdrinier former carrying a back layer (2) formed previously in a first forming unit (14), from a headbox (25) for high consistency stock and being dewatered upon being enclosed between the fourdrinier wire and a top wire (26) in said second forming unit, and in which an underliner (4) is formed in a third forming unit (34) of stock with a consistency of 0.3-1.4 % being supplied to the fourdrinier wire (6) carrying the back layer and core, from a headbox (35) for stock of low consistency. In both cases dewatering occurs under the influence of upper and lower tables (59, 60; 89, 90) in the loop of respective top wires (26; 36), said tables having slats (69, 74; 99, 104) separated by spaces (68, 75; 98, 105) and defining between them a passage through which a sandwich structure consisting of the fourdrinier wire (6), top wires (26; 36) and stock layer is conveyed and influenced alternatively by upper and lower slats so that the stock layer (3; 4) is compressed alternately from above and below, pressure pulses and shear forces thus being created in the stock layer. Furthermore, in the second forming unit for high consistency forming the stock layer (3) is kept in a fluidized state.</p> |
