Previous papers have described the effect of blade width, blade shape, wire tension, and wire wrap angle on the pressure pulses generated by a single blade in twin wire blade forming. This paper considers the influence of applied suction box suction on the same pressure pulse generation. As a result of applied suction, the forming fabric exposed to the suction is pulled down between the forming blades, producing arces shapes rather than the nearly linear fabric profiles that characterize a forming shoe without suction. THe suction also causes substantially more dewatering to occur from the suction Side(backing wire) than from the other side(conveying wire) of the web. This difference in dewatering causes more fibres to adhere to the backing wire side than to the conveying wire side, leading to singnificant two-sidedness of the paper sheet. all of these phenomena are modelled i na new computer code that has been developed to simulate suction box dewatering. The computer simulation developed here can also be used to calculate dewatering over the multiple blades comprising a forming shoe, without applied suction. This paper documents only the development of the computer code. In order to keep this paper to a reasonable length, discussion of the results of the computer simulation will be left to a companion paper.
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