method for preparing multiple walled raina and monikerrosrainain

摘要

In a two-layer example, at least one component web (W1, W2) is made by layering two differing compositions of pulp suspension (M1, M2) with the help of a multilayer head box (10, 20). Web dewatering is carried out by opposite screens (11, 12) of the gap-former, such that each suspension of differing composition is dewatered mainly through only one of the two screens (11, 12). In a two-layer example, at least one component web (W1, W2) is made by layering two differing compositions of pulp suspension (M1, M2) with the help of a multilayer head box (10, 20). Web dewatering is carried out by opposite screens (11, 12) of the gap-former, such that each suspension of differing composition is dewatered mainly through only one of the two screens (11, 12). Screened waters (S1-S4) from each gap former, are collected separately in accordance with their origins, in two screened water tanks (40, 50). From these tanks, the waters are returned to their original suspension feed tanks. An independent claim is included for the multilayer sheet forming machine comprising two sheet forming units as described, each including a number of sheet formation- and dewatering elements (13-17, 23-27). Further sections (12, 22) join together the webs (W1, W2) produced in the sheet formation units to form a multilayer web (W). A screen water system, includes components (41, 42, 45, 51, 52) passing water from the suspension (M1, M2) and screens, to the vessels as described. Based on the foregoing principles, a number of preferred variants of the equipment are detailed.