Forming section for twin-wire papermaking machine
AssigneeInternational Paper Company
InventorJohn A. Means
Life of this patent
Estimating the term…
Abstract
The web-forming section of a twin-wire papermaking machine includes a plurality of sets of web deflectors. Alternate sets are disposed on opposite sides of a pair of forming carriers between which a water suspension of fibers is disposed. Each set of deflectors has a plurality of deflectors providing forming carrier guiding surfaces spaced along a gentle convex curve. The sets of deflectors are disposed to guide the forming carriers over a tortuous path through the forming section. The tension in the forming carriers presses the outer carrier against the inner carrier at each curve, expressing water from the suspension through the carriers. The expressed water is doctored off by the deflectors.
Claims5
In a web-forming machine having means for passing a water suspension of fibers between a pair of endless foraminous forming carriers supported under tension for movement over respective paths into and through a web-forming section, the improved web-forming section comprising
- A. a plurality of sets of deflectors disposed with alternate sets spaced apart along said path on opposite sides of said pair of forming carriers for guiding said forming carriers for movement together with the fibers therebetween along a tortuous path through said web-forming section, said path deviating from vertical by no more than about 0.25 radians,
- B. each of said sets of deflectors comprising
- 1. at least three deflectors spaced apart along said path and each having respective carrier-engaging surfaces for guiding said carriers for movement over a convex curve having an overall radius of curvature of at least about two feet with a change in direction at each deflector of less than about 0.05 radians,
- 2.
Dependencies are inferred from the claim text.