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Priority to FI20227069ApriorityCriticalpatent/FI20227069A1/fi
Publication of FI20227069A1publicationCriticalpatent/FI20227069A1/fi
D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
D21F9/00—Complete machines for making continuous webs of paper
D21F9/003—Complete machines for making continuous webs of paper of the twin-wire type
D21F9/006—Complete machines for making continuous webs of paper of the twin-wire type paper or board consisting of two or more layers
D—TEXTILES; PAPER
D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
D21F11/00—Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines
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Nonwoven Fabrics
(AREA)
Abstract
Keksinnön kohteena on kuiturainan valmistuslinja (100) monikerroskuiturainan valmistamiseksi, joka kuiturainan valmistuslinja (100) käsittää muodostusosan (110), puristinosan (120) ja kuivatusosan (130), joka muodostusosa (110) käsittää perälaatikon (30) ja kaksiviiramuodostusyksikön, joka on muodostettu ensimmäisen, alaviirasilmukan (10) ja toisen, yläviirasilmukan (20) yhteisen juoksun väliin, joka puristinosa (120) käsittää kolme puristinnippiä ja joka kuivatusosa (130) käsittää ainakin yhden kuivatusryhmän, jossa on yksiviiravienti. Perälaatikko (30) on monikerrosperälaatikko ja monikerroskuiturainan (W) vienti puristinosalta (120) kuivatusosalle (130) on suljettu vienti.
1.1 Approach Flow System The forming process is preceded by an approach flow system that receives the aqueous fiber suspension, or stock, and prepares it for the forming process. Fibres are produced using kraft process or other pulping/bleaching processes (see Bleaching of wood pulps) and the proportions of fibers from different sources are blended here. Drained water from the forming process, known as whitewater, contains useful fibrous material and is continuously recycled back into the stock. Screens and centrifugal cleaners in the approach flow system remove oversize and heavy contaminants from the pulp. Additives such as minerals, pigments and dyes are introduced to make particular grades of paper and paper board. Air bubbles may be removed from the pulp suspension. The mass concentration, or consistency, of the suspension is kept low to prevent fibre flocculation prior to forming and is usually adjusted to a value in the range of 0.5 to 1.5%.