Sökning: "web dryness"

Hittade 3 avhandlingar innehållade orden web dryness.

  1. 1. Dewatering aspects at the forming section of the paper machine : Rewetting and forming fabric structure

    Författare :Björn Sjöstrand; Lars Nilsson; Christophe Barbier; David McDonald; Karlstads universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rewetting; forming fabric; forming section; dewatering; web dryness; high vacuum suction box; vacuum dewatering; forming fabric design; numerical model; Chemical Engineering; Kemiteknik;

    Sammanfattning : The underlying motives of the research undertaken here are twofold: to obtain a deeper understanding of the dewatering mechanisms at the forming section of a papermaking machine and to develop numerical models that describe the flow through forming fabrics. More comprehensive knowledge of dewatering in the forming section allows suggestions to be made for improvements that reduce the amount of energy used in the process without affecting the quality of the end product. LÄS MER

  3. 2. The influence of stress variations in wet pressing

    Författare :Jörgen Gullbrand; KTH; []
    Nyckelord :press felts; roughness; smoothness; surface structure; uniformity;

    Sammanfattning : Two methods for the measurement of micro-scale stressvariations of press felt surfaces were developed. The methodswere based on a thin plastic film that was coated with anopaque stress-sensitive layer (Cronapress conversion film). Thefilm was compressed between a felt and a smooth surface. LÄS MER

  4. 3. Measurement and prediction of dewatering characteristics for mechanical pulpsusing optical fibre analysis

    Författare :Lisa Nordin; Per Engstrand; Mattias O´Nils; Annikki Vehniäinen; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical engineering; Kemiteknik;

    Sammanfattning : On‐line measurement of relevant fibre and pulp characteristics is necessary in order to increase productivity and to maintain uniform quality. The drainage properties within the wire and the press section are important factors since they affect the dry content after the press section. LÄS MER