Search for dissertations about: "tensile index"

Showing result 1 - 5 of 46 swedish dissertations containing the words tensile index.

2. 1. Extended impregnation kraft cooking of softwood : Effects on reject, yield, pulping uniformity, and physical properties

   Author : Katarina Karlström; Mikael E. Lindström; Elisabet Brännvall; Kristofer Gamstedt; Anna Jacobs; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high kappa number pulp; extended impregnation; softwood; spruce; picea abies; pine; pinus sylvestris; uniform delignification; kappa number distribution; reject; yield; tensile index; tensile stiffness index; SCT; starch multilayers; mechano-sorptive creep; hygroexpansion; dimensional stability; eucalypt; birch; acacia; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Abstract : Converting wood into paper is a complex process involving many different stages, one of which is pulping. Pulping involves liberating the wood fibres from each other, which can be done either chemically or mechanically. READ MORE

4. 2. Modifying kraft pulping to produce a softwood pulp requiring less energy in tissue paper production

   Author : Hafizur Rahman; Per Engstrand; Mikael E. Lindström; Louise Logenius; Peter Sandström; Ulf Germgård; Mittuniversitetet; []
   Keywords : Modifying kraft pulp; tissue dewatering; polysulfide; sodium borohydride; tensile index; hemicellulose;

   Abstract : Modification of softwood kraft pulp by the addition of either polysulfide (PS) or sodium borohydride (NaBH4) has been shown to increase the pulp yield due to a higher retention of glucomannan.  The pulps with higher yield gave a paper with higher tensile index than reference pulp, especially at lower degrees of refining. READ MORE

5. 3. Development and evaluation of methods for control and modelling of multiple-input multiple-output systems

   Author : Fredrik Bengtsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Input-output scaling; Modeling; Fiber length; Tensile Index; Hold-input; Decentralized control; Gramian based measures; Delays; LQG control; TMP; Uncertain data sets; Unreliable communication links; MIMO systems; Control configuration selection; Linear regression; Freeness; Shives; CTMP;

   Abstract : In control, a common type of system is the multiple-input multiple-output (MIMO) system, where the same input may affect multiple outputs, or conversely, the same output is affected by multiple inputs. In this thesis two methods for controlling MIMO systems are examined, namely linear quadratic Gaussian (LQG) control and decentralized control, and some of the difficulties associated with them. READ MORE

6. 4. Strength Properties of Paper produced from Softwood Kraft Pulp : Pulp Mixture, Reinforcement and Sheet Stratification

   Author : Hanna Karlsson; Luciano Beghello; Lars Nilsson; Lennart Stolpe; Öyvind Gregersen; Karlstads universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; paper strength; tensile strength; tearing resistance; folding endurance; fracture toughness; handsheet former; stratify; multilayer; multiply; reinforcement; refining; beating; abaca; glass fibre; polyester; lyocell; softwood; bond strength; Cellulose and paper engineering; Cellulosa- och pappersteknik; Chemical Engineering; Kemiteknik;

   Abstract : For paper producers, an understanding of the development of strength properties in the paper is of uttermost importance. Strong papers are important operators both in the traditional paper industry as well as in new fields of application, such as fibre-based packaging, furniture and light-weight building material. READ MORE

7. 5. Fenton Pre-treatment of a Birch Kraft Pulp for MFC preparation

   Author : Pia Hellström; Helena Håkansson; Anette Heijnesson Hultén; Magnus Paulsson; Monica Ek; Karlstads universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Microfibrillated cellulose; Fenton chemistry; carbonyl groups; surface charge; total charge; Enzymatic hydrolysis; Tensile strength; z-directional strength; Chemical Engineering; Kemiteknik;

   Abstract : The potential to use acidic hydrogen peroxide in the presence of ferrous ions (Fenton’s reagent) as a pre-treatment when producing microfibrillar cellulose (MFC) from a fully bleached birch (Betula verucosa) kraft pulp was investigated and the properties of the produced MFC was compared to the properties of a MFC produced with enzymatic pre-treatment with a monocomponent endoglucanase (FiberCare® R). The mechanical treatment to MFC was performed in a laboratory colloid mill or in a pilot high-pressure homogeniser and the pre-treated pulps as well as the produced MFCs were chemically and morphologically characterised. READ MORE