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3. Mezinárodní studentský seminář 19.5.2005
In order to improve the contacts of students oriented to pulp and paper industry the Trade Fairs, Brno in cooperation with SPPC (Pulp and Paper Technical Association, Praha) enabled us to prepare at appropriate conditions a seminar of student's works in occasion of EmbaxPrint event, Brno 2005.
Cellulose protectors (CPs) are capable of suppressing cellulose degradation during ozone bleaching. This work is aimed at quantifying the performance of new six additives such as magnesium ethoxide, D-mannitol, cationic potato starch, 2-tert-butyl-5-aminopyrimidine, zirconium (IV) propoxide, methylhydroxyethyl cellulose. The effect of new additives (1% o.d. pulp) on ozone bleaching was investigated an oxygen-predeligniefied hardwood kraft pulp. The Z stage was carried out at the following conditions: 50 g o.d.p. mass pulp, the consistency 35%, pH 3, temperature 40°C, 4.45 l O2.min-1oxygen flow rate, 7.563 mg O3.l-1O2 ozone production and 0.3% o.d.p. ozone charge. Acknowledgements
INFLUENCE OF DRYING AND RECYCLING ON MECHANICAL PROPERTIES
Abstract The aim of this work was to determine the influence of the drying processes at different temperatures: 100°C and 140°C and also the influence of the numbers of recycling on the chosen mechanical properties of paper made from hardwood and softwood craft bleaching pulp. The changes in fibre structure conditioned by heating were documented by microscopy.
SEASONAL CHANGES OF THE SELECTED CHEMICAL CHARACTERISTIC IN WALNUT (J. REGIA) LEAVES e-mail: kchcht@vsld.tuzvo.sk
Many researchers are studying the interactions plant - herbivores. Pilot experiments showed, that water extracts of Juglans regia increase mortality of nun (Lymantria dispar). Because of this reason, it was needed to determine changes of selected chemicals during vegetation period: extractives by different solvents in Soxhlet, saccharides, tannins, nitrogen using micro-Kjeldhal method and ash. Results showed, that concentrations of all chemicals in walnut leaves extracts are in maximum from the middle of July to the end of August and they are in linkage with photosynthesis and breathing of plants.
THE COMPARISON OF DEACIDIFICATION METHOD OF NEWSPRINT PAPER WITH DIFFERENT ORIGINAL pH. tel.: ++421-2-59 325- 216
THE INFLUENCE OF RECYCLING ON THE SURFACE-STRUCTURAL CHARACTERISTICS OF PULP FIBRES. University of Pardubice, Faculty of Chemical Technology, Department of Wood, Pulp and Paper, Studentska 95, 532 10 Pardubice, Czech Republic tel./Fax:+420 466 038060
Abstract: The paper humidification is usual effect. The paper is attacked by air with the relative humidity higher than zero. The advantage of paper products is hygroscopicity but on the other hand causes some discrepancies of paper quality. These discrepancies hold down application of paper products. (The complete understanding of humidification process is necessary presumption for further paper expanse utilization.) The hygroscopicity of paper mass is very important behaviour especially for using of paper as packaging material. Basic equation of thermodynamics is Kelvin`s equation. From Kelvin`s equation is ensued the value of maximal equivalent cylindrical pore radius, which being occupied yet by condensed water in pore material. It`s possible to simply obtain characteristics of paper for example : value of maximal equivalent cylindrical pore radius, compactness, wet porosity, total porosity etc. The knowledge of strength and bonding properties of pulp fibres is key demand in well controlled papermaking process. Both of these demands it is possible to estimate by so called rheosedimentation method, i.e. by observation and evaluation of typical phenomenon of diluted pulp slurries with appropriate papermaking properties during their sedimentation. Both received the standard velocity of rheosedimentation, vs and final concentration of sediment, ck are characteristic parameters of pulp fibres depending on their geometry, structure and mechanical properties in wet state and bonding abilities. WRV is the last method which was used .The value of WRV is depending on bonding system. And then so on abrasion surface of fibres. Aim of our research work in near future will be the effect of recycling on the mechanical characteristics.
EVALUATION OF A T-BAR SCREEN Darmstadt University of Technology, Institution for Paper Science and Technology, Alexanderstrasse 8, 64 283 Darmstadt, BRD. tel.: 0 6151 164709
Abstract A new fractionation screen basket has been developed where the fibre suspension passes sharp 180° bends rather than slits or holes. Flexible fibres follow the 180° bend whereas stiffer fibres are more likely to follow the stream lines and therefore are rejected. There is a strong need for a reliable fibre flexibility measurement technique to be developed and used for benchmarking. The measurement technique is planned by measuring the deflection of fibres entering normal to a main channel flow from a capillary flow (T-junction). A flexibility parameter can be me measured by derivation from a standard beam model.
EUROPEAN DEINKABILITY TEST METHOD FOR PRINTED PAPER PRODUCTS Darmstadt University of Technology, Institution for Paper Science and Technology, Alexanderstrasse 8, 64 283 Darmstadt, BRD. tel.: 0 6151 163060 The INGEDE finances research work in order to improve the existing deinkability test method for printed products (INGEDE Method No. 11) and to harmonize it with methods being in use in other laboratories leading to comparable results with acceptable reproducibility. Details of the procedure, the deinkability parameters and the orientation values were presented by the poster.
PRESENTATION STUDIO PAPER AND BOOK FAVU VUT BRNO Studio of Paper and Book of the Faculty of Fine Arts of Brno University of Technology, Rybařská 13/15, 603 00 Brno, Czech Republic e- mail address: kocman@ffa.vutbr.cz tel.: +420 541 146829
Abstract In the recent twenty-five years, the media of paper and book have been newly considered independent artistic categories (Paper Art, Book Art or Artist's Books). Lately, the expressions "author papers" and "author books" have been used. The Studio of Paper and Book is an interdisciplinary base for those who are interested in the transition of craft into art. The work in the studio is thematically focused. This means that all the students are assigned one major theme. It is linked with specific seminars, where students deal with its further exploration. The students from advanced levels work on their individual themes which are inspired and led by their own initiative. The freshmen (the 1st year BA or MA students, educational stay students) are assigned so called initiatory themes. Later they can chose one of the themes which were previously worked on in the studio. The focus of the studio's work is thematic creation of original and authentic books. The autonomous work with paper can, but need not be connected with the creation of these books. The category of paper is considered independent, without reference to the make-up of the book, in the sense of Paper Art. |