Determination of Species Composition of Hardwood Pulp and Semi-Chemical Pulp

Complete text of the article:

Download article (pdf, 0.6MB )

UDС

676.16.022.6.031

DOI:

10.17238/issn0536-1036.2016.2.121

Abstract

Currently, hardwood is used for production of mass fibrous semi-finished products for paper and cardboard. The wood of birch and aspen in different ratios is mainly used in Russia. The basic structural elements of deciduous wood in the semi-finished products are the fibers of a libriform of vessels. Anatomically the fibers of a libriform are very difficult to be distinguished,
but the fibers of vessels have the characteristic diagnostic features – the structure of a perforation plate. In aspen wood it is simple, in birch wood it has a ladder structure with many partitions. On the basis of the specified features the authors developed a method of computer visualization and the program algorithm to detect an aspen and birch fiber vessels.
This program is intended for the statistical analysis of the species composition of wood fibers according to micrographs. The program was tested on the samples of sulfate unbleached pulp produced from 100 % wood of aspen and birch. Mixtures were prepared by weighing with a predetermined ratio of fibers (10 % for a step). As a result of the researches
the discrepancy of the expected and actual quantity of vessels of aspen and birch is established.
To evaluate the effect of the ratio of hardwood species on the properties of semifinished products in a laboratory three ways of semi-finished products were simulated, which are mainly used in the processing of wood of aspen and birch: cooking with green
liquor and sodium-soda cooking and kraft pulping. Laboratory samples were obtained from
these semi-finished products by mixing them by the gravimetric method (20 % for a step) in the range from 0 to 100 % of one of the species. Grinding was carried out in the Yokro's mill up to 20 °SR. The analysis of the main indicators of physical and mechanical properties (breaking length, tear resistance, strength of fibre) of laboratory castings of semi-chemical pulp (125 g/m2), and bleached sulphate pulp (60 g/m2) is conducted. The difference between the calculated and the actual ratio of the number of vessels in mixtures with a given percentage
is found. The dependence of the ratio of the composite structure on the physical and mechanical properties is studied. The dynamics of deterioration in the strength properties of
the laboratory samples with the increasing share of aspen fiber in their composition is
demonstrated.

Authors

E.O. Okulova, Postgraduate Student A.V. Gur'ev, Candidate of Engineering Sciences, Associate Professor

Affiliation

Northern (Arctic) Federal University named after M.V. Lomonosov, Naberezhnaya
Severnoy Dviny, 17, Arkhangelsk, 163002, Russian Federation;
e-mail: e.okulova@narfu.ru, a.guriev@narfu.ru

Keywords

hardwood vessel, computer visualization, breaking length, tear resistance, strength of fibre.

References

1. Bobrov A. I., Mutovina M.G., Bondareva T.A., Malyshkina V.K. Proizvodstvo voloknistykh polufabrikatov iz listvennoy drevesiny [Production of Hardwood Fibrous Semi- Finished]. Moscow, 1984. 248 p.
2. Galeeva N.A. Proizvodstvo polutsellyulozy i tsellyulozy vysokogo vykhoda [Production of High Yield Semi-Chemical Pulp and Pulp]. Moscow, 1970. 320 p.
3. GOST 10070–74. Tsellyuloza i polutsellyuloza. Metod opredeleniya stepeni delignifikatsii
[State Standard 10070–74. Pulp and Semi-Chemical Pulp. Method for the Degree of Delignification Determination]. Moscow, 1975.
4. Demidov M.L., Milovidova L.A., Gur'ev A.V. Razrabotka i optimizatsiya rezhimov varki polutsellyulozy iz osiny [Development and Optimization of Semi-Chemical Pulping of Aspen]. Bumaga. Tsellyuloza. Karton [Pulp. Paper. Board], 2011, no. 2, pp. 44– 46.
5. Kozubova G.M., Zotova-Spanovskaya N.P. Diagnosticheskie priznaki drevesiny i tsellyuloznykh volokon, primenyaemykh v tsellyulozno-bumazhnoy promyshlennosti [Diagnostic Features of Wood and Cellulose Fibers Used in the Pulp and Paper Industry]. Petrozavodsk, 1976. 152 p.
6. Mutovina M.G., Bondareva T.A., Fadeev B.A., Grudinin V.P., Serebryakov V.N., Sumarokova L.K. Vliyanie porodnogo sostava listvennoy shchepy na svoystva tsellyulozy [Influence of the Species Composition of Hardwood Chips on the Properties of Cellulose]. Tekhnologiya voloknistykh polufabrikatov [Technology of Fiber Semi-Finished Products], 1988, pp. 96–100. 7. Nikitin V.M., Obolenskaya A.V., Shchegolev V.P. Khimiya drevesiny i tsellyulozy [Wood and Pulp Chemistry]. Moscow, 1978. 386 p.
8. Okulova E.O., Gur'ev A.V. Komp'yuternaya vizualizatsiya i identifikatsiya volokon sosudov listvennoy tsellyulozy [Computer Visualization and Identification of Vessels Fibers of Hardwood Pulp]. Khimiya i tekhnologiya rastitel'nykh veshchestv: Materialy VIII Vseros. nauch. konf. [Chemistry and Technology of Plant Substances. Proc. VIII Sci. Conf.]. Kaliningrad, 2012.
9. Khimiya drevesiny [Wood Chemistry]. Ed. by M.A. Ivanov. Moscow, 1982. 400 p.
10. Sharkov V.I., Kuybina N.I. Khimiya gemitsellyuloz [Hemicellulose Chemistry]. Moscow, 1972 p. 440 p.
11. Karlsson Н. Fiber Guide – Fibre Analysis and Process Applications in the Pulp and Paper Industry. 2006. 120 p.
Received on April 30, 2015