The influence of pulping and washing conditions on the properties of Eucalyptus grandis unbleached kraft pulps treated with chelants

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• 作者：M.C. Area ; M.G.V.S. Carvalho ; P.J. Ferreira ; F.E. Felissia ; O.M. Barboza ; D.I. Bengoechea
• 关键词：Eucalyptus grandis ; Kraft pulping ; Chelating agents ; Counter-ion exchange ; Papermaking properties
• 刊名：Bioresource Technology
• 出版年：2010
• 出版时间：March 2010
• 年：2010
• 卷：101
• 期：6
• 页码：1877-1884
• 全文大小：1233 K

文摘

The influence of different addition points of a chelating agent and a counter-ion exchange on the properties of Eucalyptus grandis unbleached kraft pulps is studied. Seven pulps were considered: two laboratory kraft pulps with or without the inclusion of the chelant DTPMPA (diethylene triamine penta (methylene phosphonic acid)), a mill kraft pulp and four mill pulps after Ca⁺² or Na⁺ counter-ion exchange followed, or not, by washing with DTPMPA addition. The laboratory pulps required lower beating energy than the industrial pulps for achieving 30°SR, and the corresponding handsheets also showed better strength and optical properties, as well as a more homogeneous and smooth surface. The counter-ion exchange decreases the mechanical resistances and increases brightness. However, the effects of Ca⁺² are deeper than those of Na⁺. DTPMPA added to pulping causes a decrease in calcium content whereas as a washing additive does not have a relevant impact on the mechanical and optical properties.