scholarly journals Potential of bleached eucalyptus kraft pulp for applications in nonwoven fibrous fabrics

2020 ◽  
Vol 15 ◽  
pp. 155892502098014
Author(s):  
Sofia M Rebola ◽  
Joana Ferreira ◽  
Dmitry V Evtuguin
Keyword(s):  
Kraft Pulp ◽  
Pilot Scale ◽  
Absorption Capacity ◽  
Raw Material ◽  
Process Conditions ◽  
Fiber Morphology ◽  
Pulp Bleaching ◽  
Fiber Network ◽  
Eucalyptus Kraft Pulp ◽  
Network Strength

A series of six industrial bleached hardwood kraft pulps produced from Eucalyptus globulus (BEKPs) under variable process conditions were dry-defiberized on a pilot scale hammermill at 3500 rpm and the nonwoven air-laid fabrics evaluated for their specific volume, absorption capacity/absorption rate and fiber network strength. The effect of non-defiberized fiber aggregates (knots) on the former properties was evaluated. Processual variations in pulping and bleaching conditions revealed variability within 15% in the absorption capacity of fluff pulps and within 25% in the network strength of the air-laid formulations. These variations were attributed to changes in the chemical composition of BEKPs and fiber morphology. The importance of pulp bleaching sequence on the quality of BEKPs for fluff applications was highlighted. BEKPs, having a high residual xylan content with a greater amount of uronic/hexenuronic moieties and coarser/deformed fibers, revealed the best performance in fluff applications. The coarseness was considered a critical morphological parameter of the fibers, strongly affecting the porosity of air-laid formulations, which determined the absorption capacity and the network strength. The absorption capacity of fluffed BEKP was comparable of commercial bleached softwood kraft pulp (BSKP), although the latter showed almost triple the network strength of air-laid formulations produced with BEKP. BSKP proved to be much more vulnerable to dry defiberization conditions than BEKP and suffered a pronounced cut of fibers, producing larger amounts of fines (dust) and stronger undesirable peeling and straightening of fibers. BEKPs can be considered a promising raw material for fluff applications, whose basic properties can be adjusted according to the needs by varying conditions in the pulping and bleaching process steps.

scholarly journals Alkali Extraction of Kraft Pulp Fibers: Influence on Fiber and Fluff Pulp Properties

2012 ◽  
Vol 7 (2) ◽  
pp. 155892501200700 ◽  
Author(s):  
Kristoffer Lund ◽  
Karin Sjöström ◽  
Harald Brelid
Keyword(s):  
Kraft Pulp ◽  
Pulp Fibers ◽  
Fiber Network ◽  
Alkali Extraction ◽  
Flexible Fiber ◽  
Softwood Pulp ◽  
Softwood Kraft Pulp ◽  
Patent Literature ◽  
Network Strength ◽  
Birch Kraft Pulp

The importance of hemicelluloses for the papermaking properties of pulp fibers is well documented. In the patent literature, it can be seen that there is also an interest in this type of modification of pulp fibers for use in absorption products. In this study, a Scandinavian softwood kraft pulp and a birch kraft pulp were alkali extracted at 3 different concentrations of NaOH (2%, 4% and 8% NaOH in the suspension). The alkali extraction removed a large part of the hemicelluloses from the pulp fibers and decreased the content of the charged groups. After extraction, the pulps were dried in the form of sheets (approx. 600 g/m2). The alkali extracted pulp fibers exhibited a greater decrease in swelling when re-wetted than untreated pulp. A significant increase in the curl index after extraction with 4% and 8% NaOH was also noted. The tensile strength index of the formed sheets increased at the lowest concentration of NaOH and, at the higher concentrations, a decrease was observed. The pulp sheets were dry defibrated at different defibration intensities and the performance of the resulting pulps in fluff pulp applications was studied. The air-laid fiber networks of softwood pulp fibers showed higher network strength than the networks of birch pulps. The birch pulp extracted at the highest alkali level tended to give the highest network strength. The results from the network strength tests also indicated that the increased curl of the fibers from the softwood pulp extracted at the highest alkali level rendered a more flexible fiber network. In water absorption tests, the alkali treated softwood fibers tended to give networks with a somewhat enhanced water holding capacity under pressure.

Effects of D0-stage temperature, pH, and kappa factor on chlorine dioxide decomposition and D0-(EP)-D1 bleaching performance for eucalypt pulps

TAPPI Journal ◽  
2016 ◽  
Vol 15 (4) ◽  
pp. 285-295 ◽  
Author(s):  
UMIT SEZGI ◽  
JANAINA RESENDE ◽  
LEWIS SHACKFORD ◽  
JORGE COLODETTE ◽  
MARCELA ANDRADE
Keyword(s):  
Chlorine Dioxide ◽  
Kraft Pulp ◽  
Significant Variable ◽  
Optimum Conditions ◽  
Pulp Bleaching ◽  
Elemental Chlorine ◽  
Kraft Pulp Bleaching ◽  
Eucalyptus Kraft Pulp ◽  
Hexenuronic Acid ◽  
Proper Operation

Mills have largely used chlorine dioxide (ClO2) for eucalyptus kraft pulp bleaching. Different mills have observed significant variation in ClO2 demand to reach full brightness (≥90 ISO). These large differences in ClO2 consumption derive from many factors. The most significant include differences in carryover loads and hexenuronic acid (HexA) contents and the level of chlorate formation across bleaching. Handling of pulp with high HexA content and ClO2 losses to chlorate can be minimized by proper operation of the ClO2 stages across the bleach plant. An oxygen delignified eucalyptus kraft pulp with a kappa of 10-12 units contains only 4-6 units actually derived from lignin. This scarce amount of lignin (0.6%-0.9%) is not able to consume high ClO2 doses and, as a consequence, the excess ClO2 applied can end up being converted into chlorate. Hence, proper optimization of ClO2 bleaching stages can save significant amounts of this oxidant. This study focused on optimizing ClO2 bleaching for a typical oxygen delignified eucalyptus kraft pulp of kappa number 11.7. Elemental chlorine free bleaching was carried out with the D0-(EP)-D1 sequence. The following conditions were varied in the D0 stage: temperature, end pH, and kappa factor. The results indicated that maximum ClO2 bleaching efficiency is achieved when minimum chlorate is formed, especially when ClO2 bleaching is adjusted in such a way that residual active chlorine is maintained to a minimum. The most significant variable affecting chlorate formation is pH; however, ClO2 doses (ClO2 concentration) also play a very important role. Chlorate formation is more intense in the D1 stage in relation to the D0 stage. Optimum conditions to run the D0 stage were 90°C, 3.5 pH, and 0.22 kappa factor.

Xylanase and laccase based enzymatic kraft pulp bleaching reduces adsorbable organic halogen (AOX) in bleach effluents: A pilot scale study

2014 ◽  
Vol 169 ◽  
pp. 96-102 ◽  
Author(s):  
Abha Sharma ◽  
Vasanta Vadde Thakur ◽  
Anita Shrivastava ◽  
Rakesh Kumar Jain ◽  
Rajeev Mohan Mathur ◽  
...  
Keyword(s):  
Kraft Pulp ◽  
Pilot Scale ◽  
Pulp Bleaching ◽  
Organic Halogen ◽  
Kraft Pulp Bleaching

scholarly journals Relationship between Surface Properties and Fiber Network Parameters of Eucalyptus Kraft Pulps and Their Absorption Capacity

Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 265-281 ◽  
Author(s):  
Catarina A. Azevedo ◽  
Sofia M. C. Rebola ◽  
Eddy M. Domingues ◽  
Filipe M. L. Figueiredo ◽  
Dmitry V. Evtuguin
Keyword(s):  
Chemical Composition ◽  
Surface Properties ◽  
Network Structure ◽  
Fiber Surface ◽  
Contact Angles ◽  
Absorption Capacity ◽  
Kraft Pulps ◽  
Pulp Bleaching ◽  
Absorption Properties ◽  
Fiber Network

Water absorption capacity is a key characteristic of cellulosic pulps used for different commodities. This property is influenced by the affinity of the pulp fiber surface with water, chemical composition of the pulp, morphology, and organization of fibers in the network. In this study, surface properties of six industrial Eucalyptus bleached kraft pulps (fluff pulps) dry-defiberized in a Hammermill, which were obtained by wood pulping and pulp bleaching under different production conditions, were studied while employing dynamic water vapor sorption and contact angles measurements. The absorption properties of air-laid pulp pads were analyzed following the absorbency testing procedure and the relationship between these properties and pulp’s chemical composition and fiber network structure were assessed by multivariate analysis. The results showed that the accessibility of the fiber surface is related to the reduction of the contact angles, but, at the same time, to the longer absorption time and less absorption capacity of the fiber network. Therefore, the absorption properties of the pulps are not necessarily directly related to their surface properties. Indeed, absorptivity is related to the surface chemical composition, fiber morphology, and fiber network structure. Thus, surface carboxylic groups promote total water uptake, resulting in better absorption capacity. Greater fiber coarseness and deformations (curl and kink) provide a less wettable surface, but a more porous network with higher specific volume, resulting in more absorbent air-laid formulations.

Application of a Catalyst in Peroxide Bleaching of Eucalyptus Kraft Pulp

Holzforschung ◽  
2000 ◽  
Vol 54 (4) ◽  
pp. 407-412 ◽  
Author(s):  
L. Kühne ◽  
J. Odermatt ◽  
T. Wachter
Keyword(s):  
Hydrogen Peroxide ◽  
Kraft Pulp ◽  
Pulp Bleaching ◽  
Selective Catalyst ◽  
Peroxide Bleaching ◽  
Softwood Pulp ◽  
Kraft Pulp Bleaching ◽  
Eucalyptus Kraft Pulp ◽  
Softwood Kraft Pulp

Summary A binuclear [Mn(III)Mn(IV)(μ-O)2(μ-CH3COO)L](ClO4−)2 complex with L = 1,2 Bis-(4,7-dimethyl-1,4,7-triazacyclonon-1-yl)-ethane, described as a selective catalyst in hydrogen peroxide bleaching of softwood pulps, was tested in hardwood kraft pulp bleaching. The catalyst application gave rise to a higher consumption of peroxide which resulted in higher pulp brightness. The delignification improvement caused by the catalyst was shown to be much lower compared to catalysed peroxide bleaching of softwood kraft pulp. In contrast to the results of softwood pulp bleaching no selectivity improvements could be found when using the catalyst in bleaching of eucalyptus kraft pulp.

scholarly journals EFEKTIVITAS BERBAGAI INDIKATOR PENGGILINGAN UNTUK MEMPREDIKSI KUALITAS KERTAS

2016 ◽  
Vol 1 (02) ◽  
Author(s):  
Hana Rachmanasari ◽  
Taufan Hidayat
Keyword(s):  
Kraft Pulp ◽  
Wood Pulp ◽  
Strength Properties ◽  
Raw Material ◽  
Fiber Morphology ◽  
Mechanical Pulp ◽  
Chemical Pulp ◽  
Bleached Kraft Pulp ◽  
Drainage Rate

The experiments of refining have been done using PFI mill and Beater, at 300 mL CSF of freenessas fixed parameters. Research was aims to determine the effective indicators of refining to predict the quality of the paper. The raw material used were wood pulp, non wood pulp, chemical pulp, mechanical pulp, Leaf Bleached Kraft Pulp (LBKP) and Needle Bleached Kraft Pulp (NBKP). The parameters which analyzed for each equipments were fibers classification, fiber morphology, dimensions of its derivatives and as the value of the drainage rate. The strenght of handsheets formed from the fibers were tested including tensile, bursting, and tearing strength. According to the results of correlation analysis, the most effective and sensitive indicators of refining towards strength properties of paper, in the wo different refining methods, is the felting power slenderness with correlation values above 0.8.Key words : refining, fiber classification, fiber morphology, the strength properties, correlation valueABSTRAKTelah dilakukan percobaan penggilingan menggunakan PFI mill dan Valley Beater, pada freeness 300 mL CSF sebagai parameter tetap. Penelitian ini bertujuan untuk mengetahui beberapa indikator penggilingan yang efektif untuk memprediksi kualitas kertas. Bahan baku terdiri dari pulp kayu, pulp non kayu, pulp kimia, pulp mekanis, pulp kayudaun dan pulp kayujarum. Parameter yang dianalisa untuk masing-masing hasil penggilingan adalah klasifikasi serat, morfologi serat dan dimensi turunannya serta nilai laju drainase. Selanjutnya dilakukan uji sifat kekuatan yang meliputi ketahanan tarik, retak dan sobek. Berdasarkan hasil analisa korelasi terhadap data penelitian, indikator penggilingan yang paling efektif dan sensitif terhadap sifat kekuatan kertas pada dua metode penggilingan berbeda adalah kelangsingan dengan nilai korelasi di atas 0,8.Kata kunci : penggilingan, klasifikasi serat, morfologi serat, sifat kekuatan, nilai korelasi  

Integrating a Xylanase Treatment into an Industrial-Type Sequence for Eucalyptus Kraft Pulp Bleaching

2012 ◽  
Vol 51 (7) ◽  
pp. 2830-2837 ◽  
Author(s):  
Ursula Fillat ◽  
María Blanca Roncero ◽  
Vera M. Sacón ◽  
Alexandre Bassa
Keyword(s):  
Kraft Pulp ◽  
Pulp Bleaching ◽  
Kraft Pulp Bleaching ◽  
Eucalyptus Kraft Pulp ◽  
Type Sequence

Optimizing Alkaline Extraction for Eucalyptus Kraft Pulp Bleaching

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 12-19
Author(s):  
LEWIS D. SHACKFORD ◽  
CARLOS A. SANTOS ◽  
JORGE L. COLODETTE ◽  
ERICKA F. ALVES
Keyword(s):  
Cost Effectiveness ◽  
Kraft Pulp ◽  
Alkaline Extraction ◽  
Cost Advantage ◽  
Pulp Bleaching ◽  
Eucalyptus Pulp ◽  
Kraft Pulp Bleaching ◽  
Eucalyptus Kraft Pulp ◽  
Chlorine Demand ◽  
The Cost

This paper evaluates different approaches for the (E*) stage of the DHT(E*)D sequence for eucalyp-tus kraft pulp bleaching to 90%–91% ISO brightness, considering kappa factors 0.12, 0.16, and 0.20 in the first stage. These (E*) approaches included E, (EO), (EP), (EOP), (PO), PHT, O, and (O/O) stages run at two tempera-tures. Results were compared on the basis of total active chlorine demand, chemical cost, pulp brightness stability and viscosity, and effluent load. We concluded that a DHT kappa factor of 0.12 and a (PO) stage run at 85°C–95°C appeared to be the most attractive approach for bleaching eucalyptus pulp with the DHT(E*)D sequence, consider-ing cost-effectiveness, pulp quality, and effluent load; however, when the steam cost is taken into consideration, the cost advantage was lost.

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