Using PVA and PVA & Cationic Starch to Improve the Strength of High-Yield Pulp

2014 ◽  
Vol 496-500 ◽  
pp. 167-170
Author(s):  
Yun Yun Sun ◽  
Fan Gong Kong ◽  
Shou Juan Wang ◽  
Qin Wu
Keyword(s):  
Strength Properties ◽  
High Yield ◽  
Cationic Starch ◽  
Physical Strength ◽  
Pulp Consistency ◽  
Promising Application ◽  
Pulp Properties

Dry strength additives play an important roll in papermaking process. In this work, we aimed at analyzing the performance of poly vinyl alcohols (PVA) and PVA & cationic starch (CS), as dry strength additives, on the properties of high-yield pulp (HYP). Various dosages of PVA were applied on HYP under various conditions and the corresponding pulp properties were evaluated. It was observed that PVA increased the strength properties of the HYP significantly, and the enhanced strength properties can be kept even after refining, which gave a promising application of this method in conventional pulping process. The best conditions of PVA for dosage, pH, pulp consistency and time was 20 mg/g, 6.0, 3% and 10 min, respectively. The application of CS, combined with PVA, can further improve the final physical strength properties of HYP. The results obtained from using PVA & CS were more effective than those obtained from using only PVA.

Effects of Enzymatic Modification of Masson Pine Mechanical Pulp on Fiber Morphology and Pulp Properties

2011 ◽  
Vol 117-119 ◽  
pp. 1593-1596
Author(s):  
Qing Luo ◽  
Xin Ping Li ◽  
Ye Liu ◽  
Jun Hua Liu
Keyword(s):  
High Yield ◽  
Pulp Fiber ◽  
Shape Parameters ◽  
Enzymatic Modification ◽  
Fiber Morphology ◽  
Masson Pine ◽  
Mechanical Pulp ◽  
Physical Strength ◽  
Comprehensive Utilization ◽  
Pulp Properties

Mechanical pulping is a kind of high yield pulping that comes with the comprehensive utilization of plant material. Mechanical pulp has lots of benefits, such as simple process, low pollution, good bulkiness, fine stiffness, excellent optical performance and good printability. However, it also has disadvantages of lower paper physical strength and higher refining energy. In this paper, AU-MTPE90 enzyme and acid xylanase were used to modify the masson pine mechanical pulp before refining. The effects of modification on the shape parameters of masson pine mechanical pulp fiber and pulp properties were studied. The results showed that after modified by AU-MTPE90 enzyme and acid xylanase，the drainability of the refined pulp increased, the average fiber length increased and the fines percent decreased. The curl index and kink index increased slightly after modified by AU-MTPE90 enzyme，while the kink index decreased after modified by xylanase.

Research on Biological Modification of Pulp to Improve the Strength of Paper

2013 ◽  
Vol 848 ◽  
pp. 334-337
Author(s):  
Ai Yun Long ◽  
Chuan Shan Zhao ◽  
Wen Jia Han ◽  
Yi Fei Jiang
Keyword(s):  
Control Sample ◽  
Strength Properties ◽  
Raw Material ◽  
Paper Strength ◽  
Optimum Conditions ◽  
Wet Strength ◽  
Tensile Index ◽  
Pulp Consistency ◽  
Pulp Properties ◽  
Biological Modification

Based on the domestic OCC pulp as raw material, it was found that the optimum conditions for laccase treatment were: the concentration of laccase 16U/g dry pulp, the pulp consistency 5%, temperature 50 °C, pH=5.0 and reaction time 90min. OCC treated with laccase alone can improve paper strength properties. The dry tensile index and wet tensile index of the control sample were 21.80 Nm/g and 0.22 Nm/g, respectively. The dry tensile index and wet tensile index after OCC treated with laccase alone were 23.36 Nm/g and 0.28 Nm /g. Comparing to the control pulp, the dry tensile index and wet tensile index of OCC treated with laccase were increased by 6.88% and 27.3%, respectively. At the same time, the laccase system can obviously improve the strength of the pulp properties with adding the mediator, especially using histidine, the dry and wet strength of paper was largely improved.

Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 73-81 ◽  
Author(s):  
GISELY SAMISTRARO ◽  
PETER W. HART ◽  
JORGE LUIZ COLODETTE ◽  
RICARDO PAIM
Keyword(s):  
Energy Levels ◽  
Black Liquor ◽  
Basic Density ◽  
Paper Mill ◽  
Frost Tolerance ◽  
Strength Properties ◽  
Kappa Number ◽  
Pulp Yield ◽  
Chemical Compositions ◽  
Physical Strength

Eucalyptus dunii has been commercially used in southern Brazil because of its relatively good frost tolerance and adequate productivity in the winter months. More recently, interest has grown in cultivating Eucalyptus benthamii Maiden & Cambage, which presents even superior frost tolerance compared to E. dunii and is highly productive as well. The quality of E. benthamii for pulp production is not yet proven. Thus, the chemical, anatomical, and technological aspects of pulp made from E. benthamii were compared with those of E. dunii for unbleached paper production. Samples of E. benthamii chips were obtained and analyzed for their basic density, chemical composition, higher heating value, trace elemental analysis, and chip size distribution. The chips were kraft cooked using conditions that produced a 74 ± 6 kappa number. The pulps were characterized for kappa number, yield, viscosity, and morphologic characteristics (e.g., length, wall thickness, and coarseness). Black liquor was analyzed for total solids, organics, inorganics, sodium sulfide, sodium hydroxide, and sodium carbonate. Brownstocks were beaten at five different energy levels in a Valley beater, and the physical strength properties of 120 g/m² handsheets were measured to develop a beater curve. The results of this study showed differences in delignification between the two woods and lower pulp yield for E. benthamii , which are related to their chemical compositions and basic densities. The E. benthamii studied in this work exhibited higher amounts of lignin and extractives, lower carbohydrate content, and lower basic density. However, cooking a blend of the two woods afforded good results in pulping and in physical pulp properties.

Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART
Keyword(s):  
Physical Properties ◽  
Strength Loss ◽  
Strength Properties ◽  
Clear Correlation ◽  
Paper Properties ◽  
Physical Strength ◽  
Pulp Viscosity ◽  
Softwood Pulp ◽  
The Impact ◽  
Related Paper

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.

A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 653-664
Author(s):  
IGNACIO DE SAN PIO ◽  
KLAS G. JOHANSSON ◽  
PAUL KROCHAK
Keyword(s):  
Negative Impact ◽  
High Strength ◽  
Strength Properties ◽  
Cellulose Microfibrils ◽  
Paper Strength ◽  
Flow Loop ◽  
Cationic Starch ◽  
Reflectance Measurement ◽  
Drainage Rate ◽  
Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

scholarly journals Strong paper from spruce CTMP – Part II: Effect of pressing at nip press temperatures above the lignin softening temperature

2018 ◽  
Vol 33 (1) ◽  
pp. 142-149 ◽  
Author(s):  
Sven Norgren ◽  
Gunilla Pettersson ◽  
Hans Höglund
Keyword(s):  
Compression Strength ◽  
Kraft Pulp ◽  
Softening Temperature ◽  
Strength Properties ◽  
Kraft Pulps ◽  
Cationic Starch ◽  
Tensile Index ◽  
Very High

Abstract The main objective of the current study was to demonstrate that it is possible to enhance strength properties of sheets from spruce HT-CTMP and CTMP furnishes up to the same level as is common on sheets from softwood kraft pulps by changing conditions in papermaking. To achieve that, sheets of spruce HT-CTMP and CTMP were consolidated at densities close to that of the reference bleach kraft pulp by pressing at press nip temperatures well above the tack and softening temperatures of lignin. On sheets from spruce CTMP (CSF 420 ml), where the fibers were surface treated with cationic starch, it was possible to reach tensile index at the same level as on sheets from the untreated reference kraft pulp. The compression strength (SCT) of CTMP and HT-CTMP sheets, which were achieved at the highest press nip temperature (200 °C) in the study, was equal to or higher than that of the reference kraft pulp sheets. The results show that there is a great yet unexploited potential in papermaking from spruce HT-CTMP and CTMP furnishes, which could be utilized in manufacturing of products where very high requirements upon strength is demanded.

scholarly journals TMP properties and refining conditions in a CD82 chip refiner. Part I: Step changes of process variables, description of the tests

2018 ◽  
Vol 33 (1) ◽  
pp. 69-81
Author(s):  
Rita Ferritsius ◽  
Olof Ferritsius ◽  
Jan Hill ◽  
Anders Karlström ◽  
Karin Eriksson
Keyword(s):  
Specific Energy Consumption ◽  
Fibre Length ◽  
Thermomechanical Pulp ◽  
Process Variables ◽  
Negative Effects ◽  
Entropy Model ◽  
Tensile Index ◽  
Pulp Consistency ◽  
Pulp Properties ◽  
Flat Zone

Abstract The study explores how changes in process variables, residence time and pulp consistency in refining influence the pulp properties. The equipment utilized in this study was a conical disc chip refiner (RGP82CD) producing thermomechanical pulp (TMP). The focus was on the ratio between tensile index and specific energy consumption. Pulp properties were measured for composite pulp samples taken from the refiner blow line. Residence times and pulp consistencies were estimated by use of the extended entropy model. This showed that the CD-refiner, with the flat and conical refining zone, has a process performance similar to that of a two-stage refiner set-up, and that the consistency in both refining zones is of high importance. Comparing different periods revealed that even if the values of measured blow line consistency are similar, significant differences in the estimated consistency in the flat zone can prevail. Therefore, only monitoring blow line consistency is not enough. Specifically, it was found that the pulp consistency after the flat zone could be very high, considerably higher than in the blow line, and this could have negative effects on tensile index and fibre length.

scholarly journals Use of Oxalic-Acid-Modified Stellerite for Improving the Filter Capability of PM2.5 of Paper Composed of Bamboo Residues

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Hua Chen ◽  
Jian Lou ◽  
Fei Yang ◽  
Jia-nan Zhou ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Pore Formation ◽  
Strength Properties ◽  
Filtration Efficiency ◽  
Kraft Pulping ◽  
Paper Strength ◽  
Cationic Starch ◽  
Promising Technique ◽  
Cooking Temperature ◽  
Experimental Parameters

In this study, pulping conditions for kraft pulping of bamboo residues were investigated, predominantly focusing on cooking temperature and time during pulping. Oxalic acid and cationic starch were used for the modification of natural stellerite, and the use of modified stellerite for preparing filter paper for PM2.5 filtration was investigated. The optimal pulping technology of bamboo residues was established based on the following experimental parameters: liquor ratio of 1 : 5.5, cooking temperature of 160°C, and a holding time of 2 h. Modification by oxalic acid resulted in the promotion of pore formation at the stellerite surfaces and induced the microscopic changes. Nevertheless, paper strength remained practically unchanged after the addition of fillers, indicating that the cationic starch preblend method is a promising technique for papermaking because it enhances the strength properties of paper. With the variation in the addition of modified stellerite from 3 to 15%, while simultaneously maintaining the basis weight constant at 60 gm−2, the filtration efficiency of paper sheets first increased and then decreased later; thus the optimum stellerite content was found to be 9%. Filtration efficiency was suggested to be affected by gas flowing velocity.

Study on Magnesium Hydroxide-Based Hydrogen Peroxide Bleaching Process of Nigra poplar CTMP

2011 ◽  
Vol 233-235 ◽  
pp. 1328-1331 ◽  
Author(s):  
Qiang Zhao ◽  
De Zhi Sun ◽  
Ming Yang Zhang ◽  
Su Min Kang
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Magnesium Hydroxide ◽  
High Yield ◽  
Pulp Yield ◽  
Pulp Bleaching ◽  
Bleaching Process ◽  
Peroxide Bleaching ◽  
Bleaching Condition ◽  
Pulp Consistency

The Mg(OH)2-based peroxide bleaching process of Nigra poplar CTMP pulp was confirmed. The optimal bleaching condition were as follows: 4% H2O2,1% Mg(OH)2, 15% pulp consistency, the reaction temperature was 80°C and the suitable reaction time was 2 hours. The Mg(OH)2-based bleaching process shows significant benefits over sodium hydroxide process. In contrast, magnesium hydroxide bleaching generates higher pulp yield and lower effluent COD at the same chemical dosage. The study shows peroxide bleaching of CTMP pulp with magnesium hydroxide as alkali source is to be an option for the high-yield pulp bleaching.

Sign in / Sign up

Export Citation Format

Share Document