Role of particle size and preflocculation of talc in improvement of paper properties

TAPPI Journal ◽  
2014 ◽  
Vol 13 (4) ◽  
pp. 17-26 ◽  
Author(s):  
VIPUL SINGH CHAUHAN ◽  
NISHI KANT BHARDWAJ
Keyword(s):  
Particle Size ◽  
Strength Loss ◽  
Filler Loading ◽  
Paper Strength ◽  
Paper Properties ◽  
Viable Solution ◽  
Filler Retention ◽  
Mineral Fillers ◽  
Different Doses

Mineral fillers are added during papermaking to improve the optical and printing properties of paper and decrease energy costs. Filler loading using conventional approaches has some disadvantages, such as reduction in paper strength. The finer filler, the more the strength loss. Several methods and materials have been reported to overcome or alleviate the same, but with higher costs. Our approach provides an economically viable solution to the problem, using conventional papermaking materials. Talc filler of different particle sizes, preflocculated using different doses of cooked amphoteric starch, were used for papermaking. Relatively higher filler retention, paper strength, and hydrophobicity of paper were obtained with preflocculated talc compared to native talc. The optical properties of paper were unchanged on the loading of similar talc after preflocculation. The preflocculated talc of finer particle size provided higher opacity at similar ash, as well as paper strength, than the native talc of coarser size.

scholarly journals New Diatomite Filler for Improvement of Paper Strength Properties

2020 ◽  
Vol 71 (5) ◽  
pp. 479-490 ◽  
Author(s):  
Wei Shang ◽  
Haoran Han ◽  
Hunan Liang
Keyword(s):  
Particle Size ◽  
Strength Properties ◽  
Filler Loading ◽  
Sodium Hexametaphosphate ◽  
Paper Strength ◽  
Pulp Fibers ◽  
Cationic Starch ◽  
Coating Method ◽  
Filler Retention ◽  
Modified Diatomite

In this work, diatomite particles were modified to improve the bondability of diatomite particles with pulp fibers and filler retention via a complex of cationic starch-sodium hexametaphosphate coating method. The particle size, FTIR spectroscopy characteristic and morphology of the resulting modified diatomite were studied to confirm the successful modification. The SEM results illustrated that the surface of modified diatomite particles was covered by the complex coatings. The coating efficiency of the complex of cationic starch-sodium hexametaphosphate on diatomite surface was up to 98%. Compared with the handsheet filled unmodified diatomite, the handsheet filled with modified diatomite had higher strength properties and lower bulk. When cationic starch dosage was 7%, and filler dosage was 25% , the resulting tensile strength of filled modified diatomite handsheet was 22.1% higher than the handsheet filled unmodified diatomite. Furthermore, with the filler loading of 30%, compared with that of unmodified diatomite, filler retention of modified diatomite was increased by 20.4%. The larger particle size and higher zeta potential of modified diatomite were benefitial to increase retention of modified diatomite filler.

scholarly journals Effects of In-Situ Filler Loading vs. Conventional Filler and the Use of Retention-Related Additives on Properties of Paper

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5066
Author(s):  
Maria Emiliana Fortună ◽  
Andrei Lobiuc ◽  
Lucian-Mihai Cosovanu ◽  
Maria Harja
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Filler Loading ◽  
Carbonate Content ◽  
Sem Images ◽  
Paper Properties ◽  
Calcium Carbonate Content ◽  
Optical And Mechanical Properties ◽  
Filler Retention

In the present paper, aspects concerning the obtained and characterization of additive systems used for maximizing filler retention, and the effects on paper properties, were investigated. The effects of retention additives over properties of paper, containing fibers from in-situ loading (IS-CCP), were analyzed against the effects of additives over properties of paper containing fibers from conventional loading, obtained by the addition of calcium carbonate in precipitated form (CCP). The physico-mechanical properties were analyzed by various analyses and investigations: calcium carbonate content, X-ray diffraction, scanning electron microscopy (SEM) images, optical and mechanical properties, in order to develop the best systems of retention additives for obtaining higher retention loads for making paper with high content of nano-filler material. The obtained results reveal that at the same level of calcium carbonate content, all paper samples with in-situ loading had higher the optical and mechanical properties than the paper obtained by conventional loading in all cases the additives studied. For all studied properties, nanoparticles had a positively influence over paper properties.

Composite filler by pre-flocculation of fiber fines and PCC and its effect on paper properties

2020 ◽  
Vol 35 (2) ◽  
pp. 251-260
Author(s):  
Hyun Kang ◽  
Jong Myoung Won ◽  
Byoung-Uk Cho
Keyword(s):  
Strength Properties ◽  
Ash Content ◽  
Paper Strength ◽  
Precipitated Calcium Carbonate ◽  
Paper Properties ◽  
Loading Method ◽  
Retention Aids ◽  
Composite Filler ◽  
Filler Retention ◽  
Better Than

AbstractA composite filler was developed by pre-flocculation of fiber fines and precipitated calcium carbonate (PCC) particles with flocculants such as cationic polyacrylamide (cPAM) and bentonite. The composite filler was compared with a conventional loading method in terms of physical properties of handsheet and filler retention. The handsheets using the composite filler showed higher strength properties than that using a conventional loading at a similar paper ash content level, implying that paper ash content can be increased maintaining same level of paper strength. Optical properties such as opacity and brightness of the paper with the composite were quite similar with the paper with the conventional loading. Filler retention of the composite filler was slightly higher than that of the conventional loading even though retention aids were not used for the composite filler. Paper formation of the composite filler was better than the case of the conventional loading. However, the sheet with the composite filler showed lower bulk than that with the conventional loading. Conclusively, the composite filler technology by pre-flocculation of fines and filler has a potential to be utilized to produce a high loaded paper.

Filler modified by a sequential encapsulation and preflocculation method and its effect on paper properties

2020 ◽  
Vol 35 (1) ◽  
pp. 89-95
Author(s):  
Nannan Chen ◽  
Lijun Wang ◽  
Junchao Wen ◽  
Xianping Yao ◽  
Wenyan Zhao
Keyword(s):  
Filler Content ◽  
Strength Properties ◽  
Paper Strength ◽  
Cationic Starch ◽  
Paper Properties ◽  
Polyelectrolyte Complexes ◽  
New Methods ◽  
Charge Potential ◽  
Filler Retention ◽  
Anionic Polyacrylamide

AbstractIncreasing the filler content of sheet tends to decrease filler retention and paper strength properties. To overcome this problem and make better use of fillers, development of new methods on filler modification has never been stopped. In this study, filler modification was carried out by sequentially adding an anionic polyacrylamide, a cationic starch and a cationic polyacrylamide. It is believed that in this process, multiple polyelectrolyte complexes are formed which can not only encapsulate filler particles but also preflocculate the particles. The results showed that, compared to the single preflocculation treatment, the sequential encapsulation and preflocculation (SEP) treatment brought significantly larger particle size and higher surface charge potential of the filler, thus higher filler retention was achieved. When the modified fillers were used for papermaking and paper ash contents were controlled at the same level, the SEP modification was better in improving the tensile index, internal bond strength and tearing index of paper than the single preflocculation method, in addition, it maintained better paper formation, caused insignificant change on opacity of paper. It is believed that this newly developed SEP method is worthy of being applied to industrial scales in making various grades of filled paper.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

Fibrin Formation: The Role of the Fibrinogen-Fibrin Monomer Complex

1976 ◽  
Vol 36 (01) ◽  
pp. 037-048 ◽  
Author(s):  
Eric P. Brass ◽  
Walter B. Forman ◽  
Robert V. Edwards ◽  
Olgierd Lindan
Keyword(s):  
Particle Size ◽  
Induction Period ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Appreciable Amount ◽  
Buffer System ◽  
Homeostatic Mechanism ◽  
Fibrin Formation ◽  
Fibrin Monomer

SummaryThe process of fibrin formation using highly purified fibrinogen and thrombin was studied using laser fluctuation spectroscopy, a method that rapidly determines particle size in a solution. Two periods in fibrin clot formation were noted: an induction period during which no fibrin polymerization occurred and a period of rapid increase in particle size. Direct measurement of fibrin monomer polymerization and fibrinopeptide release showed no evidence of an induction period. These observations were best explained by a kinetic model for fibrin clot formation incorporating a reversible fibrinogen-fibrin monomer complex. In this model, the complex serves as a buffer system during the earliest phase of fibrin formation. This prevents the accumulation of free polymerizable fibrin monomer until an appreciable amount of fibrinogen has reacted with thrombin, at which point the fibrin monomer level rises rapidly and polymerization proceeds. Clinically, the complex may be a homeostatic mechanism preventing pathological clotting during periods of elevated fibrinogen.

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.

Complex formation of modified chitosan and carboxymethyl cellulose and its effect on paper properties

TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 29-35 ◽  
Author(s):  
PEDRAM FATEHI ◽  
LIYING QIAN ◽  
RATTANA KITITERAKUN ◽  
THIRASAK RIRKSOMBOON ◽  
HUINING XIAO
Keyword(s):  
Carboxymethyl Cellulose ◽  
Polymer System ◽  
Layer By Layer ◽  
Paper Strength ◽  
Anionic Polymer ◽  
Paper Properties ◽  
Modified Chitosan ◽  
Layer By Layer Assembly ◽  
Polyelectrolyte Titration ◽  
Layer Assembly

The application of an oppositely charged dual polymer system is a promising approach to enhance paper strength. In this work, modified chitosan (MCN), a cationic polymer, and carboxymethyl cellulose (CMC), an anionic polymer, were used sequentially to improve paper strength. The adsorption of MCN on cellulose fibers was analyzed via polyelectrolyte titration. The formation of MCN/CMC complex in water and the deposition of this complex on silicon wafers were investigated by means of atomic force microscope and quasi-elastic light scattering techniques. The results showed that paper strength was enhanced slightly with a layer-by-layer assembly of the polymers. However, if the washing stage, which was required for layer-by-layer assembly, was eliminated, the MCN/CMC complex was deposited on fibers more efficiently, and the paper strength was improved more significantly. The significant improvement was attributed to the extra development of fiber bonding, confirmed further by scanning electron microscope observation of the bonding area of fibers treated with or without washing. However, the brightness of papers was somewhat decreased by the deposition of the complex on fibers. Higher paper strength also was achieved using rapid drying rather than air drying.

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