Chemistry of paper—properties, modification strategies, and uses in bioanalytical chemistry

2022 ◽  
pp. 15-39
Author(s):  
Thiago R.L.C. Paixão ◽  
Carlos D. Garcia
Author(s):  
K. W. Robinson

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.


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

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.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 29-35 ◽  
Author(s):  
PEDRAM FATEHI ◽  
LIYING QIAN ◽  
RATTANA KITITERAKUN ◽  
THIRASAK RIRKSOMBOON ◽  
HUINING XIAO

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.


TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 631-638
Author(s):  
FREDERIC KREPLIN ◽  
HANS-JOACHIM PUTZ ◽  
SAMUEL SCHABEL

Paper for recycling is an important fiber source for the production of corrugated base paper. The change in production capacity toward more and more packaging papers affects the composition of paper for recycling and influences the paper quality. This research project investigated the influence of the multiple recycling of five different corrugated base papers (kraftliner, neutral sulfite semichemical [NSSC] fluting, corrugating medium, testliner 2, and testliner 3) on suspension and strength properties under laboratory conditions. The corrugated board base papers were repulped in a low consistency pulper and processed into Rapid-Köthen laboratory sheets. The sheets were then recycled up to 15 times in the same process. In each cycle, the suspension and the paper properties were recorded. In particular, the focus was on corrugated board-specific parameters, such as short-span compression test, ring crush test, corrugating medium test, and burst. The study results indicate how multiple recycling under laboratory conditions affects fiber and paper properties.


TAPPI Journal ◽  
2016 ◽  
Vol 15 (8) ◽  
pp. 515-521 ◽  
Author(s):  
EIJA KENTTÄ ◽  
HANNA KOSKELA ◽  
SARA PAUNONEN ◽  
KARITA KINNUNEN-RAUDASKOSKI ◽  
TUOMO HJELT

This paper reports experiments on silica coating formulations that are suitable for application as a thin pigment layer with foam coating technique on a paper web. To understand the foaming properties of nanosilica dispersions, the critical micelle concentration, foam half-life time, and foam bubble size stability were determined with three different foaming agents. The results indicate that the bubble stability measurement is a useful characterization method for foam coating purposes. Pilot foam coating trials were done and the effects of the chosen foaming agents were studied on the properties of the nanosilica-coated paper. The surface hydrophilicity of silica coated paper was related not only to silica pigment, but also to the chemical nature of the foaming agent. Standard paper properties were not affected by the thin silica coating.


2006 ◽  
Vol 60 (8) ◽  
pp. 1173-1179
Author(s):  
Etsuya Misawa ◽  
Rajan R. Iyer
Keyword(s):  

1996 ◽  
Vol 11 (3) ◽  
pp. 141-145 ◽  
Author(s):  
Rikurd Krook ◽  
Stig Stenström ◽  
Holger Hollmark
Keyword(s):  

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Amit Kumar ◽  
Chhotu Ram ◽  
Adebabay Tazeb

AbstractEnergy conservation has become an essential step in pulp and paper industry due to diminishing fossil reserves and high cost of energy. Refining is a mechanical treatment of pulp that modifies the structure of the fibres in order to achieve desired paper-making properties. However, it consumes considerable amount of energy. The electrical power consumption has a direct impact on paper manufacturing cost. Therefore, there is a requirement to minimize the energy cost. Enzyme-assisted refining is the environment friendly option that reduces the energy consumption for papermaking. Enzyme-assisted refining is defined as mechanical refining after pretreatment of pulp with enzymes such as cellulases and hemicellulases. It not only reduces the energy consumption but also improves the quality of finished paper. Enzymes improve the beatability of pulp at same refining degree (°SR) and desired paper properties can be achieved at decreased refining time. The selection of suitable enzyme, optimization of enzyme dose and appropriate reaction time are the key factors for energy reduction and pulp quality improvement during enzyme-assisted refining.


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