Relationship between Viscosity and Recycling of Dendrocalamus giganteus Munro Pulp

2012 ◽  
Vol 518-523 ◽  
pp. 604-607
Author(s):  
Jie He
Keyword(s):  
Low Temperature ◽  
Water Retention ◽  
High Viscosity ◽  
Kraft Pulping ◽  
Water Retention Value ◽  
Dry Heat ◽  
Pulp Viscosity ◽  
Kraft Cooking ◽  
The Relationship ◽  
Dendrocalamus Giganteus

In this paper, two groups of Dendrocalamus giganteus Munro pulp were obtained from conventional kraft pulping (the maximum pulping temperature was 165°C) and low-temperature kraft pulping (the maximum pulping temperature was only 135°C) under the premise of kappa number of about 17, and the viscosity of them were 1240 mL•g-1 and 1426 mL•g-1 respectively. Then the handsheets was treated with dry heat aging and the simulation of pulp recycling was investigated. In addition, the relationship between the pulp viscosity and recycling times of pulp were studied. The results showed that the viscosity and water retention value of two groups of pulp decreased with increasing of recycling times. However, the recycling characteristic of the pulp with high viscosity from low-temperature kraft cooking was better.

Properties of OQPaP Bleached Pulp of Pinus kesiya and Dendrocalamus giganteus Munro Made by Low-Temperature Kraft Pulping

2014 ◽  
Vol 900 ◽  
pp. 285-288
Author(s):  
Qi Xing Liu ◽  
Yang Chen ◽  
Jie He ◽  
Xin Gao
Keyword(s):  
Low Temperature ◽  
Kraft Pulp ◽  
Kraft Pulping ◽  
Paper Properties ◽  
Bleached Pulp ◽  
Pinus Kesiya ◽  
Lower Viscosity ◽  
Dendrocalamus Giganteus

In this paper, the low-temperature (the maximum pulping temperature was less than 150°C) and conventional (the maximum pulping temperature was 165°C) kraft pulp of pinus kesiya and Dendrocalamus giganteus Munro were bleached by OQPaP. Then bleaching properties and paper properties of two kinds of bleached pulp were compared and evaluated respectively. The results showed that the strength indexes of the kraft pulp at low temperature were significantly higher than those of conventional pulp with lower viscosity.

Cotton Woven Fabric with Less Energy Consumption during Home Laundry

2012 ◽  
Vol 441 ◽  
pp. 619-624 ◽  
Author(s):  
Li Ming Zhou ◽  
Yu Gao Zhang
Keyword(s):  
Energy Consumption ◽  
Water Retention ◽  
Cotton Fabrics ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Water Retention Value ◽  
Hydrophobic Agent ◽  
The Relationship

Cotton woven fabrics were treated with resin and hydrophobic agent for reducing the water retention value and improving the drying speed. The relationship among resin dosage, water retention value and drying speed were studied. The different fabrication methods of hydrophobic cottons were emphasized. When incorporating part of hydrophobic cottons in the fabric, the water retention value and drying speed of the fabric can be further improved, while the wearing comfort of the cotton fabrics can remain. By these treatments, the cotton apparels can be more easily washed and dehydrated and will consume less energy during home laundry and drying.

Unbleached and bleached handsheet characteristics of Subabul heartwood and sapwood

2020 ◽  
Vol 35 (2) ◽  
pp. 161-171
Author(s):  
Madhuri Pydimalla ◽  
Ramesh Babu Adusumalli
Keyword(s):  
Modulus Of Elasticity ◽  
Water Retention ◽  
Wood Chips ◽  
Morphological Properties ◽  
Residual Lignin ◽  
Water Retention Value ◽  
Tensile Index ◽  
Kraft Cooking ◽  
Ecf Bleaching

AbstractThe objective of this study was to understand the influence of bleaching on % residual lignin, water retention value, brightness and morphological properties of Subabul heartwood and sapwood pulps. The second aim was to compare the properties of unbleached and bleached handsheets with respect to tensile index and fractography. Screened wood chips of Subabul were subjected to kraft cooking (165 °C, 3 hours) followed by ECF bleaching and refining. When unbleached handsheets were compared, higher tensile index was found for sapwood sheets (29.8 N.m/g) than heartwood sheets (12.8 N.m/g). Therefore, it is recommended to use unbleached sapwood sheets for packaging grade applications. The bleached pulps have exhibited negligible residual lignin (0.1 %), higher water retention value (∼21) and higher brightness (88 %) compared to unbleached pulps. Subsequently, the bleached heartwood sheets revealed higher tensile index (∼7 fold) and higher modulus of elasticity (∼2.7 fold) compared to unbleached heartwood sheets. For printing grade applications bleached sapwood and bleached heartwood pulps are equally recommended, because no differences were observed in their pulp and sheet characteristics.

scholarly journals Effect of acid leaching of bamboo and hardwood chips on kraft pulping and pulp bleaching

2016 ◽  
Vol 51 (4) ◽  
pp. 247-252
Author(s):  
M Sarwar Jahan ◽  
S Islam ◽  
M Moniruzzaman ◽  
MA Quaiyyum
Keyword(s):  
Acid Leaching ◽  
Kraft Pulping ◽  
Wood Chips ◽  
Pulp Yield ◽  
Pulp Bleaching ◽  
Pulp Viscosity ◽  
Significant Difference ◽  
Kraft Cooking ◽  
Process Elements ◽  
Proven Method

Acid leaching of chips prior to pulping is a proven method to reduce non-process elements in kraft pulping process. In this paper, acid leaching of bamboo and hardwood chips was carried out at pH 2 for 1h at 80 °C prior to kraft pulping. Calcium removal in acid leaching from wood chips was 52.6% while for bamboo was only 17.4%. Acid leaching also reduced potassium (K) from 1258 mg/kg to 495.7 mg/kg for bamboo and 928 mg/kg to 562.5 mg/kg for wood chips. The effects of acid leaching on pulping, pulp bleaching, and papermaking characteristics were also determined. Acid leaching of both kinds of chips prior to kraft cooking resulted in a significant increase in the rate of delignification. Acid leached chips showed higher screen pulp yield and lower rejects at any kappa number. There was no significant difference of papermaking properties between pulps obtained from acid leached and non-leached chips. Using same ClO2 charge, acid leaching improved pulp brightness by 1% and 1.1% for hardwood and bamboo, respectively. Acid leaching improved pulp viscosity from 10.1 mP.s to 12.1 mP.s for hardwood.Bangladesh J. Sci. Ind. Res. 51(4), 247-252, 2016

Mechanisms and Defiberation Point of Dendrocalamus Giganteus Munro Kraft Pulping

2013 ◽  
Vol 690-693 ◽  
pp. 1350-1353 ◽  
Author(s):  
Chen Bi Zhou ◽  
Jie He ◽  
Yang Chen ◽  
Hong Yan Gao
Keyword(s):  
Kraft Pulping ◽  
Kraft Cooking ◽  
Dendrocalamus Giganteus

In this paper, mechanisms and defiberation point of Dendrocalamus Giganteus Munro kraft pulping were studied. The results showed that the delignification of kraft cooking could be divided into 3 stages: the bulk delignification stage, which was from the beginning of heating to 165°C for 30min, and its delignification rate was above 80%; the supplementary deligninfication stage, which was from 165°C for 30min to 90min, and about 11% of lignin was dissolved in this stage; the residual delignification stage, which was from 165°C for 90min to the end of cooking, and about 1% of lignin was dissolved in this stage. And the defiberation point during kraft cooking was at 165°C for 60min nearby.

Prehydrolysis kraft pulping of jute cutting and caddis mixture for rayon production

TAPPI Journal ◽  
2019 ◽  
Vol 18 (5) ◽  
pp. 287-293 ◽  
Author(s):  
JANNATUN NAYEEM ◽  
M. SARWAR JAHAN ◽  
RAZIA SULTANA POPY ◽  
M. NASHIR UDDIN ◽  
M.A. QUAIYYUM
Keyword(s):  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Solid Residue ◽  
Rayon Production ◽  
Kraft Cooking ◽  
Prehydrolysis Kraft

Jute cutting, jute caddis, and cutting-caddis mixtures were prehydrolyzed by varying time and temperature to get about 90% prehydrolyzed yield. At the conditions of 170°C for 60 min of prehydrolysis, the yield for 100% jute cutting was 76.3%, while the same for jute caddis was only 67.9%. But with prehydrolysis at 150°C for 60 min, the yield was 90% for jute cutting, where 49.94% of original pentosan was dissolved and prehydrolysis of jute caddis at 140°C in 60 min yielded 86.4% solid residue. Jute cutting-caddis mixed prehydrolysis was done at 140°C for 30 min and yielded 92% solid residue for 50:50 cutting-caddis mixtures, where pentosan dissolution was only 29%. Prehydrolyzed jute cutting, jute caddis, and cutting-caddis mixtures were subsequently kraft cooked. Pulp yield was only 40.9% for 100% jute cutting prehydrolyzed at 170°C for 60 min, which was 10.9% lower than the prehydrolysis at 140°C. For jute cutting-caddis mixed prehydrolysis at 140°C for 45 min followed by kraft cooking, pulp yield decreased by 3.3% from the 100% cutting to 50% caddis in the mixture, but 75% caddis in the mixture decreased pulp yield by 6.7%. The kappa number 50:50 cutting-caddis mixture was only 11.3. Pulp bleachability improved with increasing jute cutting proportion in the cutting-caddis mixture pulp.

Gebirgswaldpflege – es kommt auf den Standort an | Mountain silviculture – it all depends on the site

2001 ◽  
Vol 152 (5) ◽  
pp. 169-176 ◽  
Author(s):  
Monika Frehner
Keyword(s):  
Nature Conservation ◽  
Low Temperature ◽  
Tree Species ◽  
Forest Stand ◽  
Ground Vegetation ◽  
Mountain Forests ◽  
Research Projects ◽  
Snow Mould ◽  
The Relationship ◽  
Protection Forests

The article shows that knowledge of the site of a particular forest stand, together with research results and experience, can provide information that is important for the cultivation of mountain forests, including knowledge of the composition of the tree species and the structure and growth capacity of natural forest. Furthermore, certain sites can, thus, be characterized by factors that influence restocking, such as snow mould,lush ground vegetation or low temperature. The guidelines«minimale Pflegemassnahmen» – «Minimal tending of protection forests» (WASSER und FREHNER, 1996) are based on this principle. For individual sites, warnings about natural dangers such as rock fall or statements concerning nature conservation can be made (e.g., the occurrence of tree species, suitability as a biotope for Capercaille). In conclusion, two research projects on the relationship between site and natural dangers will be presented.

scholarly journals Influence of Preaging Temperature on the Indentation Strength of 3Y-TZP Aged in Ambient Atmosphere

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2767
Author(s):  
Ki-Won Jeong ◽  
Jung-Suk Han ◽  
Gi-Uk Yang ◽  
Dae-Joon Kim
Keyword(s):  
Residual Stress ◽  
Phase Transformation ◽  
Low Temperature ◽  
Compressive Residual Stress ◽  
Yttria Stabilized Zirconia ◽  
Ambient Atmosphere ◽  
Aged Specimen ◽  
Stabilized Zirconia ◽  
M Phase ◽  
The Relationship

Yttria-stabilized zirconia (3Y-TZP) containing 0.25% Al2O3, which is resistant to low temperature degradation (LTD), was aged for 10 h at 130–220 °C in air. The aged specimens were subsequently indented at loads ranging from 9.8 to 490 N using a Vickers indenter. The influence of preaging temperature on the biaxial strength of the specimens was investigated to elucidate the relationship between the extent of LTD and the strength of zirconia restorations that underwent LTD. The indented strength of the specimens increased as the preaging temperature was increased higher than 160 °C, which was accompanied by extensive t-ZrO2 (t) to m-ZrO2 (m) and c-ZrO2 (c) to r-ZrO2 (r) phase transformations. The influence of preaging temperature on the indented strength was rationalized by the residual stresses raised by the t→m transformation and the reversal of tensile residual stress on the aged specimen surface due to the indentation. The results suggested that the longevity of restorations would not be deteriorated if the aged restorations retain compressive residual stress on the surface, which corresponds to the extent of t→m phase transformation less than 52% in ambient environment.

Drift-dissipative instability of the electromagnetic convection mode in a low-temperature plasma

1992 ◽  
Vol 47 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Hamid Saleem ◽  
M. Y. Yu
Keyword(s):  
Low Temperature ◽  
Collisional Plasma ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Electromagnetic Effects ◽  
Dissipative Instability ◽  
Low Temperature Plasmas ◽  
The Relationship

The convection mode in a collisional plasma is investigated, with the inclusion of electromagnetic effects. It is shown that a dissipative instability can occur. The relationship to several well-known modes as well as applications to typical low-temperature plasmas are discussed.

Effects of a PFI refiner’s operational parameters on the swellability of recycled fiber

TAPPI Journal ◽  
2020 ◽  
Vol 19 (5) ◽  
pp. 239-246
Author(s):  
XIAONING SHEN ◽  
BO LI ◽  
WENXUAN MO ◽  
XIN-SHENG CHAI
Keyword(s):  
Water Retention ◽  
Fiber Quality ◽  
Operational Parameters ◽  
Fiber Morphology ◽  
Water Retention Value ◽  
Electron Microscopic ◽  
Mathematical Relation ◽  
Scanning Electron Microscopic ◽  
Recycled Fiber ◽  
Scanning Electron

This paper presents data on the effects of operational parameters (number of revolutions, linear pressure, and gap) of the PFI refiner on the swellability of recycled fiber, which was characterized by water retention value (WRV). The results showed that the increase of recycled fiber’s WRV was proportional to the number of revolutions and the linear pressure, but inversely proportional to the gap. The mathematical relation between these parameters and the fiber WRV could be described by an empirical model for gaps greater than 0.1 mm. Scanning electron microscopic images of fiber morphology showed that the basic framework of fibers could be maintained with the gap greater than 0.1 mm, but was destroyed with smaller gaps. This model provides a technical reference for quantitative control of refining treatment and an effective method for improving recycled fiber quality.

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