scholarly journals Papermaking properties of tropical wood pulp

2020 ◽  
Author(s):  
Х.М. Кхоа ◽  
М.И. Макаров ◽  
Я.В. Казаков ◽  
Е.О. Окулова
Keyword(s):  
Shape Factor ◽  
Morphological Properties ◽  
Northern Hardwood ◽  
Softwood Pulp ◽  
Before And After ◽  
Bamboo Fibers ◽  
Acacia Hybrid ◽  
Hardwood Pulp ◽  
Strength And Stiffness ◽  
Tropical Woods

В работе рассмотрены структурно-морфологические и бумагообразующие свойства целлюлозы, полученной сульфатным способом из древесины тропических пород – Bambusa blumeana и акация Acacia hybrid, местом произрастания которых является Вьетнам. Выполнено сравнение со свойствами целлюлозы из древесины традиционных северных лиственных (смесь березы и осины 50:50) и хвойных пород. Структурно-морфологические свойства определены на автоматическом анализаторе волокна L&W Fiber Tester. Цифровые микрофотографии получены на микроскопе «ImagerM2m Carl Zeiss». Исследованы образцы до и после размола на мельнице Йокро до степени помола 30 °ШР, для целлюлозы из акации – 20 °ШР. Установлено, что, по сравнению с лиственной целлюлозой, волокна бамбука более длинные (1,8 мм против 1,0 мм), с меньшей шириной (17 мкм против 26 мкм), более изогнутые (фактор формы 87,5 против 92,5) и имеют больше изломов (0,42 против 0,29). Волокна акации более короткие (0,9 мм против 1,0 мм), с меньшей шириной (19 мкм против 26 мкм), более изогнутые (фактор формы 91,6 против 92,5) и имеют больше изломов (0,44 против 0,29). По сравнению с хвойной целлюлозой волокна бамбука и акации более короткие с меньшей шириной, менее изогнутые и имеют больше изломов. Использование небеленой целлюлозы из бамбука и акации в композиции небеленых видов бумаги и картона не приведет к повышению их прочности и жесткости, но может использоваться для повышения эластичности и растяжимости, что должно быть установлено в дальнейших исследованиях. The paper considers the structural-morphological and papermaking properties of kraft pulp from tropical woods – Bambusa blumeana and Acacia hybrid, the place of growth of which is Vietnam. A comparison with the properties of traditional northern hardwood pulp (a mixture of birch and aspen 50:50) and softwood pulp was made. Structural and morphological properties are determined on an automatic fiber analyzer L&W Fiber Tester. Digital micrographs were taken with an ImagerM2m Carl Zeiss microscope. Samples were studied before and after refining at the Yokro mill to 30° SR, for acacia pulp – 20°SR. It was found that, compared with hardwood pulp, bamboo fibers are longer (1.8 mm vs 1.0 mm), with a smaller width (17 μm vs 26 μm), more curved (shape factor 87.5 vs 92.5) and have more kinks (0.42 versus 0.29). Acacia fibers are shorter (0.9 mm vs 1.0 mm), with a smaller width (19 μm vs 26 μm), more curved (shape factor 91.6 vs 92.5) and have more kinks (0.44 vs 0.29). Compared to softwood pulp, bamboo and acacia fibers are shorter with a smaller width, less curved and have more kinks. The use of unbleached pulp from bamboo and acacia in the furnish of unbleached types of paper and cardboard will not lead to an increase in their strength and stiffness, but can be used to increase elasticity and extensibility, which should be established in further studies.

From biorefineries to bioproducts: conversion of pretreated pulp from biorefining streams to lignocellulose nanofibers

TAPPI Journal ◽  
2019 ◽  
Vol 18 (4) ◽  
pp. 233-241
Author(s):  
CHENGGUI SUN ◽  
RICHARD CHANDRA ◽  
YAMAN BOLUK
Keyword(s):  
Energy Consumption ◽  
Enzymatic Hydrolysis ◽  
Rheological Behavior ◽  
Material Basis ◽  
Softwood Pulp ◽  
Energy Consumptions ◽  
Hardwood Pulp ◽  
The Stability ◽  
Lignocellulose Nanofibers

This study investigates the use of pretreatment and enzymatic hydrolysis side streams and conversion to lignocellulose nanofibers. We used a steam-exploded and partial enzymatic hydrolyzed hardwood pulp and an organosolv pretreated softwood pulp to prepare lignocellulose nanofibers (LCNF) via microfluidization. The energies applied on fibrillation were estimated to examine the energy consumption levels of LCNF production. The energy consumptions of the fibrillation processes of the hardwood LCNF production and the softwood LCNF production were about 7040-14080 kWh/ton and 4640 kWh/ton on a dry material basis, respectively. The morphology and dimension of developed hardwood and softwood LCNFs and the stability and rheological behavior of their suspensions were investigated and are discussed.

scholarly journals Corrosion Characteristics of Copper in Malaysian Bioethanol and Gasoline Blends

2013 ◽  
Vol 467 ◽  
pp. 122-126 ◽  
Author(s):  
T. Saravana Kannan ◽  
C. Piraiarasi ◽  
Abu Saleh Ahmed ◽  
Ani Farid Nasir
Keyword(s):  
Chemical Properties ◽  
Optical Microscope ◽  
Acid Number ◽  
Morphological Properties ◽  
Engine Fuel ◽  
High Concentration ◽  
Total Acid ◽  
Hardness Tester ◽  
Fuel Blends ◽  
Before And After

The present study aims to investigate the corrosion characteristics of copper commonly encountered in the spark ignition (SI) engine fuel system with Malaysian bioethanol and gasoline blends. Static immersion tests in E0 (gasoline), E10 and E85 were carried out at room temperature for 1320 h. Mechanical, physical and chemical properties of copper was investigated before and after immersion tests. Investigations were carried out on change in morphological properties using optical microscope; change in chemical structure using FTIR; change in mass and volume by weight loss measurement; hardness changes using universal hardness tester; and change of chemical properties of the fuel blends using total acid number titration method. The test results showed that corrosion of copper was increased with the high concentration of ethanol in the blends.

scholarly journals Curable Area Substantiation of Self-Healing in Concrete Using Neutral Axis

2019 ◽  
Vol 9 (8) ◽  
pp. 1537 ◽  
Author(s):  
Choonghyun Kang ◽  
Taewan Kim
Keyword(s):  
Neutral Axis ◽  
The Self ◽  
Strain Gauges ◽  
Self Healing ◽  
Distinct Area ◽  
Before And After ◽  
Strength And Stiffness ◽  
Underlying Mechanisms ◽  
Healing Assessment ◽  
Physical Recovery

The self-healing nature of concrete has been proved in many studies using various methods. However, the underlying mechanisms and the distinct area of self-healing have not been identified in detail. This study focuses on the limits of the area of self-healing. A bending specimen with a notch is used herein, and its flexural strength and stiffness before and after healing are compared and used for self-healing assessment. In addition, the neutral axis of the specimen was measured using successive strain gauges attached to the crack propagation part. Although the strength and stiffness of the concrete recovered after self-healing, the change in the location of the neutral axis before and after healing was insignificant, which indicates that physical recovery did not occur for once-opened crack areas.

Artificial weathering of tropical woods. Part 2: Color change

Holzforschung ◽  
2004 ◽  
Vol 58 (5) ◽  
pp. 558-565 ◽  
Author(s):  
Masanori Kishino ◽  
Takato Nakano
Keyword(s):  
Diffuse Reflectance ◽  
Color Change ◽  
Reflectance Spectra ◽  
Acacia Auriculiformis ◽  
Eucalyptus Marginata ◽  
Artificial Weathering ◽  
Diffuse Reflectance Spectra ◽  
Before And After ◽  
The Difference ◽  
Tropical Woods

Abstract This paper describes the change in diffuse reflectance Fourier transform infrared (DRIFT) and ultraviolet-visible (UV-Vis) diffuse reflectance spectra of the following eight tropical woods during artificial weathering up to 600 h in relation to their color changes, especially to yellowing: Amnurana acreana, Acacia auriculiformis, Dipterocarpus spp., Eucalyptus marginata, Eucalyptus robusta, Shorea spp. and Tabebuia spp. with relatively high and low specific gravity. For A. acreana, A. auriculiformis, Dipterocarpus spp. and both Tabebuia spp., Δb* (yellowing) increased with exposure up to 50 h, and decreased above 50 h. For E. marginata, E. robusta and Shorea spp., on the other hand, both Δa* (shift to red) and Δb* decreased with increased exposure time. For woods in which Δb* increased, the Δb* showed a positive dependence on the difference in relative intensity ratio of a band at 1740 cm–1 to that at 2900 cm–1 (ΔD1740/D2900) in DRIFT spectra of specimens before and after exposure. This result indicated that the increased band at 1740 cm–1 played a significant role in the increased Δb*. Then again, also for woods in which Δb* decreased, the ΔD1740/D2900 increased, but was not related to the Db*. The ΔD1740/D2900 for woods in which Δb* decreased had a positive relationship to the difference in remission function at 410 nm (ΔF(R∞)410) in UV-Vis diffuse reflectance spectra for specimens before and after exposure, while woods in which Δb* increased were independent of the ΔF(R∞)410. Therefore, it is suggested that woods in which Δb* increased and decreased differ from one another in the contribution to the increase in the band at 1740 cm–1, resulting in either an increase or decrease of Δb*.

Strength and Stiffness Optimization of Heavy-Duty Gear

2013 ◽  
Vol 712-715 ◽  
pp. 1701-1704
Author(s):  
Li Yang
Keyword(s):  
Light Weight ◽  
Heavy Duty ◽  
Body Form ◽  
Structure Characteristics ◽  
Frequency Adjustment ◽  
Stiffness Optimization ◽  
Before And After ◽  
Strength And Stiffness

In this paper, a kind of advanced gear body form is proposed, which has the structure characteristics of no weight reducing whole, thin spoke platesthick rim and large fillet. The optimization effect is confirmated by comparative analyzing the structure before and after optimization on strengthstiffnessweight and frequency adjustment performance of gear. The results show that the kind of optimization gear body is suitable for application in aviation, for which has the features of high strengthgood stiffness and light weight and which is easy to adjust gear frequency.

scholarly journals Effect of cotton padding on the setting properties of plaster slabs

2013 ◽  
Vol 95 (2) ◽  
pp. 107-109 ◽  
Author(s):  
D Barlow ◽  
R Bansal ◽  
T Barlow ◽  
SJ Rhee ◽  
JH Kuiper ◽  
...  
Keyword(s):  
Water Content ◽  
Water Immersion ◽  
Testing Machine ◽  
Materials Testing ◽  
Optimal Position ◽  
Three Point Bending ◽  
Before And After ◽  
Plastic Cylinder ◽  
Strength And Stiffness ◽  
American Society

Introduction Plaster of Paris (PoP) impregnated bandages have been used to maintain the position of bones and joints for over a century. Classically, wool dressing is applied to the limb before the PoP, which can then be moulded to the desired shape. A modification of this practice is to wrap the PoP bandages circumferentially in cotton before wetting and applying to the patient in an attempt to reduce inhalation of plaster dust and reduce mess. However, this may affect the water content of the cast and therefore also its setting properties and strength. This study compared the setting properties of PoP casts when used with and without cotton wrapping. Methods Sixty specimens, compliant with the American Society for Testing and Materials standards for three-point bending tests, were prepared, with thirty wrapped in cotton. All were weighed before and after water immersion, and wrapped around a plastic cylinder to mimic limb application. Bending stiffness and yield strength was measured on a servohydraulic materials testing machine at 2, 6, 12, 24, 48 and 72 hours. Results The water content of cotton-wrapped plaster was significantly higher (50%) than that of standard plaster. It had significantly lower strength up to 24 hours and significantly lower stiffness up to 72 hours. Conclusions The initial decrease in strength and stiffness of the cast wrapped in cotton may comprise the ability of the backslab to hold the joint or bone in an optimal position. Any modification of the standard plaster slab application technique should allow for the potential adverse effects on the plaster setting properties.

Effect of Compatibilizers on Mechanical Thermal and Morphology Properties of HDPE/TiO2 Nanocomposites

2010 ◽  
Vol 93-94 ◽  
pp. 169-172
Author(s):  
N. Wiriyanukul ◽  
S. Wacharawichanant
Keyword(s):  
Tensile Strength ◽  
Electron Microscope ◽  
High Density Polyethylene ◽  
Morphological Properties ◽  
Screw Extruder ◽  
Melt Mixing ◽  
Before And After ◽  
Twin Screw ◽  
Dispersion Of Nanoparticles ◽  
Scanning Electron

This work studies the effect of PE-g-MA compatibilizer on mechanical thermal and morphological properties of high density polyethylene (HDPE)/titanium dioxide (TiO2) nanocomposites. The HDPE/TiO2 nanocomposites with and without PE-g-MA compatibilizer were prepared by melt mixing technique in a twin screw extruder. The results found that Young's Modulus of HDPE/TiO2 nanocomposites increased with increasing TiO2 contents. The addition of PE-g-MA compatibilizer had no significant effect on the tensile strength and stress at break of HDPE/TiO2 nanocomposites. The decomposition temperatures of HDPE/TiO2 nanocomposites before and after adding PE-g-MA compatibilizer increased with increasing TiO2 contents. The dispersion of TiO2 nanoparticles in HDPE matrix was observed by scanning electron microscope (SEM). The dispersion of nanoparticles in HDPE matrix with PE-g-MA compatibilizer was relatively good, only a few aggregates exited.

Studies on Tensile Properties of Compatibilized and Uncompatibilized Low-Density Polyethylene/Jackfruit Seed Flour (LDPE/JFSF) Blends at Different JFSF Content

2017 ◽  
Vol 264 ◽  
pp. 120-123 ◽  
Author(s):  
Sung Ting Sam ◽  
Omar Sabbar Dahham ◽  
Pei Gie Gan ◽  
N.Z. Noimam ◽  
Jingi Y. Kuan ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Adipic Acid ◽  
Morphological Properties ◽  
Screw Extruder ◽  
Direct Introduction ◽  
Elongation At Break ◽  
Seed Flour ◽  
Before And After ◽  
Twin Screw ◽  
Natural Fillers

Currently, natural fillers seem to be the suitable materials in polymer industry, which have emerged as a viable and abundant replacement for the relatively high-cost and non-renewable conventional fillers. However, the direct introduction of natural fillers into polymer matrix could effect negatively on some properties. Therefore, the aim of this work is to evaluate the influence of jackfruit seed flour (JFSF) (before and after compatibilization) on the tensile properties of (LDPE/JFSF) blends. Different JFSF content (5, 10, 15 and 20 wt.%) with (63-100 𝜇𝑚) particle size were prepared in this work. Twin-screw extruder at 150°C and 50rpm screw speed followed by hot-compress machine at 150°C and 10MPa pressure were used respectively to produce (LDPE/JFSF) blends. Adipic acid (AA) solution was added as a compatibilizer into all blends equally (25wt% AA into 75wt% JFSf). The changes of tensile and morphological properties were investigated. Results shown decreasing on tensile strength and elongation at break of LDPE/JFSF and LDPE/JFSF/AA as JFSF increased. In contrast, Young’s modulus increased up to 10 wt.% of JFSF and then decreased. However, the addition of Adipic acid, particularly for JFSF 5wt.% has improved the tensile properties of LDPE/JFSF blends. The SEM micrographs showed the agglomeration at high JFSF content (20 wt%) which in turn effected negatively on the tensile properties. However, the blends show homogeneous surfaces as AA added.

scholarly journals Thermo-Mechanical and Morphological Properties of Water Hyacinth Reinforced Polypropylene Composites

2018 ◽  
Vol 3 (3) ◽  
pp. 151-161
Author(s):  
Manabendra Saha ◽  
Ali Md. Afsar
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Hyacinth ◽  
Thermal Analyses ◽  
Morphological Properties ◽  
Sem Images ◽  
Pull Out ◽  
Chemically Treated ◽  
Pp Composites ◽  
Strength And Stiffness

This paper focusses on the analysis of thermo-mechanical and morphological properties of water hyacinth (WH) fiber reinforced polypropylene (PP) biocomposites manufactured by using a single screw extruder and an injection molding machine. With a view to increasing the compatibility between the WH fibers and polypropylene matrix, raw WH fibers were chemically treated with Benzenediazonium salt in base media. Composites were manufactured with five different levels of loading (15, 20, 25, 30 and 35 wt%) of both the raw and treated WH fibers. Thermal properties of WH-PP composites were evaluated by thermogravimetric and differential thermal analyses. To analyze mechanical properties of composites, tests of tensile strength and stiffness, flexural strength and stiffness, and Charpy impact strength were carried out following ASTM standards. It was found that thermal stability and all the mechanical properties except tensile strength were improved considerably for chemically treated WH fiber composites in comparison with untreated ones. Fracture surfaces of the tensile and flexural specimens were scanned with scanning electron microscopy (SEM) to understand their surface morphologies. The SEM images clearly revealed that there were fewer fiber agglomerations, microvoids, and fiber pull out traces in treated WH-PP composites than in the untreated ones indicating better distribution of the fibers into the matrix as well as stronger fiber matrix interfacial adhesion due to treatment of WH fibers. Water absorption properties were studied to evaluate the viability of these biocomposites under specified conditions.

scholarly journals MORPHOLOGICAL PROPERTIES OF THE FIBERS OF DRY DEFIBRATION METHOD FOR CARDBOARD PRO-DUCTION

2019 ◽  
Author(s):  
Nikolay Petrovich Midukov ◽  
Yuliya Artemovna Lyalina ◽  
Viktor Sergeyevich Kurov ◽  
Aleksandr Semonovich Smolin
Keyword(s):  
Surface Roughness ◽  
Fiber Length ◽  
Ash Content ◽  
Main Flow ◽  
Morphological Properties ◽  
Combined Method ◽  
The World ◽  
Before And After ◽  
Breaking Length

Article is devoted to a research of morphological properties of the fibers produced from recovered paper by dry defibration method. Fiber length, roughness, torsion, curvature, fibrillation, fines, etc. properties of the fibers produced by the traditional conventional and dry defibration method are compared. Filler (chalk) losses are estimated by recovered paper preparation in the dry defibration method. The studied morphological properties of fibers and content of chalk define surface (roughness, thickness, whiteness) and mechanical (bursting strength, breaking length) test-liner cardboard indicators with a white surface layer. Determination of morphological properties of recovered paper stock fibers allows recommending a combined method of recovered paper preparation (including dry defibration) for test-liner cardboard manufacturers in our country and in the world. Changes of ash content data before and after dry defibration of fibers determine losses of chalk filler. It is known that content of chalk affects mechanical and surface properties of cardboard. Preliminary results of calculations of energy saving from implementation of dry method, carried out during industrial production, showed that at addition of fibers (25% of total weight of fibers in cardboard) prepared by dry method to the main flow, with preservation of mechanical indices of produced cardboard, up to 50 kWh/t of energy is saved.

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