Pulping-tailored fiber properties from a novel Brazilian Eucalyptus hybrid

Holzforschung ◽  
2014 ◽  
Vol 68 (3) ◽  
pp. 273-282 ◽  
Author(s):  
Marcelo Coelho dos Santos Muguet ◽  
Fernando José Borges Gomes ◽  
Kyösti Ruuttunen ◽  
Leena-Sisko Johansson ◽  
Anna-Stiina Jääskeläinen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Lignin Content ◽  
Eucalyptus Grandis ◽  
Physical And Mechanical Properties ◽  
Pulp Fibers ◽  
Fiber Properties ◽  
Thermomechanical Pulping ◽  
Bulk Chemical

Abstract The chemical composition and morphology of pulp fibers have a significant impact on the properties of fiber products. Pulp samples from a novel unique Eucalyptus triple hybrid [Eucalyptus grandis × (Eucalyptus urophylla × Eucalyptus globulus)] were obtained by various pulping processes – kraft, soda-anthraquinone (NaOH-AQ), and thermomechanical pulping (TMP). The chemical composition of the fiber surfaces was evaluated by X-ray photoelectron spectroscopy (XPS). The surface lignin content of NaOH-AQ pulp fibers was lower than that of the kraft counterpart. However, kraft pulp handsheets showed better physical and mechanical properties. XPS data strongly suggests that together with the pulp bulk chemical composition the xylan is more abundant on the surface of kraft fibers, which is reflected on their better mechanical properties. Moreover, the relatively low surface lignin content in TMP pulp compared to wood suggests that defibration takes place in the secondary wall, where lignin is less concentrated.

Probing the chemical and surface chemical modification of vessel cell walls during bleaching of eucalyptus pulp

Holzforschung ◽  
2012 ◽  
Vol 66 (8) ◽  
pp. 945-950 ◽  
Author(s):  
Elina Orblin ◽  
Nina Lindström ◽  
Pedro Fardim
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Wall Structure ◽  
Surface Chemical ◽  
Major Drawback ◽  
Elemental Chlorine ◽  
Eucalyptus Pulp ◽  
Vessel Elements ◽  
Cellulose Fibrils ◽  
Bulk Chemical

Abstract Eucalyptus pulp is increasingly used for the manufacture of printing papers. However, its major drawback, the vessel picking, is still waiting for a solution. The detailed features and the characteristic behaviour of vessel elements (VEs) in pulp and paper processes are poorly understood. This study focusses on the chemistry, surface chemistry and morphology of eucalyptus VEs. These properties were followed through the changes introduced by different stages of elemental chlorine-free (ECF) bleaching, by studying separated VEs. Microprobe X-ray photoelectron spectroscopy (μ-XPS) and field emission-scanning electron microscopy (FE-SEM) were applied to elucidate the surface chemical composition and morphological ultrastructure, respectively. The bulk chemical composition was investigated among others by Py-GC/MS. Lignin was detected in vessels still after completed bleaching sequence, whereas the fibres were lignin-free. The vessel lignin was mainly composed by syringyl-type units. Surface coverage by lignin and amount of surface anionic groups were practically unaffected by bleaching. The vessel cell wall structure was observed to be layered in a complex way with no particular orientation of cellulose fibrils, and the different layers seemed to be exfoliated during different bleaching stages.

Evaluation of the Influence of Pre-Alloyed Powder Fe65Nb on the Production of Metal Matrices by Powder Metallurgy

2020 ◽  
Vol 1012 ◽  
pp. 3-8
Author(s):  
A.C.G. Silva ◽  
Hellen C.P. Oliveira ◽  
Thales Eduardo Leal ◽  
Paulo Santos Assis
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Chemical Composition ◽  
Solid State ◽  
Hot Pressing ◽  
Physical And Mechanical Properties ◽  
Toxic Element ◽  
Alloyed Powder ◽  
Eds Analysis ◽  
Porosity Measurements

The objective of this paper is to study Fe65Nb-Cu metal matrices, thus varying the content of the pre-alloyed Fe65Nb powder from 10% to 100%. Therefore, powders of Fe65Nb and Cu were used, innovating in the chemical composition of the commonly used matrices. The objective is to evaluate the substitution of Co (toxic element, commonly used) by Nb (98.2% of reserves are Brazilian). For the sintering of the samples it was used hot pressing technique. The parameters were set at: 850°C / 35MPa / 3min. The sintered bodies underwent SEM/EDS analysis and density and porosity measurements were performed. From the results it is possible to say that the compositions of (10% and 30% Fe65Nb) presented the best physical and mechanical properties. The relative density decreases for the compositions with 40%, 50% and 60% Fe65Nb is justified by the presence of fragile particles in metal matrices, since they require more energy in order to efficiently transport matter (diffusion) in a solid state.

scholarly journals THE DEPENDENCE OF THE PHYSICAL MECHANICAL PROPERTIES OF EXPANDED-CLAY LIGHTWEIGHT CONCRETE ON THE COMPOSITION

2010 ◽  
Vol 2 (6) ◽  
pp. 50-55
Author(s):  
Marija Vaičienė ◽  
Jurgita Malaiškienė
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Chemical Composition ◽  
Water Absorption ◽  
Lightweight Concrete ◽  
Physical And Mechanical Properties ◽  
Concrete Mixture ◽  
Active Filler ◽  
Binder Material ◽  
Substitute Materials

Binder material is the most expensive raw component of concrete; thus, scientists are looking for cheaper substitute materials. This paper shows that when manufacturing, a part of the binder material of expanded-clay lightweight concrete can be replaced with active filler. The conducted studies show that technogenic – catalyst waste could act as similar filler. The study also includes the dependence of the physical and mechanical properties of expanded-clay lightweight concrete on the concrete mixture and the chemical composition of the samples obtained. Different formation and composition mixtures of expanded-clay lightweight concrete were chosen to determine the properties of physical-mechanical properties such as density, water absorption and compressive strength.

scholarly journals Joint Effect of Steel Addition and Press-and-Sinter on the Properties of Low-Cost PM Ti Alloys

2018 ◽  
Vol 770 ◽  
pp. 248-254
Author(s):  
Leandro Bolzoni ◽  
Elisa Maria Ruiz-Navas ◽  
Elena Gordo
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Biomedical Applications ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Steel Powder ◽  
Joint Effect ◽  
Ti Alloys ◽  
Commercial Steel ◽  
Processing Techniques

Cheap alloying elements and creative processing techniques are a way forward to open up more industrial opportunities for Ti in sectors where it is not extensively applied yet, rather than in aerospace and biomedical applications. This study focuses on understanding the joint effect of using a commercial steel powder to add Fe to pure Ti and its processing by press-and-sinter on the behaviour of low-cost PM Ti alloys. It is found that the calibrated addition of steel permits to develop new low-cost Fe-bearing Ti alloys that can satisfactorily be produced using the blending elemental PM approach. Densification of the samples and homogenization of the chemical composition are enhanced by the high diffusivity of Fe. The low-cost α+β alloys reach comparable physical and mechanical properties to those of wrought-equivalent PM Ti alloys, such as Ti-6Al-4V, and are therefore promising candidates for load-bearing lightweight products.

Influence of Aluminium Content on Behaviour of Magnesium Cast Alloys in Bentonite Sand Mould

2009 ◽  
Vol 147-149 ◽  
pp. 764-769 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Tomasz Tański
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Chemical Composition ◽  
Physical And Mechanical Properties ◽  
Aluminium Content ◽  
Cast State ◽  
Cast Alloys ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium ◽  
Cooling Methods

In this paper there is presented the structure and proprieties of the modeling cast magnesium alloys as cast state and after heat treatment, depending on the cooling medium (furnace, water, air), with different chemical composition. The improvement of the manufacturing technique and chemical composition as well as of heat treatment and cooling methods leads to the development of a material designing process for the optimal physical and mechanical properties of a new developed alloy. In the analysed alloys a structure of solid solution and fragile phase  (Mg17Al12) occurred mainly on grain borders as well as eutectic and AlMnFe, Mg2Si phase. The investigation is carried out to testy the influence of the chemical composition and precipitation processes on the structure and mechanical properties of the magnesium cast alloys with different chemical composition in its as cast alloys and after heat treatment.

scholarly journals All-lignocellulosic Fiberboard from Steam Exploded Arundo Donax L.

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2088 ◽  
Author(s):  
Diego Ramos ◽  
Nour-Eddine El Mansouri ◽  
Francesc Ferrando ◽  
Joan Salvadó
Keyword(s):  
Chemical Composition ◽  
Lignin Content ◽  
Batch Reactor ◽  
Physical And Mechanical Properties ◽  
Arundo Donax ◽  
Raw Material ◽  
Modulus Of Rupture ◽  
Pressing Pressure ◽  
Wet Process ◽  
Arundo Donax L

This paper explores the possibility of producing all-lignocellulosic fiberboards from Arundo donax L. as a source of lignocellulosic fibers with no synthetic binders. This raw material was steam exploded with a thermomechanical aqueous vapor process in a batch reactor. The Arundo donax raw material and its obtained pulp were characterized in terms of chemical composition and the results were compared to other lignocellulosic materials. The chemical composition of steam exploded Arundo fibers showed high cellulose and a moderate lignin content suggesting it was a good raw material for fiberboard production. The all-lignocellulosic fiberboards were produced on laboratory scale; using the steam exploded Arundo donax by means of a wet process. The effects of pressing pressure on physical and mechanical properties were evaluated and the conditions that optimize the responses were found. The analyzed properties were density (d); water absorption (WA); thickness swelling (TS); modulus of elasticity (MOE); modulus of rupture (MOR); and internal bond strength (IB). The tested levels of the pressing pressure range from 0.35 to 15 MPa. The optimum IB; MOE; MOR; WA and TS were 1.28 MPa, 7439 MPa, 40.4 MPa, 17.6% and 13.3%, respectively. The obtained fiberboards were of very good quality and more than satisfy the requirements of the relevant standard specifications.

scholarly journals INVESTIGATION OF HOT PLASTIC DEFORMATION OF LABORATORY AXIAL FLOATS

2021 ◽  
pp. 12-16
Author(s):  
Oleksandr Babachenko ◽  
Ganna Kononenko ◽  
Katerina Domina ◽  
Rostislav Podolskyi ◽  
Olena Safronova
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Chemical Composition ◽  
Physical And Mechanical Properties ◽  
Pressure Treatment ◽  
Initial Length ◽  
Hot Plastic Deformation ◽  
The Impact ◽  
Further Development

A review of research in the field of modeling experiments on heat treatment and pressure treatment of metal and the impact on the physical and mechanical properties of steel with a chemical composition of 0.59% C, 0.31% Si, 0.73% Mn. A mathematical model for calculating the physical and mechanical properties of steel in the process of hot plastic deformation has been developed and prospects for further development of research in this area have been identified. As a result of modeling, the following functions were obtained: the amount of deformation in the direction of the applied force divided by the initial length of the material. The coefficient of elongation of the material with the actual chemical composition at a temperature of 1250 ± 10 ° C, which was 0.32. When comparing the values of the load that was applied to the GPA in the laboratory and the results of calculations using the developed model, it was found that they have close values of about 45 MPa. This confirms the adequacy of the obtained model.A review of research in the field of modeling experiments on heat treatment and pressure treatment of metal and the impact on the physical and mechanical properties of steel with a chemical composition of 0.59% C, 0.31% Si, 0.73% Mn. A mathematical model for calculating the physical and mechanical properties of steel in the process of hot plastic deformation has been developed and prospects for further development of research in this area have been identified. As a result of modeling, the following functions were obtained: the amount of deformation in the direction of the applied force divided by the initial length of the material. The coefficient of elongation of the material with the actual chemical composition at a temperature of 1250 ± 10 ° C, which was 0.32. When comparing the values of the load that was applied to the GPA in the laboratory and the results of calculations using the developed model, it was found that they have close values of about 45 MPa. This confirms the adequacy of the obtained model.

scholarly journals INFLUENCE OF DRYING ON THE PHYSICAL AND MECHANICAL PROPERTIES OF WOOD FROM TREES GROWN IN AN AGROFORESTRY SYSTEM

2020 ◽  
Vol 44 ◽  
Author(s):  
Elder Eloy ◽  
Eduarda Bandera ◽  
Tauana Mangini ◽  
Laura da Silva Zanchetta ◽  
Rômulo Trevisan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Eucalyptus Grandis ◽  
Physical And Mechanical Properties ◽  
Agroforestry System ◽  
Bending Test ◽  
Schizolobium Parahyba ◽  
Standard Specimens ◽  
Forced Air ◽  
Air Circulation

ABSTRACT The cultivation of native and exotic species intercropped in an agroforestry system raises the interest for information on the properties of wood. Therefore, different methods are being tested to improve the technological properties of this material, including drying, which causes changes in the physical and mechanical properties of the wood. The present study investigated the influence of drying on the physical and mechanical properties of wood from tree species grown in an agroforestry system. Parapiptadenia rigida (Benth.) Brenan, Peltophorum dubium (Spreng.) Taub., Eucalyptus grandis W. Hill × Eucalyptus urophylla S.T. Blake (hybrid), and Schizolobium parahyba (Vell.) S.F.Blake were the species selected for the study. Three 9-year-old individuals of each of the species were obtained from an agroforestry system. Thirty wood samples (2.5 × 2.5 × 41 cm) were extracted from each species. The wood samples were divided between temperature treatments; 6 samples were used for each heat treatment (control, 120, 150, 180, and 210 °C), which were then dried for two hours in an oven (with forced air circulation). Following the heat treatment, the mechanical properties of wood samples were evaluated to determine the modulus of elasticity and rupture, the tension in the proportional limit, and maximum force according to the ASTM D-143-94 (2000) standard. Finally, the physical properties of the retractability of the wood samples were evaluated according to the NBR 7190 (ABNT, 1997) standard. Specimens used to analyze this variable came from sections of the wood (sample dimensions: 2.5 × 2.5 × 5 cm) not affected by the static bending test. Our findings indicate that, for all species investigated in this study, drying alters the physical and mechanical properties of the wood, with the most significant changes occurring at temperatures between 120 and 180 °C.

scholarly journals Willow wood (Salix alba) as a raw material for pulp production

2005 ◽  
Vol 59 (7-8) ◽  
pp. 175-179
Author(s):  
Bojana Klasnja ◽  
Sasa Orlovic ◽  
Nenad Radosavljevic ◽  
Miroslav Markovic
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Populus Deltoides ◽  
Chemical Properties ◽  
Physical And Mechanical Properties ◽  
Raw Material ◽  
Poplar Wood ◽  
Salix Alba ◽  
Pulp Production ◽  
Sulphate Pulp

The properties of willow wood (structural-physical and mechanical properties and chemical composition) were investigated to determine the parameters of the technological process of semichemical and sulphate pulp manufacture. The experimental material was willow wood Salix alba cl. 107/65/7. Semichemical and sulphate pulp were obtained in the laboratory. The yield, chemical properties and physical-mechanical properties of the obtained intermediate products intended for paper manufacture, were determined. The properties of poplar wood Populus deltoides Bartr. cl.725, were studied and its pulp production performed with the aim of comparison.

Influence of the Chemical Composition of Bauxite on Mineral Formation and Properties of Sulfoaluminate-Ferrite Cement

2021 ◽  
Vol 325 ◽  
pp. 53-58
Author(s):  
Aleksandr A. Ponomarenko ◽  
Fedor L. Kapustin ◽  
Elena Makarova ◽  
Ekaterina S. Gerasimova
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Mineral Composition ◽  
Cement Paste ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Mineral Formation ◽  
Quality Coefficient

The influence of the chemical composition of bauxite on the mineral formation and structure of sulfoaluminate-ferrite clinker (SAFC), and physical and mechanical properties of cement based on it is studied. Ferrous bauxite, marble crushing screenings and neutralized fluorine-anhydrite were used for the synthesis of SAFC. The compositions of raw mixes of low-and high-alkaline SAFC are calculated with modular characteristics: Mf (ferritic modulus) = 0.35 and 0.7, Мs (sulfate modulus) = 0.167 and 0.5, respectively. Clinker synthesis from a raw mix containing ferrous bauxite with a quality coefficient of 1.7 must be carried out at a temperature of 1250 °C, which is reduced to 1200 °C for burning a raw mix based on bauxite with a quality coefficient of 2.2. Intensive decomposition of anhydrite occurs with the release of sulfur dioxide into the atmosphere at a temperature of 1300 °C, so it is not recommended to burn SAFC at this temperature. The mineral composition of the obtained SAFC is represented by sulfoaluminate, calcium sulfoferrite and free anhydrite. There is no C2S as a separate phase in clinkers, since in the process of their synthesis belite dissolves in 3С(A,F)·СŜ, mainly in the aluminoferrite phase. The use of bauxite with a quality coefficient of 2.2 in the SAFC raw mix increases the cement activity up to 54.2 MPa. Increasing its specific surface from 350 to 460 m2/kg significantly reduces the setting time of cement paste and increases the strength of sulfoaluminate-ferrite cement both in the early (up to 43.4 MPa) and late hardening periods (up to 67.3 MPa).

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