Dry-Process Hardboards from Recycled Newsprint Paper Fibers

1992 ◽  
Vol 266 ◽  
Author(s):  
Andrzej M. Krzysik ◽  
John A. Youngquist ◽  
James M. Muehl ◽  
Roger M. Rowell ◽  
Poo Chow ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Mechanical Strength ◽  
Water Resistance ◽  
Wood Fiber ◽  
Strength Properties ◽  
Dry Process ◽  
Paper Fibers

AbstractDry-process hardboard represents a favorable option for recycling old newspaper fibers. However, dry-process boards tend to be less dimensionally stable than boards processed by other methods. Our objective was to determine the effects of various wood fiber (WF) to old newspaper (ONP) ratios (100:0, 50:50, and 0:100 WF/ONP) on the mechanical strength and water resistance of dry-process hardboards made from these fibers. Untreated and acetylated hardboards were made with 3 or 7 percent resin and 0.5 percent wax. Boards were tested for static bending and tensile strength properties and water resistance. As expected, increasing the resin level from 3 to 7 percent generally improved all measured properties. Acetylation substantially improved the water resistance of all boards; increasing the amount of ONP caused a corresponding deterioration in both mechanical properties and water resistance.

scholarly journals Influence of Alumina Nanofibers Sintered by the Spark Plasma Method on Nickel Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 548 ◽  
Author(s):  
Leonid Agureev ◽  
Valeriy Kostikov ◽  
Zhanna Eremeeva ◽  
Svetlana Savushkina ◽  
Boris Ivanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Strength Properties ◽  
Alumina Nanoparticles ◽  
Metal Powders ◽  
Wide Range ◽  
The Matrix ◽  
Spark Plasma ◽  
Average Size

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.

Optically Transparent Polymethyl Methacrylate Composites made with Glass Fibers of Varying Refractive Index

1997 ◽  
Vol 12 (4) ◽  
pp. 1091-1101 ◽  
Author(s):  
Seunggu Kang ◽  
Hongy Lin ◽  
Delbert E. Day ◽  
James O. Stoffer
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Refractive Index ◽  
Mechanical Strength ◽  
Glass Fiber ◽  
Polymethyl Methacrylate ◽  
Optical Transmission ◽  
Annealing Temperature ◽  
Glass Fibers ◽  
Optically Transparent

The dependence of the optical and mechanical properties of optically transparent polymethyl methacrylate (PMMA) composites on the annealing temperature of BK10 glass fibers was investigated. Annealing was used to modify the refractive index (R.I.) of the glass fiber so that it would more closely match that of PMMA. Annealing increased the refractive index of the fibers and narrowed the distribution of refractive index of the fibers, but lowered their mechanical strength so the mechanical properties of composites reinforced with annealed fibers were not as good as for composites containing as-pulled (chilled) glass fibers. The refractive index of as-pulled 17.1 μm diameter fibers (R.I. = 1.4907) increased to 1.4918 and 1.4948 after annealing at 350 °C to 500 °C for 1 h or 0.5 h, respectively. The refractive index of glass fibers annealed at 400 °C/1 h best matched that of PMMA at 589.3 nm and 25 °C, so the composite reinforced with those fibers had the highest optical transmission. Because annealed glass fibers had a more uniform refractive index than unannealed fibers, the composites made with annealed fibers had a higher optical transmission. The mechanical strength of annealed fiber/PMMA composites decreased as the fiber annealing temperature increased. A composite containing fibers annealed at 450 °C/1 h had a tensile strength 26% lower than that of a composite made with as-pulled fibers, but 73% higher than that for unreinforced PMMA. This decrease was avoided by treating annealed fibers with HF. Composites made with annealed and HF (10 vol. %)-treated (for 30 s) glass fibers had a tensile strength (∼200 MPa) equivalent to that of the composites made with as-pulled fibers. However, as the treatment time in HF increased, the tensile strength of the composites decreased because of a significant reduction in diameter of the glass fiber which reduced the volume percent fiber in the composite.

Preparation Techniques and Property Evaluations of Highly Air Permeable Needle-Punched Geotextiles

2015 ◽  
Vol 749 ◽  
pp. 278-281
Author(s):  
Jia Horng Lin ◽  
Jing Chzi Hsieh ◽  
Jin Mao Chen ◽  
Wen Hao Hsing ◽  
Hsueh Jen Tan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Service Life ◽  
Mechanical Strength ◽  
Pore Structure ◽  
Test Results ◽  
Needle Punching ◽  
Pet Fibers ◽  
Environmental Requirements ◽  
Preparation Techniques

Geotextiles are made of polymers, and their conjunction with different processes and materials can provide geotextiles with desirable characteristics and functions, such as filtration, separation, and drainage, and thereby meets the environmental requirements. Chemical resistant and mechanical strong polymers, including polyester (PET) and polypropylene (PP), are thus used to prolong the service life of the products made by such materials. This study proposes highly air permeable geotextiles that are made with different thicknesses and various needle punching speeds, and the influences of these two variables over the pore structure and mechanical properties are then examined. PET fibers, PP fibers, and recycled Kevlar fibers are blended, followed by being needle punched with differing spaces and speeds to form geotextiles with various thicknesses and porosities. The textiles are then evaluated for their mechanical strength and porosity. The test results show that a thickness of 4.5 cm and 1.5 cm demonstrate an influence on the tensile strength of the geotextiles, which is ascribed to the webs that are incompletely needle punched. However, the excessive needle punching speed corresponding to a thickness of 0.2 cm results in a decrease in tensile strength, but there is also an increase in the porosity of the geotextiles.

scholarly journals RESEARCH OF PHYSICAL AND MECHANICAL PROPERTIES OF WOOD-FIBER MATERIALS

2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina
Keyword(s):  
Mechanical Properties ◽  
Wood Fiber ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Production Method ◽  
Strength Properties ◽  
Grinding Process ◽  
Technological Parameters ◽  
Fiber Materials ◽  
Traditional Construction

This paper presents the results of experimental studies of the physical and mechanical properties of wood-fiber boards of the wet production method when regulating the design and technological parameters of the grinding process. This allowed us to determine the influence of the working clearance between the grinding discs and the concentration of fibre mass with the subject to of quality change wood fiber after defibrator using the developed construction of the disc fibrillation action on the physico-mechanical properties of boards. As a result of the experiment, regression models were obtained that adequately describe the studied grinding process and allow predicting the values of physical and mechanical properties of the finished product depending on the established  parameters process. A comparative analysis of the size and quality characteristics of the fiber semi-finished product and its fractional composition when using a developed construction the disc of refiner fibrillation action and a traditional design used in industry is carried out. The preferential efficiency of the grinding process under the fibrillating effect the disc of refiner in comparison with the traditional construction disc of refiner is established. As a result, there is a significant improvement in the quality indicators of the fiber semi-finished product and its composition due to the formation and predominance in the total mass of long and thin, respectively, flexible fibrillated fibers with high tile-forming properties, which allows to increase the strength properties of the product (by 20–25%), without using binding resins.

scholarly journals AN INVESTIGATION ON THE EFFECTS OF MICRO-PARAMETERS ON THE STRENGTH PROPERTIES OF ROCK

2021 ◽  
Vol 36 (1) ◽  
pp. 111-119
Author(s):  
Behzad Jafari Mohammadabadi ◽  
Kourosh Shahriar ◽  
Hossein Jalalifar ◽  
Kaveh Ahangari
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Friction Coefficient ◽  
Critical Stress ◽  
Friction Angle ◽  
Strength Properties ◽  
Brazilian Tensile Strength ◽  
The Relationship

Rocks are formed from particles and the interaction between those particles controls the behaviour of a rock’s mechanical properties. Since it is very important to conduct extensive studies about the relationship between the micro-parameters and macro-parameters of rock, this paper investigates the effects of some micro-parameters on strength properties and the behaviour of cracks in rock. This is carried out by using numerical simulation of an extensive series of Uniaxial Compressive Strength (UCS) and Brazilian Tensile Strength (BTS) tests. The micro-parameters included the particles’ contact modulus, the contact stiff ness ratio, bond cohesion, bond tensile strength, the friction coefficient and the friction angle, and the mechanical properties of chromite rock have been considered as base values of the investigation. Based on the obtained results, it was found that the most important micro-parameters on the behaviour of rock in the compressive state are bond cohesion, bond tensile strength, and the friction coefficient. Also, the bond tensile strength showed the largest effect under tensile conditions. The micro-parameter of bond tensile strength increased the rock tensile strength (up to 5 times), minimized destructive cracks and increased the corresponding strain (almost 2.5 times) during critical stress.

Mechanical Strength Properties of Injectable Carbonate Apatite Cement with Various Concentration of Sodium Carboxymethyl Cellulose

2017 ◽  
Vol 758 ◽  
pp. 56-60 ◽  
Author(s):  
Arief Cahyanto ◽  
Atina Ghina Imaniyyah ◽  
Myrna Nurlatifah Zakaria ◽  
Zulia Hasratiningsih
Keyword(s):  
Tensile Strength ◽  
Mechanical Strength ◽  
Carboxymethyl Cellulose ◽  
Strength Properties ◽  
Sodium Carboxymethyl Cellulose ◽  
Control Group ◽  
Carbonate Apatite ◽  
Initial Finding ◽  
Polymeric Additives ◽  
Diametral Tensile Strength

Mechanical strength is one of the key factors for clinical application of injectable carbonate apatite (CO3Ap) cement. Incorporation of polymeric additives into the mixing liquid of injectable bone cement has been known to improve cement injectability. The aim of this study is to determine whether incorporation of sodium carboxymethyl cellulose (Na CMC) into the mixing liquid would affect the diametral tensile strength (DTS) of injectable CO3Ap cement. In the present study, Na CMC, a polymeric additive and a cellulose derivative, was used to promote the injectability of CO3Ap cement. Three groups of CO3Ap cement samples consist of CaCO3 and CaHPO4 powder in each group were mixed with 0.5 %, 1%, and 2% Na CMC solution incorporated to 0.2 mol/L Na2HPO4 solution. As a control, powder mixed with 0.2 mol/L Na2HPO4 solution was used. Samples were kept in an incubator (37°C, 100% relative humidity, 24 hours). The mechanical strength properties were evaluated by diametral tensile strength (DTS). The average DTS of samples containing 0.5%, 1%, and 2% Na CMC were 3.19 MPa, 3.57 MPa, and 3.06 MPa, respectively. While the average DTS of the control group was 3.29 MPa. The groups containing Na CMC in all concentrations showed no statistical difference (p>0.05) on DTS compared to the control group. The injectability improved as the concentration of Na CMC increased. In conclusion, revealed that Na CMC does not affect the mechanical strength of CO3Ap cement. Therefore, it may be considered as an effective material to promote cement injectability. Further study of additives that can be used to promote the injectability of CO3Ap cement and enhance the mechanical strength awaits based on this initial finding.

scholarly journals Bio-Based Thermoplastic Starch Composites Reinforced by Dialdehyde Lignocellulose

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3236
Author(s):  
Peng Yin ◽  
Wen Zhou ◽  
Xin Zhang ◽  
Bin Guo ◽  
Panxin Li
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Water Resistance ◽  
Thermoplastic Starch ◽  
Contact Angles ◽  
Sem Images ◽  
Elongation At Break ◽  
Injection Process ◽  
Oxidation Damage

In order to improve the mechanical properties and water resistance of thermoplastic starch (TPS), a novel reinforcement of dialdehyde lignocellulose (DLC) was prepared via the oxidation of lignocellulose (LC) using sodium periodate. Then, the DLC-reinforced TPS composites were prepared by an extrusion and injection process using glycerol as a plasticizer. The DLC and LC were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the effects of DLC content on the properties of the DLC/TPS composites were investigated via the evaluation of SEM images, mechanical properties, thermal stability, and contact angles. XRD showed that the crystallinity of the DLC decreased due to oxidation damage to the LC. SEM showed good dispersion of the DLC in the continuous TPS phase at low amounts of DLC, which related to good mechanical properties. The tensile strength of the DLC/TPS composite reached a maximum at a DLC content of 3 wt.%, while the elongation at break of the DLC/TPS composites increased with increasing DLC content. The DLC/TPS composites had better thermal stability than the neat TPS. As the DLC content increased, the water resistance first increased, then decreased. The highest tensile strength and elongation at break reached 5.26 MPa and 111.25%, respectively, and the highest contact angle was about 90.7°.

scholarly journals Influence of Drying Temperature on Tensile and Bursting Strength of Bacterial Cellulose Biofilm

2019 ◽  
Vol 25 (3) ◽  
pp. 316-321
Author(s):  
Florentina SEDERAVIČIŪTĖ ◽  
Jurgita DOMSKIENĖ ◽  
Ilze BALTINA
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bacterial Cellulose ◽  
Strength Properties ◽  
Drying Temperature ◽  
Bursting Strength ◽  
Bacterial Fermentation ◽  
Deformation Properties ◽  
C 50 ◽  
Material Preparation

The article presents an experimental study of mechanical properties of cellulose biofilm produced by bacterial fermentation process. Naturally derived biomaterial has great current and potential applications therefore the conditions of material preparation as well as control and prediction of mechanical properties is still a relevant issue. Bacterial cellulose was obtained as a secondary product from Kombucha drink. Presented technique for material preparation and drying is particularly simple and easy to access. The influence of drying temperature (25 °C, 50 °C and 75 °C) on the sample size (thickness and planar dimensions) and mechanical properties (tensile and bursting strength) of cellulose biofilm has been evaluated. It was estimated that during drying biofilm specimens lost up to 92 % of weight and up to 87 % of thickness therefore planar specimen dimensions varied insignificantly. The study showed that the drying temperature is important for optimum strength properties of bacterial cellulose biofilm. The maximum tensile strength (27.91 MPa) was recorded for the samples dried at temperature of 25 °C, when the moisture from the biomaterial is removed gradually and good deformation properties are ensured (respectively tensile extension 18.8 %). Under higher drying temperature biomaterial shows lower values of tensile strength and higher values of bursting strength. The maximum bursting strength (57.2 MPa) was recorded for samples dried at 75 °C when punch displacement changes were insignificant for all tested samples (from 17.8 mm to 21.7 mm). DOI: http://dx.doi.org/10.5755/j01.ms.25.3.20764

Corrosion Resistance and Mechanical Properties of Carbon Steel under a High Temperature Pressurized Water

2007 ◽  
Vol 345-346 ◽  
pp. 1027-1030
Author(s):  
Sang Ll Lee ◽  
Moon Hee Lee ◽  
Jin Kyung Lee ◽  
Dong Su Bae ◽  
Joon Hyun Lee
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Steel ◽  
Corrosion Test ◽  
Water Pressure ◽  
Strength Properties ◽  
Carbon Steels ◽  
Pressurized Water ◽  
Corrosion Strength

The long-term corrosion strength properties for the carbon steels under pressurized water atmosphere have been investigated, in the conjunction with the detailed analysis of their microstructures. The corrosion test for carbon steels was carried out at the temperature of 200°C under a water pressure of 10 MPa. The corrosion test samples were maintained up to 50 weeks in the tube shaped reactor. The mechanical strength and the microstucture of carbon steels suffered from the long term corrosion test were evaluated by SEM, XRD and tensile test. The weight loss of carbon steel by the corrosion test was also examined. The tensile strength of carbon steels decreased with the increase of corrosion time under a pressurized water atmosphere, accompanying the creation of severe corrosion damages like stress corrosion crack.

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