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Tytuł:
Influence of starch content on selected properties of hardboard
Autorzy:
Wronka, Anita
Rdest, Adam
Kowaluk, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/2200220.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
potato starch
fiberboard
mechanical properties
physical properties
Opis:
Influence of starch content on selected properties of hardboard. The aim of the research was to examine the possibility of producing wet-formed fiberboard using a different content of potato starch. The scope of works included the production of plates in laboratory conditions with 0, 1, 5, 10 and 20% mass content of potato starch and subjecting them to selected physical and mechanical tests. Thanks to the research, it was possible to produce a hard fiberboard hardboard using a mass fraction of starch. The results of the tests confirmed that as the starch content in the panel increases, the value of mechanical properties increases also.
Wpływ udziału skrobi na wybrane właściwości płyt pilśniowych mokroformowanych. Celem badań było określenie możliwości produkcji płyt pilśniowych twardych (mokroformowanych) z wykorzystaniem różnego udziału skrobi ziemniaczanej, jako środka wzmacniającego. Zakres prac obejmował wytworzenie płyt w warunkach laboratoryjnych przy: 0, 1, 5, 10, 20% udziale masowym skrobi ziemniaczanej oraz poddanie ich wybranym próbom fizycznym i mechanicznym. Potwierdzono możliwość wytwarzania płyt pilśniowych twardych z wykorzystaniem skrobi.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2020, 109; 48--52
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wood plastic composites as a substitution for HDF
Autorzy:
Borysiuk, Piotr
Auriga, Radosław
Powiązania:
https://bibliotekanauki.pl/articles/2171758.pdf
Data publikacji:
2022
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
WPC
composites
PLA
mechanical properties
physical properties
Opis:
Wood plastic composites as a substitution for HDF. As part of the research, industrial HDF boards were used and WPC composites were produced, differentiated in terms of matrix (PLA and HDPE) and filler content (40%, 50% and 60%). The density and density profile was measured to compare HDF and WPC structure. In addition, the manufactured boards were tested for strength (MOR, MOE), screw holding, thickness swelling and water absorption after immersion in water for 2 and 24 hours. WPC were characterized by a higher density than HDF boards and a uniform density profile. In addition, WPC composites were characterized by lower MOR and MOE values than HDF boards. Compared to HDF boards, WPC composites were characterized by higher values of screw holding and better resistance to moisture.
Kompozyty WPC jako substytut płyt HDF. W ramach badań wykorzystano przemysłowe płyty HDF oraz wytworzono kompozyty WPC zróżnicowane pod kątem matrycy (PLA i HDPE) oraz udziału napełniacza (40%, 50% i 60%). Oznaczono gęstość i profil gęstości w celu porównania struktury HDF i WPC. Ponadto wytworzone płyty zostały przetestowane pod kątem wytrzymałości (MOR, MOE), utrzymania wkrętów, spęcznienia na grubość oraz nasiąkliwości po moczeniu w wodzie przez 2 i 24 godziny. WPC charakteryzowały się wyższa gęstością niż płyty HDF oraz jednorodnym profilem gęstości. Ponadto kompozyty WPC charakteryzowały się niższymi wartościami MOR i MOE niż płyty HDF. W porównaniu do płyt HDF kompozyty WPC charakteryzowały się wyższymi wartościami zdolności utrzymania wkrętów oraz lepszą odpornością na działanie wilgoci.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2022, 119; 84--93
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of Physical, Chemical and Mechanical Properties of Sri Lankan Coir Fibers
Autorzy:
Dharmaratne, Prasad Dhammika
Galabada, Harsha
Jayasinghe, Randika
Nilmini, Renuka
Halwatura, Rangika Umesh
Powiązania:
https://bibliotekanauki.pl/articles/1838275.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
coir fibre
characterization
physical properties
chemical properties
mechanical properties
Opis:
This study was carried out to determine the characterization of brown coir fiber which is used as a potential reinforcement in polymer composites. The fiber is extracted from the husk of the coconut seeds which are collected in Sri Lanka. Anyhow the above-mentioned characterization can hardly be seen when it comes to the Sri Lankan context. Since the evaluation of their physical, mechanical, and chemical properties are significant before commencing the material development process and applications for this fiber. Several testing were carried out to evaluate the above-mentioned properties. There, the functional groups of coir fiber were obtained by Fourier Transform Infrared analysis and Crystallinity Index and Crystallite size were determined by X-ray diffraction analysis. The surface morphology and cross-sectional features were investigated through Scanning Electron Microscopy. The thermo-gravimetric method was adopted to study the thermal stability of coir fiber. The density and diameter of coir fiber were measured utilizing pychometric method and optical microscope respectively. Tensile strength was measured using an electronic tensometer and then find out the tensile strength, modulus of elasticity, and elongation at breaking point. The average density of brown coir fibers was 1.018 g/cm3 and average diameters were 0.30 mm. The Crystallinity Index and the crystal-line size were 37.28% and 0.4331 nm respectively. Ultimate tensile strength, Young’s modulus, and Elongation of the coir fiber were ranging from 94–159 MPa, 1.2–1.8 GPa, and 21–67%, respectively.
Źródło:
Journal of Ecological Engineering; 2021, 22, 6; 55-65
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of Physical, Chemical and Mechanical Properties of Sri Lankan Coir Fibers
Autorzy:
Dharmaratne, Prasad Dhammika
Galabada, Harsha
Jayasinghe, Randika
Nilmini, Renuka
Halwatura, Rangika Umesh
Powiązania:
https://bibliotekanauki.pl/articles/1838380.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
coir fibre
characterization
physical properties
chemical properties
mechanical properties
Opis:
This study was carried out to determine the characterization of brown coir fiber which is used as a potential reinforcement in polymer composites. The fiber is extracted from the husk of the coconut seeds which are collected in Sri Lanka. Anyhow the above-mentioned characterization can hardly be seen when it comes to the Sri Lankan context. Since the evaluation of their physical, mechanical, and chemical properties are significant before commencing the material development process and applications for this fiber. Several testing were carried out to evaluate the above-mentioned properties. There, the functional groups of coir fiber were obtained by Fourier Transform Infrared analysis and Crystallinity Index and Crystallite size were determined by X-ray diffraction analysis. The surface morphology and cross-sectional features were investigated through Scanning Electron Microscopy. The thermo-gravimetric method was adopted to study the thermal stability of coir fiber. The density and diameter of coir fiber were measured utilizing pychometric method and optical microscope respectively. Tensile strength was measured using an electronic tensometer and then find out the tensile strength, modulus of elasticity, and elongation at breaking point. The average density of brown coir fibers was 1.018 g/cm3 and average diameters were 0.30 mm. The Crystallinity Index and the crystal-line size were 37.28% and 0.4331 nm respectively. Ultimate tensile strength, Young’s modulus, and Elongation of the coir fiber were ranging from 94–159 MPa, 1.2–1.8 GPa, and 21–67%, respectively.
Źródło:
Journal of Ecological Engineering; 2021, 22, 6; 55-65
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The physical and mechanical properties of magnesium oxychloride cement-based materials
Autorzy:
Malinowski, S.
Jaroszyńska-Wolińska, J.
Powiązania:
https://bibliotekanauki.pl/articles/390576.pdf
Data publikacji:
2015
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
magnesium oxychloride cement
polypropylene fibre
microsilica
mechanical properties
physical properties
Opis:
The aim of this paper was the examination of the physical-mechanical properties of Sorel cement-based material. In the experimental part the effect of polypropylene fibers (PP) and micro-silica on properties of composite materials were studied. The results show that addition of these modifiers increases compressive strength, waterproofing and resistance against corrosion. Increase of compressive strength was observed from both addition of PP and micro-silica. PP resulted in an increase in compressive strength of 0,72 MPa, whereas addition of micro-silica caused an increase of 17,5 % compared to pure Sorel’s cement. Improvement of water-tightness was observed in both additions of PP and micro-silica. Weight loss of samples with PP addition to the concrete after a 7-day bath in an aggressive solution of 5% HCl was less than about 20%.
Źródło:
Budownictwo i Architektura; 2015, 14, 4; 89-98
1899-0665
Pojawia się w:
Budownictwo i Architektura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The properties of Lightweight Stabilised Blockboard panels
Autorzy:
Roziņš, Rihards
Iejavs, Jānis
Jakovļevs, Vilnis
Spulle, Uldis
Powiązania:
https://bibliotekanauki.pl/articles/2010850.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
Lightweight Stabilised Blockboard
physical properties
mechanical properties
high density fibreboard
Opis:
Lightweight Stabilised Blockboard (LSB) panel is a product newly introduced onto the market. Research was carried out to determine the main physical and mechanical properties of the panel and to evaluate the effect of panel direction and moisture content. LSB panels have wide potential for application in the furniture industry, door production, transport, and construction board production. Potentially LSB panels are lighter, with lower density and higher form stability than solid wood and conventional fibreboard, particle board, oriented strand board (OSB) and plywood. LSB panels produced from solid pine wood core and High Density Fibreboard (HDF) skins are found to have the following physical properties: average moisture content 8.6%; density 450 kg·m,-3; shrinkage coefficients 0.36% %-1 for thickness and 0.25%·%-1 for length and width; thickness swelling 6.3% after 24 hours’ immersion in water. The following mechanical properties were determined: internal bond 0.51 N mm-2; screw withdrawal resistance 1076 N from plane and 553 N from edge; bending strength 13.4 N mm-2; and modulus of elasticity in static bending 1754 N mm-2.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2020, 63, 206; 103-119
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Environmental factors influence milling and physical properties and flour size distribution of organic spelt wheat
Autorzy:
Warechowska, M.
Warechowski, J.
Skibniewska, K. A.
Siemianowska, E.
Tyburski, J.
Aljewicz, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/298457.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
organic spelt
physical properties
mechanical properties
milling
particle size distribution
PSD
Opis:
Spelt grain harvested at four organic farms in Poland were assessed for physical and milling properties and flour size distribution. The spelt grain was diversified in relation to the majority of tested milling quality parameters. The environmental conditions had a significant impact on thousand kernel weight, vitreousness, PSI, kernel ash content, specific energy of milling and the particle size distribution of flour. The values of specific energy of milling, coefficient of grinding efficiency, rupture force and rupture energy in the spelt from the organic farms were significantly lower than common wheat. The highest spelt flour yield was obtained of kernels cultivated on ecological farm with semi-coherent and very dry soil was similar to that of common wheat; the milling yield of the spelt originating from other farms was by 9.5% to 12.7% less than from the wheat one. The greatest differences in PSD between the tested flours were detected for the values over 40 μm. The content of this fraction was determined in the range of app. 1% to almost 4.5%; the flour from common wheat contained app. 2.8% of this fraction.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2016, 19(4); 387-399
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability of selected macrostructure features, density and compression strength along the grain of “Tabórz” Scots pine wood (Pinus sylvestris L.)
Autorzy:
Wąsik, Radosław
Michalec, Krzysztof
Barszcz, Anna
Mudryk, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/342694.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
pine
annual ring width
share of latewood
physical properties
mechanical properties
Opis:
The aim of the study was to determine the variability of annual ring width, share of latewood, density and compression strength along the grain of “Tabórz” Scots pine wood (Pinus sylvestris L.). The wood samples for examination were obtained from three trunks of 260-year-old Scots pines felled in the Sosny Taborskie Nature Reserve. In total, 106 samples were obtained, with cross-sectional dimensions of 20 × 20 mm and a length of 30 mm along the grain. The mean values for all tested wood samples were as follows: annual ring width 1.28 mm, share of latewood 28.9%, wood density 0.487 g·cm-3, and compression strength 47.3 MPa. The least variability within trees was found for wood density and compressive strength along the grain. Very high positive correlation was found between wood density and compressive strength, and high positive correlations were found between share of latewood and wood density and between share of latewood and compressive strength. To the authors’ knowledge, the results presented here are the first empirical data published concerning the features of wood macrostructure, density and compression strength along the grain of the Tabórz Scots pine, the trunks of which are considered a valuable timber in Europe.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2020, 62, 205; 171-182
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Physical and Mechanical Properties of Post-Consumer Wood of Different Age
Autorzy:
Gayda, Serhiy
Kiyko, Orest
Powiązania:
https://bibliotekanauki.pl/articles/27323548.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
post-consumer wood
physical properties
mechanical properties
characteristics
strength
recycling
technology
use
Opis:
It should be noted that there is currently a problem with wood resources in the woodworking industry. A potential, unused wood reserve is post-consumer wood (PCW). The problem with the quality of this wood resource has not been fully resolved since there is no regulatory database. In fact, there is a lack of appropriate regulatory documents, which makes it impossible to describe to a full extent the physical and mechanical properties of PCW of common wood species of different ages as a source of additional raw materials for various woodworking technologies. Proceeding from the goal, the task of the study is to describe the physical and mechanical properties of postconsumer wood using the example of fir wood, which for a long period of time has been used to create furniture and joinery products. The task is also to identify patterns of change in the indicators of this resource with age – an expired service life or suitability. In order to use PCW in woodworking and to fill the scientific base with physical and mechanical indicators of fir wood of different ages with an expired product service life, the following characteristics were investigated: static hardness, swelling, coefficients of swelling, the value of transverse anisotropy, density, static bending strength, splitting strength along the fibers, modulus of elasticity in compression, and the modulus of elasticity in static bending. The characteristics of PCW of the widespread fir species in the range of use from 0 to 20 years were explored, with intermediate control over the properties every 5 years. The dynamics of the physical and mechanical indicators of fir PCW were revealed and it was found that in the course of operation time in various conditions they change, mainly decreasingly: static hardness by 9.2-9.6%; the value of transverse anisotropy by 30-32%; strength: static bending strength by 3.4-7.95%, splitting strength by 4.49-8.67%; modulus of elasticity: in compression by 3.89-4.08%, in bending by 2.75-6.64%. The main causes of changes in the properties of PCW with age: natural: weathering, partial internal rot, insect damage, other biological effects; mechanical: splitting, scratches, small holes from means of fastening and other defects due to use; operational: the influence of power and dynamic loads, the influence of surface finishing agents and other factors on the structural elements of wood products. A summary table was compiled for the selection of indicators of the physical and mechanical properties of fir PCW of different ages. When knowing the indicators and dynamics of the physical and mechanical properties of PCW with age, it can be recommended for manufacturing structural materials – blockboards and furniture panels.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2023, 66, 212; Art. no. 177453
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of High Pressure-High Temperature Method on the Selected Mechanical Properties of Steel AISI 316L with 2% TiB2
Autorzy:
Kurtyka, P.
Sulima, I.
Hyjek, P.
Jaworska, L.
Powiązania:
https://bibliotekanauki.pl/articles/356857.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high pressure-high temperature
physical properties
mechanical properties
steel matrix composites
titanium diboride
Opis:
AISI 316L/TiB2/2p composites were manufactured by HP-HT using different pressures (5 and 7 GPa) and temperatures (900-1300°C), with constant reinforcing particle content 2 vol%. The mechanical properties of the composites were evaluated on the basis of hardness (HV0.3) and compression tests (20°C, 10-5 s-1). The results showed that the role of sintering pressure increased with increasing process temperature. At temperatures of 900°C and pressures of 5 and 7 GPa the difference in measured values of compressive strength was 1-2%, while at 1300°C they reached 20%. At constant pressure of 5 GPa, a change in hardness and compressive strength of 40% were obtained with a temperature change of 900 to 1300°C. Changes in mechanical properties in the composite occurred without substantial changes in density, microstructure, reinforcement phase distribution, and phase composition in the matrix.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1585-1592
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of growing altitude, particle drying temperature and press temperature on some technological properties of particleboard produced from black alder wood
Autorzy:
Kumaş, İlknur
Aras, Uğur
Kalaycioğlu, Hulya
Serdar, Bedri
Yel, Husnu
Powiązania:
https://bibliotekanauki.pl/articles/2010795.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
black alder
drying temperature
press conditions
anatomical factors
growing altitude
physical properties
mechanical properties
Opis:
This study investigated the effects of the growing altitude, particle drying temperature and press temperature on some technological properties of particleboard produced from black alder wood. The particles were produced from wood taken from the KTÜ Campus and from Çamoba in Trabzon. Production and tests of the experimental particleboards were carried out at Kastamonu Integrated Wood Company. In production of the particleboards, wood from different growing altitudes [50 m and 250 m] was used, and different drying temperatures [120 and 150°C] and press temperatures [150 and 200°C] were applied. Mechanical, physical and anatomical properties of the produced boards were investigated. According to the results, the mechanical properties deteriorate when the altitude increases. Increasing the particle drying temperature and press temperature had a positive effect on dimensional stability. A high press temperature improved the mechanical properties of the boards. In addition, growing altitude had an effect on anatomical properties: when the altitude increased, the diameter of vessels narrowed, the number of vessels per mm2 increased, and fiber length decreased. This resulted in a deterioration in mechanical properties at the higher altitude.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2021, 64, 207; 59-71
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fizyczne właściwości warstwy podornej gleby gliniastej dla dwóch wybranych systemów uprawy
Physical and mechanical properties of loamy soil subsoil at two tillage systems
Autorzy:
Błażejczak, D.
Tomaszewicz, T.
Śnieg, M.
Powiązania:
https://bibliotekanauki.pl/articles/286516.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
gleba gliniasta
system uprawy
właściwości fizykomechaniczne
loam soil
tillage system
physical properties
mechanical properties
Opis:
Badano w warstwach: 25-30, 40-45, 55-60 cm glebę gliniastą uprawianą tradycyjnie (pług) i bezpłużnie (zestaw uprawowo-siewny). Oznaczono wybrane właściwości gleby: gęstość objętościową, porowatość aeracji, wilgotność aktualną, całkowitą pojemność wodną, naprężenie graniczne, zwięzłości gleby i opór jej ścinania w ruchu obrotowym. Stwierdzono, że siedmioletnia bezpłużna uprawa gleby nie spowodowała istotnych zmian w warstwie podornej.
The field studies were conducted on loamy soil to evaluate the impact of two compared tillage systems: ploughing and rotary cultivator, on physical and mechanical properties of the subsoil layer. The following physical and mechanical properties were examined: water content, bulk density, natural bulk density, penetration resistance, shear and pre-compaction stress. The soil samples were taken from 25-30; 40-45; 55-60 cm depth. The results showed that there was no difference between the compared tillage systems in terms of the assessed physical and mechanical properties.
Źródło:
Inżynieria Rolnicza; 2005, R. 9, nr 3, 3; 87-93
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The investigation of properties of blockboards made of post-consumer wood
Autorzy:
Gayda, Serhiy
Kiyko, Orest
Powiązania:
https://bibliotekanauki.pl/articles/2010870.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
post-consumer wood
blockboards
mathematical model
physical properties
mechanical properties
characteristics
strength
recycling
technology
use
Opis:
Today in woodworking, there are problems with the use of wood waste and the accumulation of involved wood as an additional and not fully used resource. The problem has not been completely solved, as there is no scientific basis and practical recommendations for efficient production processes with predicting the properties of products made from Post-Consumer Wood (PCW), in particular in the production of blockboards (BB). The objective of the studies is to substantiate and develop a scientific and technical basis for resource-saving and environmentally friendly technologies, to establish the influence patterns of PCW properties on the mechanical characteristics of the products obtained, to develop operating parameters and to formulate practical recommendations, confirmed by the results of experimental studies. The studies have proved the expediency of using PCW in technological processes of woodworking, in particular in the production of construction materials - blockboards with predicted characteristics. In order to rationally use raw materials for the manufacture of conventional blockboards made from Post-Consumer Wood (PCW-BB), new designs of a conventional PCW blockboard with a thickness of 22 mm and with a unified strip width of 16, 32, 48, and 64 mm, the strips are glued ones, 3 mm thick, and faced with plywood on both sides. The authors of the article found that in order to ensure improved operating characteristics of the blockboards, it is important to lay radial, semi-radial and tangential strips in structures with the ratio of width to thickness of the cross-sections of the strips - rationally and efficiently - 1:1, 2:1, 3:1. Substantiation on this basis of new designs of PCW blockboards makes it possible to reveal shortcomings of these products at the conceptual stage of the project and correct them before manufacturing taking into account the specified technical conditions and reducing costs at the development stage. Mathematical models for predicting the main characteristics of conventional PCW blockboards (PCW-BB) have been constructed, which made it possible to determine the indexes of the bending strength of the BB across the strips, σBB, and the shear strength of the BB along the glue line, τВВ. The coefficients of approximation of mathematical dependencies for predicting the strength of PCW-BBs, the strips of which were made of fir wood, were calculated, which would allow for the selection of rational designs of blockboards with appropriate characteristics. It has been established that the developed mathematical models make it possible to predict the characteristics of the PCW-BB depending on the cross-sectional dimensions of the strips, the angle of the annual rings slope to the blockboard face and the age of the PCW, and, on this basis, to propose improved designs of these blockboards for the technological processes of woodworking. The influence patterns of the properties of structural elements on the indicators of conventional PCW-BB (500 × 500 × 22 mm) were experimentally established. It was found that an increase in the width of the strips leads to a decrease in the strength indexes (by 29-37%); an increase in the angle of the annual rings slope to the BB face leads to an increase in static bending strength (by 31-33%) but to a decrease in shear strength (by 4-7%); an increase in the age of the PCW leads to a decrease in strength indexes (by 3-8%). It was found that the physical and mechanical parameters of the experimental PCW-BBs with a strip cross-sections of 1:1, 2:1, 3:1 meet the requirements of the standard (larger values: for static bending of a rate of 15 MPa and for shearing at a rate of 1 MPa), and for the 4:1 cross- -section, they partially had lower indexes by 2-3%. To ensure the strength of the developed structures of the PCW-BBs, it is recommended to use the 3:1 ratio of the sides in the cross-section of the strips, and the slope of the annual rings to the blockboard face must be at least 45o. It was found that the deviation of the values obtained by mathematical models in determining the strength in static bending and shearing in comparison with the experimental ones did not exceed 8% and 10%, respectively.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2020, 63, 206; 77-102
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena zmian wybranych właściwości podłoży leśnych przy różnych metodach zrywki drewna
Assessment of changes of the forest grounds selected properties at different methods of logging
Autorzy:
Cudzik, A.
Białczyk, W.
Czarnecki, J.
Brennensthul, M.
Powiązania:
https://bibliotekanauki.pl/articles/289029.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
podłoże leśne
zrywka drewna
właściwości fizyczne
właściwości mechaniczne
forest ground
wood logging
physical properties
mechanical properties
Opis:
W pracy przedstawiono wyniki pomiarów maksymalnych naprężeń ścinających oraz zwięzłości podłoży leśnych, na których prowadzono zrywkę drewna w sposób wleczony, półpodwieszony i nasiębierny. Sprawdzano czy i w jaki sposób liczba przejazdów przy różnych metodach zrywki wpływają na zmiany analizowanych właściwości podłoży. Na wartości mierzonych parametrów istotnie wpływała liczba przejazdów ciągnika LKT po szlaku zrywkowym. Wykazano istotny wpływ sposobu zrywki na analizowane parametry gleby.
The study presents results of the maximum shear stresses and firmness measures of the forest grounds, on which logging was carried out by means of cable logging, skidding logging and forwarding logging. The study examined whether and how the number of crossings, at various methods of logging, influences the changes of the analysed ground properties. The number of crossings of the LKT tractor on a logging route considerably influenced the values of the measured parameters. Considerable influence of the logging method on the analysed soil parameters was indicated.
Źródło:
Inżynieria Rolnicza; 2011, R. 15, nr 8, 8; 61-68
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Material Characterization of Roselle Fibre (Hibiscus sabdariffa L.) as Potential Reinforcement Material for Polymer Composites
Charakterystyka włókien ketmii szczawiowej (Hibiscus sabdariffa L.) jako potencjalnego wzmocnienia kompozytów polimerowych
Autorzy:
Nadlene, R.
Sapuan, S. M.
Jawaid, M.
Ishak, M. R.
Yusriah, L.
Powiązania:
https://bibliotekanauki.pl/articles/234165.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
Roselle fibre
physical properties
thermal properties
tensile test
mechanical properties
włókno Roselle
właściwości fizyczne
właściwości termiczne
próba rozciągania
właściwości mechaniczne
Opis:
Recently, in line with rising environmental concerns, researchers are now replacing synthetic fibres with natural ones as the main component in composites. Natural fibres are preferred to synthetic fibres because of several advantages such as biodegradable, light weight, low cost and good mechanical properties. Roselle is one of the plants found to be suitable to be used to produce natural fibres. In this work, we analysed the physical, thermal and mechanical characteristics of roselle fibre. Roselle fibre has good physical properties which lead to the dimensional stability of the composite product. The result obtained indicated that the moisture content of roselle fibre is 10.9%, while water absorption is 286.5%. Thermal gravimetric analysis (TGA) was conducted to understand the thermal stability of roselle fibre at high temperature. The results show that the initial degradation of roselle fibre starts at 225 °C and completes the decomposition of the lignocellulosic component at 400 °C. A tensile test was conducted to investigate the mechanical properties of roselle fibre. The tensile strength of roselle fibre is 130-562 MPa. On the basis of the properties of roselle fibres obtained, we concluded that roselle fibre is one of the good natural fibres that can be used as reinforced material for the manufacturing of polymer composites for different applications, while at the same time saving the cost required to manage the agro waste.
Ketmia szczawiowa jest jedną z roślin o której sądzi się, że może być przydatna do produkcji włókien naturalnych. W pracy przeanalizowano fizyczne, termiczne i mechaniczne właściwości włókien z ketmii szczawiowej. Ich dobre właściwości fizyczne przyczyniają się do wymiarowej stabilności kompozytu. Badania wykazały, że zawartość wilgoci wynosi 10.9%, podczas gdy absorpcja wody 286.5%. Analizę TGA przeprowadzono dla wykazania stabilności termicznej w wysokich temperaturach. Wyniki wykazały, że początkowa degradacja włókien zaczyna się przy 225 °C, a całkowity rozkład składników ligninocelulozowych występuje przy 400 °C. Stwierdzono, że wytrzymałość włókien na rozrywanie wynosi 130 – 562 MPa. Na podstawie analizy właściwości włókien ketmii szczawiowej można wnioskować, że włókna te są dobrymi gatunkowo włóknami naturalnymi dla wzmacniania kompozytów polimerowych przeznaczonych dla różnych zastosowań, a jednocześnie ich przerób pozwala na oszczędności przy utylizacji odpadów.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 6 (114); 23-30
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 26

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