scholarly journals Influence of incubation time on the vibration and mechanic properties of mycowood

Holzforschung ◽  
2016 ◽  
Vol 70 (6) ◽  
pp. 557-565 ◽  
Author(s):  
Marjan Sedighi Gilani ◽  
Jürg Neuenschwander ◽  
Markus Heeb ◽  
Roman Furrer ◽  
Sergio J. Sanabria ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sound Velocity ◽  
Treatment Time ◽  
Characteristic Impedance ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Longitudinal Direction ◽  
White Rot ◽  
White Rot Fungus ◽  
Fungal Treatment

Abstract The goal of the current study was to investigate the physical and mechanical properties of mycowood as a high quality tone-wood, obtained from Norway spruce by treatment of the white rot fungus Physisporinus vitreus as a function of the treatment time. In focus was the stiffness to weight ratio, which is often considered a main criterion for tone-wood selection. The vibro-mechanical properties were tested by non-destructive methods. The change of color and density were also measured after 4–12 months of fungal incubation. Density decreased up to 5% after 12 months of fungal treatment. Sound velocity was measured in small size specimens by means of the free-free vibration approach, while in large specimens the air-coupled ultrasound method was applied. The two techniques gave similar results and indicated that the sound velocity decreased in mycowood. Internal damping was increased in mycowood to a higher extent than the reduction in the specific modulus of elasticity (E/ρ) and thus the sound velocity in the material. The sound velocity was decreasing with increasing incubation times and scattering of data with this regard was larger in the transversal than in the longitudinal direction. The sound radiation coefficient and the characteristic impedance were enhanced in mycowood and its color was more brownish and richer in tone.

scholarly journals The Impact of Paraffin-Thermal Modification of Beech Wood on Its Biological, Physical and Mechanical Properties

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1102 ◽  
Author(s):  
Ladislav Reinprecht ◽  
Miroslav Repák
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Beech Wood ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
European Beech ◽  
White Rot ◽  
White Rot Fungus ◽  
Poria Placenta ◽  
The Impact

The European beech (Fagus sylvatica L.) wood was thermally modified in the presence of paraffin at the temperatures of 190 or 210 °C for 1, 2, 3 or 4 h. A significant increase in its resistance to the brown-rot fungus Poria placenta (by 71.4%–98.4%) and the white-rot fungus Trametes versicolor (by 50.1%–99.5%) was observed as a result of all modification modes. However, an increase in the resistance of beech wood surfaces to the mold Aspergillus niger was achieved only under more severe modification regimes taking 4 h at 190 or 210 °C. Water resistance of paraffin-thermally modified beech wood improved—soaking reduced by 30.2%–35.8% and volume swelling by 26.8%–62.9% after 336 h of exposure in water. On the contrary, its mechanical properties worsened—impact bending strength decreased by 17.8%–48.3% and Brinell hardness by 2.4%–63.9%.

Biomechanical Pulping of Agave sisalana

Holzforschung ◽  
2001 ◽  
Vol 55 (1) ◽  
pp. 42-46
Author(s):  
G. Idárraga ◽  
J. Ramos ◽  
R.A. Young ◽  
F. Denes ◽  
V. Zuñiga
Keyword(s):  
Mechanical Properties ◽  
Energy Consumption ◽  
Treatment Time ◽  
White Rot Fungi ◽  
White Rot ◽  
White Rot Fungus ◽  
Biological Pretreatment ◽  
Ceriporiopsis Subvermispora ◽  
Agave Sisalana ◽  
Strength Improvement

Summary The effect of biological pretreatment of sisal with several white rot fungi on the energy consumption in refining and on the mechanical properties of the pulps was evaluated in this investigation. Improvements were realized in all the mechanical properties (22–66 %) and a reduction in the energy consumption of > 39% was realized for the treated pulps with the different fungi. The best strength improvement and energy reduction results overall were obtained with the white-rot fungus, Ceriporiopsis subvermispora. The incubation time was optimized for this fungus with the optimum mechanical properties obtained with a two week treatment time.

scholarly journals Physical and Mechanical Properties Evaluation of Particle Board Produced from Saw Dust and Plastic Waste

2018 ◽  
Vol 40 ◽  
pp. 1-8 ◽  
Author(s):  
Atoyebi Olumoyewa Dotun ◽  
Adeolu Adesoji Adediran ◽  
Adisa Cephas Oluwatimilehin
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Maximum Point ◽  
Mixing Ratios ◽  
Saw Dust ◽  
Three Phase ◽  
The Matrix

The current work reports on the fabrication of composite matrix from saw dust (SD) and recycled polyethylene terephthalate (PET) at different weight ratio by flat-pressed method. Wood plastic composites (WPCs) were made with a thickness of 15 mm after mixing the saw dust and PET followed by a three phase press cycle. Physical properties (Density, Water Absorption (WA) and Thickness Swelling (TS)) and Mechanical properties (Modulus of Elasticity (MOE) and Modulus of Rupture (MOR)) were determined base on the mixing ratios according to the standard. WA and TS were measured after 2 h and 24 h of immersion in water. The results showed that as the density increased, the SD content decreased from 90 % to 50 % into the matrix. However, WA and TS decreases when the PET content increased in the matrix. Remarkably, the MOE and MOR attained a maximum point at 964.199 N/mm2and 9.03 N/mm2respectively in 50 % SD content. In comparism with standard, boards D and E can be classified as medium density boards while A, B and C are low density boards. The results indicated that the fabrication of WPCs from sawdust and PET would technically be feasible for indoor uses in building due to favorable physical properties exhibited. The mechanical properties response showed that it cannot be used for structural or load bearing application.

scholarly journals Effect of Cellulose Nanofibrils and TEMPO-mediated Oxidized Cellulose Nanofibrils on the Physical and Mechanical Properties of Poly(vinylidene fluoride)/Cellulose Nanofibril Composites

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1091 ◽  
Author(s):  
Eftihia Barnes ◽  
Jennifer A. Jefcoat ◽  
Erik M. Alberts ◽  
Mason A. McKechnie ◽  
Hannah R. Peel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vinylidene Fluoride ◽  
Cellulose Nanofibrils ◽  
Composite Films ◽  
Weight Ratio ◽  
Tensile Modulus ◽  
Physical And Mechanical Properties ◽  
Free Standing ◽  
Composite Surface ◽  
Poly Vinylidene Fluoride

Cellulose nanofibrils (CNFs) are high aspect ratio, natural nanomaterials with high mechanical strength-to-weight ratio and promising reinforcing dopants in polymer nanocomposites. In this study, we used CNFs and oxidized CNFs (TOCNFs), prepared by a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation process, as reinforcing agents in poly(vinylidene fluoride) (PVDF). Using high-shear mixing and doctor blade casting, we prepared free-standing composite films loaded with up to 5 wt % cellulose nanofibrils. For our processing conditions, all CNF/PVDF and TOCNF/PVDF films remain in the same crystalline phase as neat PVDF. In the as-prepared composites, the addition of CNFs on average increases crystallinity, whereas TOCNFs reduces it. Further, addition of CNFs and TOCNFs influences properties such as surface wettability, as well as thermal and mechanical behaviors of the composites. When compared to neat PVDF, the thermal stability of the composites is reduced. With regards to bulk mechanical properties, addition of CNFs or TOCNFs, generally reduces the tensile properties of the composites. However, a small increase (~18%) in the tensile modulus was observed for the 1 wt % TOCNF/PVDF composite. Surface mechanical properties, obtained from nanoindentation, show that the composites have enhanced performance. For the 5 wt % CNF/PVDF composite, the reduced modulus and hardness increased by ~52% and ~22%, whereas for the 3 wt % TOCNF/PVDF sample, the increase was ~23% and ~25% respectively.

scholarly journals Investigation on Physical and Mechanical Properties of Banana and Palmyra Fiber Reinforced Epoxy Composites

2020 ◽  
Vol 70 (2) ◽  
pp. 167-180
Author(s):  
Vennapusa Vijaya Bhaskar ◽  
Kolla Srinivas ◽  
Devireddy Siva Bhaskara Rao
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composites ◽  
Matrix Material ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Epoxy Composites ◽  
Fiber Reinforced ◽  
Micro Structure ◽  
Interfacial Analysis ◽  
The Matrix

AbstractThe present work addresses the physical and mechanical properties of banana and palmyra fiber reinforced epoxy composites with the aim of study on the effect of weight ratio and fiber percentage. The banana and palmyra fibers were arranged with different weight ratios (1:1, 1:3, and 3:1) and then mixed with the epoxy matrix by hand lay-up technique to prepare the hybrid composites with various fiber percentages (10%, 20%, 30% and 40%). The properties are measured by testing its density, water absorption, tensile strength, impact strength, hardness and flexural strength and compared. From the results, it was indicated that addition of banana and palmyra fiber in to the matrix material up to 30% by fiber percentage results in increasing the mechanical properties and slightly variation with weight ratios. Interfacial analysis of the hybrid composites were also observed by using scanning electron microscope (SEM) to study the internal failures and micro structure of the tested specimen.

SPECIFIC FEATURES OF DEFORMATION OF THE GROOVED CONVEYOR BELT AT LOW TENSIONS

2020 ◽  
pp. 46-53
Author(s):  
V.P. DYACHENKO ◽  
◽  
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Longitudinal Direction ◽  
Conveyor Belt ◽  
Bending Radius ◽  
Conveyor Belts ◽  
Low Tension ◽  
Rubber Fabric

The article presents analytical dependences for the maximum permissible bending radius of the conveyor belt in the longitudinal direction, in which the shape of the gutter is lost in areas with low tension, depending on the design and physical and mechanical properties of the belt. The results of calculations based on these dependencies for a number of modern rubber-fabric and rubber-rope belts are presented. The results obtained can be applied to determine the minimum allowable belt tension and the maximum allowable belt deflection, which usually occur in the loading zone of the conveyor and are the starting value when constructing a tension diagram in the process of traction calculation of the conveyor. They are also useful for determining the parameters of transition sections of conveyor belts.

Cure kinetics and autoclave-pressure dependence on physical and mechanical properties of woven carbon/epoxy 8552S/AS4 composite laminates

2021 ◽  
pp. 096739112110284
Author(s):  
Abd Baghad ◽  
Khalil El Mabrouk ◽  
Sébastien Vaudreuil ◽  
Khalid Nouneh
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Treatment Time ◽  
Physical And Mechanical Properties ◽  
Cure Kinetics ◽  
Void Content ◽  
Scanning Calorimetry ◽  
Microstructure And Mechanical Properties ◽  
The Matrix ◽  
Interlaminar Shear

The final mechanical properties of composite laminates are highly dependent on their curing cycles in the autoclave. During this cycle, the temperature, pressure, vacuum, and treatment time will influence the quality of manufactured parts. The void content is considered the most harmful defects in carbon/epoxy laminates since they weaken the matrix-dominated mechanical properties such as interlaminar shear and compressive strengths. In the present work, differential scanning calorimetry is used to characterize the influence of time/temperature on the behavior of the epoxy resin. Then, a series of [0/90/−45/+45]s laminates composites are autoclave-cured under various applied pressures to evaluate their impact on microstructure and mechanical properties. The interlaminar shear modulus, interlaminar shear strength, laminate compressive modulus, and laminate compressive strength at room and operating engine temperature were measured. The correlation between microstructure and mechanical properties was also studied. The mechanical properties of manufactured carbon/epoxy laminates are found to be dependent on pressure and microstructure. These results are explored to establish an optimal autoclave pressure route that would minimize porosity without counterbalancing mechanical properties.

scholarly journals Mechanical characteristics of bacterial cellulose-reinforced mycelium composite materials

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Elise Elsacker ◽  
Simon Vandelook ◽  
Bastien Damsin ◽  
Aurélie Van Wylick ◽  
Eveline Peeters ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Bacterial Cellulose ◽  
Mechanical Characteristics ◽  
Composite Particle ◽  
Organic Additive ◽  
White Rot ◽  
White Rot Fungus ◽  
Organic Additives ◽  
Promising Alternative

Abstract Background While mycelium is considered a promising alternative for fossil-based resins in lignocellulosic materials, the mechanical properties of mycelium composite materials remain suboptimal, among other reasons due to the weak internal bonds between the hyphae and the natural fibres. A solution could be provided by the hybridisation of mycelium materials with organic additives. More specifically, bacterial cellulose seems to be a promising additive that could result in reinforcing mycelium composites; however, this strategy is underreported in scientific literature. Results In this study, we set out to investigate the mechanical properties of mycelium composites, produced with the white-rot fungus Trametes versicolor, and supplemented with bacterial cellulose as an organic additive. A methodological framework is developed for the facile production of bacterial cellulose and subsequent fabrication of mycelium composite particle boards based on a hybrid substrate consisting of bacterial cellulose and hemp in combination with a heat-pressing approach. We found that, upon adding bacterial cellulose, the internal bond of the composite particle boards significantly improved. Conclusions The addition of bacterial cellulose to mycelium composite materials not only results in a strengthening of internal bonding of mycelium material, but also renders tuneable mechanical properties to the material. As such, this study contributes to the ongoing development of fully biological hybrid materials with performant mechanical characteristics.

A Comparative Study of the Properties of Bandage-form Splinting Materials

1982 ◽  
Vol 11 (3) ◽  
pp. 125-134 ◽  
Author(s):  
J M Gill ◽  
P Bowker
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Strength Development ◽  
X Ray ◽  
Three Point Bending ◽  
Plaster Of Paris ◽  
X Ray Absorption

The physical and mechanical properties of three new bandage-form splinting materials (Baycast, Crystona and Hexcelite) have been compared with those of plaster of Paris. Properties evaluated including working strength, rate of strength development, elastic modulus, exothermic heat and X-ray absorption coefficient. All mechanical testing was carried out on rectangular cross-section specimens in three-point bending. Whilst the three newer materials differed widely they all showed some advantages over plaster of Paris although none could be definitely stated as being superior in all respects. As regards mechanical properties, Baycast was found to be significantly stronger than the other materials and to have a higher strength to weight ratio. The difficulties in formulating laboratory tests which are clinically relevant are discussed and the need to consider other factors, such as ease of application and advantages to the patient, is emphasized.

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