Effect of molding conditions and moisture content on the mechanical properties of compression molded glassy, wheat gluten bioplastics

2013 ◽  
Vol 44 ◽  
pp. 480-487 ◽  
Author(s):  
Koen J.A. Jansens ◽  
Nhan Vo Hong ◽  
Lien Telen ◽  
Kristof Brijs ◽  
Bert Lagrain ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Wheat Gluten

scholarly journals Symmetric Nature of Stress Distribution in the Elastic-Plastic Range of Pinus L. Pine Wood Samples Determined Experimentally and Using the Finite Element Method (FEM)

Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 39
Author(s):  
Łukasz Warguła ◽  
Dominik Wojtkowiak ◽  
Mateusz Kukla ◽  
Krzysztof Talaśka
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Stress Distribution ◽  
Moisture Content ◽  
Tool Geometry ◽  
Wood Fibers ◽  
Data Set ◽  
Plastic Deformations ◽  
Pine Wood ◽  
Elastic Plastic

This article presents the results of experimental research on the mechanical properties of pine wood (Pinus L. Sp. Pl. 1000. 1753). In the course of the research process, stress-strain curves were determined for cases of tensile, compression and shear of standardized shapes samples. The collected data set was used to determine several material constants such as: modulus of elasticity, shear modulus or yield point. The aim of the research was to determine the material properties necessary to develop the model used in the finite element analysis (FEM), which demonstrates the symmetrical nature of the stress distribution in the sample. This model will be used to analyze the process of grinding wood base materials in terms of the peak cutting force estimation and the tool geometry influence determination. The main purpose of the developed model will be to determine the maximum stress value necessary to estimate the destructive force for the tested wood sample. The tests were carried out for timber of around 8.74% and 19.9% moisture content (MC). Significant differences were found between the mechanical properties of wood depending on moisture content and the direction of the applied force depending on the arrangement of wood fibers. Unlike other studies in the literature, this one relates to all three stress states (tensile, compression and shear) in all significant directions (anatomical). To verify the usability of the determined mechanical parameters of wood, all three strength tests (tensile, compression and shear) were mapped in the FEM analysis. The accuracy of the model in determining the maximum destructive force of the material is equal to the average 8% (for tensile testing 14%, compression 2.5%, shear 6.5%), while the average coverage of the FEM characteristic with the results of the strength test in the field of elastic-plastic deformations with the adopted ±15% error overlap on average by about 77%. The analyses were performed in the ABAQUS/Standard 2020 program in the field of elastic-plastic deformations. Research with the use of numerical models after extension with a damage model will enable the design of energy-saving and durable grinding machines.

scholarly journals Effect of Moisture Content on the Processing and Mechanical Properties of a Biodegradable Polyester

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1616
Author(s):  
Vincenzo Titone ◽  
Antonio Correnti ◽  
Francesco Paolo La Mantia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Moisture Content ◽  
Mechanical Testing ◽  
Hydrolytic Degradation ◽  
Slight Reduction ◽  
Biodegradable Polyester ◽  
Molding Process ◽  
Elongation At Break ◽  
Effect Of Moisture

This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing—causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens.

Influence of Moisture Content in some Mechanical Properties of Two Brazilian Tropical Wood Species

2014 ◽  
Vol 1025-1026 ◽  
pp. 42-45 ◽  
Author(s):  
Luiz A. Melgaço N. Branco ◽  
Eduardo Chahud ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Rosane A.G. Battistelle ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Analysis Of Variance ◽  
Wood Species ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Tropical Wood ◽  
Fiber Saturation ◽  
Brazilian Standard

This study aimed, with the aid of analysis of variance (ANOVA), to investigate and quantify the influence of moisture ranging between 12% and over 30% (fiber saturation) on the mechanical properties: strength and modulus of elasticity in compression and in tension parallel to grain; modulus of rupture and modulus of elasticity in static bending; shear strength parallel to grain considering wood species Ipê (Tabebuia sp) and Angelim Araroba (Vataireopsis araroba). Tests were performed according to the assumptions and calculating methods Brazilian standard ABNT NBR 7190, Anexx B, totalizing 400 tests. Results of ANOVA revealed a significant reduction (16% on average) for mechanical properties wood due to the increase in moisture content from 12% to over 30% (fiber saturation). The same behavior also occurred when assembly containing the two species was considered.

Environmental Effects on the Static and Fatigue Behaviours of Hemp Fibre under Tensile Loading

2015 ◽  
Vol 798 ◽  
pp. 410-418
Author(s):  
Anh Dung Ngo ◽  
Thu Nga Ho ◽  
Khalid Sefrioui Manar
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Failure Modes ◽  
Harmful Effect ◽  
Tensile Loading ◽  
Ambient Air ◽  
Absorption Mechanism ◽  
Hemp Fibre ◽  
Temperature And Humidity ◽  
Static Tensile

Environmental and loading mode effects on the tensile properties of Hemp fibre were investigated. At first, absorption of moisture into the fibre from ambient air and absorption of water into the fibre in immersion were studied. Then static and cyclic loadings tensile tests were conducted in various temperature and humidity conditions. It was found that, in ambient air (0% < RH < 80%) the moisture content of the studied fibre decreased with the increase of temperature conformed to the GAB model suggesting a multilayer absorption mechanism. On the contrary, for the fibre immersed in water, the moisture content increased with the increase of temperature. The activation of temperature on the diffusion of the water into the fibre by micro-pores and lumens jointly with the lack of possibility for the imprisoned water to evaporate might be the cause of this effect. Experimental results suggested that temperature and humidity could individually reduce the mechanical properties of Hemp fibre. Their interaction caused even a more harmful effect. Semi empirical and neural networks were used to predict the hygro-thermal effects on the mechanical properties under static tensile loading. Broken surfaces of the specimens were also examined showing different failure modes for static and cyclic tensile loadings. Finally, the value of the cellulose micro-fibrils angle (MFA) estimated using the static tensile stress-strain curve was 8.4o±1.9o.

scholarly journals Mechanical Properties of Grains Sorghum Subjected to Compression at Different Moisture Contents

2019 ◽  
Vol 11 (4) ◽  
pp. 279
Author(s):  
Gabrielly B. Rodrigues ◽  
Osvaldo Resende ◽  
Daniel E. C. de Oliveira ◽  
Lígia C. de M. Silva ◽  
Weder N. Ferreira Junior
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Uniaxial Compression ◽  
Deformation Modulus ◽  
Grain Sorghum ◽  
Parallel Plates ◽  
Compression Force ◽  
Moisture Contents ◽  
Rest Position ◽  
Different Temperatures

This study aimed to evaluate the influence of drying at different temperatures on the mechanical properties of grains of grain sorghum subjected to compression at the natural rest position. Grains dried at temperatures of 60, 80 and 100 &deg;C with different moisture contents (0.515; 0.408; 0.315; 0.234; 0.162 and 0.099 (d.b.)) were subjected to uniaxial compression between two parallel plates, applied at their natural rest position, at a rate of 0.001 m s-1. The force required to rupture in grains of grain sorghum increased as their moisture contents decreased, with values of 47.17 to 78.44 N, 61.81 to 69.66 N and 52.07 to 70.89 N for the temperatures of 60, 80 and 100 &deg;C, respectively. The compression force required to deform grain sorghum decreased with the increment in moisture content, and the proportional deformation modulus increases with moisture content reduction. Within the studied range of moisture content, the values were 87 &times; 10-7 to 354.99 &times; 10-7 Pa, 132.63 &times; 10-7 to 465.98 &times; 10-7 Pa and 80.18 &times; 10-7 to 429.85 &times; 10-7 Pa for the temperatures of 60, 80 and 100 &deg;C, respectively.

scholarly journals Effect of Different Hydrothermal Treatments (Steam and Hot Compressed Water) on Physical Properties and Drying Behavior of Yellow-Poplar (Liriodendron tulipifera)

2019 ◽  
Vol 69 (1) ◽  
pp. 42-52
Author(s):  
Sohrab Rahimi ◽  
Kaushlendra Singh ◽  
David DeVallance
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Moisture Content ◽  
Yellow Poplar ◽  
Pressure Steam ◽  
Percent Moisture ◽  
Drying Behavior ◽  
Hot Compressed Water ◽  
And Control ◽  
Control Samples

Abstract Nonchemical high-pressure steam treatments have been intensively researched and commercialized to produce chemical-free wood products with enhanced properties. However, the utilization of high-pressure steam involves vapor-phase reactions using high-temperature steam generated at the expense of high energy input. In this research, influences of reaction media (steam and hot-compressed water) and temperature (100°C and 140°C) during thermal treatment on physical properties and drying behavior of yellow-poplar (Liriodendron tulipifera) heartwood were compared. The length, width, and thickness of the samples were 22.53 mm, 17.18 mm, and 16.72 mm, respectively. After the treatment, the samples were dried under an isothermal temperature condition of 105°C. Data on moisture content and time of drying from drying experiments were fitted with unsteady-state molecular transport equations to calculate overall liquid diffusion coefficients. Dimensions, weight, and true volume of samples were measured for green, thermally treated, and dried samples and the values were used to calculate selected physical characteristics. Additionally, selected mechanical properties were evaluated for samples conditioned to 13 percent moisture content. Results showed that intensified hot-compressed water-treated and control samples had the highest and lowest saturated moisture contents (101% and 44%), respectively, immediately after treatments. Intensified steam-treated and control samples had the highest and lowest total porosity (95% and 82%), respectively. Furthermore, mild hot-compressed water-treated samples showed the greatest compression strength (47.8 MPa) at 13 percent moisture content. Except for steam treatment at 140°C, other treatments significantly decreased the diffusion coefficient. Collectively, samples treated with hot-compressed water at 100°C showed the most improved mechanical properties.

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