Abraham Kabutey

Deformation Curve Characteristics of Rapeseeds and Sunflower Seeds Under Compression Loading

Abstract The deformation curve characteristics of rapeseeds and sunflower seeds compressed using the equipment ZDM 50-2313/56/18 and varying vessel diameters (40, 60, 80, and 100 mm) were investigated. Maximum compressive force of 100 kN was applied on bulk oilseeds of rape and sunflower of measured height 20-80 mm and deformed at a speed of 60 mm∙min-1. The compression test using the vessel diameters of 40 and 60 mm showed a serration effect while the vessel diameters of 80 and 100 mm indicated an increasing function effect on the force-deformation characteristic curves. Clearly, the increasing function effect described the region with oil flow and that of serration effect described the region without any oil flow. However, it was observed that the serration effect could be due to the higher compressive stress inside the smaller vessel diameters (40 and 60 mm) compared to those with bigger vessel diameters (80 and 100 mm). Parameters such as deformation, deformation energy, and energy density were determined from the force-deformation curves dependency showing both increasing function and serration effect. The findings of the study provide useful information for the determination of specific compressive force and energy requirements for extracting maximum oil from oilseed crops such as rape and sunflower.

Mechanical Behavior of Ensete ventricosum Fiber Under Tension Loading

ABSTRACT The mechanical behavior of Ensete ventricosum fibers, expressed as the dependency of tension force in relation to the elongation, was determined for fibers with gauge length 50 mm and transformed into general linear mathematical model describing dependency of tension stress and strain. The average rupture force (10.88 ± 1.11) N, rupture stress (390.33 ± 21.96) MPa, rupture strain (0.021 ± 2 · 10–5), and volume energy (3.39 ± 0.22) J m−3 were also determined at this conducted study. Using image analyses, it was determined that the cross section of Ensete ventricosum fiber has circle shape and its dimension was specified. From the study, it implies that Ensete ventricosum fiber, with respect to its mechanical behavior under tension loading having regard to its density and to the fact that it is environmentally friendly, biodegradable and recyclable, could be used as a perspective construction material of the future. Determined model of mechanical behavior could be applied as background for further research focused on the Ensete fiber application.

Tangent Curve Function Description of Mechanical Behaviour of Bulk Oilseeds: A Review

Abstract The application of tangent curve mathematical model for description of mechanical behaviour of selected bulk oilseeds, namely jatropha, sunflower, rape, garden pea, and common bean in linear compression was reviewed. Based on the review analysis, the tangent curve function has been developed using MathCAD 14 software which employs the Levenberg-Marquardt algorithm for data fitting optimal for tangent curve approximation. Linear compression parameters including force (N), deformation (mm), energy (J), and/or volume energy (J-m-3) can equally be determined by the tangent model. Additionally, the theoretical dependency between force and deformation characteristic curves can be defined by the force coefficient of mechanical behaviour (N) and deformation coefficient of mechanical behaviour (mm-1) of the tangent model. In conclusion, the review results, however, shows that the tangent curve mathematical model which is dependent on experimental boundary conditions is potentialy useful for theoretical description of mechanical properties and deformation characteristics of bulk oilseeds in axial compression.

Application of a tangent curve mathematical model for analysis of the mechanical behaviour of sunflower bulk seeds

Abstract This paper evaluate the use of a tangent curve mathematical model for representation of the mechanical behaviour of sunflower bulk seeds. Compression machine (Tempos Model 50, Czech Republic) and pressing vessel diameter 60 mm were used for the loading experiment. Varying forces between 50 and 130 kN and speeds ranging from 10, 50, and 100 mm min-1 were applied respectively on the bulk seeds with moisture content 12.37±0.38% w.b. The relationship between force and deformation curves of bulk seeds of pressing height 80 mm was described. The oil point strain was also determined from the different deformation values namely 30, 35, 40, and 45 mm at speed 10 mm min-1. Based on the results obtained, model coefficients were determined for fitting the experimental load and deformation curves. The validity of these coefficients were dependent on the bulk seeds of pressing height, vessel diameter, maximum force 110 kN, and speed 10 mm min-1, where optimal oil yield was observed. The oil point was detected at 45 mm deformation giving the strain value of 0.56 with the corresponding force 16.65±3.51 kN and energy 1.06±0.18 MJ m-3. At the force of 130 kN, a serration effect on the curves was indicated; hence, the compression process was ceased.

Effect of Length of False Banana Fibre (Ensete ventricosum) on Mechanical Behaviour under Tensile Loading

Abstract The effect of gauge length of false banana fibre (Ensete ventricosum) on the tensile strength, volume energy, and modulus of elasticity under tensile loading was examined. Fibres of gauge length L0 (mm) 10, 20, 40, 80, 160, and 320 mm were prepared and tested until rupture point at strain rate of 0.05 min−1. Mathematical models describing the mechanical behaviour of the varying gauge lengths were presented. With the increasing gauge length of fibre, the tensile strength and volume energy decreased while the values of modulus of elasticity increased. The theoretical model describing the mechanical behaviour of Ensete fibre under tensile loading presented herein provides useful information for the fibres application in industry. The determined models could be used as a background for further research focused on Ensete fibre application.

Compressive loading experiment of non-roasted bulk oil palm kernels at varying pressing factors

Abstract Compression testing of non-roasted bulk oil palm kernels at different processing factors was performed using a universal compression testing machine and a pressing vessel witha plunger. The purpose of the research was to describe regression models of deformation, deformation energy and percentage kernel oil depending on force, speed and vessel diameter. The tested compression forces were 100, 125, 150, 175 and 200 kN, while the speeds were 5, 10, 15, 20 and 25 mm min−1. Three pressing vessels of diameter 60, 80 and 100 mm were used. Samples were compressed at an initial height of 60 mm. For varying forces and vessel diameters at a constant speed of 5 mm min−1, the values of deformation, deformation energy and percentage kernel oil ranged from 28.47±0.89 to 37.45±0.11 mm, 796±0.82 to 1795±49.01 J and 7.33±0.26 to 25.67±0.39%. At a constant force of 200 kN for different speeds and vessel diameters; the aforementioned determined parameters also ranged from 31.91±1.61 to 37.63±1.21 mm, 1012±26.76 to 1795±49.01 J and 14.66±0.42 to 24.98±1.37%. The results were statistically significant (p<0.05) or (F-ratio>F-critical), with high coefficients of determination between 0.74 and 0.99. Thus, higher force at specific speed may be needed to maximally recover kernel oil.

Compression behaviour of bulk rapeseed: Effects of heat treatment, force, and speed

ABSTRACT This study described the compression behaviour of bulk rapeseed using the universal compression testing machine and vessel diameter of 60 mm with a plunger. The pressing factors, namely the heat treatment temperature, speed, and force, were varied between 45 and 105°C, 5 and 25mm min−1 then 40 and 120 kN, respectively. The bulk rapeseed samples were measured at pressing heights between 20 and 100 mm. The parameters determined were maximum deformation (mm), deformation energy (J), oil yield (%), oil point strain (–), oil point force (kN), and oil point energy (J). Clearly, maximum deformation, deformation energy, and oil yield increased with the increase in force and heat treatment temperature, while that of speed showed a downward trend. A plot of the amounts of force and deformation displayed a smooth and serration curve characteristic. The area under the smooth curve behaviour described the compression process where the maximum rapeseed oil was obtained, while the serration pattern represented the ejection of the rapeseed cake through the holes of the pressing vessel as a result of the higher force and speed. The lower and upper oil points of rapeseed were detected at pressing heights 80 mm and 100 mm with corresponding strain values of 0.38 and 0.49 (–). This study provided vital information on rapeseed in axial pressing which can be applied in the industrial technology for optimizing the mechanical screw press oil production.

Oil point and mechanical behaviour of oil palm kernels in linear compression

Abstract The study described the oil point and mechanical properties of roasted and unroasted bulk oil palm kernels under compression loading. The literature information available is very limited. A universal compression testing machine and vessel diameter of 60 mm with a plunger were used by applying maximum force of 100 kN and speed ranging from 5 to 25 mm min−1. The initial pressing height of the bulk kernels was measured at 40 mm. The oil point was determined by a litmus test for each deformation level of 5, 10, 15, 20, and 25 mm at a minimum speed of 5 mmmin−1. The measured parameters were the deformation, deformation energy, oil yield, oil point strain and oil point pressure. Clearly, the roasted bulk kernels required less deformation energy compared to the unroasted kernels for recovering the kernel oil. However, both kernels were not permanently deformed. The average oil point strain was determined at 0.57. The study is an essential contribution to pursuing innovative methods for processing palm kernel oil in rural areas of developing countries.

Effect of temperature and moisture content on tensile behaviour of false banana fibre (Ensete ventricosum)

Abstract The mechanical behaviour of natural fibres as composite materials can be affected by changes in temperature and moisture content. The aim of this paper was to describe the effect of temperature and moisture content on tensile strength of false banana fibre (Ensete ventricosum) and to determine its water absorption. Samples of fibres were prepared and tested until rupture point with strain rate of 0.05 min−1 at temperature change between −20 and 220°C as well as moisture content between 10 and 90% wb. The water absorption and release of Ensete fibres at 60 and 90% relative humidity was also determined. Results showed that Ensete fibres exhibited stability of tensile strength in the temperature range from 0 to 100°C but the increase of temperature decreased statistically significantly the tensile strength. The effect of moisture content on tensile strength was not statistically significant. The equilibrium moisture content at 60% relative humidity and 25°C was determined.

Mathematical Description of Non-linear Mechanical Behaviour of Materials Under Compression Loading, Case Study: Spruce Bulk Wood Chips

This communication discusses the mathematical description of mechanical behaviour of bulk spruce wood chips under compression loading. The dependency between compressive force and deformation curve characteristic was fitted by reciprocal slope transformation (RST) and tangent curve (TC) methods. The mathematical model coefficients of both methods were respectively determined by the least squares method and Marquardt Levenberg approximation process, all applicable in MathCAD software. It is confirmed here that both methods can suitably be used for the illustration of deformation curve characteristic of bulk spruce wood chips.