Increasing the Efficiency of Food Material Cutting during Inclined and Shear Movements of Knife

Mathematical models for predicting the resistance forces that are developed during the inclined and sliding cutting of food materials have been developed. The dependence of the actual cutting angle on the angle of inclination and sliding speed of the cutting edge at various sharpening angles have been investigated. For the inclined cutting mode, the dependence of the useful resistance force on the cutting speed has been determined at various angles of inclination of the cutting edge and designed sharpening angles. For the sliding cutting mode, the dependence of the useful resistance force on the feeding speed has been demonstrated at various sliding speed values and designed knife sharpening angles. The dependence of the transformed dimensionless sharpness of the knife on the angle of inclination of the cutting edge and the sliding speed has been established for different constructional sharpness values of the knife. The results of the study indicate that the useful resistance force is significantly reduced during the inclined and sliding cutting processes when compared with the normal cutting process, and a change in the pattern of fiber destruction, which significantly increases the cutting efficiency of cutting tools, is obtained.

Morphology and Performance Characterizations of 316 Stainless Steel Additively Fabricated by Laser Thermal-Joule Heating Composite Process

The Laser Thermal-Joule Heating Composite Process was studied by orthogonal tests based on an analysis of fabrication parameters such as the laser power, wire feeding speed, and electric current. Temperature profiles and the geometric morphology of deposited layers under different process parameters were analyzed, and the overlaps between the layers and the substrate were observed. Results show that when the temperature at the bottom layer of the additive manufacturing is higher than the melting point of the substrate, and the highest temperature at the top layer does not exceed the over-firing temperature, good morphology and close bonding with the substrate can be obtained. Finally, appropriate process parameters were identified and verified to print multiple layers continuously.

The Effect of Temper Condition and Feeding Speed on the Additive Manufacturing of AA2011 Parts Using Friction Stir Deposition

In the current study, solid-state additive manufacturing (SSAM) of two temper conditions AA2011 was successfully conducted using the friction stir deposition (FSD) process. The AA2011-T6 and AA2011-O consumable bars of 20 mm diameter were used as a feeding material against AA5083 substrate. The effect of the rotation rate and feeding speed of the consumable bars on the macrostructure, microstructure, and hardness of the friction stir deposited (FSD) materials were examined. The AA2011-T6 bars were deposited at a constant rotation rate of 1200 rpm and different feeding speeds of 3, 6, and 9 mm/min, whereas the AA2011-O bars were deposited at a constant rotation rate of 200 mm/min and varied feeding speeds of 1, 2, and 3 mm/min. The obtained microstructure was investigated using an optical microscope and scanning electron microscope equipped with EDS analysis to evaluate microstructural features. Hardness was also assessed as average values and maps. The results showed that this new technique succeeded in producing sound additive manufactured parts at all the applied processing parameters. The microstructures of the additive manufactured parts showed equiaxed refined grains compared to the coarse grain of the starting materials. The detected intermetallics in AA2011 alloy are mainly Al2Cu and Al7Cu2Fe. The improvement in hardness of AA2011-O AMPs reached 163% of the starting material hardness at the applied feeding speed of 1 mm/min. The hardness mapping analysis reveals a homogeneous hardness profile along the building direction. Finally, it can be said that the temper conditions of the starting AA2011 materials govern the selection of the processing parameters in terms of rotation rate and feeding speed and affects the properties of the produced additive manufactured parts in terms of hardness and microstructural features.

Geometric and kinematic parameters of vibrating knife in the development of cutting machines

The process of cutting with a blade is largely applied in agricultural equipment and is used to process raw materials with different physical and mechanical properties. Nonetheless, the functional relation between the kinematic parameters of a vibroblade and the crucial power parameters of the vibration processing has not yet been studied in great depth so far. This type of studies is essential to create databases for further investigation and design of novel cutting machinery or technologies to ensure effective processing of vibrocutting. Our objective was to obtain the power characteristics of vibrocutting through laboratory experiments [using the example of vibrocutting of common reed (Phragmites australis)] and define the combination of factors (i.e., vibration amplitude, frequency and the blade feeding speed) at the minimum cutting force. The following relation of the blade feeding speed (V) and vibration speed of the toothed blade (Vt) has been established as optimal kinematic regime: K≅0.004. Tests have indicated that use of toothed blades for vibrocutting of the raw products of plant origin offers a greater advantage over the blades with flat edges. An optimal cutting regime, when energy expenses are at a minimum, was ensured with the following parameters of the vibroblade: vibration amplitude: 14 mm, frequency: 33.32 s–1, the blade feeding speed: 7.5×10–3 m.

DEVELOPMENT AND EVALUATION OF FINGER WHEEL AND CUTTING DISC COMBINED DEVICE FOR STALK RETURNING

Stalk returning technology was an important way to preserve soil nutrients and reduce soil erosion. It was of great significance to improve the stalk chopping quality, reduce power consumption. On the basis of the previous research, the finger wheel and cutting disc combined device for stalk returning was developed, mainly composed of the sawtooth blade group, the finger wheel and the stalk lifting grid. The stalk was fed into the cutting area of the sawtooth blades by the rotation of the finger wheel, and the operation of the stalk chopping was completed under the combination of the sawtooth blade group and the finger wheel. The movement of stalks in the device with finger wheel and sawtooth blades was analysed by high speed photography, and the rotational speed of finger wheel, the rotational speed of sawtooth blade group, the stalk feeding speed had a great influence on the movement of the stalks. Through orthogonal test and verification test, the clamping angle was 20°, the rotational speed of sawtooth blade group was 800 min-1, the stalk feeding speed was 1.45 m/s, the rotational speed of finger wheel was 110 min-1, the cut length qualified rate was 92.47% and the cutting power was 529.97 W. The test results met the quality requirements of the Chinese national standard. The related research can provide reference for the research of stalk returning device.

Studi Eksperimen Pengaruh Variasi Kecepatan Potong dan Kedalaman Pemotongan Terhadap Kekasaran Permukaan Benda Kerja Hasil Pembubutan Material Baja ST 41 Menggunakan Pahat HSS

The benchmark for the results of the machining process can be seen from the results of the products, one of which is the level of surface smoothness. The purpose of this experimental research is to find out how much cutting speed (Vc) and depth of cutting produce a workpiece with the smoothest level of surface roughness for the turning process carried out by students at the Bangka Belitung State Manufacturing Polytechnic Workshop. This research is using experimental method. The cutting speeds (Vc) used were 23 m/min, 24 m/min, 25 m/min, the cutting depths used were 0.5 mm, 0.8 mm, and 1.0 mm and the feeding speed was set at 0.040 mm/rev. The results showed that the best turning results using a cutting speed (Vc) of 23 m/min was using a cutting depth of 0.5 mm with a roughness value (Ra) of 1.372 m, using a cutting speed (Vc) of 24 m/min using a depth of cut. 0.5 mm with a roughness value (Ra) of 1.189 m and using a cutting speed (Vc) of 25 m/min using a depth of 0.5 mm with a surface roughness value (Ra) of 3.14 m. The lowest value for the level of surface roughness of the turning process was obtained using a cutting speed (Vc) of 24 m/min with a depth of 0.5 mm with a surface roughness value (Ra) of 1.189 m.

A combined GWAS approach reveals key loci for socially-affected traits in Yorkshire pigs

Socially affected traits in pigs are controlled by direct genetic effects and social genetic effects, which can make elucidation of their genetic architecture challenging. We evaluated the genetic basis of direct genetic effects and social genetic effects by combining single-locus and haplotype-based GWAS on imputed whole-genome sequences. Nineteen SNPs and 25 haplotype loci are identified for direct genetic effects on four traits: average daily feed intake, average daily gain, days to 100 kg and time in feeder per day. Nineteen SNPs and 11 haplotype loci are identified for social genetic effects on average daily feed intake, average daily gain, days to 100 kg and feeding speed. Two significant SNPs from single-locus GWAS (SSC6:18,635,874 and SSC6:18,635,895) are shared by a significant haplotype locus with haplotype alleles ‘GGG’ for both direct genetic effects and social genetic effects in average daily feed intake. A candidate gene, MT3, which is involved in growth, nervous, and immune processes, is identified. We demonstrate the genetic differences between direct genetic effects and social genetic effects and provide an anchor for investigating the genetic architecture underlying direct genetic effects and social genetic effects on socially affected traits in pigs.

Research on Parameters of Wire-Filling Laser Welding and Quenching Process for Joints Microstructure and Mechanical Property of BR1500HS Steel

With the aim to investigate the effect of parameters and the quenching process on the joint microstructure and mechanical properties of hot stamping steel by laser welding, BR1500HS boron steel was welded by wire-filling laser welding with ER70-G welding wire under different parameters. The welded specimens were heated to 900 °C and held for 5 min before water quenching. A universal material test machine, optical microscope, Vickers hardness tester, scanning electron microscope, and electron backscatter diffraction (EBSD) were used to characterize. The results show that the heat input should be greater than 1040 J/cm and the optimal wire-feeding speed is between 160 cm/min and 180 cm/min. The tensile strength of the quenched joint can reach greater than 1601.9 MPa at compatible parameters. More retained austenite distributes in the fusion zone (FZ) and fine grain zone (FGZ) than the coarse grain zone (CGZ) before quenching. However, the retained austenite in FZ and heat-affected zone (HAZ) decreases clearly and distributes uniformly after quenching. The grain diameter in FZ before quenching is not uniform and there are some coarse grains with the diameter greater than 40 μm. After quenching, the grains are refined and grain diameter is more uniform in the joint. With the increase in heat input, the microhardness of FZ and HAZ before quenching decreases from 500 HV to 450 HV. However, if the wire-feeding speed increases, the microhardness of FZ and HAZ before quenching increases from 450 HV to 500 HV. After quenching, the joint microhardness of all samples is between 450 HV and 550 HV. The fracture morphology of the joint before quenching consists of a large number of dimples and little river patterns. After quenching, the fracture morphology consists of a large amount of river patterns and cleavage facets due to the generation of martensite.

An Experimental Study on Performance and Structural Improvements of a Novel Elutriator

During the transportation and packaging of low density polyethylene (LDPE) granular materials, fine dusts such as floccules, powder and fiber will be produced, which pollute the environment, affect product quality and generate fire hazards. In this work, the separation performance of fine dust and optimal operating conditions of an improved elutriator were investigated experimentally. Experiments were carried out to investigate the effects of air speed, feeding speed, and grid layout on the removal efficiency of fine particles. Experimental data showed that the separation efficiency of the novel elutriator ranged from 96% to 98.50%, which was more stable and an average of 51.44% higher than that of the original elutriator. By setting internals and improving the structure, the gas flow field in the equipment was regulated, the particle dispersion was intensified, and the static electricity was eliminated, which significantly improved the separation efficiency of fine dust.