• Korean Journal of Food Science and Technology
• /
• v.6 no.3
• /
• pp.133-137
• /
• 1974

In and attempt to investigate the milling method of barley, four kinds of barley were used for this study. The results are summerized as follow: 1) The optimum tempering and priority of milling quality of barley is shown as following table. Barley is Tempering moisture 15%, Tempering time 24hr. Naked barley is Tempering moisture 14%, Tempering time 48hr. Barley and Naked barley are Tempering moisture 13%, Tempering time 48hr. 2) Economic value of pearled materials milling is disadvantageous, because of the milling expenses are burdensome and flour extractions are fallen down 12.5% in barley and 13.6% in naked barley as compared with unpearled materials milling. 3) Wheat flour milling process may be used without any adjustment when mixed with 90% of wheat and 10% of barley. 4) Unpearled naked barley is the most suitable for flour milling when mixed with wheat.

• Journal of Biosystems Engineering
• /
• v.3 no.2
• /
• pp.88-99
• /
• 1978

In this study, rice harvesting systems suitable to Korean situations and the optimum timing of these systems were determined, respectively, based on experimentally determined factors such as filed yield and the milling quantity and quality measured at various levels of the grain moisture content at harvest. Rice varieties used for the experiment were the AKIBARE (Japonica-type) and the SUWEON 251 (high yielding TONGIL sister-line variety), The harvesting systems studied by the experimental work of this study were traditional system with both the wet material and dry-material threshing system by use of binder with both the dry-material and wet-material threshings, and system by use of combine. Grain samples were taken from final products of the paddy rice harvested from the experiment a fields for each system to measure the recovery rates of the milled rice. The results may be summarized as follows; 1. The milling recovery rate of the AKIBARE variety had highest value within the range of the grain moisture at harvest, showing from 21 to 26 percent. The head-rice recovery for the same variety was a little greater in the wet-material threshing than in the dry-material threshing , higher values of which , were 20 to 25 percent , seen within the range of grain moisture at harvest regardless of the harvesting systems tested. 2. The milling recovery of the SUWEON 251 , when tested for different harvesting systems and harvesting grain moisture, did not show a statistically significant different. In contrast , head-rice recovery for the systems operated by the wet-material threshing was much greater than that by the -material threshing. The difference of the recoveries between these systems range from 2.6 to 4.7 percent. 3. An assessment of the optimum period of -harvest timing for each of the harve\ulcornersting systems tested were made bJ.sed on (a) the maximum total milled-rise yield and (b) the percentage reduction in the total milled-rice yield due to untimely harvest operations. The optimum period determined are: 23-19% for the ATD, AC, STD, SBW, STW systems, 25-21% for the ATW ani ABW systems, and 27-18% for the ABD, SBD, and SC systems, respectively.

• 대한공업교육학회지
• /
• v.31 no.2
• /
• pp.350-363
• /
• 2006

Recently, the micro end-milling processing is demanded the high-precise technique with good surface roughness and rapid time in milli-structure parts, micro machine parts and molding industry. The cutting conditions of micro end-milling has an effect on surface roughness of cutting surface. Therefore this study was carried out to cut stainless steel using high revolution air bearing spindle and micro end-mill and analyze the cutting condition to get the optimum surface roughness by design of experiment. From this study, surface roughness have an much effect according to priority on depth of cut, revolution of spindle and feed.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.6
• /
• pp.860-866
• /
• 2004

In the end milling operation the deflection of the cutter is an important factor affecting the accuracy of machining, with implications on the selection of cutting parameters and economics of the operation. Several studies were devoted to the end mill deflection and its effects, notably, providing a useful insight into the problem. Although the deflection affects adversely the accuracy, the flexibility of the cutter is beneficial in attenuating the overload in a sudden transient situation, as well as in attenuating chatter. The deflection of the end mill was studied both experimentally with strain gauge, tool dynamometer, laser measuring apparatus and on a finite element model of the cutting using ANSYS software. The deflection of machining tool with various helix angles was studied with FEM simulation and experiment. ANSYS analysis performed on the finite element model of the end mill provides deflection results which agree within 15.0% with the experimental ones.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.23 no.3
• /
• pp.273-278
• /
• 2014

This study presents a chatter vibration avoidance program for the milling process. Chatter vibration has a negative effect on workpieces and spindle-tools. When chatter vibration occurs, the cutting tool is loaded dynamically, a chatter pattern is generated on the workpiece, and the tool life is reduced. The developed program is composed of various modules such as an FFT analyzer, an impact test analyzer, a chatter vibration indicator, and a spindle speed recommender. The proposed program is verified using an AISI D2 cutting experiment in milling process. The effect of chatter vibration on the machining condition can be simulated by the suggested method, and successfully exploited to avoid chatter vibration.

• Textile Coloration and Finishing
• /
• v.4 no.2
• /
• pp.76-83
• /
• 1992

Wool tropical and nylon taffeta were treated with low temperature plasma of $O_2$, $N_2$, NH$_3$, CF$_4$ and CH$_4$ for the intervals of 10 to 300 sec, and then dyed with leveling and milling type acid dyes in presence or absence of buffer solution. From the color depth of dyed fabrics, effect of plasma gases, treated time, dyeing time and temperature on dyeing property was studied. The results of the experiment can be summarized as follows: 1) The plasma treatments except methane gas increased the color depth of dyed wool fabrics, but not that of dyed nylon fabrics regardless of the plasma gases used. 2) The color depth of wool fabrics dyed in the dye bath without buffer solution was increased by the low temperature plasma, especially increased much more by CF$_4$ plasma treatment. It is found that with the identification of F- ion in the residual dye bath the hydrogen fluoride gas was adsorbed on wool fabrics in the plasma treatment. 3) The color depth of wool fabrics was increased with the time of $O_2$ and CF$_4$ plasma treatments. 4) In both cases of the leveling and milling type acid dyes, the rate of dyeing was increased in the low temperature plasma treatments, and it is found that the leveling type acid dye increased the color depth at relatively low temperature below 4$0^{\circ}C$, compared with the milling type acid dye.

• Structural Engineering and Mechanics
• /
• v.31 no.1
• /
• pp.57-74
• /
• 2009

Power signals resulting from spindle and feed motor, present a rich content of physical information, the appropriate analysis of which can lead to the clear identification of the nature of the tool wear. The partial least-squares regression (PLSR) method has been established as the tool wear analysis method for this purpose. Firstly, the results of the application of widely used techniques are given and their limitations of prior methods are delineated. Secondly, the application of PLSR is proposed. The singular value theory is used to noise reduction. According to grey relational degree analysis, sample variable is filtered as part sample variable and all sample variables as independent variables for modelling, and the tool wear is taken as dependent variable, thus PLSR model is built up through adapting to several experimental data of tool wear in different milling process. Finally, the prediction value of tool wear is compare with actual value, in order to test whether the model of the tool wear can adopt to new measuring data on the independent variable. In the new different cutting process, milling tool wear was predicted by the methods of PLSR and MLR (Multivariate Linear Regression) as well as BPNN (BP Neural Network) at the same time. Experimental results show that the methods can meet the needs of the engineering and PLSR is more suitable for monitoring tool wear.

• Journal of the Korean Ceramic Society
• /
• v.22 no.5
• /
• pp.47-53
• /
• 1985

In view of innovated utilization of Korean clay resources conventional techniques for pulverization are reviewed in comparison with fluid energy milling processes of fluidized-bed type. Throughout experiment indigenous halloysite ores (white grade) after usual pretreatment are employed as typical sample. It is evidenced that grinding by means of porcelain ball mills has limitation in reducing clay particles to less than 10${\mu}{\textrm}{m}$ in diameter regardless of whether it is processed in dry or wet. Upon use of tungsten carbide bull mill particulation to submicron sizes could be effected with relative ease but severe coloration in grey is attended indicating metallic contamination possibly from friction of the grinding apparatus itself. In contrast the modified fluid en ergy milling enables particulation to $\leq$10${\mu}{\textrm}{m}$ in diameter with simultaneous classification int olimited ranges of particle size distributions. Since this technique is in principle based on the interparticle collisions rather than on the frictions between particles and mill surfaces minimum impurity attendance would be an additional advantage. Evidence leads to the conclusion that the fluidized-bed type milling is regarded as highly effective in puverization as well as fractionation of the clay minerals under examination. This is especially so in contemplating high-value and/or high-purity clay products.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.6 no.1
• /
• pp.83-86
• /
• 2005

This study is predicted tool deformation by cutting forces and chip-tool interface temperature in machining process. Modeling of tool is made using 3D CAD software, finite element method is performed by cutting forces and temperature. Cutting forces and temperature used load conditions are predicted using the cutting force model based on machining theory. Experimental milling tests have been conducted to verify the cutting force model. Finally, this study is predicted cutting force components and temperature using cutting conditions, material property, tool geometry without experiment and tool deformation is predicted by cutting forces and temperature in machining process.

• Journal of Powder Materials
• /
• v.10 no.4
• /
• pp.270-274
• /
• 2003

Recently, the fabrication process of W-Cu nanocomposite powders has been researched to improve the sinterability by mechanochemical process (MCP), which consists of ball milling and hydrogen-reduction with W- and Cu-oxide mixture. However, there are many control variables in this process because the W oxides are hydrogen-reduced via several reduction stages at high temperature over 80$0^{\circ}C$ with susceptive reduction conditions. In this experiment, the W-15 wt%Cu nanocomposite powder was fabricated with the ball-milling and hydrogen-reduction process using W and CuO powder. The microstructure of the fabricated W-Cu nanocomposite powder was homogeneously composed of the fine W particles embedded in the Cu matrix. In the sintering process, the solid state sintering was certainly observed around 85$0^{\circ}C$ at the heating rate of 1$0^{\circ}C$/min. It is considered that the solid state sintering at low temperature range should occur as a result of the sintering of Cu phase between aggregates. The specimen was fully densified over 98% for theoretical density at 120$0^{\circ}C$ for 1 h with the heating rate of 1$0^{\circ}C$/min.