• Title, Summary, Keyword: extruder die

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Simulation of Heat and Fluid Flow in the Single Screw Extruder with Coupling of the Metering Section and Die (단축 스크류 압축기에서 계량화부와 다이를 동시에 고려한 열 및 유동해석)

  • Yoon, Jung-Bae;Kwag, Dong-Seong;Kim, Woo-Seung
    • Proceedings of the KSME Conference
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    • pp.246-251
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    • 2000
  • In the present study, the analysis on heat and fluid flow in the single screw extruder is carried out by simultaneously considering the metering section and the die. The finite difference method and the finite volume method are applied to the metering section and the die, respectively. The zonal method is used to couple the metering section and the die. To investigate the effect of die on the characteristics of heat and fluid flow in the single screw extruder, the pressure back flow is included in the analysis. The screw-tip rotation is also considered by employing the quasi 3-dimensional die model. The present results are compared with the numerical and experimental data available in the literatures.

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Performance Evaluation and Analysis of the Screw and Die of the Single Screw Extruder Using the CFD (CFD를 이용한 단축압출기 스크류 및 다이스의 성능시험평가 및 해석에 관한 연구)

  • Kim, Jae-Yoel;Chung, Hyo-Hee
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.2
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    • pp.194-200
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    • 2009
  • The extruder type is classified as screw type and non-screw type in terms of the extrusion method. The screw type extruder, which is the most frequently used, is classified as the single screw extruder and the multi-screw extruder. They are classified as vertical type and horizontal type in terms of structure; and those for compounding and for forming in terms of function. The single screw extruder is a universal extruder, most of which is suitable for the extrusion forming of thermoplastic resin. The multi-screw(two-screw, three-screw and four-screw) extruder can increase the extrusion power using the engagement of the screw flank. The single screw extruder does not have a good mixing ratio of the raw material and stable extrusion power, while it has low construction cost and operation cost. In this study, the single screw extruder, which has many weak points compared with the multi-screw extruder, was studied. There have been many studies on the single screw extruder, and they led to its significant development. The existing study method, however, had complex analysis processes and required much time. In this study, the CFD was applied to the performance test and analysis of the extruder, and the optimal design condition of the extrusion power for the screw and die of the single screw extruder was found by comparing the analysis results with the actual performance measurement of the single screw extruder.

The Effects of the Type of Cereal Powder and Extruder Operation Conditions on the Barrel Temp.-distribution (원료곡분의 성상과 압출 조건이 Extruder 내부 온도분포에 미치는 영향)

  • Ryu, Gi-Hyung;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
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    • v.20 no.3
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    • pp.303-309
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    • 1988
  • The heat generation at the start-up period of an autogeneous single screw extruder was determined with various feed materials, die structure and operational conditions. The highest heat generation rate was observed with defatted soybean meal, while the lowest value was obtained with rice flour, and wheat and barley flour showed the intermediate rate. As the moisture content of the flour decreased and the screw speed increased, the electric power requirement and heat generation rate increased. The temperature at compression section increased with the decrease in the particle size. The same effect was also observed as breaker plate was installed. The optimum operation was established as the temperature profile was maintained in decreasing order of metering section, die and compression section.

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In-line measurement of residence time distribution in twin-screw extruder using non-destructive ultrasound

  • Lee, Sang-Myung;Park, Jong-Cheol;Lee, Sang-Mook;Ahn, Young-Joon;Lee, Jae-Wook
    • Korea-Australia Rheology Journal
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    • v.17 no.2
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    • pp.87-95
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    • 2005
  • In this study, we performed RTD measurement at the die exit of co-rotating twin-screw extruder using a non-destructive ultrasonic device. The ultrasonic device was attached at slit die and was composed of a steel buffer rod and 10 MHz longitudinal piezoelectric ultrasonic transducer. This in-line ultrasonic monitoring method is based on the ultrasonic response of $CaCO_3$ filled in polymer. The RTD is evaluated by variation of ultrasonic attenuation with time caused by change of the tracer concentration during extrusion. The ultrasonic tracer, pellet type of compounded $CaCO_3$ in polymer was used in this study. The effects of tracer concentration on RTD and flow patterns were studied. Evaluation for the residence functions at different screw speeds, feeding rates and screw configurations were also carried out.

Extrusion-cooking Using Twin-screw Extruder on Cordyceps Pruinosa (이축 압출 성형기를 이용한 붉은자루 동충하초의 압출 성형)

  • Kim D. E.;Sung J. M.;Kang W. S.
    • Journal of Biosystems Engineering
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    • v.30 no.1
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    • pp.8-16
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    • 2005
  • The extrusion-cooking condition on Cordyceps pruinosa was designed using twin-screw extruder. Response surface methodology (RSM) was used to investigate extrusion-cooking using a central composition design with varying die temperature $(114-146^{\circ}C)$, feed moisture $(22-38\%)$, feed rate (4-14 ka/h) and screw speed (120-280 rpm). System parameters (die pressure and specific mechanical energy (SME)) and extrudate parameters (density and water solubility index (WSI)) were statically analyzed using RSH. Die pressure was significantly affected by temperature, moisture contents and feed rate. SM was affected by screw speed and feed rate. When die temperature is $130^{\circ}C$ and moisture content $25\%$, the optimum pressure is shown. SME is about 20 Wh/kg, when feed rate is $10\~12kg/min$ and screw speed $200\~250rpm$. WSI was affected by temperature and moisture contents. Density was not affected by any factor. WSI increases by $7\%$ from about $23\%$ to about $30\%$, as temperature is raised from $120^{\circ}C\;to\;140^{\circ}C$. The WSI of Cordyceps pruinosa pulverized after extruding (PE) is about $26.97\%$ higher than that of raw material and $10\%$ higher than that of pulverized after drying (PD). The content of unsaturated fatty acid were not significantly different in PD and PE. Anti-oxidative activity of PE was 1.67-2.2 times higher than that of PD in Cordyceps pruinosa using 1- dipheny1-2-picrylhydrazyl method (DPPH).

High-pressure rheology of polymer melts containing supercritical carbon dioxide

  • Lee Sang-Myung;Han Jae-Ro;Kim Kyung-Yl;Ahn Young-Joon;Lee Jae-Wook
    • Korea-Australia Rheology Journal
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    • v.18 no.2
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    • pp.83-90
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    • 2006
  • Supercritical carbon dioxide ($scCO_2$) has advantages of being incorporated in polymer with high solubility and of being recovered easily by depressurizing. $scCO_2$ reduces the viscosity of polymer melt and it is expected to be use as a plasticizing agent. In this work, we studied on the effect of $scCO_2$ on the rheological properties of polymer melts during extrusion process. Slit die attached to twin screw extruder was used to measure the viscosity of polymer melts plasticized by supercritical $CO_2$. A gas injection system was devised to accurately meter the supercritical $CO_2$ into the extruder barrel. Measurements of pressure drop within the die, confirmed the presence of a one phase mixture and a fully developed flow during the measurements. The viscosity measurement of polypropylene was performed at experimental conditions of various temperatures, pressures and $CO_2$ concentrations. We observed that melt viscosity of polymer was dramatically reduced by $CO_2$ addition.

Development of CNC Extruder for Variable Cross-Section Extrusion Process and its Applied Research (가변단면 압출기 개발 및 응용 연구)

  • Choi, H.J.;Lim, S.J.;Shin, H.T.;Choi, S.
    • Transactions of Materials Processing
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    • v.17 no.2
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    • pp.130-134
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    • 2008
  • Resource and energy saving is a very important practice for the future as well as for today. Weight saving of structural parts, which are formed by extrusion, plays a key role in manufacturing field. The cross-sections of extruded parts with industrial aluminum are constant in the axial direction by conventional extrusion method. Especially, these aluminum parts used and manufactured in the car industry need other processes to vary the cross-section in the axial direction. However, applications of these parts are often limited by high cost. If the cross-section of the parts is variable by only extrusion with newly developed method, the application of extruded aluminum parts will actually increase. Therefore, a new CNC extruder that can control the section area of a car part was invented for the first time in the nation. Using the extrusion machine, the experiment was performed to validate its workability during the variable section extrusion process. Also, numerical analysis was carried out to investigate the flow mode with different speeds of main ram and various pocket shapes of a die-set in the variable section extrusion process.

Physicochemical and Sensory Textural Properties of Rice Extrudate Depending on Extrusion Conditions

  • Chung, Kang-Hyun
    • Preventive Nutrition and Food Science
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    • v.5 no.1
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    • pp.25-31
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    • 2000
  • Extrusion conditions for production of rice extrudate were studied. The optimal production conditions of rice extrudate were determined by the relationship between dependent variables such as expansion ratio, shear strength and color change and independent variables such as moisture content of raw material, screw speed, and die tem-perature of extruder. The textural quality of rice exturdate was significantly affected by the moisture content of raw material (x1), screw speed (x2), and die temperature (x3) of extruder. The expansion ratio of rice extrudate showed the highest value at the moisture content of 18% of raw material, and the lowest at 24%, and whose regression equation was Y=34.8967 - 3.219X1 - (0.623$\times$10-2)X2 + 0.136X3 + (0.648$\times$10-1)X12 + (0.138$\times$10-3)X1X2 + (0.456$\times$10-4)X22 + (0.719$\times$10-3)X1X3 -(0.515$\times$10-3)X2X3- (0.552$\times$10-3)X32. The most desirable texture of rice extrudate determined by shear test and sensory evaluation was obtained at the following conditions : mois-ture content of 18% of raw material, screw speed of 210 rpm and die temperature of 11$0^{\circ}C$. The rice extrudate prepared under the above conditions showed the lowest shear force of 954g at which the highest sensory score was obtained.

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CNC Extruder for Varied Section Products (CNC 제어 가변단면 압출기 개발)

  • Choi, H.J.;Lim, S.J.;Shin, H.T.;Choi, S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.246-249
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    • 2007
  • It is very important that there are saving resource and energy in the future as well as in these day. Weight saving of structural parts, which are formed by extrusion, plays a key role in manufacturing field. Extruded aluminum parts' cross sections are constant in the axial direction by conventional extrusion method. Especially these aluminum parts used in the car need other processes to vary the cross section in the axial direction. Thus, applications of these parts are limited by high cost. if the cross section of the parts is variable by only extrusion, application of extruded aluminum parts will more increase. Therefore, a new CNC extruder which can control the section area of a car part was invented the nation's first. Using the extrusion machine, the experiment was performed to validate the workability.

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Fogrming Experiment using Improved CNC Extruder and FE Analysis in Varied Section Extrusion Process (가변단면 압출기 제조와 그에 따른 성형실험 및 유한요소 해석)

  • Choi, H.J.;Lim, S.J.;Shin, H.T.;Choi, S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.128-131
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    • 2007
  • It is very important that there are saving resource and energy in the future as well as in these day. Weight saving of structural parts, which are formed by extrusion, plays a key role in manufacturing field. Especially these aluminum parts used in the car need other processes to vary the cross section in the axial direction. Thus, applications of these parts are limited by high cost. if the cross section of the parts is variable by only extrusion, application of extruded aluminum parts will more increase. Therefore, a new CNC extruder which can control the section area of a car part was invented the nation's first. Using the extrusion machine, the experiment and FE analysis were performed during the varied section extrusion process.

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