• Title/Summary/Keyword: Extruder screw

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An Analysis of a Thermo-plastic Melt Flow in the Metering Zone of a Polymer Extruder (고분자 압출기에 있어서 계량부 용융수지의 유동해석)

  • Choi, Man Sung;Kim, Kwang Sun
    • Journal of the Semiconductor & Display Technology
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    • v.11 no.4
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    • pp.7-12
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    • 2012
  • Extrusion is one of the most important operations in the polymer-processing industry. Development of models for extrusion and computer tools offer a route to developing reliable and optimized process designs. The models are based on the analysis of physical phenomena encountered during the process. Balance equations for mass, momentum and energy are fundamental to the problem. A predictive computer model has been developed for the single screw extruders with conventional screws of different geometry. The model takes into account melting zones of the extruder and describes an operation of the extruder system, making it possible to predict mass flow rate of the polymer, pressure and velocity profiles along the extruder screw channel. The simulation parameters are the material and rheological properties of the polymer; the screw pitch, and screw speed.

Construction of Single-screw Food Extruder and its Mechanical Properties and Product Characteristics for Corn Grits Extrusion-cooking (Single-screw Food Extruder의 제작과 Corn Grits 팽화시의 기계적 성질과 제품 특성)

  • Lee, C.H.;Lim, J.K.;Kim, J.D.;Lee, M.H.
    • Korean Journal of Food Science and Technology
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    • v.15 no.4
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    • pp.392-398
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    • 1983
  • A pilot single-screw food extruder was constructed, and its mechanical properties and product characteristics were investigated by using corn grits. The screw rotational speed was varied and the changes in temperature profile of the barrel for the start-up period of operation were measured. The rate of heat generation for the start-up period was affected by the screw speed and feed rate. The screw speed resulted in a great influence on the estimated dough viscosity. The changes in the dough viscosity could indicate the on-set of termoplastic reaction in the barrel. The expansion ratio during the start-up period mainly depended on the barrel temperature and the degree of thermoplastic reaction in the barrel. The barrel temperatures for the gelatinization and burning of corn grits depended on the screw speed as well as the feed rate.

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A Review on the Screw Configuration of Intermeshing Co-rotating Twin Screw Extruder (교합형 동방향 이축압출기의 스크류 조합에 대한 고찰)

  • Lee, Shichoon;Kim, Hyungsu
    • Korean Chemical Engineering Research
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    • v.59 no.3
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    • pp.305-315
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    • 2021
  • An intermeshing corotating twin screw extruder is mainly used for compounding polymeric materials. Twin screw extruder can adopt modular-type screw configurations, which directly controls the quality and productivity of the products. The types, shapes, and specifications of the screw and kneading elements are summarized, and the effects of screw configuration on the processabiliy of the materials are discussed. The principles of screw configuration universally applied to mass production of general-purpose resins are explained, and the guidelines of screw combination according to the roles of feeding, melt mixing, and metering zones are listed. The strategies of screw combination suitable for various cases, such as side feeding of liquid additives or inorganic fillers, reactive extrusion, devolatilization process, production of products requiring bright color and transparency, and processing of materials with low apparent specific gravity, are presented.

Three-Dimensional Heat and Fluid Flow Simulations for Non-Newtonian Fluid in a Single Screw Extruder (단축 스크류 압출기 내의 비뉴턴유체에 대한 3차원 열 및 유동해석)

  • Kwag, Dong-Seong;Kim, Woo-Seung;Lyu, Min-Young
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.337-342
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    • 2001
  • A numerical study of three-dimensional fluid flow and heat transfer in the metering section of a single screw extruder has been performed. The mathematical model for the screw channel is simplified by unwound channel and fixing the coordinate system to the screw. The pressure boundary and the prescribed mass flow rate conditions are imposed on the inlet and outlet, respectively. The commercial code STAR-CD based on the finite volume method is used to obtain the results of the present work. The computation of the reverse flow, which cannot be computed by the marching-type 3-D model, is performed in the present study.

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A Study on Analysis of Polymer Extruder Process Using Finite Element Method (유한요소법을 이용한 폴리머 압출 공정해석에 관한 연구)

  • Ye Youngsoo;Kim Hongbum;Lee Jaewook;Kim Naksoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.1 s.232
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    • pp.145-155
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    • 2005
  • In this study, a finite element method program code which can be accomodate boundary conditions on the complex surfaces has been developed to simulate polymer extruder processes. The analysis method includes the fractional 4-step method for efficient computation time and compact usage of memory storage to solve the velocities and the pressure values from the Navier-Stokes equation. By using the developed program which was verified with simple Poiseuille flow mixture phenomena in single-and twin-screw extruder are analyzed. It is concluded that the proposed method resulte Poiseuille Poiseuille d in fair agreement with the exact solution of simple flow and the back flow near the entrance happens in single-screw model. It is identified that the location and values of maximum pressure in the twin screw extruder model. It is expected that the Velocity field found can be used to predict the degree of mixture in the extruder barrel.

A Study on Machining of the Self-Wiping Co-Rotating Twin Screw (밀폐형 동회전 2축 스크류의 제작에 관한 연구)

  • 최부희;이상혁;최상훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1426-1429
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    • 2003
  • This paper describes screw tool design and machining method witch is able to design tool profile and 3-dimensional geometry for screws in self-wiping co-rotating twin screw extruder. The geometric features of screws for co-rotating twin screw extruders are developed from kinematic principles. Closely self-wiping screw segments are manufactured in universal milling machine by using designed screw tools. It is shown that experimental results verified the closely intermeshing condition in twin screw.

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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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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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    • 2000.04b
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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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Development and Performance Evaluation of Single screw Polymer Extruder System (단축스크류 고분자압출기 시스템의 개발 및 성능평가)

  • Kim, Jae-Yeol;Jung, Hyo-Hee;Choi, Jin-Ho
    • Tribology and Lubricants
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    • v.25 no.3
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    • pp.182-186
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    • 2009
  • Extruders can be basically divided into bisk and screw type of extruders. Though plastic extruders are often used for its simplicity for water and oil transportation pumps, these days screw extruders are mostly used. Screws are used in many extrusion processes to manufacture complex and complicated shaped parts made of plastics, medicine materials, food, polymer composites, iron and ceramic powders, etc. Also, material correction of deformities is caused by flow and physicochemical reaction phenomenonand material extrusion is processed according to heat transfer. various material comes to hopper because extruder has function by blender and mixing of materials can go well before come out through dice. These change process is so complicated that process condition is decided by trial and error that process condition is underground mainly at extrusion molding process.

Design Parameters and Conveying Characteristics of Twin Screw Extruder (2축(軸) 압출기(押出機)의 설계요인(設計要因) 및 이송량(移送量)에 관한 분석(分析))

  • Song, D.B.;Koh, H.K.;Kim, Y.H.
    • Journal of Biosystems Engineering
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    • v.19 no.1
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    • pp.50-61
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    • 1994
  • This research was conducted to determine a preliminary design parameters for the development of twin screw extruder using Booy's screw design method, and to analyze a extrusion process using Janssen's mathematical flow model. In processing process, the experimental mass flow rates of com flour and wheat flour were almost the same as theoretical values corrected by correction factors of 0.95 and 0.6 respectively. It was appeared that the mathematical model would be suitable to predict the conveying capacity.

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