extrusion - UNIVERSITY OF UNIVERSITY OF FLORIDA EMA 4666C -...

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Unformatted text preview: UNIVERSITY OF UNIVERSITY OF FLORIDA EMA 4666C - Polymer Processing Extrusion Dr. Anthony Brennan University of Florida Department of Materials Science & Department Engineering Engineering 07/17/11 EMA 4666C - Polymer Processing 1 UNIVERSITY OF UNIVERSITY OF Agenda FLORIDA Introduction Extruder Design General Principles Process Parameters Troutonian Viscosity Flow Properties 07/17/11 EMA 4666C - Polymer Processing 2 UNIVERSITY OF UNIVERSITY OF FLORIDA Ram Accumulator Blow Molding Hopper Die Control/Power Unit Heater Extrudate Ram Drive Blower Zone 4 07/17/11 Zone 3 Zone 2 Zone 1 EMA 4666C - Polymer Processing 3 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 Barrel Configuration EMA 4666C - Polymer Processing 4 UNIVERSITY OF UNIVERSITY OF FLORIDA Screw Geometry Terms: – e - width of flight; δ - Gap between Flight and Barrel width Wall Wall – w - spacing of flight; D - Diameter of Barrel; spacing or Helical Angle; L - total channel length or e φ - Flight φ δ h w D L 07/17/11 EMA 4666C - Polymer Processing 5 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 Single Phase Screws EMA 4666C - Polymer Processing 6 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 Grooved Screws EMA 4666C - Polymer Processing 7 UNIVERSITY OF UNIVERSITY OF FLORIDA Drag Flow Analysis Pitch = π D tan φ Vd = π D N cos φ w = ( π D tan φ − e ) cos φ Ls tan φ = πD Qd = (1 / 2 w h ) Vd Net Drag Flow for the Extruder 1 π 2 D 2 N h sin φ cos φ Qd = 2 07/17/11 EMA 4666C - Polymer Processing 8 UNIVERSITY OF UNIVERSITY OF FLORIDA Pressure Flow Analysis Pitch = π D tan φ w = ( π D tan φ − e ) cos φ Ls tan φ = πD Vd = π D N cos φ 1 dP Qp = . w h3 12 µ dz Net Pressure Flow for the Extruder π D h sin φ dP Qp = dL 12 µ 3 07/17/11 2 EMA 4666C - Polymer Processing 9 UNIVERSITY OF UNIVERSITY OF FLORIDA Extruder Output (Mass Throughput) Mass throughput = Mass π 2 Eh 2 m = ρ bulkπ D tan φ ( DB − Ds ) − sin φ 4 • 07/17/11 EMA 4666C - Polymer Processing 10 UNIVERSITY OF UNIVERSITY OF FLORIDA Extruder/Die Characteristics Extruder/Die K1 = Thick LDPE Open Discharge 07/17/11 K2 = Thin Closed Discharge EMA 4666C - Polymer Processing 11 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 Flow and Pressure Profiles EMA 4666C - Polymer Processing 12 UNIVERSITY OF UNIVERSITY OF FLORIDA Profiles Dimensionless throughput m m= ρ bulk N D 3 • ^ ∆ pD ∆ p= n mN L ^ 07/17/11 EMA 4666C - Polymer Processing 13 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 Melting Behavior in Screw EMA 4666C - Polymer Processing 14 UNIVERSITY OF UNIVERSITY OF FLORIDA Melt Profile of Extruder Separates the melt from the solid bed 07/17/11 EMA 4666C - Polymer Processing 15 UNIVERSITY OF UNIVERSITY OF FLORIDA Design Project Potential Areas – Automotive • Water Pump • Air Bag • Intake Manifold – Biomedical • • • • 07/17/11 VAD Prosthesis Stent Valve – Electronics • Low cost CD • IC Package • Drive Motor Drive Housing Housing – Aerospace • Aerilons • Seats • Nose Cone – Recreation • Bicycle Frame • Helmetd EMA 4666C - Polymer Processing 16 UNIVERSITY OF UNIVERSITY OF FLORIDA Design Criteria Specifications – Mechanical – Physical – Environmental – Cost • Material • Process • Recycling 07/17/11 Design – Strength Analysis – Dynamic (Cyclic) Dynamic conditions conditions – Process Selection – Material Selection – Cost Analysis • • • • Materials Process Time Distribution EMA 4666C - Polymer Processing 17 UNIVERSITY OF UNIVERSITY OF FLORIDA Design Proposal Proposal – Follow outline given – 10 to 15 Pages (Not Including 10 Figures) Figures) Presentation – Plan on 20 Minutes – Consider Computer Presentation 07/17/11 EMA 4666C - Polymer Processing Grading based upon written & oral 18 UNIVERSITY OF UNIVERSITY OF FLORIDA Throughput of Extruder Grooved Feeds < 3.5 D 07/17/11 EMA 4666C - Polymer Processing 19 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 Examples of DIes EMA 4666C - Polymer Processing 20 UNIVERSITY OF UNIVERSITY OF FLORIDA Typical Pressures Vbz W ( h − δ ) π n D cos φ dP Qp = dL 12 µ Vbz = π n D cos φ Solve for P (Assume Poiseuille Flow) π D h3 sin 2 φ dP µ= 12 Q dL p 07/17/11 EMA 4666C - Polymer Processing 21 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 EMA 4666C - Polymer Processing 22 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 EMA 4666C - Polymer Processing 23 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 EMA 4666C - Polymer Processing 24 UNIVERSITY OF UNIVERSITY OF FLORIDA 07/17/11 EMA 4666C - Polymer Processing 25 UNIVERSITY OF UNIVERSITY OF FLORIDA References Introduction to Physical Polymer Science, 2nd Introduction Edition, Lesley H. Sperling, Wiley Interscience (1992) ISBN 0-471-53035-2 Interscience Some figures were reproduced from: Polymer Some Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. Cincinnati, The Physics of Polymers, Gert Strobl (1996) The Springer-Verlag, New York. Springer-Verlag, 07/17/11 EMA 4666C - Polymer Processing 26 ...
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This note was uploaded on 07/17/2011 for the course EMA 4666c taught by Professor Brennan during the Spring '08 term at University of Florida.

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