Slide-Set-10-Extrusion

Slide-Set-10-Extrusion - Slide Set 10 Extrusion Extrusion...

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Unformatted text preview: Slide Set 10 Extrusion Extrusion Dr. Anthony Brennan University of Florida Department of Materials Science & Engineering EMA 4161C - Physical Properties of Polymers 1 Learning Objectives Learning • Introduction • PU Extrusion Process - Extruder Design General Principles • Process Process Parameters Parameters Troutonian Troutonian Viscosity Viscosity Flow Properties EMA 4161C - Physical Properties of Polymers 2 Ram Accumulator Blow Molding Ram Hopper Die Control/Power Unit Heater Extrudate Ram Drive Blower Zone 4 Zone 3 Zone 2 Zone 1 EMA 4161C - Physical Properties of Polymers 3 Barrel Configuration Barrel Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers 4 Screw Geometry Screw •Terms: – e - width of flight; δ - Gap between Flight and Barrel width Wall Wall – w - spacing of flight; D - Diameter of Barrel; φ - Flight or spacing Helical Angle; L - total channel length Helical e φ δ h w D L EMA 4161C - Physical Properties of Polymers 5 Single Phase Screws Single Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers 6 Grooved Screws Grooved Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers 7 Drag Flow Analysis Drag 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 EMA 4161C - Physical Properties of Polymers 8 Pressure Flow Analysis Pressure 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 2 EMA 4161C - Physical Properties of Polymers 9 Extruder Output (Mass Throughput) Extruder Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. Polymer Mass throughput = Mass π 2 Eh 2 m = ρ bulkπ D tan φ ( DB − Ds ) − sin φ 4 • EMA 4161C - Physical Properties of Polymers 10 Extruder/Die Characteristics K1 = Thick LDPE Open Discharge K2 = Thin Closed Discharge EMA 4161C - Physical Properties of Polymers EMA 11 Flow and Pressure Profiles Flow EMA 4161C - Physical Properties of Polymers 12 Profiles Profiles Dimensionless throughput m m= ρ bulk N D 3 • ^ ∆ pD ∆ p= n mN L ^ Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers 13 Melting Behavior in Screw Melting Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers 14 Melt Profile of Extruder Melt Separates the melt from the solid bed Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers 15 Throughput of Extruder Throughput Grooved Feeds < 3.5 D Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers 16 Examples of Dies Examples Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers 17 Typical Pressures Typical 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 EMA 4161C - Physical Properties of Polymers 18 Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers EMA 19 Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers EMA 20 Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers EMA 21 Polymer Processing Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. EMA 4161C - Physical Properties of Polymers EMA 22 Summary • Four primary phases of extrusion. • Output is a rate • Output is dependent upon balance Output between drag flow and pressure flow between • Output of die is pressure controlled • Melt profile defines output efficiency 23 23 References • Introduction to Physical Polymer Science, 4th Edition, Lesley H. Sperling, Wiley Interscience (2006) ISBN 13 978Lesley 0-471-70606-9 • Principles of Polymer Chemistry, P.J. Flory (1953) Cornell Principles University Press, Inc., New York. University • The Physics of Polymers, Gert Strobl (1996) SpringerVerlag, New York. • Some figures were reproduced from: Polymer Processing Some Fundamentals, Tim A. Osswald (1998), Hanser/Gardner Publications, Cincinnati, OH. Publications, • Figures were reproduced from Polymer Physics, (1996) Figures Ulf Gedde, Chapman & Hall, New York. Ulf 24 24 ...
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This note was uploaded on 07/17/2011 for the course EMA 4161c taught by Professor Staf during the Fall '10 term at University of Florida.

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