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Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006
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Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Jan 18, 2018

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Roy Harrington

Overview Project objectives Theory Experimental setup and procedures Results Conclusions and Recommendations References Wrap up Q & A
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Page 1: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Extrusion of PolyethyleneJared StradleyCHEN 4903December 4, 2006

Page 2: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Extruders

Page 3: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Overview Project objectives Theory Experimental setup and procedures Results Conclusions and Recommendations References Wrap up Q & A

Page 4: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Project objectives Characterize the flow of

polyethylene in cylindrical die Estimate the maximum flow rate

through a 1” diameter pipe die

Page 5: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Theory Basically, it’s flow through a pipe or

an annulus

Page 6: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Theory cont. Major equations

Pipe flow:

LRPPQ c

8)( 421

drdV

LPPr

2)( 21

Page 7: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

More theory Annular flow:

/1ln11

8)( 22

44

21

LRPP

Q

Page 8: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Experimental setup

Page 9: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Experimental procedures Ran polyethylene at 155, 160 and

165 °C at 3, 5, 10 and 15 rpm Collected samples of each run Ran polypropylene at 200, 205 and

210 °C at 3, 5, 10 and 15 rpm Also collected samples Calculated Q, and dv/dr

Page 10: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

ResultsShear Stress vs. Velocity Gradient for Polyethylene (pipe flow)

0.0E+00

5.0E+05

1.0E+06

1.5E+06

2.0E+06

2.5E+06

3.0E+06

0 2000 4000 6000 8000 10000 12000

dv/dr (1/s)

τ (Pa

)

155 °C160 °C165 °C

Page 11: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Results cont. Bingham plastic:

o drdV

Page 12: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Results cont.Pressure Drop vs. Velocity for Polyethylene (annulus)

0.00E+00

5.00E+05

1.00E+06

1.50E+06

2.00E+06

2.50E+06

3.00E+06

0.000 5.000 10.000 15.000 20.000 25.000 30.000 35.000 40.000

Velocity (cm/s)

Pres

sure

dro

p (P

a)

155 °C

160 °C

165 °C

Page 13: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Some more resultsPressure drop vs. rpm for polypropylene (pipe flow)

2.00E+06

2.50E+06

3.00E+06

3.50E+06

4.00E+06

4.50E+06

5.00E+06

0 2 4 6 8 10 12 14 16 18

rpm

Pres

sure

dro

p(Pa

)

200 °C

205 °C

210 °C

Maximum pressure drop: 6.40 MPa

Page 14: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Final result

Pressure Drop vs. Velocity for Polyethylene (annulus)

y = 115926x - 318281y = 109967x - 235980

0.00E+00

5.00E+05

1.00E+06

1.50E+06

2.00E+06

2.50E+06

3.00E+06

0.000 5.000 10.000 15.000 20.000 25.000 30.000 35.000 40.000

Velocity (cm/s)

Pres

sure

dro

p (P

a) 155 °C160 °C165 °C

Maximum velocity possible: 59.180 + 4.127 cm/s (95% CI)

Page 15: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Conclusion Polyethylene can be extruded at a

velocity of 59.180 + 4.127 cm/s through a 1” cylindrical pipe die

(95% CI) This result holds for temperatures

between 155 and 165 °C This value compares well with the

industrial flow rate of 0.5 m/s

Page 16: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Recommendations Run both Polyethylene and

Polypropylene at more temperatures Run both at higher rpm Take samples on same day

Page 17: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

References Bird, R. B., W. E. Stewart, E. N. Lightfoot.

Transport Phenomena. New York: John Wiley & Sons, 1960.

Ring, T. A. Fundamentals of Ceramic Powder Processing and Synthesis. San Diego: Academic Press, 1996.

de Nevers, N. Fluid Mechanics for Chemical Engineers. New York: McGraw-Hill, 2005.

www.chemfinder.com www.nicodemus.org www.search.com

Page 18: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Wrap up Project objectives Theory Experimental setup and procedures Results Conclusions and Recommendations References

Page 19: Extrusion of Polyethylene Jared Stradley CHEN 4903 December 4, 2006.

Questions?