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 Title: |
US5637268:
Method of extruding plastics
[ Derwent Title ]
>> View Certificate of Correction for this publication
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| Country: |
US United States of America
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| Inventor: |
Slattery, John C.; College Station, TX
Giacomin, A. J.; Antibes, France
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| Assignee: |
Texas A & M University System, College Station, TX
other patents from TEXAS A AND M UNIVERSITY (677107) (approx. 421)
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| Published / Filed: |
1997-06-10
/ 1994-05-06
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| Application Number: |
US1994000238953
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| IPC Code: |
Advanced:
B29C 47/10;
B29C 47/76;
Core:
more...
IPC-7:
B29C 47/76;
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| ECLA Code: |
B29C47/10; B29C47/76;
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| U.S. Class: |
Current:
264/102;
264/176.1;
264/349;
Original:
264/102;
264/176.1;
264/349;
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| Field of Search: |
264/101,102,349,176.1
425/203,467
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| Priority Number: |
| 1994-05-06 |
US1994000238953 |
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| Abstract: |
The present invention relates to a process for minimizing the flow instability of molten plastics caused by slippage of the melt at the die wall during the extrusion process. The slippage, and therefore the flow instability, is minimized by removing the air from, or "degassing", the polymer prior to the extrusion process, preferably by subjecting the molten polymer to a vacuum for an extended time, typically 24 hours. Further, air is preferably prevented from being introduced into the molten polymer, the extrusion die or the extrusion process from the ambient conditions surrounding the extrusion process during the extrusion process by creating a vacuum over the polymer hopper, the feed region of the extrusion system, the exit portion of the die, the entire extrusion system or any combination thereof.
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| Attorney, Agent or Firm: |
Vaden, Eickenroht & Thompson, L.L.P. ;
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| Primary / Asst. Examiners: |
Vargot, Mathieu D.;
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| Maintenance Status: |
E1 Expired Check current status
CC Certificate of Correction issued
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| INPADOC Legal Status: |
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| Family: |
None
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First Claim:
Show all 20 claims |
What is claimed:
1. A method of reducing slippage of the melt at the die wall during the extrusion of polymers comprising:
- (a) heating the polymer in a vacuum oven until the polymer reaches a molten state; and
- (b) evacuating the space in the oven over the polymer.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 2 U.S. patent(s) that reference this one
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| Foreign References: |
None
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| Other Abstract Info: |
DERABS C97-319023
DERC97-319023
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| Other References: |
Adrian, D. W., The Quasiperiodic Nature of Wall Slip for Molten Plastics in Large Amplitude Oscillatory Shear, MS Thesis, Texas A&M University (1992).
Adrian, D.W., and Giacomin, A.J., The Quasiperiodic Nature of a Polyurethane Melt in Oscillatory Shear, J. Rheol. 36 1227 (1992).
(17 pages)
[ISI abstract]
Dussan V., Elizabeth B. and Davis, Stephen H., On the motion of a Fluid-fluid interface along a solid surface, J. Fluid Mech., vol 65 part 1, 71-95 (1974).
Cited by 5 patents
Dussan V., E.B. and Davis, S.H., Stability in systems with moving contact lines, J. Fluid Mech., vol. 173, 115-130 (1986).
(16 pages)
Giacomin, A.J., Samurkas, T. and Dealy, J.M., A Novel Sliding Plate Rheometer for Molten Plastics, Polymer Engineering & Science, vol 29, 499-504 (1989).
(6 pages)
Hatzikiriakos, S.G. and Dealy, J.M., Wall slip of Molten high density polyethylene. I. Sliding plate rheometer studies, J. Rheol, vol 35, 497-523 (1991).
(27 pages)
Cited by 28 patents
[ISI abstract]
Hocking, L.M., A moving fluid interface on a rough surface, J. Fluid Mech., vol 76, 801-817 (1976).
(17 pages)
Huh, Chun and Scriven, L.E., Hydrodynamic Model of Steady Movement of a Solid/Liquid/Fluid Contact Line, Journal of Colloid and Interface Sci., vol. 35, 85-101 (1971).
Cited by 3 patents
Huh, C. and Mason, S.G., The steady movement of a liquid meniscus in a capillary tube, J. Fluid Mech, vol 81, part 3, 401-419, (1977).
(19 pages)
Jeyaseelan, Ranjit S., Giacomin, A.J. and Oakley, Jason G., Simplification of Network Theory for Polymer Melts in Nonlinear Oscillatory Shear, AIChE Journal, vol 39, No. 5, 846-854 (1993).
(9 pages)
[ISI abstract]
Li, A.C. and Slattery, J.C. Non-Uniform particle Distributions During Tube Flows of Neutrally Buoyant Suspensions in Second-Order Fluids. Chem. Eng. Comm., vol 101, 17-38 (1991).
(22 pages)
[ISI abstract]
Whitaker, Stephen and Pigford, R.L., Numerical Differentiation of Experimental Data, Ind. Eng. Chem, vol 52, 185-187 (1960).
Young, G.W. and Davis, S.H., A plate oscillating across a liquid interface: effects of contact-angle hysteresis, J. Fluid Mech., vol 174, 327-356 (1987).
(30 pages)
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