Plastic and nonmetallic article shaping or treating: processes – Pore forming in situ – By mechanically introducing gas into material
Patent
1995-11-09
1998-01-13
Kuhns, Allan R.
Plastic and nonmetallic article shaping or treating: processes
Pore forming in situ
By mechanically introducing gas into material
294 51, 294DIG5, B29C 4420
Patent
active
057075735
ABSTRACT:
Thermoplastic foams are provided by a process in which a gaseous blowing agent of nitrogen, air, carbon dioxide, argon or mixtures thereof is injected into a melted thermoplastic polymer and the pressure is used to form a solution of the blowing agent and the melted polymer. The solution is cooled to a temperature which is within 10.degree. C. of the polymer freezing point while the pressure is held to a point within which both of the following conditions exist: A) the pressure must be high enough to keep the gas blowing agent in the solution with the melt, and B) the pressure must be low enough to avoid adding more heat to the solution. Just before the cooled solution is extruded, it is important to have the solution at a temperature which is sufficiently uniform to make: A) the thermoplastic foam at least about 65% by volume in closed cells, and B) a substantially uniform cell size in the product. The cooled solution is then extruded out of an extruder die to where the pressure drop across the die is in the range of from about 70 to about 90% of the pressure in the extruder so that a cellular product is formed.
REFERENCES:
patent: 2714747 (1955-08-01), Lindemann et al.
patent: 2751627 (1956-06-01), Lindemann
patent: 3523988 (1970-08-01), Roehr et al.
patent: 4424287 (1984-01-01), Johnson et al.
patent: 4473665 (1984-09-01), Martini-Vvedensky et al.
patent: 4649001 (1987-03-01), Nakamura et al.
patent: 5034171 (1991-07-01), Kiczek et al.
patent: 5158986 (1992-10-01), Cha et al.
patent: 5160674 (1992-11-01), Colton et al.
patent: 5180751 (1993-01-01), Park et al.
patent: 5250577 (1993-10-01), Welsh
patent: 5266605 (1993-11-01), Welsh
patent: 5348984 (1994-09-01), Lee
patent: 5416129 (1995-05-01), Chandhary et al.
patent: 5589519 (1996-12-01), Knaus
M.C. Gabriel, "New Foam Extrusion Technology is Environmentally Friendly", Plastic Technology, Aug. 1995.
S.K. Dey, C. Jacob, M. Xanthos, "Inert-Gas Foam Extrusion of Rigid PVC Foam", Antec, May 7-11, 1995.
C. Jacob, S.K. Dey, "Inert Gasses as Alternative Blowing Agents for Extruded Low Density Polystyrene Foam", Journal of Cellular Plastics, Jan. 1995.
C. Jacob, S.K. Dey, J.A. Biesenberger, "Effect of Physical Blowing Agents on Crystallization Temperature of Polymer Melts", Antec, May 1-5, 1994.
C. Jacob, S.K. Dey, "Inert Gases as Alternative Blowing Agents for Extruded Low Density Polystyrene Foam", Antec, May 1-5, 1994.
"Inert Gas Foam Extrusion Technology", PPI Seminar, Somerset, N.J., Sep. 26, 1994.
S.K. Dey, "Low Density Foams From Environmentally Inert Physical Blowing Agents", PPI, Apr. 1993.
S. Dey, C. Jacob, M. Xanthos, "Monitoring Continuous Compounding Through On-Line Instrumentation", Society of Plastics Engineers, Nov. 30-Dec. 2, 1993.
S.K. Dey, "Instrumentation News: Measurement of Solubility of Gases in Polymer Melts", Advances in Polymer Technology, vol. 14, No. 4, pp. 327-328, 1990.
Debbie Stover, "Going For The Foam", Plastics World, pp. 33-37, Jul. 1994.
Biesenberger Joseph A.
Dey Subir K.
Todd David B.
LandOfFree
Method of preparing thermoplastic foams using a gaseous blowing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of preparing thermoplastic foams using a gaseous blowing , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of preparing thermoplastic foams using a gaseous blowing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-323805