Plastic and nonmetallic article shaping or treating: processes – Pore forming in situ – Composite article making
Patent
1974-12-18
1976-02-24
Anderson, Philip
Plastic and nonmetallic article shaping or treating: processes
Pore forming in situ
Composite article making
260 25F, 260 25HB, 264 53, 264328, 264DIG5, 264DIG14, 264DIG83, 428320, B29D 2700, B29F 100
Patent
active
039404676
ABSTRACT:
A process for producing a swirl-free, indent-free foamed thermoplastic structural article in which water is utilized as a foaming agent. Water and a melted thermoplastic resin are mixed together in an extruder to form a pressurized foamable mixture. The foamable mixture from the extruder is collected in an accumulator and from there is delivered to a cavity in a mold in a suitable clamping device. The pressure in the cavity is lower than the pressure of the foamable mixture in the accumulator or extruder therefore when the foamable mixture enters the cavity the foaming agent is released and the thermoplastic resin is frothed and expands to completely fill the cavity. The melted foamed thermoplastic resin cools in the mold and solidifies to form a foamed thermoplastic structural article. The quantity of water introduced into the extruder is between about 0.1 weight percent to about 0.5 weight percent of the thermoplastic resin charge in the extruder.
To produce a swirl-free foamed thermoplastic structural article the quantity of water introduced into the extruder is between about 0.1 weight percent and about 2.0 weight percent of the thermoplastic resin charge in the extruder.
REFERENCES:
patent: 2928130 (1960-03-01), Gray
patent: 3151192 (1964-09-01), Jacobs et al.
patent: 3268636 (1966-08-01), Angell
patent: 3436446 (1969-04-01), Angell
patent: 3674401 (1972-07-01), Annis et al.
Czerski, J. "Injection-Moulded Foams," In Plastics & Polymers, Dec., 1971, pp. 406-411.
Bernhardt, Ernest C., Edt., "Processing of Thermoplastic Materials," New York, Reinhold, c 1959, pp. 154-165 (SPE Plastics Engineering Series).
Brydson, J. A., "Plastics Materials," Princeton, N.J., D. Van Nostrand, c 1966, pp. 64-73.
Anderson Philip
Bethlehem Steel Corporation
O'Keefe Joseph J.
Simitz John S.
Wilkinson Charles A.
LandOfFree
Method of injection molding a structural foamed thermoplastic ar 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 injection molding a structural foamed thermoplastic ar, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of injection molding a structural foamed thermoplastic ar will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2079840