Plastic and nonmetallic article shaping or treating: processes – Pore forming in situ – Composite article making
Patent
1982-11-01
1984-10-30
Anderson, Philip
Plastic and nonmetallic article shaping or treating: processes
Pore forming in situ
Composite article making
264 403, 264 51, 264101, 264334, 264DIG83, 425159, 425444, 425546, 425812, 425817R, B29D 2700
Patent
active
044799144
ABSTRACT:
A method for forming foamed plastic articles which includes the steps of closing a mold; prepressurizing the mold cavity with gas to prevent premature diffusion of blowing gas from the material injected into the cavity; injecting a short shot of molten synthetic resin material containing a blowing agent into the cavity; venting a portion of the prepressurization gas during the injection step; and venting the remaining prepressurization gas from the mold cavity to a vacuum chamber means to allow expansion of the injected foamable resin material within the mold cavity, the vacuum drawing the resin material throughout the mold cavity. In addition, the vacuum chamber is coupled to the mold cavity through plural spaced passageways so that the vacuum is drawn at various locations throughout the cavity to thereby enhance the complete filling of the cavity with the injected material as it expands. The mold is vented following the injection step automatically at the expiration of a predetermined time following the closing of a nozzle of the injection apparatus. A mold for carrying out the process includes improved gas flow means for delivering gas to and venting gas from the mold cavity. The mold also includes improved sealing means for sealing the mold to maintain it in a pressurized state as desired.
REFERENCES:
patent: 3268635 (1966-08-01), Kraus et al.
patent: 3436446 (1969-04-01), Angell, Jr.
patent: 3773873 (1973-11-01), Spaak et al.
patent: 3960996 (1976-06-01), Balevski
patent: 4031176 (1977-06-01), Molbert
patent: 4092385 (1978-05-01), Balevski
patent: 4096218 (1978-06-01), Yasuike et al.
patent: 4129635 (1978-12-01), Yasuike et al.
patent: 4153231 (1979-05-01), Hayakawa et al.
patent: 4208368 (1980-06-01), Egli
patent: 4229395 (1980-10-01), Nagumo et al.
patent: 4255368 (1981-03-01), Olabisi
patent: 4296055 (1981-10-01), Harris
The brochure Cashiers' Pressure Process, A Revolutionary Development in Smooth Structural Foam.
The article "From Design Concept to Finish Product".
The article "The State of the Art in Processing Thermoplastics Containing Blowing Agents, with Special Consideration of the Gas Counterpressure Process & Coinjection Molding Process", Eckardt, Helmut & Alex, Kurt, Battenfeld, 11/1979.
Whittington's Dictionary of Plastics, by Lloyd R. Whittington, Stamford, Conn., Technomic, .COPYRGT.1968, Preface, pp. 59 and 60.
Anderson Philip
Cashiers Plastics
LandOfFree
Process and mold for molding foamed plastic articles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and mold for molding foamed plastic articles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and mold for molding foamed plastic articles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1101678