US4927600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for molding of powders
Assignee: JFE Engineering Corp
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Filing: 1987-10-08
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Granted: 1990-05-22
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Expires: 2007-10-08
Abstract
Abstract The invention is concerned with the method of compression molding a metallic or ceramic powders. The method includes the step of maintaining a negative pressure within a first mold of noncompactable powders for intimately contacting on its inner surface a pouch-like member of thin-walled resilient material for producing a second mold, and the step of compactly charging starting powders into the second mold and exhausting air from and sealing the second mold, taking out a pre-molded body of the metallis or ceramic powders together with the second mold and the step of processing the pre-molded body by a cold or hot isostatic press.
Inventors
- 👤 Tsuneo Miyashita
- 👤 Hiroaki Nishio
- 👤 Kazuya Yabuta
- 👤 Yoshio Takagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:15
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/1208; B22F3/1216; B22F3/1233; B22F3/02; B22F3/04; B28; B28B; B28B7/00; B28B7/34; B28B7/342; B30; B30B; B30B11/00; B30B11/001; B30B11/002; Y; Y10; Y10S; Y10S264/00; Y10S264/78
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
222 words
A method of molding powders of metals or ceramics comprising the steps of: forming a cavity within an air-permeable mold carrier of a powdered filler material, a wall of said cavity being coated with a water-soluble film, and maintaining the shape of said powdered filler material by use of a vacuum; introducing into said cavity of said mold carrier a pouch-like member of thin-walled rubber-like resilient material, said pouch-like member carrying moisture on the outer surface thereof; dissolving said water-soluble film by contacting said water-soluble film with said pouch-like member, during the use of said vacuum in such a degree that said pouch-like member is inflated and tightly contacted to said wall of said cavity in said mold carrier, thereby forming a mold; charging starting powders into said mold; discharging air from the inside of the mold to a desired degree of vacuum through an opening of said pouch-like member; sealing said evacuated mold while the pouch-like member is within the cavity of said mold carrier; re-establishing an atmospheric pressure to said powdered filler material thereby disintegrating the air-permeable mold carrier so as to remove a preformed molding in a form contained in said sealed pouch-like member; and pressing the preformed molding while the molding is sealed within the pouch-like member by a cold or hot isostatic press to densify the same.
Claim 2
Independent Claim
222 words
A method of molding powders of metals or ceramics comprising the steps of: forming a cavity within an air-permeable mold carrier of a powdered filler material, a wall of said cavity being coated with a water-soluble film, and maintaining the shape of said powdered filler material by use of a vacuum; introducing into said cavity of said mold carrier a pouch-like member of thin-walled rubber-like resilient material, said pouch-like member carrying moisture on the outer surface thereof; dissolving said water-soluble film by contacting said water-soluble film with said pouch-like member, during the use of said vacuum in such a degree that said pouch-like member is inflated and tightly contacted to said wall of said cavity in said mold carrier, thereby forming a mold; charging starting powders into said mold; discharging air from the inside of the mold to a desired degree of vacuum through an opening of said pouch-like member; sealing said evacuated mold while the pouch-like member is within the cavity of said mold carrier; re-establishing an atmospheric pressure to said powdered filler material thereby disintegrating the air-permeable mold carrier so as to remove a preformed molding in a form contained in said sealed pouch-like member; and pressing the preformed molding while the molding is sealed within the pouch-like member by a cold or hot isostatic press to densify the same.
Claim 3
Dependent Claim
23 words
A molding method according to claim 1, wherein said water-soluble film is selected from the group consisting of PVA and methyl cellulose films.
Claim 4
Dependent Claim
20 words
A molding method according to claim 1, wherein said water-soluble film has a thickness ranging from 20 to 200 μm.
Claim 5
Dependent Claim
25 words
A molding method according to claim 1, wherein said water-soluble film is soluble in water within a working temperature range of 10° to 35° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-21 | 1993-11-20 | 1994-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-21 | 1997-11-20 | 1998-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-21 | 2001-11-20 | 2002-05-22 | $7700.00 | Window Closed / Lapsed |