US4252759A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross flow filtration molding method
Assignee: Massachusetts Institute of Technology
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Filing: 1979-04-11
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Granted: 1981-02-24
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Expires: 1999-04-11
Abstract
Abstract A cross flow filtration molding apparatus and method are disclosed which are particularly useful for forming complicated shapes from dispersions of particles in a liquid medium. Dispersion is pumped through a mold which has porous walls and a sufficient pressure differential is applied to drive a portion of the liquid medium through the porous walls which results in deposition of particles on the walls to form a shaped article. The shaped article may inherently have sufficient structural integrity, or it may be post-treated to provide additional structural integrity.
Inventors
- 👤 Ioannis V. Yannas
- 👤 David L. Sieverding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:29
CPC Classifications
B; B28; B28B; B28B1/00; B28B1/26; A; A61; A61F; A61F2/00; A61F2/02; A61F2/04; A61F2/06; A61F2/062; A61L; A61L27/00; A61L27/14; A61L27/22; A61L27/24; B29; B29C; B29C41/00; B29C41/02; B29C41/16; A61F2310/00; A61F2310/00005; A61F2310/00365
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
162 words
A cross flow filtration process for molding articles in a predetermined shape from dispersions of particles in a liquid medium, comprising: a. pumping said dispersion in a continuous flow from an input port to an output port through a mold, the interior walls of which are formed in said predetermined shape, said walls being porous to allow transport of a portion of said dispersion through the pores in said walls under a pressure differential thereby causing particles in said dispersion to deposit on said mold walls and the liquid medium to pass to the outside of the mold; b. applying a pressure differential across the porous walls of said mold to drive such portion of said dispersion through the porous walls as dispersion is pumped through said mold between said input and output ports; c. collecting the remaining portion of said dispersion at the output port; and d. maintaining said flow until said deposit has accumulated on said walls to predetermined thickness.
Claim 2
Dependent Claim
162 words
A cross flow filtration process for molding articles in a predetermined shape from dispersions of particles in a liquid medium, comprising: a. pumping said dispersion in a continuous flow from an input port to an output port through a mold, the interior walls of which are formed in said predetermined shape, said walls being porous to allow transport of a portion of said dispersion through the pores in said walls under a pressure differential thereby causing particles in said dispersion to deposit on said mold walls and the liquid medium to pass to the outside of the mold; b. applying a pressure differential across the porous walls of said mold to drive such portion of said dispersion through the porous walls as dispersion is pumped through said mold between said input and output ports; c. collecting the remaining portion of said dispersion at the output port; and d. maintaining said flow until said deposit has accumulated on said walls to predetermined thickness.
Claim 3
Dependent Claim
26 words
The process of claim 1 in which the walls form a generally cylindrical body and the flow between input and output ports is generally axially directed.
Claim 4
Dependent Claim
19 words
The process of claim 2 in which the dispersion is filtered before passing through the pores in said walls.
Claim 5
Dependent Claim
13 words
A method of claim 1 wherein said particles are comprised of a polymer.
Claim 6
Dependent Claim
14 words
A method of claim 1 wherein said polymeric particles are a collagen-mucopolysaccharide reaction product.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |