US5174934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of in-situ fabrication of foamed thermoplastic articles and article
Assignee: Sundstrand Corp
•
Filing: 1991-01-10
•
Granted: 1992-12-29
•
Expires: 2011-01-10
Abstract
Abstract Processes using high temperature thermoplastic polymers in the in-situ fabrication in the formation of foamed composite sandwich or foam articles often result in weak unsound products which may be avoided by utilizing a high temperature thermoplastic in powder form (22), a blowing agent having a high decomposition temperature (24), and, if desired, reinforcers and/or fillers (28), admixing the thermoplastic, blowing agent and reinforcer and fillers (30), placing the admixture in a mold and, if forming a composite structure, in abutment with at least one skin (34), compacting the contents of the mold (37), and applying sufficient heat and/or pressure to the mold and its contents to melt the thermoplastic and generate gas within said mixture by decomposition of the blowing agent (38). Also, an activator may be included with the blowing agent which promotes the production of gas (26). The thermoplastic should be free from any material which will react with the blowing agent or the activator at temperatures below the melting point of the thermoplastic. Articles made by the process are also disclosed.
Inventors
- 👤 Hossein Saatchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:12
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/065
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
87 words
A process for the production of foamed, high temperature thermoplastic articles comprising the steps of: (a) providing a generally powder-like admixture comprising a high temperature thermoplastic, magnesium hydroxide and sodium borohydride, the thermoplastic being free from materials that will react with the sodium borohydride at a temperature less than the melting temperature of the thermoplastic; (b) providing a mold; (c) introducing the admixture into the cavity of the mold; and (d) compacting the contents of the mold at a temperature below the melting temperature of the thermoplastic.
Claim 2
Dependent Claim
87 words
A process for the production of foamed, high temperature thermoplastic articles comprising the steps of: (a) providing a generally powder-like admixture comprising a high temperature thermoplastic, magnesium hydroxide and sodium borohydride, the thermoplastic being free from materials that will react with the sodium borohydride at a temperature less than the melting temperature of the thermoplastic; (b) providing a mold; (c) introducing the admixture into the cavity of the mold; and (d) compacting the contents of the mold at a temperature below the melting temperature of the thermoplastic.
Claim 3
Dependent Claim
28 words
The process in accordance with claim 1 further comprising a step prior to the compaction step of (d) of introducing at least one skin into the mold cavity.
Claim 4
Dependent Claim
34 words
The process in accordance with claim 1 wherein the admixture further comprises an activator that will cause activation of the sodium borohydride at a temperature near or above the melting point of the thermoplastic.
Claim 5
Dependent Claim
19 words
The process in accordance with claim 1 wherein the admixture further comprises at least one of reinforcers or fillers.
Claim 6
Dependent Claim
16 words
The process in accordance with claim 1 wherein the step of compacting occurs at ambient temperature.
Claim 7
Dependent Claim
34 words
The process in accordance with claim 1 further comprising, after the compacting step, the step of (e) applying at least one of heat or pressure to the mold to cause consolidation of the thermoplastic.
Claim 8
Dependent Claim
20 words
The process in accordance with claim 1 wherein the thermoplastic is selected from the group of polyetheretherketones, polyetherimides and polyetherketoneetherketoneketones.
Claim 9
Dependent Claim
24 words
The process in accordance with claim 1 wherein the step of compacting includes compacting the contents of the mold to the desired final shape.
Claim 10
Dependent Claim
20 words
The process in accordance with claim 1 further comprising the step of controlling the compaction of the contents using shims.
Claim 11
Dependent Claim
11 words
An article made in accordance with the process of claim 1.
Claim 12
Dependent Claim
94 words
A process for the production of foamed, high temperature thermoplastic articles from a generally powder-like admixture that is placed in a mold the admixture has a high temperature thermoplastic and a blowing agent wherein the thermoplastic is free from materials that will react with the blowing agent at a temperature below about the melting point of the thermoplastic and wherein the blowing agent has a decomposition temperature near the melting point of the thermoplastic, comprising the step of compacting the contents of the mold at a temperature below the melting temperature of the thermoplastic.
Claim 13
Dependent Claim
94 words
A process for the production of foamed, high temperature thermoplastic articles from a generally powder-like admixture that is placed in a mold the admixture has a high temperature thermoplastic and a blowing agent wherein the thermoplastic is free from materials that will react with the blowing agent at a temperature below about the melting point of the thermoplastic and wherein the blowing agent has a decomposition temperature near the melting point of the thermoplastic, comprising the step of compacting the contents of the mold at a temperature below the melting temperature of the thermoplastic.
Claim 14
Dependent Claim
24 words
The process in accordance with claim 11 wherein the step of compacting includes compacting the contents of the mold to a desired final shape.
Claim 15
Dependent Claim
20 words
The process in accordance with claim 11 further comprising the step of controlling the compacting of the contents using shims.
Claim 16
Dependent Claim
11 words
An article made in accordance with the process of claim 9.
Claim 17
Dependent Claim
19 words
The process in accordance with claim 11 further comprising the step, after the compacting step, of melting the thermoplastic.
Claim 18
Dependent Claim
116 words
A process for the production of foamed, high temperature thermoplastic articles comprising the steps of: (a) providing a general powder-like admixture comprising a high temperature thermoplastic, magnesium hydroxide and sodium borohydride, the thermoplastic being free from materials that will react with the sodium borohydride at a temperature less than the melting temperature of the thermoplastic; (b) providing a mold defining a cavity therein; (c) introducing the admixture in a powder-like condition into the cavity of the mold; (d) compacting the powder-like admixture in the mold at a temperature below the melting temperature of the thermoplastic; and (e) consolidating the thermoplastic after the compacting step by applying at least one of heat or pressure to the thermoplastic.
Claim 19
Dependent Claim
116 words
A process for the production of foamed, high temperature thermoplastic articles comprising the steps of: (a) providing a general powder-like admixture comprising a high temperature thermoplastic, magnesium hydroxide and sodium borohydride, the thermoplastic being free from materials that will react with the sodium borohydride at a temperature less than the melting temperature of the thermoplastic; (b) providing a mold defining a cavity therein; (c) introducing the admixture in a powder-like condition into the cavity of the mold; (d) compacting the powder-like admixture in the mold at a temperature below the melting temperature of the thermoplastic; and (e) consolidating the thermoplastic after the compacting step by applying at least one of heat or pressure to the thermoplastic.
References Cited (Backward Citations)
US4036923A
Cited
US4025686A
Cited
US4077821A
Cited
US4379103A
Cited
US4447565A
Cited
US4540455A
Cited
US4655861A
Cited
US4692381A
Cited
US4675231A
Cited
US4769397A
Cited
US4861537A
Cited
US4933131A
Cited
US4837251A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-12-29 | 1996-06-29 | 1996-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-29 | 2000-06-29 | 2000-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-29 | 2004-06-29 | 2004-12-29 | $7700.00 | Window Closed / Lapsed |