Patent US6030575A successfully refreshed from Google Patents.
US6030575A
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US
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Method for making preforms
Assignee: Dow Chemical Co
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Filing: 1996-11-20
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Granted: 2000-02-29
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Expires: 2016-11-20
Abstract
Abstract An improvement in the preparation of fiber preforms in which binder and fibers are dispersed to contact on vacuum-supplied screens is disclosed, comprising particularly (a) selecting a particulate binder material which is solid at 25° C; (b) heating the binder material, during initial contact with the fibers, to a viscosity and for a time which is the same as or proportional to 1,000 centipoise for one second; and (c) dispersing the binder material and the fibers such that the preform exhibits a variation in the ratio of fibers and binder which correlates to a coefficient of variation which is less than or equal to about 5 percent. The resulting preform shows superior compaction and uniformity of constitution even when it is prepared in sections or in asymmetric configurations. A wide variety of binders can be used, including thermoplastic and thermoset polymers, glasses, ceramics, metals, and the like, and the binder can also be selected from multi-component systems which are reactive with one another, such as epoxy-based systems, and/or reactive with a resin impregnant which may be subsequently introduced. In an alternative embodiment the preforms can be heated and pressed to make final composite articles, with or without direct application of a molding resin.
Inventors
- 👤 James H. Barron
- 👤 James Entringer
- 👤 Randy S. Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:49
CPC Classifications
B; B29; B29B; B29B11/00; B29B11/14; B29B11/16; D; D04; D04H; D04H1/00; D04H1/40; D04H1/58; D04H1/60; B29B15/00; B29B15/08; B29B15/10; B29B15/12; B29C; B29C2949/00; B29C2949/07; B29C2949/081; B29C2949/0811
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
155 words
A method of making a fiber preform, suitable for use in preparing a composite article, comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having a vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen reaches a predetermined minimum level and after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to a solid state within a time period in seconds equal to the predetermined minimum level of viscosity in centipoise times 1/1000.
Claim 2
Independent Claim
155 words
A method of making a fiber preform, suitable for use in preparing a composite article, comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having a vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen reaches a predetermined minimum level and after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to a solid state within a time period in seconds equal to the predetermined minimum level of viscosity in centipoise times 1/1000.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein the binder material is a thermoplastic organic polymer and the fibers are glass, graphite, carbon or high flexural modulus organic polymer fibers.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein the binder material is a thermoplastic epoxy resin.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein the fibers have a diameter from about 1 to about 1000 microns.
Claim 6
Dependent Claim
35 words
The method of claim 1 wherein the binder material is employed in an amount of from about 1 to about 20 parts by weight of binder material to about 100 parts by weight of fibers.
Claim 7
Independent Claim
162 words
A method for making a fiber preform, suitable for use in preparing a composite article, comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein (i) the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen reaches a predetermined minimum level of less than about 1,000 centipoise, and (ii) after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to its solid state in about t seconds wherein t equals the predetermined minimum level of viscosity in centipoise times 1/ 1000.
Claim 8
Independent Claim
162 words
A method for making a fiber preform, suitable for use in preparing a composite article, comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein (i) the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen reaches a predetermined minimum level of less than about 1,000 centipoise, and (ii) after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to its solid state in about t seconds wherein t equals the predetermined minimum level of viscosity in centipoise times 1/ 1000.
Claim 9
Independent Claim
160 words
A method for making a fiber preform, suitable for use in preparing a composite article, comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having a vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein (i) the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen is a predetermined minimum level of from 1,000-2,000 centipoise, and (ii) after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to its solid state in about t seconds wherein t equals the predetermined minimum level of viscosity in centipoise times 1/1000.
Claim 10
Independent Claim
160 words
A method for making a fiber preform, suitable for use in preparing a composite article, comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having a vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein (i) the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen is a predetermined minimum level of from 1,000-2,000 centipoise, and (ii) after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to its solid state in about t seconds wherein t equals the predetermined minimum level of viscosity in centipoise times 1/1000.
Claim 11
Independent Claim
165 words
A method of comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having a vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen reaches a predetermined minimum level and after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to a solid state within a time period in seconds equal to the predetermined minimum level of viscosity in centipoise times 1/1000 to thereby form a preform; and (c) impregnating the preform with a resin which is reactive or non-reactive with the binder material.
Claim 12
Independent Claim
165 words
A method of comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having a vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen reaches a predetermined minimum level and after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to a solid state within a time period in seconds equal to the predetermined minimum level of viscosity in centipoise times 1/1000 to thereby form a preform; and (c) impregnating the preform with a resin which is reactive or non-reactive with the binder material.
Claim 13
Independent Claim
164 words
A method of making a composite article, comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having a vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen reaches a predetermined minimum level and after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to its solid state within a time period in seconds equal to the predetermined minimum level of viscosity in centipoise times 1/1000 to thereby form a preform; and (c) heating and pressing the preform to form a composite article.
Claim 14
Independent Claim
164 words
A method of making a composite article, comprising the steps of: (a) selecting a thermoplastic binder material which is particulate and solid at 25° C.; (b) concurrently depositing reinforcing fibers and the binder material onto one side of a foraminous screen having a vacuum means positioned on the opposite side thereof which maintains the fibers and binder material in position on the one side of the screen, wherein the binder material is heated and deposited by means of a flame spray device; wherein the binder material is heated sufficiently by the flame spray device such that its viscosity on the screen reaches a predetermined minimum level and after the viscosity of the binder material has reached the predetermined minimum level, the binder material is returned to its solid state within a time period in seconds equal to the predetermined minimum level of viscosity in centipoise times 1/1000 to thereby form a preform; and (c) heating and pressing the preform to form a composite article.
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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) | 2003-02-28 | 2003-08-30 | 2004-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-02-28 | 2007-08-30 | 2008-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-02-28 | 2011-08-30 | 2012-02-29 | $7700.00 | Window Closed / Lapsed |