US4483889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the production of fibre composite materials impregnated with resin
Assignee: Kemanord AB
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Filing: 1983-08-02
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Granted: 1984-11-20
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Expires: 2003-08-02
Abstract
Abstract A method for the production of a composite material in the form of a web, the material comprising fibres, a curable resin and expanded microspheres. A web of fibres and microspheres is formed, and the curable resin is added subsequently.
Inventors
- 👤 Bengt Andersson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:12
CPC Classifications
B; B32; B32B; B32B38/00; B32B38/08; B32B5/00; B32B5/18; C; C08; C08J; C08J9/00; C08J9/32; D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/46; D21H17/47; D21H21/00; D21H21/50; D21H21/52; D21H21/54; B32B2260/00; B32B2260/02; B32B2260/021; B32B2260/04; B32B2260/046; B32B2262/00; B32B2262/06; B32B2262/062; B32B2305/00; B32B2305/74
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
189 words
A method for the manufacture of a composite material in the form of a web and comprising fibres, a formaldehyde-based resin and expanded thermoplastic microspheres comprising the steps of (a) forming a liquid suspension of fibres and unexpanded thermoplastic microspheres containing a blowing agent, (b) depositing a web containing fibres and the unexpanded microspheres from said liquid suspension, the amount of fibres deposited being between 20 and 500 g/m 2 and the thickness of the web being between 0.01 and 1.5 mm, (c) heating the deposited web to a temperature sufficient to expand the thermoplastic microspheres but insufficient for melting the thermoplastic material of the microspheres, (d) drying the web containing the expanded thermoplastic microspheres, (e) impregnating the dried web with a precondensate of the formaldehyde-based resin to give a ratio of microspheres to the sum of microspheres and resin between 2 and 80 percent by weight, and (f) drying the web containing the precondensate of the formaldehyde based resin while maintaining the resin in a nonsticky B-stage, whereby the volume content of microspheres in the dried web containing resin and expanded microspheres is between 70 and 90 percent.
Claim 2
Independent Claim
189 words
A method for the manufacture of a composite material in the form of a web and comprising fibres, a formaldehyde-based resin and expanded thermoplastic microspheres comprising the steps of (a) forming a liquid suspension of fibres and unexpanded thermoplastic microspheres containing a blowing agent, (b) depositing a web containing fibres and the unexpanded microspheres from said liquid suspension, the amount of fibres deposited being between 20 and 500 g/m 2 and the thickness of the web being between 0.01 and 1.5 mm, (c) heating the deposited web to a temperature sufficient to expand the thermoplastic microspheres but insufficient for melting the thermoplastic material of the microspheres, (d) drying the web containing the expanded thermoplastic microspheres, (e) impregnating the dried web with a precondensate of the formaldehyde-based resin to give a ratio of microspheres to the sum of microspheres and resin between 2 and 80 percent by weight, and (f) drying the web containing the precondensate of the formaldehyde based resin while maintaining the resin in a nonsticky B-stage, whereby the volume content of microspheres in the dried web containing resin and expanded microspheres is between 70 and 90 percent.
Claim 3
Dependent Claim
22 words
A method according to claim 1 wherein the curable resin is a formaldehyde-based resin with phenol, or resorcinol, or urea or melamine.
Claim 4
Dependent Claim
12 words
A method according to claim 1 wherein the fibres comprise cellulose fibres.
Claim 5
Independent Claim
166 words
A method for the manufacture of a composite material in the form of a web and comprising fibres, a formaldehyde-based resin and expanded thermoplastic microspheres comprising the steps of (a) forming a suspension in liquid of fibres and unexpanded thermoplastic microspheres containing a blowing agent, (b) depositing a web containing the fibres and unexpanded microspheres from the suspension, (c) drying the web containing fibres and the unexpanded thermoplastic microspheres at a temperature below the vaporizing temperature for the blowing agent of the thermoplastic microspheres, (d) impregnating the dried web containing unexpanded thermoplastic microspheres with a precondensate of a formaldehyde-based resin to give a ratio of microspheres to the sum of microspheres and resin between 2 and 80 percent by weight, and (e) heating the web impregnated with the precondensate of formaldehyde-based resin to a temperature sufficent to expand the thermoplastic microspheres while maintaining the resin in a non-sticky B-stage, whereby a dry web having a volume content of microspheres between 70 and 95 percent is obtained.
Claim 6
Independent Claim
166 words
A method for the manufacture of a composite material in the form of a web and comprising fibres, a formaldehyde-based resin and expanded thermoplastic microspheres comprising the steps of (a) forming a suspension in liquid of fibres and unexpanded thermoplastic microspheres containing a blowing agent, (b) depositing a web containing the fibres and unexpanded microspheres from the suspension, (c) drying the web containing fibres and the unexpanded thermoplastic microspheres at a temperature below the vaporizing temperature for the blowing agent of the thermoplastic microspheres, (d) impregnating the dried web containing unexpanded thermoplastic microspheres with a precondensate of a formaldehyde-based resin to give a ratio of microspheres to the sum of microspheres and resin between 2 and 80 percent by weight, and (e) heating the web impregnated with the precondensate of formaldehyde-based resin to a temperature sufficent to expand the thermoplastic microspheres while maintaining the resin in a non-sticky B-stage, whereby a dry web having a volume content of microspheres between 70 and 95 percent is obtained.
Claim 7
Dependent Claim
23 words
The method of claim 4 wherein the dried web containing resin and expanded thermoplastic microspheres has a thickness above 2 or 3 mm.
Claim 8
Dependent Claim
21 words
method according to claim 4 wherein the curable resin is a formaldehyde-based resin with phenol, or resorcinol or urea or melamine.
Claim 9
Dependent Claim
13 words
A method according to claim 4 wherein the added fibres comprise cellulose fibres.
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) | 1987-11-20 | 1988-05-21 | 1988-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-20 | 1992-05-21 | 1992-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-20 | 1996-05-21 | 1996-11-20 | $7700.00 | Window Closed / Lapsed |