US5374474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite board and method of manufacture
Assignee: Earth Partners Inc
•
Filing: 1991-09-26
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Granted: 1994-12-20
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Expires: 2011-09-26
Abstract
Abstract Composite boards made primarily from recycled waste paper and methods for production of such boards are described.
Inventors
- 👤 Ronald Pratt
- 👤 John Chedester
- 👤 John Pommerening
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:41
CPC Classifications
B; B27; B27N; B27N3/00; B27N3/007; Y; Y10; Y10S; Y10S52/00; Y10S52/07; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31591
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
114 words
A composite board consisting essentially of recycled newsprint paper fibers and a thermoset polyisocyanate resin, said board being from about 0.125 to about 1.00 inch thick, being formed at a pressure of from about 900 psi to 1000 psi and having a density of 50-75 pounds per cubic foot, an internal fiber to resin bond of at least 190 pounds per square inch, with a resin content of from about 2% to about 4% by weight, and a modulus of rupture of at least 3000, a modulus of elasticity of at least 300,000 and, after a 24-hour soak test, water absorption of not more than 25% and thickness swell of not more than 15%.
Claim 2
Dependent Claim
114 words
A composite board consisting essentially of recycled newsprint paper fibers and a thermoset polyisocyanate resin, said board being from about 0.125 to about 1.00 inch thick, being formed at a pressure of from about 900 psi to 1000 psi and having a density of 50-75 pounds per cubic foot, an internal fiber to resin bond of at least 190 pounds per square inch, with a resin content of from about 2% to about 4% by weight, and a modulus of rupture of at least 3000, a modulus of elasticity of at least 300,000 and, after a 24-hour soak test, water absorption of not more than 25% and thickness swell of not more than 15%.
Claim 3
Dependent Claim
17 words
A composite board as defined by claim 1 in which said resin is a diphenylmethane diisocyanate resin.
Claim 4
Independent Claim
167 words
A method for preparing a composite board from waste newsprint paper having a moisture content of from about 5% to about 10% by weight which method consists essentially of: (i) refining said waste paper to provide a fiber product having a bulk density of from about 1 to about 5 pounds per cubic foot; (ii) blending said fiber product with an aqueous emulsion of a thermosetting polyisocyanate resin to provide a blended product having a moisture content of from about 8% to about 12% by weight, and a resin content of from about 2% to about 4% by weight on a 100% solid basis; (iii) forming said blended product into a mat; and (iv) pressing said mat at a temperature of from about 280° F. to about 320° F. to a pressure of from about 900 psi to about 1000 psi and for a time period of from about 1 to about 20 minutes to produce a composite board from about 0.125 to about 1.00 inches thick.
Claim 5
Independent Claim
167 words
A method for preparing a composite board from waste newsprint paper having a moisture content of from about 5% to about 10% by weight which method consists essentially of: (i) refining said waste paper to provide a fiber product having a bulk density of from about 1 to about 5 pounds per cubic foot; (ii) blending said fiber product with an aqueous emulsion of a thermosetting polyisocyanate resin to provide a blended product having a moisture content of from about 8% to about 12% by weight, and a resin content of from about 2% to about 4% by weight on a 100% solid basis; (iii) forming said blended product into a mat; and (iv) pressing said mat at a temperature of from about 280° F. to about 320° F. to a pressure of from about 900 psi to about 1000 psi and for a time period of from about 1 to about 20 minutes to produce a composite board from about 0.125 to about 1.00 inches thick.
Claim 6
Dependent Claim
40 words
A method as defined by claim 3 in which said refined paper product of step (i) is a fiber product obtained by refining newsprint to produce a refined product having a bulk density of about one pound per cubic foot.
Claim 7
Dependent Claim
30 words
A method as defined by claim 4 in which the fibers in said fiber product are substantially in the form of the original fibers from which said newsprint was made.
Claim 8
Dependent Claim
41 words
A method as defined by claim 3 in which said aqueous emulsion of a synthetic resin in step (ii) also includes a wax and in which said blended product contains about 0.5 to about 2% wax on a 100% solids basis.
Claim 9
Dependent Claim
26 words
A method as defined by claim 3 in which said mat formed in step (iii) is vacuum-formed onto a forming screen and passed through a precompressor.
Claim 10
Dependent Claim
64 words
A method as defined by claim 3 in which said composite board produced by step (iv) has an internal particle or fiber to resin bond of at least 190 pounds per square inch, a modulus of rupture of at least 3,000 and, after a 24-hour soak test, a water adsorption of not more than 25% and a thickness swell of not more than 15%.
References Cited (Backward Citations)
US3666593A
Cited
US3718536A
Cited
US4111730A
Cited
US4012561A
Cited
US4148952A
Cited
US3919017A
Cited
US3930110A
Cited
US4100328A
Cited
US4268565A
Cited
US4131705A
Cited
US4209433A
Cited
US4221751A
Cited
US4279788A
Cited
US4382108A
Cited
US4505868A
Cited
US4528154A
Cited
US4609513A
Cited
US4692292A
Cited
US4740575A
Cited
US4742144A
Cited
US4772442A
Cited
US4999390A
Cited
US5092953A
Cited
US5096945A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-19 | 1998-06-20 | 1998-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-19 | 2002-06-20 | 2002-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-19 | 2006-06-20 | 2006-12-20 | $7700.00 | Window Closed / Lapsed |