US4265846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of binding lignocellulosic materials
Assignee: HER MAJESTY IN RIGHT OF CANADA FORESTRY, Minister of
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Filing: 1979-10-05
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Granted: 1981-05-05
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Expires: 1999-10-05
Abstract
Abstract A low cost method of binding lignocellulosic materials utilizing ammonium based spent sulfite liquor alone as the binder. Hot pressing a mat comprising lignocellulosic material and ammonium spent sulfite liquor at a temperature above 170 DEG C. decomposes the spent sulfite liquor. The decomposition products subsequently condense and polymerize in the presence of lignocellulosic materials to produce a composite product. An exterior grade board can be produced under certain operating conditions. Utilizing the lower molecular weight fraction of the liquor provides a more efficient binder.
Inventors
- 👤 Kuo-Cheng Shen
- 👤 David P. C. Fung
- 👤 Louis Calve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:10
CPC Classifications
C; C08; C08L; C08L97/00; C08L97/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
62 words
A method for binding lignocellulosic materials which comprises; forming a mixture of the lignocellulosic materials and at least 2%, by weight, ammonium based spend sulfite liquor solids, forming a mat with the mixture and hot pressing the mat at a temperature of 170° C., or higher, for a time sufficient for thermosetting and consolidation of the mat to provide a composite product.
Claim 2
Independent Claim
62 words
A method for binding lignocellulosic materials which comprises; forming a mixture of the lignocellulosic materials and at least 2%, by weight, ammonium based spend sulfite liquor solids, forming a mat with the mixture and hot pressing the mat at a temperature of 170° C., or higher, for a time sufficient for thermosetting and consolidation of the mat to provide a composite product.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein the mat is hot-pressed at 210° C., or higher.
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein the hot-pressed mat is subjected to an elevated temperature for a period of time for further thermosetting.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein the mat is hot-pressed at 230° C., or higher.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein the ammonium based spend sulfite liquor used has been fractionated to provide an increased concentration of low molecular weight materials.
Claim 7
Dependent Claim
16 words
The method of claim 5 wherein the fractionated liquor has a molecular weight less than 30,000.
Claim 8
Dependent Claim
18 words
The method of claim 6 wherein the fractionated liquor has a molecular weight of about 10,000, or less.
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) | 1984-05-04 | 1984-11-03 | 1985-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-04 | 1988-11-03 | 1989-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-04 | 1992-11-03 | 1993-05-05 | $7700.00 | Window Closed / Lapsed |