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US4597928A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for fiberboard manufacture

Assignee: PROIZVODSTVENNOE OBIEDINENIE "LITBUMPROM" USSR LENINGRAD
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Filing: 1984-03-23
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Granted: 1986-07-01
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Expires: 2004-03-23
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Abstract

Abstract Disclosed in accordance with the invention is a method for fiberboard manufacture comprising the steps of steaming and grinding woodchips to obtain a wood pulp, using said wood pulp to prepare a slurry of wood pulp in water, mixing said slurry with a binder, a cure catalyst for the binder, a water-repellent additive, peat, and carbamide to obtain a mixture, casting said mixture and dewatering said mixture to obtain a mat, and compacting said mat to obtain fiberboard which is subjected to heat treatment, in which method the peat used has a moisture content of between 25 and 70 percent and the peat content in said mixture is between 2.5 and 50 percent by mass, with the ratio of absolutely dry peat to said binder equal to between 1.0-7:1.0, respectively, while the carbamide content in said mixture is between 0.2 and 2.0 percent by mass, with the ratio of said carbamide to said binder equal to between 0.02-1:1, respectively.

Inventors

  • 👤 Otto A. Terentiev
  • 👤 Anatoly V. Burov
  • 👤 Ekaterina Y. Vorobieva
  • 👤 Ekaterina I. Grudinka
  • 👤 Gennady T. Nesterchuk
  • 👤 Oleg I. Shapovalov
  • 👤 Khamdam U. Usmanov
  • 👤 Shavkat M. Mirkamilov
  • 👤 Tolkun M. Mirkamilov
  • 👤 Vladimir V. Sharkov

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 01:19
CPC Classifications
D; D21; D21J; D21J1/00; C; C08; C08L; C08L97/00; C08L97/02; D21H; D21H17/00; D21H17/03; D21H17/05; D21H17/07

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 164 words
A method for fiberboard manufacture comprising the steps of steaming and grinding woodchips to obtain a wood pulp, using said wood pulp to prepare a slurry of wood pulp in water, mixing said slurry with a binder, a cure catalyst for the binder, a water-repellent additive, peat, and carbamide, casting the resultant mixture and dewatering said mixture to obtain a mat, and pressing said mat to obtain fiberboard which is subjected to heat treatment, the peat used having a moisture content of between 25 and 70 percent and the peat content in said mixture being between 2.5 and 50 percent by mass, with the ratio of absolutely dry peat to said binder equal to between 1.0-7:1.0, respectively, while the carbamide content in said mixture is between 0.2 and 2.0 percent by mass, with the ratio of said carbamide to said binder equal to between 0.02-1:1, respectively, said slurry being having a pH of about 5 and said binder being insoluble is water after cure.
Claim 2
Independent Claim 164 words
A method for fiberboard manufacture comprising the steps of steaming and grinding woodchips to obtain a wood pulp, using said wood pulp to prepare a slurry of wood pulp in water, mixing said slurry with a binder, a cure catalyst for the binder, a water-repellent additive, peat, and carbamide, casting the resultant mixture and dewatering said mixture to obtain a mat, and pressing said mat to obtain fiberboard which is subjected to heat treatment, the peat used having a moisture content of between 25 and 70 percent and the peat content in said mixture being between 2.5 and 50 percent by mass, with the ratio of absolutely dry peat to said binder equal to between 1.0-7:1.0, respectively, while the carbamide content in said mixture is between 0.2 and 2.0 percent by mass, with the ratio of said carbamide to said binder equal to between 0.02-1:1, respectively, said slurry being having a pH of about 5 and said binder being insoluble is water after cure.

References Cited (Backward Citations)

US768599A Cited
US2442897A Cited
GB811533A Cited
US3231526A Cited
US3174940A Cited
US3306864A Cited
US3293200A Cited
US4003866A Cited
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US4073753A Cited
US4229183A Cited
US4303561A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-06-30 1989-12-30 1990-07-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-06-30 1993-12-30 1994-07-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-06-30 1997-12-30 1998-07-01 $7700.00 Window Closed / Lapsed

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