US3880975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous hardboard production
Assignee: B PROJEKT INGF AB
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Filing: 1973-01-02
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Granted: 1975-04-29
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Expires: 1993-01-02
Abstract
Abstract A thin resin-bonded hardboard is produced by forming from a practically dry starting material containing a major part of defibrated ligno-cellulose plant substances and only a small percentage of synthetic resin binders a continuous, porously felted fiber mat which is continuously passed between a pair of cooperating hot press rollers under such conditions that the thickness of the mat is reduced to only a small fraction of the original one and the fibers are bonded together partly by the aid of the lignin and partly by the added binder in at least the surface layers of the rolled web. The web may be press-rolled to substantially its final thickness at once between the hot press rollers or be further treated in a hot plate press operating stepwise.
Inventors
- 👤 Lars-Erik Lundmark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:17
CPC Classifications
B; B27; B27N; B27N3/00; B27N3/08
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
13 words
to compact it to a reduced thickness exceeding that of the final product,
Claim 2
Dependent Claim
13 words
to compact it to a reduced thickness exceeding that of the final product,
Claim 3
Dependent Claim
12 words
to compact it to about twice the thickness of the final product,
Claim 4
Dependent Claim
12 words
to compact it to about twice the thickness of the final product,
Claim 5
Dependent Claim
144 words
An improved process for manufacturing a continuous flexible web of resin-bonded hardboard within the thickness range of between 0.15 and 3.0 millimeters which comprises a. providing an air suspension of a fiber-binder mixture containing a major part of defibrated ligno-cellulose plant substances and less than 10% of a thermosetting synthetic resin binder, b. felting said air suspended fiber-binder mixture into a fluffy continuous mat having a moisture content between 2 and 10%, c. preheating said mat to a temperature between about 30*C, and 80*C, d. supporting said preheateD mat upon a belt of thin wire cloth, e. feeding said supported mat continuously into a nip formed by cooperating press rollers at 40 - 100 centimeters and heated to a temperature of between 180*C and 250*C while subjecting it to a pressure of between 20 and 250 kilograms per centimeter in said nip so as
Claim 6
Dependent Claim
144 words
An improved process for manufacturing a continuous flexible web of resin-bonded hardboard within the thickness range of between 0.15 and 3.0 millimeters which comprises a. providing an air suspension of a fiber-binder mixture containing a major part of defibrated ligno-cellulose plant substances and less than 10% of a thermosetting synthetic resin binder, b. felting said air suspended fiber-binder mixture into a fluffy continuous mat having a moisture content between 2 and 10%, c. preheating said mat to a temperature between about 30*C, and 80*C, d. supporting said preheateD mat upon a belt of thin wire cloth, e. feeding said supported mat continuously into a nip formed by cooperating press rollers at 40 - 100 centimeters and heated to a temperature of between 180*C and 250*C while subjecting it to a pressure of between 20 and 250 kilograms per centimeter in said nip so as
Claim 7
Dependent Claim
20 words
to convert a substantial part of its moisture content into steam which is driven out backwards through the mat, and
Claim 8
Dependent Claim
20 words
to convert a substantial part of its moisture content into steam which is driven out backwards through the mat, and
Claim 9
Dependent Claim
124 words
An improved process for manufacturing a continuous flexible web of resin-bonded hardboard within the thickness range of between 0.15 and 3.0 millimeters which comprises a. providing an air suspension of a fiber-binder mixture containing a major part of defibrated ligno-cellulose plant substances and less than 10% of a thermosetting synthetic resin binder, b. felting said air suspended fiber-binder mixture into a fluffy continuous mat having a moisture content between 2 and 10%, c. supporting said mat upon a thin wire cloth, d. feeding said supported mat continuously into a nip formed by cooperating press rollers that are heated to a temperature of between 160*C and 350*C while subjecting it to a pressure of at least 20 kilograms per centimeter in said nip so as
Claim 10
Dependent Claim
124 words
An improved process for manufacturing a continuous flexible web of resin-bonded hardboard within the thickness range of between 0.15 and 3.0 millimeters which comprises a. providing an air suspension of a fiber-binder mixture containing a major part of defibrated ligno-cellulose plant substances and less than 10% of a thermosetting synthetic resin binder, b. felting said air suspended fiber-binder mixture into a fluffy continuous mat having a moisture content between 2 and 10%, c. supporting said mat upon a thin wire cloth, d. feeding said supported mat continuously into a nip formed by cooperating press rollers that are heated to a temperature of between 160*C and 350*C while subjecting it to a pressure of at least 20 kilograms per centimeter in said nip so as
Claim 11
Dependent Claim
20 words
to convert a substantial part of its moisture content into steam which is driven out backwards through the mat, and
Claim 12
Dependent Claim
20 words
to convert a substantial part of its moisture content into steam which is driven out backwards through the mat, and
Claim 13
Dependent Claim
143 words
AN IMPROVED PROCESS FOR MANUFACTURING A CONTINOUS FLEXIBLE WEB OF RESIN-BONDED HARDBOARD WITHIN THE THICKNESS RANGE OF BETWEEN 0.15 AND 3.0 MILLIMETERS WHICH COMPRISES A. PROVIDING AN AIR SUSPENSION OF A FIBER-BINDER MIXTURE CONTAINING A MAJOR PART OF DEIBRATED LIGNO-CELLULOSE PLANT SUBSTANCES AND LESS THAN 10% OF A THERMOSETTING SYNTHETIC RESIN BINDER. B. FELTING SAID AIR SUSPENDED FAFIBER-BINDER MIXTURE INTO A FLUFFY CONTINOUS MAT HAVING A MOISTURE CONTENT BETWEEN 2 AND 10%, C. FEEDING SAID MAT CONTINOUSLY INTO A NIP FORMED BY COOPERATING PRESS ROLLERS HEATED TO A TEMPERATURE ABOVE 160*C WHILE SUBJECTING IT TO A PRESSURE OF AT LEAST 20 KILOGRAMS PER CENTIMETER IN SAID NIP, SO AS TO COMPACT IT TO ABOUT TWICE THE THICKNESS OF THE FINAL PRODUCT, TO CONVERT A SUBSTANTIAL PART OF ITS MOISTURE CONTENT INTO STEAM WHICH IS DRIVEN OUT BACKWARDS THROUGH THE MAT, AND TO ACTIVATE
Claim 14
Dependent Claim
143 words
AN IMPROVED PROCESS FOR MANUFACTURING A CONTINOUS FLEXIBLE WEB OF RESIN-BONDED HARDBOARD WITHIN THE THICKNESS RANGE OF BETWEEN 0.15 AND 3.0 MILLIMETERS WHICH COMPRISES A. PROVIDING AN AIR SUSPENSION OF A FIBER-BINDER MIXTURE CONTAINING A MAJOR PART OF DEIBRATED LIGNO-CELLULOSE PLANT SUBSTANCES AND LESS THAN 10% OF A THERMOSETTING SYNTHETIC RESIN BINDER. B. FELTING SAID AIR SUSPENDED FAFIBER-BINDER MIXTURE INTO A FLUFFY CONTINOUS MAT HAVING A MOISTURE CONTENT BETWEEN 2 AND 10%, C. FEEDING SAID MAT CONTINOUSLY INTO A NIP FORMED BY COOPERATING PRESS ROLLERS HEATED TO A TEMPERATURE ABOVE 160*C WHILE SUBJECTING IT TO A PRESSURE OF AT LEAST 20 KILOGRAMS PER CENTIMETER IN SAID NIP, SO AS TO COMPACT IT TO ABOUT TWICE THE THICKNESS OF THE FINAL PRODUCT, TO CONVERT A SUBSTANTIAL PART OF ITS MOISTURE CONTENT INTO STEAM WHICH IS DRIVEN OUT BACKWARDS THROUGH THE MAT, AND TO ACTIVATE
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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) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |