US4214027A
Expired / Lapsed
US
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Process for the production of fiber-containing plaster boards
Assignee: Knauf Gips KG
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Filing: 1979-03-27
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Granted: 1980-07-22
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Expires: 1999-03-27
Abstract
Abstract Fiber containing plaster boards are prepared by superimposing a plurality of board blanks one on top of the other such that the direction of the fiber orientation in the superimposed blanks deviates one from the other. The board blanks are formed in a conventional manner from a suspension of calcium sulfate capable of setting, reinforcing fibers and a quantity of water beyond the quantity of water necessary for setting the calcium sulfate capable of setting. After mechanically removing excess water from the suspension to form the board blanks, two or more of these blanks are placed one on top of the other and are connected under pressure and dried. Thereafter, a predetermined number of board blanks having a direction of the fiber orientation deviating one from the other, are placed one on top of the other and are pressed together prior to or during the setting of the calcium sulfate.
Inventors
- 👤 Alfons Knuaf
- 👤 Jorg Bold
- 👤 Siegfried Franke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:07
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/14; B; B28; B28B; B28B1/00; B28B1/52; B28B1/522; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24058; Y10T428/24124; Y10T428/24132; Y10T442/00; Y10T442/60; Y10T442/643; Y10T442/644; Y10T442/645; Y10T442/646
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
98 words
A monolithic, fiber-reinforced board which is sufficiently thick to be suitable for use as a floor element, which board comprises a plurality of layers each of which contains substantially homogeneously distributed reinforcing fibers and calcium sulfate binder, wherein the reinforcing fibers in each said layer are oriented predominantly in one direction, and wherein the direction of predominant fiber orientation in each layer deviates by about 90° from that in adjacent layers, said plurality of layers being molded together under pressure prior to the setting of the calcium sulfate binder to consolidate said layers into a monolithic, fiber-reinforced board.
Claim 2
Dependent Claim
98 words
A monolithic, fiber-reinforced board which is sufficiently thick to be suitable for use as a floor element, which board comprises a plurality of layers each of which contains substantially homogeneously distributed reinforcing fibers and calcium sulfate binder, wherein the reinforcing fibers in each said layer are oriented predominantly in one direction, and wherein the direction of predominant fiber orientation in each layer deviates by about 90° from that in adjacent layers, said plurality of layers being molded together under pressure prior to the setting of the calcium sulfate binder to consolidate said layers into a monolithic, fiber-reinforced board.
Claim 3
Dependent Claim
24 words
The fiber containing board of claim 1, wherein the bending strength is substantially the same in each horizontal direction of extension of said board.
Claim 4
Dependent Claim
68 words
The fiber containing board of claim 2, wherein said board has a bending strength of at least 150 kp/cm 2 , the isotropy of said bending strength in the horizontal space coordinates x:y is from 1:1 to 1:0.8, the elasticity modulus is at least 30,000 kp/cm 2 , the density is at least 1.2 g/cm 3 , and the fiber content is from 5 to 25% by weight.
Claim 5
Dependent Claim
67 words
The fiber containing board of claim 1, wherein said board has bending strength of at least 150 kp/cm 2 , the isotropy of said bending strength in the horizontal space coordinates x:y is from 1:1 to 1:0.8, the elasticity modulus is at least 30,000 kp/cm 2 , the density is at least 1.2 g/cm 3 , and the fiber content is from 5 to 25% by weight.
Claim 6
Dependent Claim
192 words
In a process for producing a monolithic, fiber-reinforced board which is sufficiently thick to be suitable for use as a floor element, which process comprises the steps of superimposing a plurality of fiber-reinforced board blanks, molding and drying; the improvement which comprises: (a) using as said plurality of board blanks uncured board blanks containing substantially homogeneously distributed reinforcing fibers, calcium sulfate binder and a quantity of water in excess of the quantity necessary for setting said binder, wherein the reinforcing fibers of each board blank are oriented predominantly in one direction; (b) superimposing said uncured board blanks such that the direction of predominant fiber orientation in each board blank deviates by about 90° from that in adjacent board blanks, thereby substantially reducing the anisotropy of bending strength in the horizontal directions of extension in the molded product of step (c); and (c) molding the resultant superimposed board blanks under sufficient pressure prior to the setting of said calcium sulfate binder contained in said board blanks to form a monolithic fiber-reinforced board; whereby the steps of setting and drying the individual board blanks and then gluing together the resultant cured blanks are avoided.
Claim 7
Dependent Claim
192 words
In a process for producing a monolithic, fiber-reinforced board which is sufficiently thick to be suitable for use as a floor element, which process comprises the steps of superimposing a plurality of fiber-reinforced board blanks, molding and drying; the improvement which comprises: (a) using as said plurality of board blanks uncured board blanks containing substantially homogeneously distributed reinforcing fibers, calcium sulfate binder and a quantity of water in excess of the quantity necessary for setting said binder, wherein the reinforcing fibers of each board blank are oriented predominantly in one direction; (b) superimposing said uncured board blanks such that the direction of predominant fiber orientation in each board blank deviates by about 90° from that in adjacent board blanks, thereby substantially reducing the anisotropy of bending strength in the horizontal directions of extension in the molded product of step (c); and (c) molding the resultant superimposed board blanks under sufficient pressure prior to the setting of said calcium sulfate binder contained in said board blanks to form a monolithic fiber-reinforced board; whereby the steps of setting and drying the individual board blanks and then gluing together the resultant cured blanks are avoided.
Claim 8
Dependent Claim
33 words
The process of claim 5, wherein after setting, said monolithic plaster board is dried at from 200° C. to 400° C. to a free water content of from 0 to 0.2% by weight.
Claim 9
Dependent Claim
23 words
The process of claim 5, wherein the superposed board blanks are molded with a pressure of about 30 to 160 kp/cm 2 .
Claim 10
Dependent Claim
24 words
The process of claim 5, wherein a layer of fibers or fabric is placed between two adjacent board blanks prior to superimposing said blanks.
Claim 11
Dependent Claim
22 words
The process of claim 8, further comprising impregnating said layer of fibers or fabric with a water suspension of calcium sulfate binder.
Claim 12
Dependent Claim
59 words
The process of claim 5, wherein said uncured board blanks are prepared by forming a fleece from said reinforcing fibers, said suspension of calcium sulfate binder and said quantity of water in excess of the quantity necessary for setting said binder, by mechanical removal of excess water, and layering said fleece to form a board blank of desired thickness.
Claim 13
Dependent Claim
49 words
The process of claim 10, wherein said fleece is formed on a continuous, water-permeable belt having means to remove excess water, layered on a molding roller to a desired thickness and removed from said roller before the calcium sulfate binder begins to set, thereby forming said uncured board blanks.
Claim 14
Dependent Claim
23 words
The process of claim 11, wherein the superposed board blanks are molded with a pressure of about 30 to 160 kp/cm 2 .
Claim 15
Dependent Claim
24 words
The process of claim 11, wherein a layer of fibers or fabric is placed between two adjacent board blanks prior to superimposing said blanks.
Claim 16
Dependent Claim
22 words
The process of claim 13, further comprising impregnating said layer of fibers or fabric with a water suspension of calcium sulfate binder.
Claim 17
Dependent Claim
23 words
The process of claim 10, wherein the superposed board blanks are molded with a pressure of about 30 to 160 kp/cm 2 .
Claim 18
Dependent Claim
24 words
The process of claim 10, wherein a layer of fibers or fabric is placed between two adjacent board blanks prior to superimposing said blanks.
Claim 19
Dependent Claim
22 words
The process of claim 16, further comprising impregnating said layer of fibers or fabric with a water suspension of calcium sulfate binder.
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) | 1983-07-22 | 1984-01-21 | 1984-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-22 | 1988-01-21 | 1988-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-22 | 1992-01-21 | 1992-07-22 | $7700.00 | Window Closed / Lapsed |