US3940466A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of providing a structural shape
Assignee: Individual
•
Filing: 1973-12-07
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Granted: 1976-02-24
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Expires: 1993-12-07
Abstract
Abstract A method of providing a structural shape includes starting with waste paper and treating the waste paper in a hammer mill to produce paper fibers. The fibers are put through a screen. The screened fibers are mixed with a binder such as a thermosetting epoxy foaming resin or with a phenolic resin in water in preferred proportions. The water or other solvent is kept to a very small value to provide a relatively dry process. The mixture is then pressed in a geometrical shape under substantial pressure (3 to 600 psi). The pressed mixture is then baked or cured at an elevated temperature (175°F to 375°F) for a predetermined time (three minutes to three hours).
Inventors
- 👤 King W. Evers
- 👤 George H. Larsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:42
CPC Classifications
D; D21; D21J; D21J3/00; C; C08; C08L; C08L1/00; C08L1/02; Y; Y10; Y10S; Y10S264/00; Y10S264/17; Y10S264/911; Y10S264/913; Y10S264/914
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
119 words
A method of providing a structural shape comprising: a. introducing dry waste paper into an operating hammer mill to make dry paper fibers; b. withdrawing said dry paper fibers from said mill; c. passing said dry paper fibers through a screen; d. mixing said dry paper fibers with a thermosetting resin binder in water in the proportion by weight of paper fibers of from about 3-35% water and from 3-35% binder; e. pressing the mixture at a pressure of from 3-600 psi while permitting said water to escape, and; f. heating said mixture while under said pressure to a temperature of 250°-375°F. for from three to thirty minutes to cure said resin binder and thereby form said structural shape.
Claim 2
Independent Claim
119 words
A method of providing a structural shape comprising: a. introducing dry waste paper into an operating hammer mill to make dry paper fibers; b. withdrawing said dry paper fibers from said mill; c. passing said dry paper fibers through a screen; d. mixing said dry paper fibers with a thermosetting resin binder in water in the proportion by weight of paper fibers of from about 3-35% water and from 3-35% binder; e. pressing the mixture at a pressure of from 3-600 psi while permitting said water to escape, and; f. heating said mixture while under said pressure to a temperature of 250°-375°F. for from three to thirty minutes to cure said resin binder and thereby form said structural shape.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein said resin binder is phenolic.
Claim 4
Independent Claim
116 words
A method of providing a structural shape comprising: a. introducing dry waste paper into an operating hammer mill to make dry paper fibers; b. withdrawing said dry paper fibers from said mill; c. passing said dry paper fibers through a screen; d. mixing said dry paper fibers with a thermosetting resin foaming binder in dry form in the proportions by weight of about 400 grams of paper fiber and 50 grams of binder; e. pressing the dry mixture at a pressure of 5-400 psi; and, f. heating said mixture while under said pressure to a temperature of about 350°F. for three minutes to three hours to cure said resin binder and thereby form said structural shape.
Claim 5
Independent Claim
116 words
A method of providing a structural shape comprising: a. introducing dry waste paper into an operating hammer mill to make dry paper fibers; b. withdrawing said dry paper fibers from said mill; c. passing said dry paper fibers through a screen; d. mixing said dry paper fibers with a thermosetting resin foaming binder in dry form in the proportions by weight of about 400 grams of paper fiber and 50 grams of binder; e. pressing the dry mixture at a pressure of 5-400 psi; and, f. heating said mixture while under said pressure to a temperature of about 350°F. for three minutes to three hours to cure said resin binder and thereby form said structural shape.
Claim 6
Dependent Claim
17 words
The method of claim 3 wherein said resin binder is an epoxy resin in finely particulate form.
References Cited (Backward Citations)
US3235530A
Cited
US3736221A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-23 | 1979-08-25 | 1980-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-23 | 1983-08-25 | 1984-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-23 | 1987-08-25 | 1988-02-24 | $7700.00 | Window Closed / Lapsed |