Patent US4081884A successfully refreshed from Google Patents.
US4081884A
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Method for making dimensionally stable articles
Assignee: Dr Carl Hahn GmbH
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Filing: 1977-05-11
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Granted: 1978-04-04
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Expires: 1997-05-11
Abstract
Abstract A method is provided for manufacturing a dimensionally stable compressed article such as an absorbent catamenial tampon comprising compressed cellulosic fibers. The method comprises the steps of first radially compressing a cylindrical blank to form a radially compressed blank having a length in excess of the desired finished length; then axially compressing the blank in a heated chamber to a length less than the desired finished length; then allowing the blank to expand to the desired finished length; and then maintaining the blank at this length while still in the heated chamber until the blank obtains the desired stability.
Inventors
- 👤 Wolfgang Johst
- 👤 Axel Friese
- 👤 Stefan Simon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 23:14
CPC Classifications
A; A61; A61F; A61F13/00; A61F13/15; A61F13/20; A61F13/2082; A61F13/2085; A61F13/2051; D; D06; D06C; D06C21/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
156 words
A method for providing a relatively dimensionally stable absorbent body comprising compressed cellulosic fibers, said method comprising the steps of: radially compressing a generally cylindrical blank comprising said cellulosic fibers, said radially compressed blank having a length in excess of the desired finished length; introducing said blank into a chamber having heated walls; axially compressing said blank to a length less than the desired finished length by continuously applying a force against at least one end of the blank while the sides and other end are held confined within said heated chamber; releasing said force to the extent necessary for said blank to expand in length to the desired length; and immediately upon having the blank expanded to said desired length, continuously maintaining a force resistant to further expansion against said one end of the blank while still maintaining said blank within the confines of said heated chamber until said blank attains the desired dimensional stability.
Claim 2
Independent Claim
156 words
A method for providing a relatively dimensionally stable absorbent body comprising compressed cellulosic fibers, said method comprising the steps of: radially compressing a generally cylindrical blank comprising said cellulosic fibers, said radially compressed blank having a length in excess of the desired finished length; introducing said blank into a chamber having heated walls; axially compressing said blank to a length less than the desired finished length by continuously applying a force against at least one end of the blank while the sides and other end are held confined within said heated chamber; releasing said force to the extent necessary for said blank to expand in length to the desired length; and immediately upon having the blank expanded to said desired length, continuously maintaining a force resistant to further expansion against said one end of the blank while still maintaining said blank within the confines of said heated chamber until said blank attains the desired dimensional stability.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein said force resistant to further expansion is maintained for a period of at least about 10 seconds.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein said force resistant to further expansion is maintained for a period of at least about 15 seconds.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein said blank is axially compressed to a length of about 92 to about 98% of the desired finished length.
Claim 6
Dependent Claim
20 words
The method of claim 4 wherein said compression is accomplished in a period of time of at least 1 second.
Claim 7
Dependent Claim
15 words
The method of claim 5 wherein said period of time is at least 2 seconds.
Claim 8
Dependent Claim
25 words
The method of claim 5 wherein less than 50% of the total axial compression is accomplished in the first 10% of said period of time.
Claim 9
Dependent Claim
21 words
The method of claim 1 wherein said chamber walls are heated to a temperature of about 120° to about 150° C.
Claim 10
Dependent Claim
26 words
The method of claim 1 wherein said radially compressed blank has a length of about 20 to about 40% in excess of the desired finished length.
Claim 11
Dependent Claim
22 words
The method of claim 1 wherein the radially compressed blank is compressed to a density of about 0.2 to about 0.7 gm./cc.
References Cited (Backward Citations)
US2076389A
Cited
US2433675A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |