US4749423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a bonded nonwoven web
Assignee: Kimberly Clark Tissue Co
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Filing: 1986-05-14
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Granted: 1988-06-07
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Expires: 2006-05-14
Abstract
Abstract A method of making a nonwoven fibrous web. A web of primary fibers having uniformly distributed throughout secondary fibers containing 3 to 7 percent polyethylene by weight of the final web is formed on a conveying means. The polyethylene of the secondary fibers has a melting point that is lower than the melting point of the primary fibers. The web is then heated to a temperature below the melting point of the primary fibers but above the melting point of the polyethylene of the secondary fibers thereby causing some of the polyethylene fibers to bond to each other or to the primary fibers. The web is then heated to a temperature above the melting point of the primary fibers to form primary fiber-to-primary fiber thermal bonds which provide substantially all of the useful strength of the web.
Inventors
- 👤 Lawrence Vaalburg
- 👤 H. Paul Kaiser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:10
CPC Classifications
D; D04; D04H; D04H1/00; D04H1/40; D04H1/54; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24826; Y10T442/00; Y10T442/60; Y10T442/69
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
165 words
A method of making a nonwoven fibrous web comprising the steps of: (a) forming on a conveying means a web of primary fibers having uniformly distributed throughout secondary fibers containing 3 to 7 percent polyethylene by weight of the final web, the polyethylene having a melting point that is lower than the melting point of the primary fibers; (b) heating the web to a temperature below the melting point of the primary fibers but above the melting point of the polyethylene to cause some of the polyethylene to bond to each other or to the primary fibers thereby giving the web minimal strength to withstand unsupported transfer to a next process step; then (c) subjecting discrete areas of the web to pressure and heating the fibers in those discrete areas to a temperature above the melting point of the primary fibers to form primary fiber-to-primary fiber thermal bonds, the primary fiber-to-primary fiber thermal bonds providing substantially all of the useful strength of the final web.
Claim 2
Independent Claim
165 words
A method of making a nonwoven fibrous web comprising the steps of: (a) forming on a conveying means a web of primary fibers having uniformly distributed throughout secondary fibers containing 3 to 7 percent polyethylene by weight of the final web, the polyethylene having a melting point that is lower than the melting point of the primary fibers; (b) heating the web to a temperature below the melting point of the primary fibers but above the melting point of the polyethylene to cause some of the polyethylene to bond to each other or to the primary fibers thereby giving the web minimal strength to withstand unsupported transfer to a next process step; then (c) subjecting discrete areas of the web to pressure and heating the fibers in those discrete areas to a temperature above the melting point of the primary fibers to form primary fiber-to-primary fiber thermal bonds, the primary fiber-to-primary fiber thermal bonds providing substantially all of the useful strength of the final web.
Claim 3
Dependent Claim
81 words
The method as recited in claim 1 wherein the forming step comprises the steps of: (a) forming two or more layers of primary fibers, at least one of the layers having a minor percent by weight of secondary fibers uniformly distributed therein, so that the finished web contains up to 7 percent by weight of secondary fibers; (b) subjecting two or more of the layers to randomizing means for reorienting the fibers; and (c) depositing the layers on a conveyor means.
Claim 4
Dependent Claim
48 words
The method as recited in claim 1 wherein after the first heating step and before the bonding step: (a) the web is transferred from the conveying means to a spreading means; and (b) spreading the web in the cross direction from about 10 percent to over 60 percent.
Claim 5
Dependent Claim
35 words
The method as recited in claim 1 wherein the secondary fibers are bicomponent fibers having a polyethylene sheath in an amountt such that the formed web contains up to 7 percent by weight of polyethylene.
Claim 6
Dependent Claim
26 words
The method as recited in claim 1 wherein the formed web comprises between 93 to 97 percent polypropylene fiber and 3 to 7 percent polyethylene fiber.
Claim 7
Dependent Claim
48 words
The method as recited in claim 2 wherein after the first heating step and before the bonding step: (a) the web is transferred from the conveying means to a spreading means; and (b) spreading the web in the cross direction from about 10 percent to over 60 percent.
Claim 8
Dependent Claim
35 words
The method as recited in claim 6 wherein the secondary fibers are bicomponent fibers having a polyethylene sheath in an amount such that the formed web contains up to 7 percent by weight of polyethylene.
Claim 9
Dependent Claim
26 words
The method as recited in claim 6 wherein the formed web comprises between 93 ot 97 percent polypropylene fiber and 3 to 7 percent polyethylene fiber.
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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) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |