EP0462574A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Nonwoven web and method of forming same
Assignee: Kimberly Clark Worldwide Inc
•
Filing: 1991-06-18
•
Granted: —
•
Expires: 2011-06-18
Abstract
Abstract A nonwoven web (32) suitable as a barrier layer in an SMS fabric laminate (12) is provided. The web is formed at commercially acceptable polymer melt throughputs (greater than 3 PIH) by using a reactor granule polyolefin, preferably polypropylene, that has been modified by the addition of peroxide in amounts ranging from up to 3000 ppm to reduce the molecular weight distribution from an initial molecular weight distribution of from 4.0 to 4.5 Mw/Mn to a range of from 2.2 to 3.5 Mw/Mn. Also the addition of peroxide increases the melt flow rate (lowers viscosity) to a range between 800 up to 5000 gms/10 min at 230°C. The resulting web has an average fiber size of from 1 to 3 µm and pore sizes distributed predominantly in the range from 7 to 12 µm, with a lesser amount of pores from 12 to 25 µm, with virtually no pores greater than 25 µm, and with the peak of the pore size distribution less than 10 µm.
Inventors
- 👤 Terry Kramer Timmons
- 👤 Peter Michalovich Kobylivker
- 👤 Lin-Sun Woon
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 20:12
CPC Classifications
D; D04; D04H; D04H3/00; D04H3/005; D04H3/007; D04H3/02; D04H1/00; D04H1/40; D04H1/42; D04H1/4282; D04H1/4291; D04H1/54; D04H1/542; D04H1/544; D04H1/559; D04H1/56
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
39 words
A nonwoven web of fine fibers formed from a reactor granule of a modified polymer which polymer has a molecular weight distribution between 2.2 and 3.5 Mw/Mn and a melt flow rate greater than 800 gms/10 min at 230°C.
Claim 2
Dependent Claim
39 words
The nonwoven web of claim 1 formed from a reactor granule of a modified polymer which polymer has a molecular weight distribution between 2.8 and 3.5 Mw/Mn and a melt flow rate greater then 3000 gms/10 Min at 230°C.
Claim 3
Dependent Claim
28 words
The nonwoven web of claim 2, wherein the modified polymer results from adding up to 500 ppm of peroxide to the reactor granlues prior to forming the web.
Claim 4
Dependent Claim
39 words
The nonwoven web of claim 1 formed from a reactor granule of a modified polymer which polymer has a molecular weight distribution between 2.2 and 2.8 Mw/Mn and a melt flow rate greater than 800 gms/10 min at 230°C.
Claim 5
Dependent Claim
29 words
The nonwoven web of claim 4 wherein the modified polymer results from adding from 500 to 3000 ppm of peroxide to the reactor granules prior to forming the web.
Claim 6
Dependent Claim
23 words
The nonwoven web of one of the preceding claims, wherein the web is formed at a polymer throughput of greater than 3 PIH.
Claim 7
Dependent Claim
47 words
The nonwoven web of one of the preceding claims, wherein the web has an average fiber size from 1 to 3 µm and pore sizes distributed predominantly in the range from 7 to 12 µm with the peak of the pore size distribution less than 10 µm.
Claim 8
Independent Claim
52 words
A method of forming a nonwoven web having fine fibers and a small pore size distribution comprising the steps of melt-blowning a reactor granule of a modified polymer which polymer has a molecular weight distribution between 2.2 and 3.5 Mw/Mn and a melt flow rate greater than 800 gms/10 min at 230°C.
Claim 9
Dependent Claim
56 words
A method of forming a nonwoven web according to claim 8, having fine fibers and a small pore size distribution comprising the steps of melt-blowing a reactor granule of a modified polymer which polymer has a molecular weight distribution between 2.8 and 3.5 Mw/Mn and a melt flow rate greater than 300 gms/10 min at 230°C.
Claim 10
Dependent Claim
28 words
The method of claim 9, wherein the modified polymer results from adding up to 500 ppm of peroxide to the reactor granules prior to forming the nonwoven web.
Claim 11
Dependent Claim
56 words
A method of forming a nonwoven web according to claim 8, having fine fibers and a small pore size distribution comprising the steps of melt-blowing a reactor granule of a modified polymer which polymer has a molecular weight distribution betwen 2.2 and 2.8 Mw/Mn and a melt flow rate greater than 800 gms/10 min at 230°C.
Claim 12
Dependent Claim
29 words
The method of claim 11, wherein the modified polymer results from adding from 500 to 3000 ppm of peroxide to the reactor granules prior to forming the nonwoven web.
Claim 13
Independent Claim
21 words
The method of one of claims 8 to 12, wherein the polymer is throughput at a rate greater than 3 PIH.*
Claim 14
Dependent Claim
32 words
Use of the nonwoven web according to one of claims 1 to 7 or made according to one of claims 8 to 13 as a barrier layer in a nonwoven fabric laminate.
Claim 15
Dependent Claim
67 words
The use of claim 14 wherein the resulting fabric laminate has pore sizes distributed predominantly in the range from 5 to 10 µm with a lesser amount of pores from 10 to 15 µm and virtually no pores greater than 22 µm, with the peak of the pore size distribution being preferably shifted downwardly by up to 5 µm from the peak of the melt-blown web alone.
Claim 16
Dependent Claim
26 words
A nonwoven fabric laminate comprising a nonwoven web according to one of claims 1 to 7 or made according to one of claims 8 to 13.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.