Fibrous nonwoven structure having improved physical characteristics and method of preparing
View Patent ↗Disclosed is a fibrous nonwoven structure comprising meltblown fibrous materials and at least one secondary fibrous material and method of preparing. In one aspect, the fibrous nonwoven structure has a formation index of between 70 and 135. In another aspect, the fibrous nonwoven structure has an opacity that is greater than 72 percent at a basis weight of between about 35 and 55 grams per square meter. The fibrous nonwoven substrate may be utilized as a moist wipe.
1. A fibrous nonwoven structure comprising:
at least one meltblown fibrous material, the at least one meltblown fibrous material having an average diameter of about 0.5 to 40 μm;
at least one secondary fibrous material, wherein a weight ratio of the at least one secondary fibrous material to the at least one meltblown fibrous material is in between about 40/60 to about 90/10;
wherein a basis weight of the fibrous nonwoven structure is in a range of about 20 gsm to about 500 gsm; and
wherein the formation index of the fibrous nonwoven structure is greater than 70.
2. The fibrous nonwoven structure of claim 1 wherein the at least one secondary fibrous material is incorporated into a mixture of the at least one meltblown fibrous material.
3. The fibrous nonwoven structure of claim 1 having an average meltblown fibrous material fiber diameter of less than 3.5 μm at a polymer throughput of between about 0.88 ghm and 1.76 ghm.
4. The fibrous nonwoven structure of claim 1 having an average meltblown fibrous material fiber diameter of less than 3.5 μm at a polymer throughput of between about 3.5 pih and 7 pih.
5. The fibrous nonwoven structure of claim 1 wherein the formation index of the fibrous nonwoven structure is between about 70 to 135.
6. The fibrous nonwoven structure of claim 1 wherein the formation index of the fibrous nonwoven structure is between about 75 to 115.
7. The fibrous nonwoven structure of claim 1 wherein a machine tensile strength of the fibrous nonwoven structure is between about 650 grams-force and 1500 grams-force at a polymer throughput of between about 0.88 ghm and 1.76 ghm.
8. The fibrous nonwoven structure of claim 1 wherein a machine tensile strength of the fibrous nonwoven structure is between about 650 grams-force and 1500 grams-force at a polymer throughput of between about 3.5 pih and 7 pih.
9. The fibrous nonwoven structure of claim 1 , wherein a surface roughness of the fibrous nonwoven structure is in a range of about 0.03 to about 0.06 mm.
10. The fibrous nonwoven structure of claim 1 , wherein an opacity of the fibrous nonwoven structure is greater than 72 percent at a basis weight of between about 35 gsm and 55 gsm.
11. The fibrous nonwoven structure of claim 1 having a lint count between about 200 to about 950.
12. The fibrous nonwoven structure of claim 1 wherein a volume weighted mean diameter of the meltblown fibrous materials is between about 4.0 and about 8.0 μm at a polymer throughput of between about 0.88 ghm and 1.76 ghm.
13. The fibrous nonwoven structure of claim 1 wherein a volume weighted mean diameter of the meltblown fibrous materials is between about 4.0 and about 8.0 μm at a polymer throughput of between about 3.5 pih and 7.0 pih.
14. The fibrous nonwoven structure of claim 1 having an anisotropy ratio between about 0.4 and about 0.65.
15. The fibrous nonwoven structure of claim 1 for use as a wet wipe, wherein the wet wipe has from about 150 to 600 weight percent of a liquid based on a dry weight of the fibrous nonwoven structure.
16. A fibrous nonwoven structure comprising:
at least one meltblown fibrous material, the at least one meltblown fibrous material having an average diameter of about 0.5 to 40 μm;
at least one secondary fibrous material, wherein a weight ratio of the at least one secondary fibrous material to the at least one meltblown fibrous material is in between about 40/60 to about 90/10;
wherein an opacity of the fibrous nonwoven structure is greater than 72 percent and a basis weight of between about 35 gsm and less than 55 gsm.
17. The fibrous nonwoven structure of claim 16 having an average meltblown fibrous material diameter of less than 3.5 μm at a polymer throughput of between about 0.88 ghm and 1.76 ghm.
18. The fibrous nonwoven structure of claim 16 having an average meltblown fibrous material diameter of less than 3.5 μm at a polymer throughput of between about 3.5 pih and 7.0 pih.
19. The fibrous nonwoven structure of claim 16 wherein the formation index of the fibrous nonwoven structure is between about 70 to 135.
20. The fibrous nonwoven structure of claim 16 wherein a machine tensile strength of the fibrous nonwoven structure is between about 650 grams-force and 1500 grams-force at a polymer throughput of between about 0.88 ghm and 1.76 ghm.
21. The fibrous nonwoven structure of claim 16 wherein a machine tensile strength of the fibrous nonwoven structure is between about 650 grams-force and 1500 grams-force at a polymer throughput of between about 3.5 pih and 7.0 pih.
22. The fibrous nonwoven structure of claim 16 , wherein a surface roughness of the fibrous nonwoven structure is in a range of about 0.03 to about 0.06 mm.
23. The fibrous nonwoven structure of claim 16 having a lint count between about 200 to about 950.
24. The fibrous nonwoven structure of claim 16 wherein a volume weighted mean diameter of the meltblown fibrous materials is between about 4.0 and about 8.0 μm at a polymer throughput of between about 0.88 ghm and 1.76 ghm.
25. The fibrous nonwoven structure of claim 16 wherein a volume weighted mean diameter of the meltblown fibrous materials is between about 4.0 and about 8.0 μm at a polymer throughput of between about 3.5 pih and 7.0 pih.
26. The fibrous nonwoven structure of claim 16 having an anisotropy ratio between about 0.4 and about 0.65.
27. The fibrous nonwoven structure of claim 16 for use as a wet wipe, wherein the wet wipe has from about 150 to 600 weight percent of a liquid based on a dry weight of the fibrous nonwoven structure.
28. A process of making a fibrous nonwoven structure comprising:
providing a first stream and a second stream of meltblown fibrous materials with a meltblown die, the meltblown fibrous materials having an average diameter of about 0.5 to 40 μm, the first stream and second stream meeting at a formation zone, wherein the meltblown die has a machine direction width of less than 16 cm;
providing a stream of natural fibers meeting the first stream and the second stream at the formation zone and forming into a product stream;
collecting the product stream on a forming wire as a mixture of meltblown fibrous materials and natural fibers; and
wherein the formation index of the fibrous nonwoven structure is between about 70 to 135.