Spunbond laminate and method of making same

Patent metadata

Field	Value
Publication number	US-12343975-B2
Application number	US-202318383060-A
Country	US
Kind code	B2
Filing date	Oct 24, 2023
Priority date	Jul 30, 2019
Publication date	Jul 1, 2025
Grant date	Jul 1, 2025

Abstract

A spunbond nonwoven laminate has a first spunbond nonwoven layer having crimped filaments formed by a first component on an outer surface of the filaments of the first layer consisting or substantially consisting of a polyolefin and a second component consisting or substantially consisting of a plastic having a higher melting point than the polyolefin of the first component of the filaments of the first layer. A second outermost spunbond nonwoven layer on the first layer having filaments as a cover layer and formed by a first component on an outer surface of the filaments of the second layer consisting or substantially consisting of a polyolefin, and a second component consisting or substantially consisting of a plastic having a higher melting point than the polyolefin of the first component of the filaments of the second layer.

First claim

The invention claimed is:

1. A method of making a spunbond nonwoven laminate, the method comprising the steps of:
providing a first spunbond nonwoven layer having crimped multicomponent or bicomponent filaments of an eccentric core-sheath configuration and formed by
a first sheath component forming over at least 20% of a filament circumference a substantially constant thickness, and consisting or substantially consisting of a polyolefin, and
a second component consisting or substantially consisting of a plastic having a higher melting point than the polyolefin of the first component of the filaments of the first layer

preconsolidating the first layer with hot air;
providing a second outermost spunbond nonwoven layer having multicomponent or bicomponent filaments to and formed by
a first component on an outer surface of the filaments of the second layer consisting or substantially consisting of a polyolefin, and
a second component consisting or substantially consisting of a plastic having a higher melting point than the polyolefin of the first component of the filaments of the second layer, a polyolefin portion of the first component of the filaments of the second layer being greater than a polyolefin portion of the first component of the filaments of the first layer;

preconsolidating the second layer with hot air;
forming the first and second preconsolidated layers into the spunbond nonwoven laminate; and
finally consolidating the spunbond nonwoven laminate formed by the first and second layers with hot air.

2. The method according to claim 1 , wherein after the second layer is preconsolidated, the first spunbond nonwoven layer is formed on the second spunbond nonwoven layer and is then preconsolidated.

3. The method according to claim 1 , further comprising the step of using multicomponent or bicomponent filaments for the second spunbond nonwoven layer.

4. The method according to claim 1 , further comprising the step of:
imparting to the filaments of the second outermost layer a titer that is less than a titer of the filaments of the first layer.

5. The method according to claim 1 , wherein the second component of the filaments of the first layer consists or substantially consists of polypropylene or polyester.

6. The method according to claim 1 , wherein the polyolefin portion of the filaments of the first layer is less than 40% by weight.

7. The method according to claim 1 , further comprising the step of:
imparting to the filaments of the first layer a titer of more than 1.5 den.

8. The method according to claim 1 , wherein the polyolefin of the first component of the filaments of the first layer is polyethylene having a melt flow rate of less than 35 g/10 min.

9. The method according to claim 1 , wherein the second component of the filaments of the first layer consists or substantially consists of polypropylene having a melt flow rate of more than 25 g/10 min.

10. The method according to claim 1 , wherein the second component of the filaments of the second layer consists or substantially consists of polypropylene.

11. The method according to claim 1 , wherein the polyolefin portion of the filaments of the second layer is more than 33% by weight, and the polyolefin portion is 40% by weight to 65% by weight.

12. The method according to claim 1 , wherein the multicomponent or bicomponent filaments of the second layer have an eccentric core-sheath configuration or a side-by-side configuration.

13. The method according to claim 1 , wherein the first component on the outer surface of the filaments of the second layer consists or substantially consists of polyethylene having a melt-flow rate greater than 15 g/10 min.

14. The method according to claim 13 , wherein the melt flow rate of the polypropylene of the second component of the second layer is more than 25 g/10 min.

15. The method according to claim 1 , further comprising the step of:
imparting to the second layer a weight per unit area of less than a weight per unit area of the first layer.

16. The method according to claim 1 , wherein a strength of the spunbond nonwoven laminate in the machine direction is greater than 25 N/5 cm, the spunbond nonwoven laminate in particular having a basis weight of 12 to 50 g/m 2 .

17. The method according to claim 1 , wherein a thickness of the spunbond nonwoven laminate is more than 0.50 mm, and the spunbond nonwoven laminate has in particular a basis weight from 12 to 50 g/m 2 .

18. The method according to claim 1 , wherein a difference between a titer of the filaments of the first layer and a titer of the filaments of the second layer is at least 0.2 den.

19. The method according to claim 1 , wherein a degree of crimp of the filaments of the second layer is equal to or less than a degree of crimp of the filaments of the first layer.

Assignees

• Reifenhaeuser Masch

Inventors

• Wagner Tobias
• Sommer Sebastian
• Bohl Patrick
• Roesner Andreas
• Geus Hans-Georg
• Linke Gerold
• Kunze Bernd

Classifications

• B32B2323/00

  Polyalkenes · CPC title

• B32B2310/0454

  Hot air · CPC title

• B32B2309/08

  Dimensions, e.g. volume · CPC title

• B32B2305/20

  in the form of a non-woven mat · CPC title

• B32B2323/10

  Polypropylene · CPC title