Method for making a spunbonded high loft nonwoven web

Patent metadata

Field	Value
Publication number	US-10435829-B2
Application number	US-201715597171-A
Country	US
Kind code	B2
Filing date	May 17, 2017
Priority date	May 18, 2016
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

The invention relates to a method for making a spunbonded high loft nonwoven web comprising crimped multicomponent fibers, the process comprising continuously spinning the fibers, directing the fibers to a spin-belt by deflectors and/or air streams, laying down the fibers on the spinbelt and pre-consolidating the fibers after laydown using one or more pre-consolidation rollers to form a pre-consolidated web, wherein a first component of the fibers comprises a PP homopolymer and a second component of the fibers comprises a PP/PE copolymer, wherein the pre-consolidation rollers are operated at a temperature of smaller 110° C. and/or a linear contact force of smaller 5 N/mm.

First claim

The invention claimed is:

1. A method for making a high loft spunbonded nonwoven web comprising crimped multicomponent fibers, the process comprising continuously spinning the fibers, directing the fibers to a spin-belt by deflectors or air streams or both, laying down the fibers on the spin-belt and pre-consolidating the fibers after laydown using one or more pre-consolidation rollers to form a pre-consolidated web, wherein a first component of the fibers comprises a polypropylene (PP) homopolymer and a second component of the fibers comprises a polypropylene/polyethylene (PP/PE) copolymer, wherein the pre-consolidation rollers are operated at a temperature of below 100° C. and a linear contact force of below 5 N/mm.

2. The method of claim 1 , wherein the pre-consolidation rollers are operated at a temperature of from 20° C. to less than 100° C.

3. The method of claim 1 , wherein the pre-consolidation rollers are operated at a linear contact force of 1-4 N/mm.

4. The method of claim 1 , wherein the content of ethylene-stemming repetitive units in the PP/PE copolymer is >0-5 wt %.

5. The method of claim 1 , wherein the PP/PE copolymer is a random copolymer.

6. The method of claim 1 , wherein the PP homopolymer is isotactic.

7. The method of claim 1 , wherein the melt flow rates or the polydispersities of the PP homopolymer and the PP/PE copolymer or both differ by less than 30%.

8. The method of claim 1 , wherein the melting points of the PP homopolymer and the PP/PE copolymer differ by 10° C. or more or by 20° C. or less, or both.

9. The method of claim 1 , wherein the multicomponent fibers are bicomponent fibers and/or have a side-by-side configuration.

10. The method of claim 1 , wherein the weight ratio of the first to second component in the multicomponent fibers is 40/60-80/20.

11. The method of claim 1 further comprising bonding the pre-consolidated web using one or more calandering rolls, at least one of which is embossed, and/or hot air through bonding.

12. The method of claim 11 , wherein the calandering rolls are operated at a temperature of and/or the air used in hot air through bonding has a temperature of 120-145° C.

13. The method of claim 1 , wherein the pre-consolidation rollers are operated at a temperature of 40-90° C.

14. The method of claim 1 , wherein the pre-consolidation rollers are operated at a temperature of 55-75° C.

15. The method of claim 1 , wherein the pre-consolidation rollers are operated at a linear contact force of 1-2.5 N/mm.

16. The method of claim 1 , wherein the melt flow rates or the polydispersities of the PP homopolymer and the PP/PE copolymer or both differ by less than 20%.

17. The method of claim 1 , wherein the weight ratio of the first to second component in the multicomponent fibers is 40/60-60/40.

Assignees

• Fibertex Personal Care As
• Reifenhaeuser Masch

Inventors

• Hansen Morten Rise
• Broch Thomas
• Sommer Sebastian

Classifications

• D01D5/22

  with a crimped or curled structure; with a special structure to simulate wool (producing crimped or curled effects in filaments or threads after formation D02G1/00) · CPC title

• D04H3/007

  Addition polymers · CPC title

• D04H3/16

  with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion · CPC title

• D04H3/14 Primary

  with bonds between thermoplastic yarns or filaments produced by welding · CPC title

• D04H3/147 Primary

  Composite yarns or filaments · CPC title