Making a nonwoven from filaments

Patent metadata

Field	Value
Publication number	US-11618983-B2
Application number	US-202016940884-A
Country	US
Kind code	B2
Filing date	Jul 28, 2020
Priority date	Jul 30, 2019
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

An apparatus for making a nonwoven fabric from thermoplastic plastic filaments has an air permeable deposit conveyor having a horizontal face displaceable in a horizontal travel direction and a spinneret above the conveyor for spinning the filaments and depositing the spun filaments on the deposit conveyor in a deposit area of the conveyor as a nonwoven web for conveyance in the travel direction. An extractor beneath the conveyor draws air or process air through the deposit conveyor in the deposit area in a main extraction area below the deposit conveyor and is delimited by, relative to the travel direction, upstream and downstream suction partitions. One of the partitions has an upper edge set at a predetermined vertical spacing below the conveyor equal to between 10 mm and 250 mm.

First claim

We claim:

1. An apparatus for making a nonwoven fabric from thermoplastic plastic filaments, the apparatus comprising:
a conveyor that is air permeable and has a horizontal face displaceable in a horizontal travel direction;
a spinneret above the conveyor for spinning the filaments and depositing the spun filaments on the face of the conveyor in a deposit area of the conveyor as a nonwoven web for conveyance in the travel direction; and
an extractor beneath the conveyor that draws air or process air through the conveyor in the deposit area in a main extraction area below the conveyor and delimited by, relative to the travel direction, upstream and downstream suction partitions, one of the partitions having an upper end with an upper edge set at a predetermined vertical spacing below the conveyor equal to between 10 mm and 250 mm, the one suction partition having an upper end formed by a partition section that is angled from the rest of the one suction partition and forms a spoiler, the upper edge of the spoiler with the shortest vertical spacing from the conveyor having the predetermined vertical spacing from the conveyor, the spoiler
being more angled relative to the vertical extending perpendicular to the face than an upper partition section of the other suction partition and/or
in its projection onto the conveyor face having a greater length than the corresponding projection of an upper, angled or bent upper partition section of the other suction partition and/or
having a greater spacing from the conveyor relative to its upper end than an upper edge of the upper partition section of the other suction partition.

2. The apparatus according to claim 1 , wherein the one suction partition has at its upper end a spoiler in the form of an angular element with two spoiler parts arranged at an angle to one another, and an upper end edge of this spoiler has the predetermined vertical spacing from the conveyor.

3. The apparatus according to claim 2 , wherein the spoiler has a spoiler part that is oriented transversely or substantially perpendicularly to the face of the conveyor, and the spoiler also has a spoiler part oriented parallel or substantially parallel to the face.

4. The apparatus according to claim 1 , wherein only the downstream suction partition has the spoiler.

5. The apparatus according to claim 1 , wherein the spoiler is aligned or angled to a side of the respective suction partition facing away from a center of the main extraction area or the spoiler is aligned or angled toward a center of the main extraction area.

6. The apparatus according to claim 1 , wherein
at least two of the spinnerets are provided spaced in the direction above the conveyor for spinning the filaments and therefore being upstream and downstream spinnerets, respective upstream and downstream main suction areas in which air or process air is sucked through the conveyor being associated with the respective upstream and downstream spinnerets, each of these main suction areas being delimited by two respective upstream and downstream suction partitions, at least one suction partition of each main suction area having a spoiler,
the spoiler of the upstream suction area is aligned or angled to the side of the respective suction partition facing away from the center of the upstream suction area, and
the spoiler of the downstream main extraction area is aligned or angled toward the center of the downstream main suction area.

7. The apparatus according to claim 1 , further comprising:
a cooler downstream of the spinneret and above the conveyor;
a stretcher downstream of the cooler and above the conveyor; and
a diffuser downstream of the stretcher and above the conveyor.

8. The apparatus according to claim 7 , wherein the cooler and the stretcher form a subassembly closed to the admission of outside air other than cooling air in the cooler.

9. The apparatus according to claim 7 , wherein the diffuser has relative to the direction upstream and downstream diffuser walls having respective lower diverging diffuser wall sections that are asymmetrical relative to a center plane of the diffuser or of the apparatus with the upstream diffuser wall section forming a smaller angle with the center plane of the diffuser or of the apparatus than the downstream diffuser wall section.

10. The apparatus according to claim 7 , wherein the diffuser has relative to the direction upstream and downstream diffuser walls forming respective upstream and downstream secondary air inlet gaps at an upper end of the diffuser such that lower secondary air streams enter through the secondary air inlet gaps.

11. The apparatus according to claim 1 , wherein
the extractor has second upstream and downstream partition walls spaced in the direction from the main extraction area and forming a second extraction area where air or process air is drawn through the conveyor,
when the second extraction area is downstream of the main extraction area, the extractor draws air through it at extraction speed v 2 lower than an extraction speed V H in the main extraction area, and/or
when the second extraction area is upstream of the main extraction area, the extractor draws air through it at an extraction speed lower V v than the extraction speed in the main extraction area.

12. The apparatus according to claim 11 , wherein the downstream partition wall of the main extraction area and the second downstream partition wall of the second extraction area are spaced differently from the face of the conveyor such that there is a continuous uniform transition between the extraction speed v H of the main extraction area and the extraction speed v 2 of the second extraction area.

13. The apparatus according to claim 11 , further comprising:
a preconsolidater for preconsolidating the nonwoven fabric on or above the second extraction area.

14. The apparatus according to claim 13 , wherein a spacing in the direction between a center plane of the diffuser and the preconsolidater is 100 mm to 1000 mm.

15. A method of making a nonwoven fabric, the method comprising the steps of:
displacing an air-permeable conveyor belt in a horizontal travel direction;
delimiting a main extraction area below the conveyor belt by, relative to the direction, a downstream suction partition and by an upstream suction partition;
spinning filaments and depositing the spun filaments on an air-permeable conveyor belt at the main extraction area to form a nonwoven web;
delimiting below the conveyor belt a second extraction area spaced upstream or downstream from the main extraction area;
drawing air through the belt at the main extraction area at a greater extraction speed in the main extraction area than in the second extraction area, the extraction speed in the main extraction area being 1.5 to 4 times greater than the extraction speed in the second extraction area; and
when the second extraction area is upstream of the main extraction area, spacing an upper end of the upstream suction partition below the belt or, when the second extraction area is downstream of the main section area, spacing an upper end of the downstream suction partition below the belt such that the extraction speed of the air flow through the belt decreases uniformly between the main extraction area and the second extraction area.

16. The method according to claim 15 , wherein the filaments are continuous multicomponent filaments.

17. The method according to claim 15 , wherein a change in the extraction speed between the speed in the main extraction area and the speed in the second extraction area ha

Assignees

• Wagner Tobias
• Sommer Sebastian
• Bohl Patrick
• Roesner Andreas
• Geus Hans Georg
• Reifenhaeuser Masch

Inventors

• Wagner Tobias
• Sommer Sebastian
• Bohl Patrick
• Roesner Andreas
• Geus Hans-Georg

Classifications

• D04H3/002 Primary

  Inorganic yarns or filaments · CPC title

• D10B2331/04

  polyesters, e.g. polyethylene terephthalate [PET] · CPC title

• D04H1/435

  Polyesters · CPC title

• D01G25/00

  Lap-forming devices not integral with machines specified above (forming mats or batts of continuous filaments for non-woven fabrics D04H) · CPC title

• D04H3/02 Primary

  characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments · CPC title