Headgear comprising spacer fabric

1. A positioning and stabilising structure for a patient interface for delivery of a supply of pressurized air or breathable gas to a patient's airways, the positioning and stabilising structure comprising:

a first spacer fabric section including:

a first inner fabric layer;

a first outer fabric layer;

a first central fabric layer between the first inner fabric layer and the first outer fabric layer; and

a connector fabric layer on the first outer fabric layer such that the first outer fabric layer is between the first central fabric layer and the connector fabric layer,

wherein the first central fabric layer, the first inner fabric and the first outer fabric are warp/weft knitted together, and

wherein the connector fabric layer comprises unbroken loops and is configured to fasten to hooks of a hook and loop fastener to enable length adjustment of the positioning and stabilising structure;

a second spacer fabric section joined to the first spacer fabric section, the second spacer fabric section including:

a second inner fabric layer;

a second outer fabric layer;

a second central fabric layer between the second inner fabric layer and the second outer fabric layer,

wherein the second spacer fabric section does not include a layer of unbroken loops, and

wherein the second central fabric layer, the second inner fabric layer and the second outer fabric layer are warp/weft knitted together, and

wherein the first spacer fabric section has 6% to 10% elongation when a 10 Newtons force is applied, and

wherein the second spacer fabric section has 10% to 20% elongation when a 10 Newtons force is applied.

2. The positioning and stabilising structure according to claim 1 , wherein the first central fabric layer, the first inner fabric layer and the first outer fabric layer form a strap of the positioning and stabilising structure.

3. The positioning and stabilising structure according to claim 2 , wherein the strap is porous.

4. The positioning and stabilising structure according to claim 2 , wherein the strap is elastic at least along a length of the strap.

5. The positioning and stabilising structure according to claim 2 , wherein the strap does not comprise foam.

6. The positioning and stabilising structure according to claim 1 , wherein the first inner layer is hydrophilic.

7. The positioning and stabilising structure according to claim 1 , wherein the first outer layer is hygroscopic.

8. The positioning and stabilising structure according to claim 1 , wherein the first inner fabric layer, the first outer fabric layer and the first central fabric layer are made by warp knitting.

9. The positioning and stabilising structure according to claim 1 , wherein the first central fabric layer is made by a 3D knitting machine.

10. The positioning and stabilising structure according to claim 1 , wherein the first spacer fabric section is 2.0 mm to 6.0 mm thick.

11. The positioning and stabilising structure according to claim 10 , wherein the first spacer fabric section is 6.0 mm thick.

12. The positioning and stabilising structure according to claim 10 , wherein the first spacer fabric section is 4.0 mm thick.

13. The positioning and stabilising structure according to claim 1 , wherein the first central fabric layer, the first inner fabric layer and the first outer fabric layer together have a compression strength that is 15 kilopascals to 25 kilopascals.

14. The positioning and stabilising structure according to claim 1 , wherein the first spacer fabric section has a thickness of 2.0 mm to 4.0 mm, and the second spacer fabric section has a thickness of 4.0 mm to 6.0 mm.

15. The positioning and stabilising structure according to claim 1 , wherein the second spacer fabric section has 10% to 15% elongation when a 10 Newtons force is applied.

16. The positioning and stabilising structure according to claim 1 , wherein the first central fabric layer is a yarn layer.

17. The positioning and stabilising structure according to claim 16 , wherein yarn of the yarn layer comprises cotton.

18. The positioning and stabilising structure according to claim 16 , wherein yarn of the yarn layer comprises polyester.