Garment with higher coefficient of friction when stretched

1. A garment comprising:

a fabric portion having an inner face that is configured to contact a wearer's body while the garment is worn;

the fabric portion being configured to be stretched while the garment is worn on the wearer's body;

wherein a coefficient of friction of the inner face of the fabric portion is greater while the fabric portion is stretched on the wearer's body than while the fabric portion is not stretched; and

wherein the fabric portion comprises an intrinsically sticky yarn that is knitted with longer loops on a background of shorter loops, and the intrinsically sticky yarn is raised from the background when the fabric portion is stretched.

2. The garment of claim 1 , wherein the fabric portion further comprises a non-intrinsically sticky yarn that is configured to at least partially cover the intrinsically sticky yarn;

the non-intrinsically sticky yarn covering the intrinsically sticky yarn more while the fabric portion is not stretched than while the fabric portion is stretched.

3. The garment of claim 1 , wherein the intrinsically sticky yarn comprises polyurethane.

4. The garment of claim 3 , wherein the intrinsically sticky yarn is spandex yarn.

5. The garment of claim 4 , wherein the spandex yarn is 40 Denier monofilament.

6. The garment of claim 1 , wherein the fabric portion comprises a knitted fabric, a woven fabric, a non-woven fabric, a lace fabric, and/or an elastic band.

7. The garment of claim 1 , wherein the fabric portion is a warp knitted fabric.

8. The garment of claim 1 , wherein the garment is a brassiere, and the fabric portion is used in a wing, a cup, and/or a strap of the brassiere.

9. A garment comprising:

a garment portion having an inner face that is configured to contact a wearer's body while the garment is worn on the wearer's body;

wherein the inner face of the garment portion has an unstretched coefficient of friction while no tensile force is applied to the garment portion, the inner face of the garment portion has a stretched coefficient of friction while a tensile force is applied to the garment portion, and the stretched coefficient of friction is greater than the unstretched coefficient of friction; and

wherein the garment portion comprises an intrinsically sticky yarn that is knitted with longer loops on a background of shorter loops, and the intrinsically sticky yarn is raised from the background while tensile force is applied to the garment portion.

10. The garment of claim 9 , wherein the garment is configured such that tensile force is applied to the garment portion while the garment is worn on the wearer's body.

11. The garment of claim 9 , wherein the garment portion further comprises a non-intrinsically sticky yarn that is configured to at least partially cover the intrinsically sticky yarn;

the non-intrinsically sticky yarn covering the intrinsically sticky yarn more while no tensile force is applied to the garment portion than while tensile force is applied to the garment portion.

12. The garment of claim 9 , wherein the intrinsically sticky yarn comprises polyurethane.

13. The garment of claim 9 , wherein the garment portion comprises a knitted fabric, a woven fabric, a non-woven fabric, a lace fabric, and/or an elastic band.

14. The garment of claim 9 , wherein the garment portion is made of a warp knitted fabric.

15. The garment of claim 14 , wherein the stretched coefficient of friction is greater than the unstretched coefficient of friction while tensile force is applied in a warp direction of the warp knitted fabric and while tensile force is applied in a weft direction of the warp knitted fabric.

16. The garment of claim 9 , wherein the garment is a brassiere, and the garment portion is used in a wing, a cup, and/or a strap of the brassiere.