Textile fabric having randomly arranged yarn segments of variable texture and crystalline orientation
View Patent ↗A knit fabric wherein at least a portion of the interconnected yarn loops are formed from segments of a common yarn of multi-filament construction. In the fabric the common yarn includes a first group of yarn segments having a first average cross-sectional filament area and at least a second group of yarn segments having a second average cross-sectional filament area. The second average cross-sectional filament area is greater than the first average cross-sectional filament area. The average level of crystalline orientation of the first group of yarn segments is greater than the average level of crystalline orientation of the second group of yarn segments.
1. A knit fabric comprising a face portion including a plurality of interconnected yarn loops, wherein at least a portion of the interconnected yarn loops are formed from segments of a common yarn of multi-filament construction and wherein in the fabric the common yarn comprises a first group of yarn segments having a first average cross-sectional filament area and at least a second group of yarn segments having a second average cross-sectional filament area which is greater than the first average cross-sectional filament area, and wherein in the fabric the average level of crystalline orientation of the first group of yarn segments as measured by the Herman Orientation Function is at least 5% greater than the average level of crystalline orientation of the second group of yarn segments.
2. The invention as recited in claim 1 , wherein the average level of crystalline orientation of the first group of yarn segments as measured by the Herman Orientation Function is at least 6% greater than the average level of crystalline orientation of the second group of yarn segments.
3. The invention as recited in claim 1 , wherein the average level of crystalline orientation of the first group of yarn segments as measured by the Herman Orientation Function is at least 7% greater than the average level of crystalline orientation of the second group of yarn segments.
4. The invention as recited in claim 1 , wherein the average level of crystalline orientation of the first group of yarn segments as measured by the Herman Orientation Function is at least 8% greater than the average level of crystalline orientation of the second group of yarn segments.
5. The invention as recited in claim 1 , wherein the average level of crystalline orientation of the first group of yarn segments as measured by the Herman Orientation Function is at least 9% greater than the average level of crystalline orientation of the second group of yarn segments.
6. The invention as recited in claim 1 , wherein the fabric is a Tricot knit fabric.
7. The invention as recited in claim 1 , wherein the fabric is a Raschel knit fabric.
8. The invention as recited in claim 1 , wherein the common yarn is a multi-filament PET polyester yarn.
9. The invention as recited in claim 1 , wherein in the fabric the first group of yarn segments of the common yarn comprises a plurality of substantially smooth parallel yarn filaments and the second group of yarn segments of the common yarn is characterized by a substantially non-parallel arrangement of crimped yarn filaments.
10. The invention as recited in claim 1 , wherein in the fabric the second average cross-sectional filament area is at least 1.56 times the first average cross-sectional filament diameter.
11. The invention as recited in claim 10 , wherein in the fabric at least a portion of the yarn filaments in the second group of yarn segments are characterized by a cross-sectional area which is at least 4 times the cross-sectional area of one or more yarn filaments in the first group of yarn segments.
12. A knit fabric comprising a face portion including a plurality of interconnected yarn loops, wherein at least a portion of the interconnected yarn loops are formed from segments of a common yarn of multi-filament construction and wherein in the fabric the common yarn comprises a first group of yarn segments having a first average cross-sectional filament area and at least a second group of yarn segments having a second average cross-sectional filament area which is at least 1.56 times the first average cross-sectional filament area, and wherein the average level of crystalline orientation of the first group of yarn segments as measured by the Herman Orientation Function is at least 10% greater than the average level of crystalline orientation the second group of yarn segments.
13. The invention as recited in claim 12 , wherein the fabric is a Tricot knit fabric.
14. The invention as recited in claim 12 , wherein the fabric is a Raschel knit fabric.
15. The invention as recited in claim 12 , wherein the common yarn is a multi-filament PET polyester yarn.
16. The invention as recited in claim 12 , wherein in the fabric the first group of yarn segments of the common yarn comprises a plurality of substantially smooth parallel yarn filaments and the second group of yarn segments of the common yarn is characterized by a substantially non-parallel arrangement of crimped yarn filaments.
17. The invention as recited in claim 12 , wherein in the fabric at least a portion of the yarn filaments in the second group of yarn segments are characterized by a cross sectional area which is at least four times the cross sectional area of one or more yarn filaments in the first group of yarn segments.
18. A method of forming a knit fabric comprising a face portion including a plurality of interconnected yarn loops, wherein at least a portion of the interconnected yarn loops are formed from segments of a common yarn of multi-filament construction and wherein in the fabric the common yarn comprises a first group of yarn segments having a first average cross-sectional filament area and at least a second group of yarn segments having a second average cross-sectional filament area which is greater than the first average cross-sectional filament area, the method comprising the steps of:
underdrawing a partially oriented multi-filament yarn across a heat source at a rate such that portions of the yarn undergo substantially complete heat treatment and other portions do not undergo substantially complete heat treatment;
forming the underdrawn yarn into the knit fabric such that portions of the underdrawn yarn are disposed across the face portion of the fabric; and
heating the knit fabric such that portions of the yarn which did not undergo substantially complete heat treatment during the underdrawing undergo selective shrinkage and self texturing.
19. The invention as recited in claim 18 , wherein the fabric is a Tricot knit fabric.
20. The invention as recited in claim 18 , wherein the fabric is a Raschel knit fabric.
21. The invention as recited in claim 18 , wherein the common yarn is a multi-filament PET polyester yarn.
22. The invention as recited in claim 18 , wherein in the fabric the first group of yarn segments of the common yarn comprises a plurality of substantially smooth yarn filaments and the second group of yarn segments of the common yarn is characterized by a substantially non-parallel arrangement of crimped yarn filaments.
23. The invention as recited in claim 18 , wherein in the fabric the second average cross-sectional filament area is at least 1.56 times the first average cross-sectional filament area.
24. The invention as recited in claim 23 , wherein in the fabric at least a portion of the yarn filaments in the second group of yarn segments are characterized by a cross sectional area which is at least four times the cross sectional area of one or more yarn filaments in the first group of yarn segments.