In woven fabric construction; two types of yarn use, they are warp and weft yarn. It is important to know the number of yarn in a woven fabric. To know that, warp and weft yarn is calculate by an EPI and PPI test. For calculating that, we have to identify the warp and weft yarn in a woven fabric. For this reason, I have given some identifying sign for identify the warp and weft yarn of a woven fabric.
Identification of warp and weft of a fabric: Warp and weft yarn has some characteristics by which way we can identify the warp and weft yarn. Followings are the main characteristics of warp and weft yarn of a fabric.
- The selvedge direction is warp direction.
- In most cases, EPI/EPCm is more than PPI/PPCm.
- Normally warp count is finer than weft count.
- Warp yarn is more twisted than weft yarn.
- If any yarn contains any size particle then the sized yarn is warp yarn.
- Normally stripe effect is done in warp direction (both woven and printed fabric).
- Warp yarns are relatively hairy yarn.
- Warp crimp is expected to be less than weft crimp due to high warp tension on the loom.
In woven fabric manufacturing process, warp and weft yarn is used for interlacement for producing woven fabric. After producing a woven fabric, we have to identify the warp and weft yarn.
I think above characteristics will help you to identify the warp and weft direction of a fabric.