Features of Warp Knitting Structure

1. The introduction of warp knitting structure

The warp knitting structure is gradually built up from row after row of intermeshing loops. The newly fed yarn is converted into a new loop in each hook. Then, the needle first passes the new loop end through the old (fabric) loop, which is retained from the previous knitting cycle. At the same time, the needles are released (discarded or knocked out) so that their heads hang over the feet of the new coils, which remain in the hooks of the needles. Thus, a viscous knitted stitch structure is created by the combination of intermeshing needle loops and yarns passing from needle loop to needle loop.

2. The difference between warp knitting and weft knitting

The characteristic feature of the warp knitting structure is its interwoven loops. Two basic types of knitted fabrics can be defined depending on the approximate direction of travel of the looped threads in the fabric. In weft knitting, the threads run laterally and the loops are formed from a single weft thread. In warp knitting, the direction of the stitches is warp, and all the stitches that make up a horizontal row are formed at the same time. Simple weft and warp knitted fabrics provide all-round extensibility and are therefore suitable for deep draw forming techniques. Directional stability can be established by adding inlaid (non-knitted) yarn in the desired direction.

The warp knitting structure consists of interlocking loops of yarn with an anisotropic structure. The properties of a knitted fabric differ from those of a woven construction because the yarns are not oriented in any direction and the yarn direction is constantly changing. The yarn loops can move with each other in the structure, and the knitted fabric is elastic and easy to set. The knotting lines of warp and weft knitted fabrics are perpendicular to each other. Compared to weft knitted yarns, warp knitted yarns bend more from the weaving direction, resulting in reduced yarn flow, which increases the stability of the warp knitting structure.

High yield before tearing is a characteristic of warp knitting structures, as the yarns in the structure slide due to strain. warp knitting structures also have higher burst strength, and their yarn density is generally lower than that of woven structures. This results in higher porosity and lower thickness and compressive strength. In general, knitted fabrics have a high degree of conformability, they are able to create smooth and even contact on uneven anatomy. Additionally, warp knitting structures can be used as filling cavities as they can be compressed and easily inserted into small cavities.

Using knitted fabrics, both flat and tubular structures are possible. It is also possible to make holes in the warp knitting structure, which increases the breathability of the knitted fabric. The high surface area and open-cell structure create a high ingrowth potential, and the properties of the knitted spacer structure are determined by the characteristics of the surface knitted fabric and the nature of the yarns in the gaps. Surface knitting adds elasticity and permeability to the structure.