Woven fabric:
Woven fabrics are manufactured by interlacing two sets of yarn perpendicular (0°/90°) to each other by crossing each over and under the other in alternating fashion (Figure 1). The yarns along the fabric length are termed warp yarns, and those along its width are termed weft or fill yarns. In woven fabrics, the yarns are connected together by friction at the joint points, so a sufficient number of connection points are needed to hold the fabric together in a stable manner. Thus, these fabrics are relatively dense so that the yarns will not come apart during service, and therefore, they cannot be in a mesh form. In woven fabric, due to the method of connection, that is, passing the warp and fill yarns under and over each other, both yarns in both directions are in crimp shapes. A woven fabric which is used in clothing and garments or for decoration and covering purposes. Woven fabric is also ideal as upholstery fabric.
Figure 1: Woven fabric, plain weave structure
Knitted fabric: The knitted fabric structure is produced by interlooping the yarns, which in the knitted fabrics is manufactured using a set of closely spaced needles that pull the yarns to form the loops (stitches) (Figure 3). This type of fabric can be produced using either flat bed or circular knitting machines. The vertical column of loops along the length of the fabric is called ‘wale’ and the horizontal row of loops along the width of the fabric is called ‘course’. The respective directions are called ‘wale direction’ and ‘course direction’. A single knit loop comprises a head loop, two side limbs and two sinker loops as shown in Figure 2.
Figure 2: Schematic representation of various portions of a typical knit loop
The two main knitted fabric production methods are weft knitting (Figure 3a) and warp knitting (Figure 3b).
Weft knitted fabrics are very common in clothing applications and used less frequently for reinforcing applications, as the ultimate fabric shape ends up with high curvature. In these cases, the yarn forming the loops runs in the weft (cross-machine) direction of the fabric, passing from one loop to the next. Similar to the method used in hand knitting, the whole fabric structure can be produced from a single yarn. Moreover, because they possess low dimensional stability, weft-knitted fabrics are easily stretched.
In warp knitted fabrics, the yarns that make the loops run in the fabric’s warp direction (lengthwise, in the machine direction). To produce the whole fabric structure, multiple yarns are needed. The method involves connecting a set of warp yarns together by loops that shift in a zigzag manner along the fabric length from one column to another, alternately, depending on the fabric geometry required for the intended end use. Compared to weft-knitted fabrics, these fabrics exhibit much higher structural stability. Due to the strong, loop-based connection at the fabric joints, warp-knitted fabrics can be produced in a wide range of mesh openings and mesh structures.
Knitted fabric has useful properties that make it suitable for a range of garments including tights, gloves, underwear and other close fitting garments. The loop structure of knitted fabric stretches and moulds to fit body shapes. The air trapped by the loops keeps the wearer warm.
Difference between of Woven and Knitted Fabric:
We already know that the woven fabrics produced by interlacement of two sets of yarn and knitted fabrics formed by the interloping of yarn, have unique characteristics and have their own end-user applications. In most of the cases, both fabrics can be a substitute for each other and selection of the right fabric can possibly meet the requirement of the wearer in a better way. Below Table presents a difference between woven and knitted fabric.
Table: Comparison between woven and knitted fabrics, machine and process.
Parameter
Woven Fabric
Knitted Fabric
Process requirement
Fabric requires two sets of yarn for interlacement, one is warp and other is weft yarn.
Fabric can be produced from a single end or a cone of a yarn in case of weft knitting.
Fabric construction
Woven fabric is at least made up of two separate groups of yarns (warp and weft).
Knitted fabric can be made up of one yarn only.
Dimensional stability
More stable
Less stable. Careful handling is required for knitted fabric during wet processing and stitching.
Thickness and handle
Woven fabric is thinner and easy to handle.
Knitted fabric is much thicker and softer than woven fabric as it has a complicated 3-dimensional structure.
Comfort
Less comfort due to tight structure
More open spaces that give better air permeability and moisture management.
Fabric Density and Cover
Generally, woven fabric can be produced in extremely tight and higher coverage when compared with knitted fabric.
Generally, knitted fabric is looser in structure.
Shape retention
Woven garments retain their own shape
Knitted garments get the shape of the wearer’s body, hence, best for undergarments.
Elasticity
Woven fabric has poor extensibility.
Knitted fabric has higher extensibility and instant recovery ability than woven fabric. up of one yarn only.
Fabric can be produced from yarn package. So process route is very short.
Conversion cost
Conversion from yarn to fabric involves various processes. The conversion cost is higher.
Conversion requires no preparation, so conversion cost is low.
Fabric Application
However, if fabric requires good dimensional stability, high tenacity like trousers, jackets, canvas, woven fabric is the right choice.
The popularity of sportswear, hosiery, underwear and high fashion knitwear make a strong demand on knitted fabric every year which cannot be replaced by woven fabric.
Environmental effect
Preparation includes a sizing of warp yarn that has to remove before color application, that may cause environmental pollution.
The yarn is just waxed. No need to size the yarn, so development cause less environmental hazards.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
