Knitting is a fundamental method of fabric production, distinct from weaving, where fabrics are made by interlocking loops of yarn. Knitted fabrics are generally classified into two main types based on the direction and method of loop formation: warp knitting and weft knitting. Both processes yield fabrics with unique structures and properties that suit various applications in apparel, technical textiles, and industrial uses.
1. Introduction to Knitting
Knitting involves the formation of interconnected loops of yarn to produce fabric. Unlike woven fabrics, which are constructed by interlacing warp and weft yarns at right angles, knitted fabrics are formed by continuous loops running either vertically or horizontally.
Weft knitting: Loops are formed in a horizontal (weft) direction.
Warp knitting: Loops are formed in a vertical (warp) direction.
2. Weft Knitted Fabrics
2.1 Definition
Weft knitting creates fabric by feeding yarn horizontally across the width of the fabric, where loops are formed sequentially in rows. The yarn travels back and forth across the fabric width, looping through previously formed loops.
2.2 Manufacturing Process
Typically produced on circular or flat-bed knitting machines.
The yarn runs from a spool and is fed across the machine needles.
Needles create loops, which interlock horizontally.
Common stitch types: knit stitch, purl stitch, rib stitch, and tuck stitch.
2.3 Fabric Structure
Loops interlinked horizontally.
The fabric has considerable stretch and elasticity, especially in the width direction.
Can be single jersey, rib, purl, or interlock fabric types depending on needle arrangements and stitch types.
2.4 Characteristics
High stretchability and elasticity.
Good recovery after stretching.
Comfortable and breathable.
Can unravel easily if cut because loops are interconnected horizontally.
Soft and flexible.
2.5 Applications
T-shirts, sweaters, underwear, hosiery, sportswear.
Fashion and casual wear due to softness and elasticity.
Home textiles such as blankets.
2.6 Advantages
Comfortable fit due to stretch.
Quick and economical production.
Versatile designs and patterns.
Breathable and flexible.
2.7 Disadvantages
Prone to laddering (runs) and unraveling.
Less dimensional stability compared to woven fabrics.
Weaker mechanical strength.
3. Warp Knitted Fabrics
3.1 Definition
Warp knitting forms fabric by interlocking loops vertically along the length (warp direction). Multiple yarns run parallel to the fabric length and interloop in a zig-zag pattern along the fabric’s warp.
3.2 Manufacturing Process
Produced on warp knitting machines such as tricot or raschel machines.
Multiple yarns are fed simultaneously from beams, each yarn forming loops on its own needle.
The loops interlock vertically, with each yarn producing a separate loop column.
The fabric does not unravel easily because of vertical interlooping.
3.3 Fabric Structure
Loops are formed vertically along the fabric length.
More stable and less stretchable in the width than weft knits.
Different machine types produce distinct fabrics:
Tricot knit: Smooth surface, used for lingerie and linings.
Raschel knit: Open, lace-like, or patterned, used for nets and lace.
3.4 Characteristics
Higher dimensional stability.
Resistant to runs and laddering.
Moderate stretch, mainly along the warp.
Stronger and more durable than weft knits.
Can be engineered for technical applications.
3.5 Applications
Sportswear and swimwear linings.
Lace, mesh, netting, and industrial textiles.
Automotive textiles, upholstery.
Medical textiles such as bandages.
3.6 Advantages
Does not unravel easily.
Higher mechanical strength.
Dimensional stability.
Can produce large-area fabrics without seams.
Versatile for producing technical textiles.
3.7 Disadvantages
Generally less stretchable than weft knits.
More complex and expensive machinery.
Less comfortable for some apparel due to lower elasticity.
4. Comparison Between Warp and Weft Knitting
Feature Weft Knitting Warp Knitting
Direction of loops Horizontal (across fabric width) Vertical (along fabric length)
Yarn feeding Single yarn back-and-forth Multiple yarns simultaneously
Stretchability High (especially across width) Moderate, mainly along warp
Dimensional stability Lower Higher
Tendency to unravel High (runs possible) Low (hard to unravel)
Fabric examples Jersey, rib, interlock Tricot, raschel
Typical applications Casual wear, hosiery, sportswear Technical textiles, lace, nets
Production speed Generally faster, simpler More complex, slower
5. Conclusion
Both warp and weft knitted fabrics hold essential places in textile production, each with unique structural properties suited to different end uses. Weft knitting excels in stretch, comfort, and versatility, making it ideal for everyday apparel. Warp knitting offers durability, stability, and technical functionality, preferred in industrial and specialty textiles.
Understanding these differences helps manufacturers, designers, and consumers select the right fabric for performance, comfort, and aesthetic requirements.
