How is cotton made into knit fabric?

Transforming raw cotton into knit fabric is a multi-stage industrial process that moves from spinning (fiber to yarn) to knitting (yarn to fabric) and finally finishing (wet processing).¹

For a manufacturer, understanding these stages is critical because quality defects (like torque/spirality or pilling) often originate in the early spinning stages, not just the knitting stage.

Here is the technical breakdown of the process.

Phase 1: Yarn Production (Spinning)

Before knitting can begin, the raw cotton bolls must be converted into a continuous thread.

1. Ginning & Cleaning: The cotton is separated from seeds and trash.² The fibers are then pressed into bales.

2. Carding (The Alignment): The raw fibers pass through “cards” (wire-toothed rollers) that separate and align the fibers into a thin web, which is condensed into a thick rope called a “sliver.”

   • Quality Check: Carded vs. Combed. For high-quality knit fabric, the sliver is “combed” to remove short fibers.³ This reduces pilling in the final fabric.

3. Spinning: The sliver is drawn out (thinned) and twisted to add tensile strength.⁴

   • Ring Spun: The industry standard for premium softness. It creates a smoother, stronger yarn.⁵

   • Open End: A faster, cheaper method that creates a coarser, “crispier” yarn (often used for cheaper streetwear)

Phase 2: The Knitting Process (Fabric Formation)

Unlike weaving (which interlaces two sets of yarns at right angles), knitting involves interlooping a single yarn system.⁶

The Machine: Circular Knitting

Most commercial “knit fabric” (jersey, French terry, pique) is produced on Circular Knitting Machines.7

1. Creeling: Hundreds of cones of cotton yarn are loaded onto a rack (creel) above the machine. The yarn is fed down into the knitting cylinder.

2. Loop Formation: The machine cylinder rotates at high speed. Thousands of latch needles and sinkers work in cam tracks to catch the yarn and pull it through the previous loop.⁸

   • Weft Knitting: The yarn runs horizontally (in a spiral) around the fabric tube

3. Take-Down: The newly formed fabric is pulled down inside the cylinder. It is essentially a giant seamless tube.

4. The Output: The result is “Greige Goods” (pronounced “grey”). This is raw, unbleached, yellowish fabric that feels harsh and contains natural cotton oils and waxes.

Phase 3: Wet Processing (Dyeing & Finishing)

The greige fabric is not yet usable. It must be processed to become stable clothing material.

1. Scouring & Bleaching: The fabric is washed in hot chemical baths to remove natural waxes, seeds, and oils. This makes the cotton absorbent (hydrophilic) so it can take dye.⁹

2. Dyeing: The fabric is dyed in large pressurized vats (jets) or continuous ranges. This requires precise temperature control to ensure color fastness.

3. Slitting: The tubular fabric is sliced open (unless it is for seamless body-size garments) to create a flat open-width fabric.

4. Stentering (Heat Setting): The wet fabric is stretched onto a frame (stenter) and passed through a drying oven.¹⁰ This sets the width and stabilizes the fabric.

5. Compacting (Sanforizing): This is the most critical step for shrinkage control. The fabric is physically compressed (overfed) between steam rollers to force the loops to relax and shrink before the garment is cut. Without this step, a cotton t-shirt would shrink 10-15% in the wash; with it, shrinkage is reduced to <5%.

Summary: The “Quality” Checklist

If you are evaluating knit fabric suppliers, ask about:

1. Combed Yarn: Ensures smoothness and low pilling.¹¹

2. Compacting: Ensures the garment won’t shrink significantly.

3. Torque (Spirality): A common defect in single jersey where the side seams twist to the front. This is caused by high-twist yarn and poor finishing.