Understanding Weft Knit Fabric Thickness

The thickness of a weft knitted fabric is influenced by its structure, yarn properties, and density. For fabrics produced with the same mass per unit area (e.g., grams per square meter) using identical yarns, the structure that traps more air will generally result in higher thickness.

Comparing Knit Structures for Thickness

Different weft knit structures have varying degrees of compactness and loop formation, affecting their bulkiness:

• Plain Knit (Jersey): The simplest structure, offering minimal bulk and less trapped air.
• Rib Knit: Alternating wales of face and back loops create a more elastic fabric, but often still relatively compact.
• Purl Knit: Features alternating courses of face and back loops, resulting in a reversible fabric that can be thicker than plain knit but is often denser than interlock.
• Interlock Knit: This is a double-knit structure, essentially two separate plain jersey fabrics knitted together so that the wales of one needle-bed directly interlock with the wales of the other. This construction creates a thicker, more stable fabric with significant trapped air between the two layers.

Interlock Structure and Maximum Thickness

Comparing these structures at the same mass per unit area:

• The Interlock structure provides the highest thickness.
• This is because its double-knit nature creates a bulkier fabric profile compared to single-knit structures like Plain, Rib, or Purl. The interlocking mechanism allows for more air entrapment within the fabric layers, increasing its overall thickness.

Therefore, the Interlock structure yields the highest thickness under the given conditions.