Defects in Knitted Fabrics

A line or design running at a slight angle across the knitted fabric.

Distortion in the knitted fabric caused by faulty take-up mechanism, making a line curve.

Vertical lines in the fabric due to variations in tightness or looseness of wales (knitting ridges).

An unknitted stitch, typically caused by improper yarn carrier setting or loose stitch knitting.

A row of dropped stitches in the knitted fabric.

Large holes in the fabric resulting from broken yarns or machine malfunctions during the knitting process.

Fabric falling out, often after a dropped stitch, caused by an empty needle removing the yarn.

A striped effect in the knitted fabric, with shaded edges, horizontal on weft knits and vertical on warp knits.

The tendency of knitted loops to bend over, causing wales to be diagonal instead of perpendicular to the courses.

Problems caused by spirality in knitted garments, such as seams shifting, pattern mismatch, and sewing difficulties.

A finishing process that corrects loop spirality by making wale lines perpendicular to the course lines. It involves techniques like resin treatment, heat, and steam.

The appearance of unwanted surface fibres, creating a fuzzier or hairier surface on a garment.

The gradual withdrawal of fibres from the surface layer of yarns (migration), caused by frictional forces during wear or abrasion.

Facing-up can occur throughout a garment or in specific areas, often caused by high abrasion forces.

Short or broken fibres are less anchored and migrate more easily, leading to increased facing-up.

Finer fibres tend to be shorter and migrate more easily, contributing to facing-up.

Spirality occurs when using an unbalanced yarn, where yarn twist is uneven. It can happen during knitting or after finishing.

Spirality is a common problem in single jersey knit fabrics as there is only one layer of knit. This affects both aesthetics and fabric functionality.

Spirality is less common in interlock and rib knits because the wales on both the face and back counterbalance each other, making the fabric more stable.

There's little to be done to fix spirality once it's in the fabric. The best solution is using balanced yarn with even twist.

Steam setting an unbalanced yarn while knitting on a single bed structure can sometimes help prevent spirality. It sets the yarn twist more firmly, making it less prone to skewing.

Certain yarns prone to spirality can be knitted in a rib structure. The skewing on both the front and back beds should cancel each other out, minimizing the effect.

The amount of twist in a yarn is important for knit fabric stability. Balanced yarn has even twist, making it less prone to spirality.

Cockling is a surface irregularity in knit fabrics caused by distorted loops twisting out of their normal symmetrical arrangement. It often appears in groups and creates a bumpy or uneven texture.

Woolen knitwear made with worsted yarns is particularly susceptible to cockling. This is because worsted yarns are not subjected to milling, a finishing process that helps to disguise imperfections by creating a fuzzy surface.

This type of cockling occurs where a rib knit structure meets a plain knit structure. It happens because the two structures have different relaxed widths, causing tension imbalances.

Panel-edge cockling arises when neighboring knit structures have different relaxed dimensions. This happens because loops near the edges are often stretched during shaping, causing contraction in nearby plain knit areas.

Random all-over cockling occurs when an unsuitable yarn is used. These yarns tend to create distorted loops throughout the fabric, often affecting rib/plain and panel edges as well.

There's a direct relationship between fiber diameter and cockling. Larger fibers lead to greater loop distortion and more cockling.

Package dyeing increases cockling because it sets the fibers and yarns in a more rigid state. This rigidity makes the fibers less flexible and more resistant to forming loops during knitting.

While yarn count has little effect, yarn twist regularity does influence cockling. Large variations in twist can lead to loop distortion and cockling.