Page 146 - CTS - Sewing Technology - TP - Volume - 2-0

SEWING TECHNOLOGY - CITS

17 Needle Lines
Needle lines appear in weft knit fabrics, and appear as prominent vertical streaks or lines in the fabric.

Causes
Defective needles are a direct cause for needle lines. Needle latches, hooks or stems might be: (Fig 17)
• Mixed
• New
• Dirty or contaminated with lint

• Bent
• Worn
Prevention: If needle lines occur individually, you’ll likely only need to trace the needle line to the associated
defective needle and replace it to prevent further needle lines. If needle lines appear in a band, you’ll likely need
to replace multiple defective needles.
An improper dial or cylinder condition with the machine might also cause needle lines. Verify that your supplier
has established and maintained proper maintenance and cleaning policies to prevent future issues with needles
and equipment.
18 Coarse Pick
A coarse pick is where the filling yarn used in the fabric is unusually large in diameter. (Fig 18)

Fig 17 Fig 18

This defect is also known as coarse filling or thick filling.
Coarse pick is usually classified as a major defect during fabric inspection.
Causes and Prevention

Probable causes for coarse pick include:
• Lashing of broken end with adjoining end at roving frame
• Disturbed weight of back-top rollers at roving frame and ring frame cause the material to slip under the back-
top roller and crease a coarse yarn
19 Coarse End
Coarse end appears in fabric with warp yarn. (Fig 19)

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CITS : Apparel - Sewing Technology - Exercise 30 CITS : Apparel - Sewing Technology - Exercise 30