Barre in Fabrics | Fabric Fault

In textile industry, one of the most common and perplexing quality control problems is barre (repetitive yarn direction streaks). The factors which can cause or contribute to barre are varied and diverse. Barre is defined as "unintentional, repetitive visual pattern of continuous bars or stripes usually parallel to the filling of woven fabric or to the courses of circular knit fabric."

Causes of Barre

Fibre properties:

• Fibre Micronaire variation
• Fibre color variation
• Improper mixing of cotton from different origin
• Improper mixing of cotton from different varieties
• Improper mixing of cotton grown in different seasons

Yarn properties:

• Yarn linear density variation
• Yarn twist variation
• Yarn hairiness variation
• Yarn package lot mixing
• Hard or soft winding of yarn package

knitting:

• Tight loops: This may take the form of a shaddow ( several courses involved) or a discreet line ( one course involved). It will normally show up as a dark or dense line or shaddow
• Slack loop: Similar to above, but it shows up as a sheer or light line.
• Improper stich length at a feed
• Improper tension at a feed
• Variation in fabric take-up from loose to tight
• Worn needles, which generaly produce length direction streaks
• Uneven cylinder height needles(wavy barre)

Weaving:

• Uneven warping tension
• Uneven take-up tension
• Uneven let-off motion
• Uneven tension on filling
• Scuffing or filling yarn on the beam
• Bent beam gudgeons