Yarn Faults and it's Characteristic

Introduction of Yarn Faults

Card sliver contain 20,000 to 40,000 fiber in its cross-section and 40 to 1000 fiber at the stage of spinning a yarn. Some random variation mass/yarn thickness & mass variation or portion in the yarn are called yarn fault.

A portion in yarn is designated as a yarn faults it

• It can hamper quality of fabric production from it or
• It may cause a break in the subsequent process.
• It may hamper quality of fabric produced as well as cause a break in the subsequent process.

SLUB

• Slub are fish shaped thick place 1-4 on long and about 5-8 times larger than the average yarn diameter thick portion.
• The fiber mass of the slack from an integral part the yarn but has less twist in it because twist tent to flow less in thick portion than in thinner portion.
• Slub are formed due to lack of individuation in carding.
• The loose lint i.e. fiber mass flying here and there in spinning department may adhere to yarn during spinning & twisted with yarn.

CRACKER’S

• Crackers are coil like places produce in the yarn having man-made staple fiber as a component.
• The faults is generated when a fiber is not cut properly during it manufacture and is longer. Such fiber gets stretched in drafting zone and is crackers are produced when the yarn is stretched at this fault, the  thick coil like fault get straightened and longer fiber break producing a cracking sound.

SPINNER’S DOUBLE

• Spinner double consist of the portion in yarn where it become twice coarser and continues over long length & mass get double.
• When two single yarn are twisted to from a ply yarn, if one of them carried a portion with spinners double giving a crock screw appearance to ply yarn.
• The causes of spinner double is going of broken strand on flyer frames with adjacent running roving and twisting with it.

BAD PIECING

• Piecing in ring frame is the process of joining the yarn from ring fame bobbin with the drafted strand coming out of front roller.
• If the piecing id done carelessly, a longer length of drafted roving overlap with yarn end resulting in a thick place with bad appearance called piecing.

DOUBLE GATTING

• It is bad practice in which at yarn break instead of stopping bobbin and taking end from it, he puts a fresh length of yarn and wind it on rotating bobbin and then pieces it.
• This causes discontinuity in yarn and so, causes stop in winding and increases yarn waste.

SLOUGH OFF

• It is a fault in winding package in which coils of yarn slip off from improperly built ring frame bobbin during unwinding. These slough May from a three strand loop and pass on to the winding package.

REF: - fundamentals of yarn winding by Milind Koranne (Woodhead Publishing India in textile)

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