Faults In Ring Frame - Causes and Remedies


Ring frame yarn faults Causes and Remedies

Introduction:
Ring Spinning is the most widely used technology for manufacturing of yarn as it has various advantages over other spinning process. Fine varieties of yarn can be used using ring spinning machine. On Ring spinning machine the roving is attenuated by using drawing rollers then with the help of ring and traveller the yarn is wound on to the bobbin. It is very important to control the machine parameters in order to produce a good quality of ring spun yarn. In this article different yarn faults which produced during the ring spinning is explained along with their causes and remedies.

For producing high quality of yarn, it is necessary to follow quality standards according to the customer need and Market requirements:
  • For producing high quality yarn, there is need of high standard raw material hence 70-80% of basic yarn quality is decided by raw material.
  • Fibre length should be more than 28 mm, this fibre length effects on yarn strength and yarn uniformity. 
  • End breakage also depends upon fibre length. For better yarn quality fibre length should be more than 28 mm.
  • In the carding if wires are selected properly then 70% quality will be achieve in carding section.
  • Grinding of the flat tops should be done once in a 3 months for better yarn quality. 
  • Flat tops play a major role in reducing the neps.
  • Autoleveller setting in the card should be proper. 
  • Nominal draft should be correct.


POSSIBLE REASONS OF FAULT
  • Bad condition of carding, blow room, trash in yarn.
  • Fluffs foreign matters, dirty drafting zones, neps.
  • Ring front zone dirty, fly waste in trumpet.
  • Fibres damaged in process, spindles without aprons.
  • Fluff in travelers, unsuitable travelers, bad piecing.
  • Bad piecing in cans, sliver entanglements.
  • Gauge problem of roving frame, spacer problems.
  • Bad piecing in ring yarns, roving and back process.
  • Mostly eccentric bobbins on roving and ring frames.


Yarn faults
  • Slubs
  • Crackers
  • Spinner double
  • Thick thin places
  • Neps
  • Spun in fly
  • Hairiness


Slubs:-
  • Slubs are fish shaped thick places varying from 1cm to 4cm long.
  • It is about 5-8 time larger in diameter than the average yarn diameter at the thickest portion.
  • Slubs has less twist.
  • The strength of the yarn at the slub is sufficient therefore, it passes through ring and traveler gap and thus on to the bobbin.
  • These slubs can become a basis of warp breaks in the loom shed or spoil the appearance of superior quality fabrics.


Causes of slubs are:-
  • The slubs are forms due to poor individualization of fibers at the card.
  • Also the slubs are formed at ring frame drafting due to lack of adequate fibre control.
  • Due to poor drafting.


Remedies on slubs are:-
  • In carding, the conditions of wire points should be improved and uniform setting should be required.
  • In ring frame, uniformity of pressure on all top rollers and a good condition of the same is important.
  • Good condition of aprons and apron spacers are important.


Crackers:-
  • Crackers are the short coil- like places in the yarn.
  • When the yarn is stretched the thick coil like fault is straightened sometimes with a cracking noise.
  • In the top arm drafting systems crackers are no more a problem in cotton spinning.
  • Crackers however occur frequently in polyester or polyester-cotton  blend yarns.


Causes of crackers are:-
  • Due to the presence of long fibre more than the distance between the front and middle roller.
  • Excessive apron or middle roller grip, coupled with high interfere cohesion of fiber between the apron.
  • A very low spinning tension can also cause the formation of crackers.


Remedies on crackers are:-
  • Increase top arm pressure.
  • Buff the top roller(remove any abnormality, if observed)
  • Traverse motion functions should be properly.
  • Application of large diameter  and narrow width top rollers.
  • Application of wider apron spacers.
  • Increase breaks draft.
  • Keep  wider back zone setting.
  • Use heavier traveler, if necessary.


Spinner Double:-
  • The name itself indicates that the fault consist of the yarn becoming ‘double` in its thickness at the defective portion.
  • A spinner’s double is normally neither seen at the ring frames, nor caught at the winding machine. 
  • The fault is observed on the modern winding machine.
  • This fault is seen in the fabric as thick yarn in the warp or weft.
  • This fault is usually several times longer than the cloth width.


Causes of spinner double:-
  • Rove from an inter bobbin in the creel at ring frame going along with the neighboring end.
  • Bad piecing- Tenter on ring frame permitting doubled rove to fed in to the drafting system, at the time of replacing a near empty interbobbin at the creel and the strand issuing from the front rollers at ring frames going along with an neighboring end yarn on to the ring bobbin.


Remedies on spinners double:-
  • The attentiveness of ring tender. (operator)
  • Prevent more breakages in the beginning by running the machine at slow speed.
  • Make sure effective working of pneumatic suction system.
  • Prevent more creel breaks, by increasing slight twist in roving.


Hairiness:-
Hairiness the protruding fibers from the yarn body.

Causes of hairiness are:-
  • Badly centered spindles, unstable yarn tension.
  • Due to wrong ring and traveler combination.
  • Rough machine surfaces, roughen the yarn surface .
  • Open anti balloon ring.     
  • The fibers getting electro statically charged.
  • Poor ring centering.
  • Friction of the yarn owing to very high traveler weight.
  • Rough gliding surface of the ring.


Remedies on hairiness are:-
  • To reduce abrasion machine parts.
  • Used well combination of ring and traveler.
  • Maintain proper humidity in the department.


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