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Nội dung
SPINNING & YARN FAULTS Prepared By : Mazadul Hasan sheshir ID: 2010000400008 13 th Batch Wet Processing Technology Email: mazadulhasan@yahoo.com Southeast University Southeast University Department Of Textile Engineering I/A 251,252 Tejgaon Dhaka Bangladesh Prepared By : Y A R N F A U L T LOW COP CONTENT Yarn content in the cop is less 1 1 EFFECT • • CAUSES !" # $ % RECTIFICATION &' () $ *) +,)-" .) +/),- SLUBS An abnormally thick place or lump in yarn showing less twist at that place. 2 2 EFFECT 0) ) %) CAUSES 1223) 4) 5 #) RECTIFICATION () ) *) 46) .) 7) 8) 7"6) -) &9: ;) %<) =6'> #) NEPS 3 3 EFFECT • % • 1 CAUSES 1223 4) 5 #) RECTIFICATION ) () 46) *) 7) .) 7"6) =?@5 SNARL 4 4 [...]... snarl-like places in the yarn which disappear when pulled with enough tension or Yarn with spring –like shape 8 EFFECT More breaks in winding • More noticable in polyester and cotton blended yarns CAUSES Mixing of cottons of widely differing staple length Closer roller settings Eccentric top and bottom rollers Non optimum temperature and relative humidity in the spinning shed Over spinning of cottons... Correct spacers to be utilised SOFT YARN Yarn which is weak indicating lesser twist 6 EFFECT: More end breaks in subsequent processes • Shade variation in dyed fabrics CAUSES: Slack tapes dirty jockey pulleys Improper bobbin feed on the spls Less twist in the yarn Bad clearing at the travellar RECTIFICATION: Vibration of bobbins on the spindles to be avoided 1 Proper yarn clearing to be ensured 2 Periodic... varying widely in fiber lengths and use of immature cottons CAUSES Higher than normal twist in the yarn Presence of too many long thin places in the yarn RECTIFICATION Optimum twist to be used for the type of cotton processed 1 Drafting parameters to minimise thin places in the yarn to be adopted 2 The yarn to be conditioned 3 Correct tension weights and slub catcher settings to be employed at winding... CORK SCREW YARN It is a double yarn which one yarn is straight and other is coiled over it 15 EFFECT Breaks during winding •Causes streaks in the fabric CAUSES Feeding of two ends (instead of one ) in ring frame Lashing -in ends in ring frame RECTIFICATION Tenters are to be trained in piecing methods(or) practices 1 Pneumafil ducts to be kept clean and properly set SLOUGH OFF Coils of yarn coming... preparatory processes Negligence in segregating the oily waste from process waste RECTIFICATION Yarn contact surfaces to be kept clean 1 Oilers to be trained in correct procedures of lubrication 2 Proper segregation of oily waste from process waste KITTY YARN Presence of black specks of broken seeds, leaf bits and trash in yarn 11 EFFECT Damaged fabric appearance • Production of specks during dyeing • Needle... Unduly thick piecing in yarn caused by over End piecing 9 EFFECT More end breaks in subsequent process • Increase in hard waste CAUSES Wrong method of piecing and over end piecing Twisting the ends instead of knotting RECTIFICATION Tenters to be trained in proper methods of piecing 1 Separators to be provided 2 Excessive end breaks in spinning to be avoided OILY SLUB Slub in the yarn stained with oil... travellars and suitable 2 Roller settings to be maintained 3 Optimum relative humidity to be maintained in the spinning room 4 Wide variation in the properties of cottons used in the mixing to be avoided FOREIGN MATTERS Metallic parts, jute flannel and other similar foreign matters spun along with yarn 13 EFFECT Breaks during winding • Formation of holes and stains in cloth • Damaged fabric appearance CAUSES... bits) to be ensured during preparation of mixing 1 Installation of permanent magnets at proper 2 Places in blow room lines to be ensured SPUN IN FLY Fly or fluff either spun along with the yarn or loosely embedded on the yarn 14 EFFECT More breaks in winding CAUSES Accumulation of fluff over machine parts Fanning by workers Failure of over head cleaners Malfunctioning of humidification plant RECTIFICATION... at the travellar RECTIFICATION: Vibration of bobbins on the spindles to be avoided 1 Proper yarn clearing to be ensured 2 Periodic replacement of worn rings and travellars to be effected OIL STAINED YARN Yarn stained with oil 7 EFFECT Damaged fabric appearance • Occurrence of black spot in fabric CAUSES Careless oil in the moving parts,over head pulleys etc Piecings made with oily or dirty fingers... too many seed coat fragments RECTIFICATION Cleaning efficiency of blow room and cards to be improved 1 Optimum humidity in the departments to be ensured HAIRINESS Protrusion of fibre ends from the main yarn structure 12 EFFECT More end breaks in winding • • Uneven fabric surface Beads formation in the fabric in the case of polyester/cotton blends CAUSES Use of cottons differing widely in the properties . SPINNING & YARN FAULTS Prepared By : Mazadul Hasan sheshir ID: 2010000400008 13 th Batch Wet Processing. 7) 8) 7"6) -) &9: ;) %<) =6'> #) NEPS 3 3 EFFECT • % • 1 CAUSES 1223 4) 5 #) RECTIFICATION ) (). ! EF=G CRACKERS 8 8 EFFECT • " CAUSES0"3 !< " H &" RECTIFICATION & ()