DEFECT FREE FABRIC

DEFECT FREE FABRIC

ABSTRACT:

Quality means customer is coming back not our goods. Due to increase in the demand for quality   fabrics, high quality requirements are today greater since customer has become more aware of poor quality problems. To avoid the rejection of goods it is necessary to avoid   the defects. Yarn faults also plays very important role in ability of process and fabric appearance. Along with the appearance it will effects on spinning operation. So maintaining yarn defects is very important for spinner. 

DEFECTIVE FABRIC

NON DEFECTIVE FABRIC

SPINNING DEFECTS:

        ·         Slubs (Soft thick places)

        ·         Oily slub

        ·         Cockled Yarn

        ·         Uneven yarn

        ·         Soft Yarn

        ·         Tangles Yarn

        ·         Kitty or leafy or seedy yarn

        ·         Ozzy Yarn

        ·         Yarn with ring traveler

        ·         Soft built bobbins

        ·         High end breakages in ring frame

        ·         Neppy Yarn

·         Slub (Soft thick places):

           The slub is a thick strand of fibers having less twist and more diameter compared to normal yarn. It will Show thick spot in fabric which will give the shade variation after dyeing.

Causes:

1) Improper Piecing of yarn whenever end breakage occurs

2) Fluff generation in ring frame causes thick place formation

3) Long tail in creeling in new roving bobbin

4) Rough and damaged top roller surface

5) Variation in draft

6) Change in surface speed of feed roller

7) Broken teeth on gear

Remedies:

1) Trained workers should be there for piecing

2) Regular cleaning of floor to avoid generation of fly and fluff

3) By keeping uniform draft and speed of front roller

4) Maintenance of gears

·         Oily slubs:

Oily slubs are formed due to improper lubrication system or mal practices of workers. The yarn having oily slub show dark spot in fabric. Sometimes it forms the hole in the fabric when the slub is harder. Oily slubs mainly found in conventional machines than that of modern machines because of manual lubrication process.

Causes:

1) Oily hands of piecer during piecing of broken end.

2) Oily waste dropped while removing the drafting rollers

3) Oily fluff blown into yarn from adjoining frame recently oiled or open for cleaning

3) Oily fluff on roving enters into drafting zone which will lead to form oily yarn

4) Any oil dropped on sliver at card or draw frame or any oily fluff going in sliver.

Remedies:

1) The hands of piecer should be clean during piecing

2) Avoid formation of fluff in drafting area

3) If we found any oily stain on sliver then that oily portion should   cut   immediately.

·         Cockled Yarn:

The yarn is characterized by irregular thick and thin and uneven lumpy spots in the yarn. This yarn when woven in the fabric will give slub like effect irregularly on the face of the cloth. This is an objectionable defect.

Causes:

1) Improper gauge setting of drafting system

2)  Roller clearer covering too slack or damaged.

3) Humidity too low in spinning unit

Remedies:

1) Proper gauge setting of drafting system

2) Buffing of cots should be done on regular basis

3) Maintain adequate humidity in spinning unit

·         Uneven yarn:

This type of yarn having uneven diameter and length. The unevenness can be short term or long term variation. The short term unevenness is repetitive that is thick and thin places repeats more as compared to long term unevenness. The fabric woven from this yarn appears wavy. The yarn with long term variation produces thick or thin bar warp way or weft way.

Causes:

      A)      Long term variation

1)      Automatic feed control device on blowroom not working properly

2)      Fan or beater speed is very high or very low

3)      Card are feed with rejected laps

4)      Uneven waste extraction at card and draw frame

5)      Uneven noil extraction in comber

6)      Drafting roller eccentric, uneven or damaged

7)      Improper meshing of drafting gears.

Remedies:

1)      Regular checking of automatic feed control device

2)      Set the fan speed according to the cleaning efficiency

3)      Proper extraction of waste and noil in comber, card and draw frame

4)      Drafting roller should be eccentric

5)      The setting of drafting gears should be proper.

     B) Short term variations:

             1)   Eccentricity of drafting rollers or damaged top rollers

             2)   Missing tooth on drafting gear

             3)   Use of   damaged rings

             4)   The stretched   roving (due to rough guide rods, blocked roving trumpets)

             5)   Loose cots of top roller

             Remedies:

             1)   Placing the new topper by removing old damaged top roller.

             2)   Replacement of damaged gear.

·         Soft yarn:

  This type of yarn consists of lesser twist as compared to normal yarn. The  soft   produced on some spindles of ringframe while other spindles are spinning normal yarn .If  soft yarn is used as weft then weft breakages takes  place i.e defect will introduce in  fabric like missing pick, cut pick or pattern defects.

Causes:

          1) Loosening of spindle tape

          2) Bent spindles or worn out spindles.

          3) Dirty jockey pulleys that is having waste in brackets or fluff over pulleys.

Remedies:

         1) Regularly checking of spindle tape

         2) Replacement of damaged spindled with new spindle.

         3) Cleaning of jockey pulley

·         Tangled Yarn:

      The yarn which entangles with another yarn and it is harder to remove the entanglement. If this yarn is used as weft this will cause weft breakage causing jerky motion in the plain ordinary loom which creates the hard waste. The whole bobbin has to be cut or waste removed from bobbins till tanglement is removed.

      Causes:

           1)      Yarn is too low or too high on bobbins as ring rail is not levelled

           2)      Building cams or rolls worn out

           3)      Poker bars or channels chocked with cotton fluff causing jerky movement of ring rail

           4)      Building motion not set properly that is taper on bobbin at top or bottom too short

           5)      Not piecing the yarn with broken end but taking yarn from bobbin and winding on bobbins  and piecing.

Remedies:

           1)      The setting of ring rail should be proper

           2)      The maintenance of building cams and rolls should be proper

           3)      There should be suction on ring frame to avoid fly and fluff generation

           4)      Building motion should set properly

·         Kitty or leafy or seedy yarn:

    The fabric woven from yarn containing the leafy or seedy matter will give specks in the cloth. When the proportion of leafy, kitty or seedy is more, the same is not removed in bleaching. This cloth when dyed gives specky dyeing.

     Causes:

             1)      The quality of cotton is inferior that it contains lot of leafy and seedy matter

             2)      The number of beating points used in blow room are less

             3)      Beater blades worn out

             4)      The setting of beating points in blow room is not proper

             5)      The dust extraction system is inefficient in blow room

             6)      Humidity level in blow room department is high

             7)      The licker- in to licker-in under casing setting close

             8)      Cylinder and flats settings not proper

             9)   Use of crush roller after doffer  is recommended

           10)   The top comb setting is not proper in case of combed yarn.

Remedies:

1) Use of good quality of raw material

2) More number of beating points

3) Avoid use of worm out beaters

4) Proper setting between licker-in to licker-in under casing and cylinder and flat.

·         Ozzy Yarn:

      Ozzy yarn is having frayed fibers all over the body of yarn. When the fabric is produced from this yarn, there will be rolled up of fluff or hairy appearance and surface of the fabric will not be even. In case of polymer cotton blended fabric the ozzy yarn will form beads after wear.

Causes:

            1) The short fiber percentage is very high in the cotton because of inferior quality of cotton used in mixing.

2) Closer setting of drafting roller for longer staple length.

3) Traveler is not having smooth movement.

4) Very low humidity in preparatory processes, in case of static electricity fibers will repel with each other

5) If traveler is not used according to the count then it may strike on the separators

6) Use of damaged traveller causes ozzy yarn formation

7) Unfiltered water used in humidification causes coating on yarn body and traveller etc.

Remedies:

1) Usage of good quality of raw material

2) Gauge setting according to staple length

3) Smooth movement of traveller

4) Humidity in the department should be optimum

5) Traveller must be used according to count

6) Water filters should used

·         Yarn with ring traveller and iron particles:

This type of yarn containing a small pieces traveler iron particles. This type of yarns will holes on fabric.

Causes:

1) During changing of traveller if care not taken it will go over roving or on the adjacent ringframe which will spun the yarn with traveller.

2) Sometimes during working of ringframe if traveller breaks and spun in the yarn.

3) Any iron particles get cot in the preparatory department

Remedies:

           1)      After changing the traveller cleaning should be done.

           2)      By using sensors

·         Soft build bobbins:

          This type of bobbins when used in loom for insertion of weft, yarn will slough off from the bobbin which causes shuttle trap or thick bar of weft yarn in the fabric.

Causes:                                                                                    

            1)      Ring traveller are not used according to the count.

            2)      Ring rail is chocked, which causes yarn layer accumulation at one place.

            3)      Slack of spindle tapes.

            4)      Worn out cams and cam roller causes ring rail to dwell at changes.

            5)      Improper setting of cam.

            6)      If shape of taper is too blunt.

Remedies:

1) Traveller must be used according to the count.

2) By changing the slacked spindle tape.

3) Proper setting of cam.

·         High end breakage  in ringframe:

      End breakage is the main problem in the ringframe, piecing of two ends will responsible for slub, oily slub, tangled yarn etc. these yarns will show defect in the fabric.

Causes:

            1)      Eccentricity of spindles.

2) By using damaged top rollers.

3) Improper spacing of balloon separators.

4) By using damaged bobbins.

5) By using damaged spindles.

6) If speed is beyond the limit.

7) Gears are not meshed properly or gears with broken tooth. 

Remedies:

1) Setting of balloon separator should be proper.

2) Avoid using of damaged spindles.

3) Limited speed must be there according to the count of yarn.

4) Use of travellers according to count.

·         Neppy Yarn:

     The Yarn which contains small rolled fiber mass in form of entangled balls is known as neppy      yarn. Neppy yarn spoils the appearance of the fabric. If the neppy fabric is dyed it shows the specks. Neps in the case of polyester/ cotton blended fabrics show up on the fabric surface. These are prominent when the cotton and polyester components are dyed with contrasting shades.

Causes:

                  At Blowroom:

1)      The immature cotton fiber or the characteristics of cotton used in mixing are widely differing

2)      The beating points in blowroom are more than that of the required

3)      The settings of beaters or blades are too close

      At cards:

1) The setting between feed plate and licker in is very close

2) The setting between the cylinder and doffer is wide.

3) The clothing of cylinder, doffer, licker-in is damaged.

       At combers:

            The top comb is not set properly or the needles damaged or worn out.

Remedies:

1) Proper setting between two rollers.

2) Quality of cotton fiber should be good.

3) Proper setting of top comb.

• PUBLISHED BY:

VIDYASHREE HANAMANT HIPPARAGI.

DEPT. OF TEXTILE TECHNOLOGY.

DKTE TEXTILE AND ENGINEERING INSTITUTE.