Knitting Defects

• High Yarn Tension
• Yarn Overfeed or Underfeed
• High Fabric Take Down Tension
• Defects like Slubs, Neps, Knots etc.
• Incorrect gap between the Dial & Cylinder rings.

• High Yarn Tension
• Count Variation
• Mixing of the yarn lots
• Package hardness variation

• Ensure uniform Yarn Tension on all the feeders.
• The average Count variation in the lot should not be more than + 0.3
• Ensure that the yarn being used for Knitting is of the same Lot .
• Ensure that the hardness of all the yarn packages is uniform using a hardness tester.

• Faulty winding of the yarn packages.
• Yarn running out of the belt on the Pulley

• Winding of the yarn package should be proper.
• The yarn should be running between the belt and around the pulley.

• Big Knots, Slubs & Neps in the yarn, Thick & Thin yarn.

• Specify the quality parameters of the yarns to be used for production to the yarn supplier.

• High twist in the yarn.

• Twist in the yarn should be in required TPM.

• Presence of dead fibers & other foreign materials, such as; dyed fibers, husk & synthetic fibers etc.
• Dyed & other types of fibers flying from the adjacent Knitting machines cling to the yarn being used for knitting & get embedded in the Grey Fabric.

• Use rich fiber mixing for the yarns to be used for Knitting in order to have less dead fibers appearing in the fabric.
• Rigid control measures in the Blow Room to prevent the mixing of foreign matters in the Cotton mixing.
• Segregate the Spinning & Knitting Machines, with Plastic Curtains or Mosquito Nets, to prevent the fibers flying from the neighboring machines, from getting embedded in the yarn / fabric.

• High T.P.I. of the Hosiery Yarn
• Uneven Fabric tension on the Knitting machine.
• Unequal rate of Fabric feed on the Stenter, Calender & Compactor machines.

• Use the Hosiery yarns of the recommended TPM level for Knitting.
• Ensure uniform rate of feed of the dyed fabric on both the edges while feeding the fabric to the Calender, Compactor or Stenter machines.

• Bent Latches, Needle Hooks & Needle stems
• Wrong Needle selection (Wrong sequence of needles, put in the Cylinder or Dial)

• Inspect the grey fabric on the knitting machine for any Needle lines.
• Check the Needle filling sequence in the Cylinder / Dial grooves (tricks).

• Fault in bobbin
• Irregular tension on cams.

• Replace that bobbin.
• Check cams positioning 

• High Yarn Tension
• Bad Setting of the Yarn Feeders
• Old & Worn out Needle set
• Cylinder Grooves are too tight restricting needle movement
• Breakage of hook or butt in needle.

• Ensure uniform & the right Yarn tension on all the feeders.
• Keep the recommended gap between the Yarn Feeders & the Needles.
• Periodically change the complete set of needles.
• Remove fly or blockage from groove.
• Replace defective needle.

• Bent or Worn out Sinkers
• Sinkers being tight in the Sinker Ring grooves

• Replace all the worn out or bent sinkers causing Sinker lines in the fabric.
• Sinker lines are very fine & feeble vertical lines appearing in the fabric.
• Remove the fibers clogging the Sinker tricks (Groove

• Fibers & fluff accumulated in the needle tricks which remain soaked with oil.
• Excessive oiling of the needle beds.

• Fibers accumulated in the needle tricks cause the oil to seep into the Fabric.
• Some lubricating oils are not washable & can not be removed during Scouring.
• Remove all the Needles & the Sinkers of the machine periodically.
• Clean the grooves of the Cylinder & Dial of the machine thoroughly with petrol.
• Blow the grooves of the Cylinder Dial & Sinker ring with dry air after cleaning.

• High Yarn Tension
• Yarn exhausted on the Cones.

• Ensure correct yarn tension on all the feeders.
• Ensure that the Yarn detectors on all the feeders are working properly.
• Depute a skilled & alert machine operator on the knitting machine.

• End breakage on feeders with all needles knitting.
• Yarn feeder remaining in lifted up position due to which the yarn doesn’t get fed in the hooks of the needles.

• Needle detectors, should be set precisely to detect the closed needles & prevent the fabric tube from completely pressing off.
• Proper yarn tension should be maintained on all the feeders.

• Abrasion due to the contact with rough surfaces
• Excessive surface hairiness caused, due to the abrasive tumbling action
• Fabric friction in the Tumble Dryer
• Rough Dyeing process & abrasive machine surfaces (Soft Flow Machine tubes, Tumble Dryer drum etc.)
• Reprocessing of the fabric is, also a major cause of piling.

• Avoid using the Tumble Dryer.
• Control shrinkage by maximum fabric relaxation & over feed in the processing.
• Regularly inspect the fabric contact points on all the machines, for any rough & sharp surface.
• Avoid repeated reprocessing of the fabrics.
• Use anti pilling chemical treatments for the fabrics prone to pilling.

• Caused by the pulling or the plucking of yarn from the, fabric surface, by sharp objects.

• Inspect & rectify the fabric contact points on all the machines (Soft Flow Dyeing, Tumble Dryer & Centrifuge etc), on which snagging is taking place.

• Uneven distribution of tensions across the fabric width while dyeing or finishing the fabric.

• Bowing can be corrected by reprocessing the fabric by feeding it from the opposite end.
• A special machine (MAHLO) is also available for correcting the bowing in the knitted fabrics.

• Inadequate Scouring of the grey fabric is one of the primary causes of the dyeing patches.
• Improper leveling agent is also one of the causes of dyeing patches.
• Correct pH value not maintained.
• Dyeing machine stoppage due to power failure or the fabric entanglement in the dyeing machine are a major cause of the dyeing patches.

• Scour the grey fabric thoroughly to remove all the impurities from the fabric before dyeing.
• Use appropriate leveling agents to prevent patchy dyeing.
• Maintain the correct pH value during the course of dyeing.
• Use a power back up (Inverter) for the dyeing operation to be completed uninterrupted.

• Softener not being uniformly dissolved in water

• Scour the grey fabric thoroughly to remove all the impurities from the fabric before dyeing.
• Ensure that the softener is uniformly dissolved in the water & doesn’t remain un-dissolved as lumps or suspension.
• Use the right softener & the correct procedure for the application.
• Maintain the correct pH value of the softener before application.

• Dyeing Machine not cleaned thoroughly after dyeing a lot.
• Grease & Oil stains from the unguarded moving machine parts like; Gears Shafts Driving Pulleys & Trolley wheels etc.
• Fabric touching the floors & other soiled places during transportation, in the trolleys.
• Handling of the fabric with soiled hands & stepping onto the stored fabric with dirty feet or shoes on.

• Wash & clean the dyeing machine thoroughly after dyeing every dye lot.
• Follow the dyeing cycle of Light- Medium- Dark shades & then the reverse the cycle while dyeing the fabric.
• All the lubricated moving machine parts should be protected with safety guards.
• Make sure that the fabric is neatly packed in or covered with Polythene sheets while transporting or in storage.
• Handle the fabric carefully with clean hands & do not let anyone step onto the stored fabric.

• Dyeing recipe i.e. the poor fixing of the dyes is a major cause of color fading.
• Using the wrong combination of colors in a secondary or tertiary shade.
• Use of strong detergents & the quality of water are also the common causes for color fading.
• Prolonged exposure to strong light will also cause the colors to fade.
• High level of acidity or alkalinity in the perspiration of individuals also causes color fading.

• Use the correct dyeing recipe i.e. the appropriate leveling, fixing agents & the correct combination of dyes.
• Follow the wash care instructions rigidly.
• Use mild detergents & soft water for washing the garments.
• Don’t soak the garments for more than 10- 15 minutes in the detergent prior to washing
• Turn the wet garments inside out while drying.
• Dry in shade & not in direct sunlight.
• Protect the garments against prolonged direct exposure to strong lights (show rooms or exhibitions etc.).

• Shade variation can be as a result of mixing of the, fabrics of two different lots.
• Shade variation is also caused, by the variation in the process parameters i.e. Time, Temperature & Speed etc. from one fabric roll, to the other.
• Shade variation can appear to be, in fabrics with GSM variation, caused due to the uneven stretching, unequal fabric overfeed % etc.

• Ensure that the grey fabric used for one shade is knitted from the same lot of the yarn.
• Ensure that the same process parameters (Width, Overfeed, Temperature & Machine Speed etc.) are used for each roll of a dye lot.

• Wrong Dyeing recipe
• Wrong leveling agent selection or wrong dyes combinations.
• Improper fabric Scouring.
• Impurities like Oil & Wax etc. not being completely removed in Scouring
• Level dyeing not being done due to the inappropriate leveling agents.
• Variation in the process parameters, e.g. Temperature, Time & Speed etc .

• Use appropriate leveling agents to ensure uniform & level dyeing.
• Scour the grey fabric thoroughly to ensure the removal of all the impurities.
• Ensure that the whole lot of the dyed fabric is processed under uniform process parameters.

• These marks are caused due to the excessive pressure, of the squeezer rolls of the Padding Mangle, on the wet fabric, while rinsing.

• Use the Padding mangle only for the application of the softener.
• Use a hydro extractor (Centrifuge) for the extraction to avoid the squeezer roll marks.
• Soon after extraction open the fabric manually to prevent crease marks in the damp fabric.

• High pressure of the fabric Take Down rollers of the Knitting machine on the grey fabric is one of the main causes.
• Too much pressure of the feeding rolls of the Calander & Compactor is the primary cause of the folding marks in the knitted fabric.

• Adjust the gap between the two rolls as per the thickness of the fabric sheet .
• Gap between the two Calander rolls should be just enough to let the rolls remove the wrinkles in the fabric but put no pressure on the fabric sheet especially in the case of Pique & structured fabrics.

• Damp fabric moving at high speed in twisted form, in the Hydro extractor (Centrifuge)

• Use anti Crease, during the Scouring & the Dyeing process .
• The use of anti Crease, swells the Cellulose & prevents the formation of Crease mark.
• Spread the fabric in loose & open form & not in the rope form, in the Hydro Extractor.

• High Stresses & strains exerted on the fabric, during Knitting, Dyeing & Processing & the fabric not being allowed to relax properly, thereafter.
• High shrinkage is primarily due to the fabric being subject to high tension, during the Knitting, Dyeing & the Finishing processes

• Keep the Grey Fabric in loose plated form, immediately after the roll is cut.
• Store the finished fabric also in the plated form & not in the roll form.
• Allow the fabric to relax properly, before it is cut.
• Give maximum overfeed to the fabric, during the processing, on the Stenter, Compactor & the Calandering machines.

• Roll to roll variation in the, process parameters, of the fabric, like; Overfeed & Width wise stretching of the dyed fabric, on the Stenter, Calender & Compactor machines.
• Roll to roll variation in the fabric stitch length.

• Make sure that all the fabric rolls in a lot, are processed under the same process parameters.
• The Knitting Machine settings, like; the Quality Pulley diameter etc. should never be disturbed.

• Grey fabric of the same lot, knitted on different makes of Knitting Machines, having varying number of Needles in the Cylinder.
• Roll to roll difference, in the Dyed Fabric stretched width, while feeding the fabric on the Stenter, Calander & Compactor.

• The whole lot of the grey fabric should be knitted on the same make of knitting machines.
• For the same gauge & diameter of the knitting machines, there can be a difference of as high as 40 needles, from one makes to the other make of the machine.
• This difference, in the number of needles, causes a difference of upto 2”-3” in the finished width of the fabric
• The stretched width of the grey fabric should remain constant, during finishing on the stenter.

• Shrinkage caused due to the inadequate relaxation of the knitted fabrics, before cutting.
• Mixing of the garment parts cut from, different layers or different rolls of the knitted fabric.

• Use a trolley, for laying the fabric on the table, to facilitate a tension free, laying.
• Let the fabric relax for a few hours, before cutting, especially the Lycra fabrics.
• Ensure the numbering of the different layers of the fabric, to prevent the mix up of the components.