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Dyeing, printing & processing defects

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Dyeing, printing & processing defects

  2. 2. Common causes of dyeing defects 1.The material is not well prepared for dyeing and printing  Material having dead fibres or other defective fibres  Left over of Chemicals after bleaching etc.  Material not properly desized.  Material not properly mercerised.  Absorbency of the fabric not proper  Sticking of insoluble material on the fibres  Impurities are not removed properly  Uneven heat treatment.
  3. 3. 2.Water Quality not Proper  More Hardness of water  Water has metal ions such as iron.  pH of water not proper  Water having more chlorine 3. Due to Shortcomings in making Dyeing Solution  Improper weight ratio of colours, material and chemicals.  Improper material to water ratio • Improper filtering of concentrated colours 4. Due to Shortcomings in the dye machinery • Coming out of Dye liquor during dyeing • Defective instruments controlling temperature, pressure speed etc.
  4. 4. Influence of Fiber Related Properties on Dyeing behavior  Un-drawn or partially oriented yarns - Easy to dye. – Low Molecular orientation –Rapid dyeing.  Drawn material – higher Molecular orientation – dye slowly.  Synthetic fibers are produced at various draw ratio (low – staple fibers to high values – draw bulked yarn)  Material having relatively small differences in their rates of dyeing – but very considerable differences in color. .
  5. 5. • The differences arise in the strike stage of the dyeing process, Why uneven dyeing occurs? 1. Improper leveling of dyes - – Effectiveness of the redistribution of dye during the subsequent leveling stage. – If the leveling action is poor, as in carrier dyeing at 98°C or when dyes of poor migration properties have been used, – The effects of small variations in spinning and drawing conditions may be expected to show as variations in color in dyed materials. For Staple Fibers, – The problem is more difficult, but of less practical significance,
  6. 6. 2. The Effects of Heat and Tension • Yarns and fibers are subjected – heat or of mechanical stress or both • The effects of variation in temperature or in tension during heat treatment are more severe . • And can produce relatively large color differences if the differently treated fibers are dyed in the same bath. • Reduction in rate of dyeing between. 130°C and 150°C, followed by leveling off. • Uniform tension over the yarn during H.S, leads to perform better leveling off.
  7. 7. 3. The Effects of fiber lubricants and spotting agents  Fibre Lubricants -- Source of variation – can affect quality of the dye bath  After long storage , they can also produce significant local alterations in the rates of migration of dyes in the fibre  Spotting agents sometimes applied to loom stains by weavers, and produce localized dark spots that show up after dyeing.  For this reason, the use of such spotting agents outside the dye works is to be discouraged.
  8. 8. 4. The Effects of Fiber Structure • Drawing the fiber - Growth of highly ordered regions – oriented along the axis of fiber • Heat treatment induces further growth in these highly ordered regions at the expense of less ordered regions. • Number, size, spacing and distribution of these highly ordered regions That these influence, the number and arrangement of chain folds in the polymer.
  9. 9. 5. Carriers  Fibre becomes more open structure or less ordered regions around the structural dislocations contain spaces just large enough to admit the molecules of disperse dyes under the influence of thermal agitation.  Thermal agitation – leads to increases in the rate of diffusion of dyes at Tg,  Suitable carriers are used to locate uniform striking of dyes.
  10. 10. 6.Barre Effects: Differences in the rate effect. • Differ in the fractions of their internal volumes that are available for the absorption of dyes • Differences in the dye uptake during initial dye transfer, – Rate of diffusion – Differences in the accessibility of this available region. – Accessibility – a property of the less ordered regions of fibre structure. – Availability – associated with an internal area. • How to Reduce barre effect ? – High temperature leveling treatment, possibly in the presence of a small amount of a suitable carrier – May increased by the presence of carrier during the early stages of dyeing. – Drawing – hot stretching produce decreases in both availability and accessibility as the general orderliness of the fiber structure increases.
  11. 11. 7. Ring Dyed Material in Synthetic yarn • Most of the dye present on the fiber surface layer less than one third of the radius of the fiber in depth. • Causes: dyeing time, bath temperature or the level of carrier addition to the bath is inadequate. • Even high temperature dyeing can be ring dyed if insufficient time has been allowed for the full penetration of slowly migrating dyes.
  12. 12. Some common dyeing problems 1. Un levelness • cause – improper dyeing conditions. • Ending problems causes countermeasures 1. unstable dye dispersion 1. select dyes with better dispersion stability, use efficient dispersants . 2. unsuitable dye combination 2. Attention should be given to uniform dye behaviour . 3. wrong dyeing program 3. Optimum dyeing process should be followed .
  13. 13. Cloudy dyeing Causes Countermeasures 1. inadequate pre-treatment 1. select optimum conditions and chemicals 2. channelling due to irregular winding 2. pay particular attention to winding of the material 3. poor circulation of the goods due to 3. adjust the machine more carefully interruptions, knots, etc. 4. too much foam in the dyebath 4. use antifoams, e.g. Antimussol brands 5. wrong dyeing programme 5. Optimum dyeing process
  14. 14. Pale Areas Causes Countermeasures 1. Inadequate Pre-treatment 1. Select optimum conditions and chemicals 2. Air pockets in the material 2. Use special chemicals, e.g. wetting (e.g. cheeses) agent / defoamer combinations, or greater pressure
  15. 15. 2. Unlevelness cause: due to material. Barriness Causes Countermeasures 1. Variations in temperature during 1. -adapt dye selection fibre manufacture(texturizing), draft - select higher dyeing temperature differences - select suitable carriers and chemicals - possibly set fibres at a higher temperature. 2. Variations in the density of the 2. Relax material thoroughly material (weaving, knitting)
  16. 16. 3. Unlevelness cause: due to other reasons. Skitterness Causes Countermeasures 1. inadequate pretreatment (e.g. desizing) 1. pay attention to perfect pretreatment 2. fibres of different origins in the material 2. pay particular attention to the appropriate dyeing process and programme 3. poorer solidity on both components of fibre blends 4. irregular thread tension during weaving or warp knitting
  17. 17. Listing Causes Countermeasurement 1. Inconsistent setting temperature 1. select special dyes (small- moleculed) 2. Irregular tension in the material due 2. relax material thoroughly to weaving or warp knitting 3. Poorly wound material 3. pay particular attention to winding 4. Rolled in selvedges due to irregular 4. -set the goods tension in the material (weaving, warp - size the selvedges knitting) - check the weaving or knitting machine
  18. 18. Pale areas after dyeing. Causes Countermeasures effect of aggressive vapours -efficient ventilation of vapours and (e.g. acid, chlorite, formaldehyde) gases - avoid contact with dangerous substances
  19. 19. •4.Reproducibility. Deviation of shade Causes Countermeasure 1. dye sensitivity to hydrolysis, 1. -select dyes carefully, control pH reduction, electrolyte exactly (buffer system) - pay attention to stability of dye to electrolytes 2. dye sensitivity to metal ions in the 2. use suitable sequestering agent dyebath 3. dyes of different chemical 3. pay particular attention to selection constitution affect each other (rare) of dyes and chemicals 4. dye buildup affected by chemicals 4. carry out lab tests (retarding effect)
  20. 20. Causes Countermeasure 5. different dyeing programmes 5. pay attention to consistent dyeing conditions 6. different liquor ratios 6. pay attention to consistent dyeing conditions 7. dye shows differences in standard 7. check supplies conformity 8. unsuitable dye combination 8. pay attention to behaviour of individual elements 9. sedimentation of liquid dyes 9. stir before removal from container 10. bath exhaustion affected by 10. adapt dye selection and process reserve of adjacent fibre
  21. 21. 5. Fastness properties Unexpectedly poor light fastness causes countermeasure 1. carrier residues on fabric 1. repeat thermo fixation (at higher (inadequate thermo fixation) temperature) 2. stained adjacent fibre 2. adapt dyeing process, select appropriate dyes 3. catalytic fading due to unsuitable 3. adjust dye selection dye combination
  22. 22. Unexpectedly poor wet and rub fastness causes countermeasures 1. thermomigration due to finishing and 1. adjust dye and chemical selection softening chemicals 2. inadequate dye fixation due to too 2. Optimize dyeing process, reduction short dyeing time or too low fixation clear temperature 3. stained adjacent fibre 3. Improve dyeing process
  23. 23. 6. Spots, marks Precipitates in the dye-bath causes countermeasures 1. dye precipitates due to poor 1. - pay special attention to dispersing dispersion or dyes with poor dispersion instructions stability - pay attention to dye selection (dispersion stability) - use dispersants 2. dye crystallization due to variations 2. pay attention to perfect liquor in temperature in the dyebath circulation 3. coloured spots due to dye deposits 3. pay attention to cleanness in the on the machine machine
  24. 24. causes countermeasure 4. use of volatile carriers 4. select suitable carriers, use overhead heating in the machine 5. silicones in the dyebath 5. use silicone-free de foamers 6. unstable chemicals 6. select suitable chemicals 7. oil and spinning preparations 7. thorough pre treatment 8. oligomers in the dyebath 8. drop dyebath hot, shorter dyeing time, use special chemicals
  25. 25. • Singeing droplets causes countermeasures 1. as a result of singeing before dyeing, 1. singe after dyeing fibre tips exhibit higher affinity for dyes . • Change of shade (e.g. blue spots in brilliant red shades) causes countermeasures 1. dye is sensitive to metal ions 1. use a sequestering agent 2. alkali residues 2. neutralize the goods 3. finishing chemicals 3. scour and select finishing chemicals carefully
  26. 26. • Dark spots causes countermeasures 1. solvent residues from pre treatment 1. complete removal of solvents • Specks causes countermeasures 1. contamination of the material by 2. do not store material near dyes; use dyestuff dust low dusting dyes • Dirt spots causes countermeasures 1. contamination of the material by 1. pay attention to clean machines and rust, oil, graphite, etc. clean working methods
  27. 27. 7. Appearance of the goods • Dimensional stability (shrinkage) causes countermeasures 1. insufficient relaxation during pre 1. adapt relaxation and setting to treatment material in question 2. Inadequate setting of material 2. adapt relaxation and setting to material in question 3. lengthwise distortion caused 3. adjust dyeing machine to material by dyeing machine
  28. 28. • Creasing causes countermeasures 1. inadequate pre treatment 1. select optimum pre treatment conditions (scouring, relaxation, setting) 2. due to quality of goods (structure, 2. adjust dyeing machine to material, select e.g. tightly woven fabric, weight) correct setting temperature, adjust stenter correctly 3. poor suitability of dyeing machine 3. select more suitable dyeing machine 4. too heavy batch of fabric 4. add a lubricant, e.g. lmacol brand 5. incorrect loading of machine 5. add a lubricant, e.g. lmacol brand 6. dyeing process (heating, cooling) 6. adjust temperature programme, add a lubricant, e.g. lmacol brand
  29. 29. •Chafe marks causes countermeasures 1. mechanical friction due to overloading 1. add a lubricant e.g. lmacol brand 2. rough patches in the machine 2. add a lubricant e.g. lmacol brand 3. stationary material in the running 3. add a lubricant e.g. lmacol brand machine (knots) 4. too high machine speed 4. add a lubricant e.g. lmacol brand
  30. 30. •Stitch distortion (knits) causes countermeasures 1. inadequate pre treatment 1. selection optimum pre treatment (relaxation, setting) conditions 2. mechanical effects, e.g. passage of 2.straight seams along weft and stitches goods in machine, squint seams •Moire effects (on beam) causes countermeasures 1. inadequate pre treatment 1. -select suitable setting conditions (setting, rolling up) - roll up carefully
  31. 31. • Lustre causes countermeasures 1. physical change in fibre due to local 1. avoid prolonged contact of stationary pressure and high temperature on material material with the hot machine 2. excessive setting 2. select suitable setting temperature • Handle causes countermeasures 1. unfavourable conditions between machine and 1. select optimum conditions material 2. inadequate pre treatment 2. can be corrected during finishing (relaxation, setting) 3. wrong dyeing programme 3. can be corrected during finishing (temperature / time)
  32. 32. • Pilling (staple fibres) causes countermeasures 1. susceptible fibre origin (also in fibre 1. select fibres carefully, use selected blends) softeners 2. inconsistent dimensional stability due 2. setting to shrinkage (fibres protrude from fibre bundle)
  33. 33. 8. Thermosol dyeing problems • Listing causes countermeasures 1. one-sided liquor feed into the 1. check injection pipe or mount a distribution plate trough 2. different nip roller pressure 2. check rollers (pickup) regularly 3. unlevel migration in 3. -check temperature and air current over the entire intermediate drying width in the drier - avoid migration by using lowest possible pickup and a suitable migration inhibitor. Select dyes with little tendency to migrate. 4. uneven thermosolling or fixation 4. check fixation units regularly with thermopaper or of dyes due to temperature temperature sensors differences - use more reliable dyes with as little sensitivity as possible to temperature deviations
  34. 34. •Two-sidedness causes countermeasures 1. deflecting roller touched on 1. check injection pipe or mount a distribution plate one side only 2. deflecting roller stationary 2. check rollers (pickup) regularly 3. pad rollers not the same 3. - check temperature and air current over the entire width in the drier - avoid migration by using lowest possible pickup and a suitable migration inhibitor. Select dyes with little tendency to migrate. 4. uneven drying from side to 4. - check fixation units regularly with thermopaper or side temperature sensors - use more reliable dyes with as little sensitivity as possible to temperature deviations
  35. 35. • Ending causes countermeasures 1. dye substantivity 1. - with lndigosol dyes add Lyogen WL - use a smaller volume of liquor - dye at higher fabric speed 2. dye sedimentation 2. - keep the liquor in motion - keep the temperature below 35°C
  36. 36. • Dark or pale selvedges causes countermeasures 1. one-sided liquor feed into the trough 1. check liquor feed 2. narrow goods impregnated on a wide 2. move to a suitable machine padder 3. worn rollers, rollers bend due to over 3. check the nip pressure, reduce pressure if compensation necessary, change rollers if necessary, chick hydraulics 4. varying drying conditions over the width 4. check the air jets and circulation of the goods 5. alkali residues in the goods 5. add acetic acid to the padliquor for pH 5-6
  37. 37. • Barry dyeings causes countermeasures 1. uneven jet pressure in the drier 1. check the air jets 2. inadequate evenness of tension in drier, 2. check guidance of goods in drier crease formation 3. alkali residues in the goods 3. add acetic acid to padliquor for pH5-6
  38. 38. Defects in Sulphur Dyeing • Uneven Dyeing and Oxidation Marks This may occur due to: a. Lower strength of sodium sulphide b. Using improper amount of sodium sulphide. c. Sodium sulphide does not wash off fully after washing. d. Variation in temperature. e. If colours are not dissolved properly, or colours are not of good quality f. If the chemical used for oxidation is not of good quality g. Fabrics are not worked upon properly at the time of dyeing.
  39. 39. Bronziness This defect normally occurs in heavy shades. Given below are the reasons: 1. More time gap between dyeing and washing 2. Using more of less strength sodium sulphide 3. Using more salt. 4. Oxidiser doesn't get washed off properly during washing 5. Sodium sulphide doesn't get washed off properly during washing. 6. More presence of iron and copper ions in water.
  40. 40. • Poor colourfastness to rubbing the reasons are : a. type of colour b. Lower strength of sodium sulphide c. Poor absorbency of the fabric d. Fabric is not washed properly e. The quality of soap used for washing is not proper f. Dyeing bath made of iron instead of steel g. Frequent addition of colours and chemicals h. Using Cationic finishing agent in finishing also lowers the colourfastness to rubbing i. Improper colour solution, Improper material to liquor ratio etc.
  41. 41. Roughness in Fabric The reasons are: 1.Using more amount of sodium sulphide that doesn't get washed off during washing. 2. Heavier shade 3. Improper washing 4. Not using anionic softening agent in finishing 5. Not using wetting agent. Tendering Tendering in the fabric takes place because sulphur is converted into sulphuric acid after oxidation which is harmful for the cellulosic fibers. This defect can occur on account of not proper washing of the fabric after dyeing which results in retaining of sulphuric acid on the cloth.
  42. 42. Defects in Dyeing with Reactive Dyes • Colours are not fast to washing, Abrasion; Staining in the fabric when transporting from place to the other, water marks on the fabric . • Bleeding in colours during washing, abrasion . • The fabric has been dyed in darker shade, uneven dyeing . • Uneven dyeing, marks of water, marks of colours. • The fabric has become stiff and rough after dyeing . • Colour staining of fabric, uneven dyeing . • Colour staining in fabrics of darker shade, uneven dyeing
  43. 43. Defect in Vat Dyeing • Poor Colorfastness in Vat Dyeing the reasons • Frequent addition of colors in the dye bath to match the shade. It disturbs the equlibrium between colors and chemicals. • Improper oxidation • Improper washing • Some peculiar colors such as blue and brown also leads to this defect. • Hardness in the water used • Mixing of incompatible colors • Usage of large quantities of reducing agent and alkali • Improper temperature • Improper wringing of the cloth • Faults in the machine • Not using essential chemicals such as dispersing agent or leveling agents. • Dyeing in a finished cloth ( Resin or Silicon Finish)
  44. 44. •Listing defects in vat dyeing The reasons are: • Improper batching. • Non Uniformity in the selvedge • Redyeing of the fabric • Foam on the two sides of the jigger. • Slippage of the fabric from the roller during dyeing. • Shortcomings in the machine such as malfunctioning of guide roll, expander roller or improper squeezing. • Improper filteration of the colors, improper circlation of the liquor during dyeing. Difference in temperature of liquor in the centre and at the ends. • Mixing of colors which are not properly compatible. • Improper singeing
  45. 45. Uneven Shade (shading OR listing) • differences in the shade of a fabric from edge to edge or one end of a fabric to the other Called selvedge- to-selvedge (or selvedge to center) shading or end-to- end shading respectively.
  46. 46. MAIN CAUSES: — Often caused in jig dyeing through difference of temperatures between the selvedges & centre of the batched up fabric on the jig roller. — by uneven batching of the cloth on the roller. MENDING Non-mendable. Minor Major Serious Not reckoned Up to 15 cm along > 15 cm along the the length length
  47. 47. Patchy/ streaky/ uneven dyeing • The fabric is characterized by an area of light or heavy dyeing along and across the width of fabric. Also, light or heavy dyed patches or light and dark streaks appear on the fabric. It also includes shade variation and light or heavy dyeing on selvedges.
  48. 48. MAIN CAUSES: • Improper scouring. • Cloth fed to the dyeing machine not crease free. • Proper time & temperature not given in dyeing. • Defective padding roller. • Fluff or thread on the fabric or in the color in the dye stuffs. MENDING: Non-mendable. Minor Major Serious Up to 1 sq. cm 1 sq cm to 6 sq. cm >6 sq cm
  49. 49. Shade Bar • shade change in fabric which appears as a horizontal selvedge-to selvedge change. Caused by a filling change (new filling bobbin) or loom stop and subsequent start up
  50. 50. MAIN CAUSES • Improper scouring • Defective padding roller • Proper time & temperature not given in dyeing. • Difference in count/ fiber composition of weft yarn. MENDING Non-mendable. Minor Major Serious Not reckoned Up to 15 cm along the length > 15 cm along the length
  51. 51. Dyestuff Stain • An unwanted color mark on a fabric qualifies as a dye stain. MAIN CAUSES: • Improper scouring. • Improper mixing of dye stuffs. MENDING: Non-mendable. Minor Major Serious Up to 1 sq. cm 1 sq cm to 6 sq. cm >6 sq cm
  52. 52. White Spot • The fabric is characterized by a white spot on otherwise well dyed adjacent fabric. MAIN CAUSES: • Improper scouring. • The mixture used for dyeing is not compatible. • Colors not properly dissolved. • Proper time & temperature not given in dyeing. MENDING: Non-mendable. Minor Major Serious Up to 1 sq. cm 1 sq cm to 6 sq. cm >6 sq cm
  53. 53. Color Crocking • color in a dyed fabric which rubs off rather easily onto other fabric surfaces. • Causes- – May be caused by inadequate soaping at the completion of dyeing cycle. – Due to faulty or improper dyeing procedures, OR preparation of the fabric prior to dyeing, OR imperfections in the fabric itself.
  54. 54. • Most frequently occurring imperfections – result from dyeing processes
  55. 55. Tender spots • Places in the fabric which have been excessively weakened, usually by exposure to processing chemicals. When the entire fabric is weakened, it is referred to as Tender goods. Also occurs in printing and finishing procedures.
  56. 56. Stained, streaked • A discolored area on the cloth. Caused by foreign matter such as dirt, grease, oil or residues of sizing on the fabric being dyed
  57. 57. Color bleeding • loss of color from a dyed fabric when immersed in a liquid. Liquid subsequently becomes colored
  58. 58. Off shade • an expression referring to the fact the color of the dyed fabric does not match the std. color or referenced sample
  59. 59. Barre • In woven fabrics, a horizontal band off-shaded yarns extending from selvedge to selvedge caused by differences in filling yarn size or difference in tension of warp or filing yarns
  60. 60. Defect caused by hanging thread • A break in the pattern of the printed fabric caused by hanging thread MAIN CAUSES: • Loose threads in the fabric not trimmed before printing. MENDING: Non-mendable . MINOR MAJOR SERIOUS Not Prominent Not prominent reckoned
  61. 61. Misprint or absence of print • A misprint can be one or more of the following – The printing is not per as required the required design. – The outlines and the colors in the design are not remain at its proper place. – A bare place without any printing.
  62. 62. MAIN CAUSES: • The design is not set properly. • Unequal pressure at different places during printing. • Design not properly engraved/ screened. • Improper cloth used for printing. • Improper stitching of cloth. • Cloth fed with uneven tension to the printing machine. • Improper storage or cleaning of the screen. MENDING: Non-mendable. Minor Major Serious Not reckoned Up to 15 cm along the length > 15 cm along the length
  63. 63. Uneven printing (tinting) • In a printed fabric the design at one place is bold as required, while at other place the same is hazy , light and unclear.
  64. 64. MAIN CAUSES: • Uneven pressure on printing rollers & doctor blade. • Uneven lapping of central drum in printing machine. • Diameter of printing roller is uneven. • Printing paste level not maintained. • Defective doctor blade. • Printing table is not proper. MENDING: Non-mendable. Minor Major Serious Not reckoned Up to 15 cm along the length > 15 cm along the length
  65. 65. Blurred (dark) patch • Unwanted blotch or bar in a printed/ dyed fabric results in a blurred patch
  66. 66. MAIN CAUSES: — Improper scouring. — Unclean doctor blade & printing roller. — Doctor blade not properly aligned. MENDING Non-mendable. Minor Major Serious Not reckoned Up to 15 cm along > 15 cm along the the length length
  67. 67. Water mark • An unwanted ripple effect/ light mark produced on the fabric is known as water mark.
  68. 68. MAIN CAUSES: — Improper scouring. — Surface pressure of one layer on another. — Contamination with water prior to tinting or dyeing on the padding mangle resulting in a reduction of intake of dye liquor. MENDING Non-mendable. Minor Major Serious Not reckoned Up to 15 cm along > 15 cm along the the length length
  69. 69. Misfits • A misfit is a print defect caused by improper alignment of the screens. Also known as “out of registration,” misfits leave unprinted areas in the design. For example, a green leaf may overlap its black outline or print over another color. Up to 10 % of printed goods designated as first quality contain some level of misfit.
  70. 70. Stick-in • A stick-in occurs when a small fiber or piece of lint gets stuck in the screen opening. The result is a small pen tip sized unprinted circle in the design. A stick-in is very difficult to see and often goes unnoticed during a long run.
  71. 71. Scrimps • A scrimp defect occurs when the fabric creases underneath one of the screens during the printing process. The pattern is then printed on top of the crease, leaving a large unprinted area when the fabric returns to its relaxed state.
  72. 72. Wicking • Wicking, also known as flushing, occurs when the printed area bleeds out into the unprinted area. The result is a “haloing” or shadowing effect around the outline of the pattern design. Residual salts left in the fabric during resin finishing and / or poor fabric preparation often cause wicking.
  73. 73. Spotting After printing some spots occur on printed fabric
  74. 74. Print color variation Can occur due to uneven roller or squeegee pressure while printing paste is applied
  75. 75. Flipped yarn MAIN CAUSE: • The part that look like •Insufficient penetration of color paste. •Treatment after printing is not carried out scratches because the appropriately. warp & weft have turned upside down
  76. 76. Bleeding MAIN CAUSE: •Too low viscosity of color paste. • A printed motif blurs •Too high concentration of dyestuff in print & as a result the paste. outline of design •The amount of color paste printed or appears unclear amount of hygroscopic agent used is too large.
  77. 77. Blebbiness • A part of printed surface became blebby with a rough appearance like that of sharkskin. MAIN CAUSE: •Unsuitability of color paste viscosity. •Screen mesh. •Uneven adhesion.
  78. 78. • The printed cloth is piled up after insufficient Staining during drying or apart of the cloth touches another steaming during steaming. MAIN CAUSE: •Poorly washed printing table. •Irregular (high ) steam & temperature.
  79. 79. Stains
  80. 80. Slight touching MAIN CAUSE: •Slow replenishment of color paste. • Some area in a motif •Uneven squeegee pressure. has pale spots. •A squeegee with inappropriate hardness. •Bad squeegee relay. •Uneven surface of printing table. •Inappropriate viscosity of color paste. •Inappropriate use of thickener.
  81. 81. • Disfigured designs or overlapped motifs Poorly adjusted screen MAIN CAUSE: •Inaccurate adjustments of the belt-drive and point.
  82. 82. • Designs printed are a little off. Double printing MAIN CAUSE: •Disfigured designs. •Poor engraving. •Poor cloth adhesion.
  83. 83. Pressing paste by • A frame mark appears in the printed area. frame MAIN CAUSE: •Poor belt-drive and frame installation.
  84. 84. Banding • defect created by the print head’s movement over the substrate. • If the head is not properly aligned, or if the substrate advances unevenly, the result is a slight horizontal “band” or line of unprinted area. • Banding can be reduced or prevented :- – with nozzle redundancy and multiple passes by the scanning print head. – In addition, banding is naturally reduced by most fabric substrates.
  85. 85. Misfire • occurs when the inkjet nozzle fails to send a drop of ink onto the fabric. Similar to a stick-in, the result is a small, unprinted area. In addition to misfires, nozzle clogging also plays a big role in digital defects. • When an inkjet nozzle clogs, the pattern may lose some or all of one colour. Fortunately, the inkjet drop is tiny, and most misfires and clogs are not seen if the printer has been designed with nozzle redundancy.
  86. 86. Incorrect Fabric Handling • Fabric handling also plays a role in the creation of defects with digital printing. Because most digital printers use a scanning head to print across the width of the fabric, the fabric must remain perfectly still or the image can be distorted. • One of the biggest fabric handling related defects occurs when the fabric buckles or gets wrinkled, causing the scanning inkjet head to come in contact with the fabric. The result is a nasty ink smear and possibly a damaged print head.
  87. 87. Defects Description Fading The loss of colour brilliance through exposure to factors such as sunlight or cleaning agents. Frosting A change of fabric colour caused by localized abrasive wear, such as that occurring at collar points or garment creases. Fume Fading A change of shade in dyed fabric caused by the chemical reaction of certain disperse dyes with atmospheric contaminants such as burnt gas fumes and ozone. Fuzzy Pattern Design lines in printed fabrics that are meant to be sharp demarcations of colour but that are muted or blurred. Migration The transfer of colour from one area of the fabric to another.
  88. 88. Defects Description Metamerism A phenomenon, also known as flare, that is observed when materials are viewed under different light sources. The spectral reflectance curves are not identical, so the viewer sees one color under one light source (incandescent) and a different color under another light source (fluorescent). Off Grain Lacking trueness. In printing, the design is transferred to the fabric so the design of the fabric is not aligned with the yarns. Off Register Lacking color alignment. In printing fabrics, the color separation is imperfect, producing a situation in which the different color components of the design are not aligned.
  89. 89. Defects Description Crease Streak Occurs in tubular knits. Results from creased fabric passing through squeeze rollers in dyeing process. Depending on the product; usually Major for fashion outerwear, Minor for underwear. Color Smear The result of color being smeared during printing. Color Out The result of color running low in reservoir on printing machine Back Fabric Backing fabric is often used to cushion fabric being printed. If there Seam is a joining seam in the backing fabric, an impression will result on Impression printed fabric. Mottled Color applied unevenly during printing
  90. 90. Condition wherein the weft and warp yarns do not keep at Bowing right angles.
  91. 91. MAIN CAUSES: • Improper stretch during scouring, dyeing or finishing. • Uneven tension during weaving/ processing. MENDING: Non-mendable.
  92. 92. Piling The entangling of fibers during washing, dry cleaning or while being worn form balls or pills and stand on the surface of a fabric and are of such density that light cannot pass through them.
  93. 93. MAIN CAUSES: • Span length not maintained in spinning. • Broken filament or low twist yarn. • More abrasion on surface of cloth during processing. MENDING: Non-mendable. MINOR MAJOR SERIOUS Not prominent Prominent Not reckoned
  94. 94. Askewed or Bias • Condition where filling yarns are not square with wrap yarns on woven fabrics or where courses are not square with wale lines on knits. MAIN CAUSES: • Improper stretch during scouring, dyeing or finishing. • Uneven tension during weaving/ processing. MENDING: Non-mendable.
  95. 95. Sanforize Pucker • Fabric will appear wavy or puckering when spread on cutting table. MAIN CAUSE: • Results from uneven wetting out on sanforize; usually caused by defective spray heads. • Difficult to detect during inspection on inspection machine with fabric under roller tension.
  96. 96. Pin Holes MAIN CAUSE: • Holes along selvage caused by pins holding fabric while it processes through tenter frame. • Major> if pin holes extend into body of fabric far enough to be visible in the finished product.
  97. 97. Crease Mark • Differs from crease streak in that streak will probably appear for entire roll. • Crease mark appears where creases are caused by fabric folds in the finishing process. • On napped fabric, final pressing may not be able to restore fabric or original condition. • Often discoloration is a problem. •
  98. 98. Selvedge torn MAIN CAUSE: • Usually caused by excessive tension while processing through tenter frames.
  99. 99. Various finishing processes Aesthetics finishes Description Parchmentizing A finishing process to give cellulosic fabrics such characteristics as transparency, linen-like hand, and texture. Softening Softening agents are frequently used to improve the hand and drape of fabric. The most commonly used softeners are oils, fats, wax emulsions, soaps and synthetic detergents, and silicone compounds. Silicone compounds produce relatively durable softening. Stiffening Some fabrics need to be made stiffer and more crisp than they would otherwise be in order to meet an intended end use. Stiffening may be done by any of several chemical finishes, all applied by pad and either dried or cured. Starch is widely used but starch finishes are temporary.
  100. 100. Aesthetic finishes Description Plissé This is a permanent finish, produced on cotton by the treatment of sodium hydroxide to produce a puckered or crinkled fabric. Embossing This is a process to produce a raised design or pattern in relief on fabrics by passing the cloth between hot engraved rollers that press the design into the fabric. Surface/ texture Description finishes Napping Napping uses a series of 24-30 cylinders covered with fine metal wires bent into small hooks, to produce a thick, raised fiber surface on fabrics produced from loosely twisted staple-fiber yarns. Sueding A process similar to napping, it is a mechanical finish that produces a soft, suede-like surface on the fabric.
  101. 101. Luster finishes Description Calendering A finishing process producing a flat, glossy, and smooth surface by passing the fabric under pressure between cylinders. Ciré Ciré is a highly polished fabric produced by impregnating the fabric with wax or a thermoplastic material and then passing it through friction rollers. Glazing A process that produces a smooth, high polish on the surface of the fabric. Moiré A moiré finish is characterized by a soft luster and an optical effect, which is created by interference between light rays reflected from the crushed and uncrushed parts of the fabric. Schreinering A finishing process where the fabric is passed under pressure between an engraved steel calender roller and a smooth roller. The engraved roller has 180-360 fine lines embossed.
  102. 102. Luster finishes Description (optical) Delusterants A process of dulling the luster of manufactured fibers, yarns, or fabrics with pigments or chemical treatment. Optical Optical brighteners are used in finishing to maintain white and bright Brighteners fabrics. They adhere to the fabric and create an appearance of whiteness or brightness by the way they reflect light; they absorb ultraviolet light and reflect it as visible blue light. Care finishes Description Durable Press This finish provides garments with shape retention, durable pleats and pressed creases, durably smooth seams, and wrinkle resistance. Soil Release A finish that increases the absorbency of a fabric, and which makes it easier to remove soil and stains in washing.
  103. 103. Care finishes Description Stain- and Soil- Stain and soil-resistant finishes reduce the rate of soil deposition on a resistant Finishes fabric either by creating an electric charge that repels the soil or by producing a smooth surface to which soil will not adhere. Durability finishes Description Abrasion-resistant Abrasion-resistant finishes are used on fabrics subject to prolonged Finish abrasive wear such as pockets, waistband lining, and hatbands. Slip-resistant Finishes applied to a fabric to reduce or eliminate yarn slippage and Finishes reduce seam fraying are called antislip, slip-resistant,or nonslip finishes. Compressive Used for woven cotton, tubular knit cotton, linen and rayon; the Shrinkage method consists of mechanically compressing the fabric lengthwise (Relaxation by overfeeding onto a large roller with damp blankets. Sanforized is a Method) well known trade mark for fabrics treated by this method.
  104. 104. Durability finishes Description Heat Set Used for fabrics from thermoplastic fibers such as nylon, polyester (Relaxation Method) and acrylic; it is based on the principle that thermoplastic materials will become stabilized in their configuration in which they happen to be when heated to their softening temperature. Sponging (Relaxation Used for woolen and worsted fabrics; it consists of thoroughly Method) wetting the fabric with water or steam and allowing the material to dry slowly in a relaxed tensionless state. Resin Treatments Used for fabrics of rayon and cotton; it involves impregnating (Relaxation Method) rayon and cotton with resins and then curing which stabilizes the fabric and thus reduces its tendency to distort.
  105. 105. Comfort finishes Description Antistatic A finish that helps reduce or eliminate static build-up in fabrics. They are chemical compounds that, when applied to a fabric, reduces or eliminates the accumulation of static electricity. Chemical-protective These are finishes that prevent penetration of herbicide or Finishes pesticide through clothing and prevent easy removal by laundering of any pesticide on the surface of clothing. Flame Retardant fabrics treated with these finishes burn in the direct path of flame Finish but self-extinguish when the source of flame is removed. Water and Stain They are chemical finishes that resist the penetration of water Repellent Finishes through the fabric but permit the passage of air or moisture Waterproof Finishes These are finishes that resist wetting and the penetration of water.
  106. 106. Environmental finishes Description Antimicrobial Finish They are applied to fabrics to prevent growth of microorganisms. Fume Fading Inhibitors Some colours fade, particularly disperse dyes on acetate, caused by exposure to oxides of nitrogen in the atmosphere. Simple alkaline substances such as borax are sometimes used as after-treatments, but they are not permanent. Metallic and Plastic Metallic and plastic coatings are applied to the back of fabrics. Coatings Aluminium coatings, modify the warmth and coolness of fabrics, are used for drapery lining. Plastic coatings help reduce the amount of soil that penetrates the fabric and delay the passage of heat through the fabric. Mothproofing Finish Moth larvae and carpet beetles are known to attack animal-fiber fabrics. Mothproofing is a chemical that is added to the dyebath during dyeing of wool fabrics. Treated wool fabrics and silk fabrics are less susceptible to damage by moths and other insects.