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Finishing defects

Finishing defects,remeadies

sheshir
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Finishing defects

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  1. ....DYEING , ....DYEING , PRINTING PRINTING AND FINISHING FINISHING DEFECTS AND REMEDIES…. AND REMEDIES…. AND DEFECTS

  2. The reasons like water, fiber sources & processing conditions is responsible for defects during wet processing. However, in order to overcome/ minimize the processing related problems it is essential to first understand the Symptoms (problems), Diagnose (ascertain the probable cause) & Cure (adopting remedial measure). Some defects of various stages are disscussed below:

  3. Causes Of Dyeing Defects  Due to Material: – Material having dead fibers or other defective fibers. – Left over of Chemicals after scouring, bleaching etc. – Material not properly singed, desized. – Material not properly mercerized. – Absorbency of the fabric not proper. – Sticking of insoluble material on the fibers. – Impurities are not removed properly. – Uneven heat treatment.

  4. Causes Of Dyeing Defects  Due to Water Quality: – More Hardness of water – Water has metal ions such as iron. – pH of water not proper – Water having more chlorine  Due to Improper Dye Solution: – Improper weight ratio of colors, material and chemicals. – Improper material to water ratio – Improper filtering of concentrated colors.

  5. Dyeing Defects

  6. Bleeding • It’s a loss of color when the dyed fabric is wetted or emerged in water. • The water here, becomes colored and may cause discoloration of other fabrics. • This is usually due to either improper dye selection or poor dye fastness.

  7. Crocking • It is the rubbing off of the color. • It may rub onto another fabric. • This may be due to inadequate scoring subsequent to dyeing.

  8. Shade Bar • It is a horizontal band of a different hue running across the fabric. • It may be caused by a change of filling bobbin in the loom or a loom stop and start up

  9. Hole in sulfur dyed fabric • Caused due to tendering which takes place because sulphur is converted into sulphuric acid after oxidation which is harmful for the cellulosic fibers. • This is a major defect. The defect occurred after washing the garment.

  10. Off Shade • It refers to color that doesn't exactly match the standard or the prepared sample. • This may be due to faulty dye foundation or application or may be due to variation in dye lot.

  11. Uneven Dyeing

  12. Batch to batch Shade Variation

  13. Patchy Dyeing Effect

  14. Roll to Roll Variation

  15. Crease Mark

  16. Printing Defects

  17. Flushing/Wicking • Caused due to Low viscosity of print paste. • It 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.

  18. Bleeding • Caused due to Low viscosity of print paste • It is major defect as it happens throughout the fabric unless the viscosity is corrected.

  19. 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.

  20. Banding • Defect created by the print head’s movement over the substrate. • Use of scanning print head, or a print head that moves back and forth across the substrate in straight line placing drops of ink at precise locations along the line. • 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.

  21. Unwanted pigment marking on fabric • Caused due to screen has holes in it that should have been covered. This could be because of ageing of the screen and eventual damage or just improper exposure to light.

  22. Crack or miss alignment in transfer printed fabric. • Incomplete transfer of design from paper to fabric on transfer printing due to removal of transfer of paper while the fabric was still hot.

  23. Finishing Defects

  24. FABRIC FINISHING • A series of processing operations applied to gray fabrics to enhance their appearance and hand, properties and possible applications. • Play a fundamental role for the commercial excellence of the results of textiles

  25. FABRIC FINISHING • The most simple form of finishing is the ironing or pressing on the fabric. • In finishing , the fabric is subjected to mechanical and chemical treatment in which its quality and appearance are improved and its commercial value enhanced. • Physical finishing techniques(dry finishing processes) or chemical finishing methods(wet finishing) are used.

  26. FABRIC FINISHING • Functional finish: – Wearability, Hand, Mechanical resistance, Easy care, Wettability, Washability, Deformability, Anti bacterial, Anti fungal, Soil-proof and Fire-proof ability • Aesthetic finishes: – Aesthetic looks

  27. Unwanted marks on fabric. • Oily stains with dust adhered to surface which makes the stains more prominent and difficult to remove, due to contact with oil or grease covered exposed machine parts, careless handling could be another cause.

  28. Decolorized patch on fabric • Caused due to – chemical spillage on fabric. – Localized excess bleaching. – Localized excess enzyme wash. • Can be result into weakening of the fabric.

  29. Pin Holes • Holes along selvage caused by pins holding fabric while it processes through tenter frame. • Major defect if pin holes extend into body of fabric far enough to be visible in the finished product.

  30. Sanforize Pucker • Results from uneven wetting out on sanforize. • usually caused by defective spray heads. • Fabric will appear wavy or puckering when spread on cutting table. • Difficult to detect during inspection on inspection machine with fabric under roller tension.

  31. Bowing • Usually caused by finishing. • Woven filling yarns lie in an arc across fabric width; in knits the course lines lie an arc across width of goods. • Establish standards of acceptance. Critical on stripes or patterns; not as critical on solid color fabrics.

  32. Pilling • Pilling is a common fabric defect occurring on knitted and woven fabrics. • In producing a yarn, long fibers tightly-twisted produce a serviceable yarn. When short stable fibers are mixed into the yarn the result is a yarn that will not hold together. The short staple fibers will separate from the yarn and curl up in a ball, forming what is referred to as a pill. • Pilling is accentuated by the friction of normal wear, washing and routine dry cleaning.

  33. Water Spots • Usually caused by wet fabric being allowed to remain too long before drying; color migrates leaving blotchy spots. Selvage Torn • Usually caused by excessive tension while processing through tenter frames.

  34. Cuts or Nicks • Caused by indifferent handling of scissors. snips or mechanical trimmers. Soil Caused by oil, grease or dirt. Often times originating from a dirty work area or machinery not properly cleaned

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