It is in reality fun to get a good deal while buying a fabric for any given purpose from dress material to bed sheets. Nobody minds saving a bit during shopping spree, except for the business organisations; it is a huge loss to the business when a fabric has to be sold as seconds or even at lower price. While determining the percentages of various costs which add to the garment cost it is realised that the raw material cost 50 percent, direct labour cost 20 percent, indirect labour charges and factory overheads 30 percent. An error during fabric manufacturing can imply reduction in the relative cost of fabric. Though all the factors involved in making a garment are significant, it is the fabric that dominants the cost factors and thus it should be managed properly. It can save a lot of funds if properly managed.


Identifying the faults that occur during manufacturing process at various stages is a must for the textile houses, as a single fault can reduce the cost of fabric by 45 percent to 65 percent. The defects that occur during fabric manufacturing process are classified as yarn related defects, knitting elements related defects, machine settings related defects, dyeing and finishing related defects, non-woven fabric defects and other common defects.


Yarn related defects: The yarn related faults appear in the horizontal direction on the fabric. These defects include barriness, thick and thin lines, dark or light horizontal lines (due to the difference in dye pick up), imperfections, contaminations, snarling and spirality.


ff2.jpgKnitting elements related defects: Almost all the defects appearing in the vertical direction in the knitted fabrics are as a cause of bad knitting elements. Needle, sinker lines and drop stitches etc. are examples of the same.


Machine setting defects: Machine settings related defects appear randomly in the knitted fabrics due to the wrong knitting machine settings and that of the machine parts. The defects mainly include yarn streaks, fabric press off, barriness, drop stitches, spirality and broken ends.


Dyeing related defects: This category includes softener marks, dyeing patches, colour fading, tonal variation, crease or rope marks and shade variation.


Finishing related defects: Defects caused mainly due to the wrong process parameters in finishing process are high shrinkage, skewing, surface hairiness and snagging (sharp points in the dyeing machine or trolley etc.), tonal variation, wet squeezer marks, fold marks, fabric width variation, pilling, GSM variation, and curling.


Defects in non-woven: Fabric faults in non-woven fabric include weight variation, needle break, poor opening, needle punch not up to the level, weak adhesive, defective spraying, defective stitching, defective felting and bonding.


Other common defects: Nevertheless, the most common faults in fabric include abrasion mark, which is a place in the fabric where the surface has been damaged due to friction or abnormally weakened by any operation through which it has been passed. There's double pick i.e. two yarns running simultaneously, mostly in the weft yarn. Oil stain marks during manufacturing process on the fabric are also common. A hole in fabric, resulting from a breakage of yarns in the fabric involving more than two yarns, bow which emerges as lines of yarn dyed stripes that form a bow shape along the width of fabric, et al are frequently occurring defects that spoil the richness of fabric during manufacturing process.


Recognising the various sorts of defects in fabric can help and some of the faults can easily be prevented. In yard related defects, ensuring uniform yarn tension on all the feeders with a tension meter can help in avoiding the faults. Also rating of yarn feed should be strictly regulated as per the required stitch length; the fabric tube should be just like a fully inflated balloon, not too tight or too slack; the yarn being used should have no imperfections like slubs, neps and big knots and the gap between the cylinder and the dial should be correctly adjusted as per the knitted loop size, to avoid faults.


To avoid barriness the average count variation in the lot should not be more than + 0.3, yarn being used for knitting should also be of the same lot and the hardness of all the yarn packages must be uniform. If winding of the yarn package is proper and the yarn is run between the belt and around the pulley, streakiness will never occur. To overcome the defect of imperfections, use of rich fibre mixing for the yarns in order to have less dead fibres appearing in the fabric is must. It is also required to take rigid control measures in the blow room to prevent the mixing of foreign matters in the cotton mixing. To overcome barriness segregation of the machines is required to avoid the fibres from flying in the machines placed nearby or also from getting entrenched in the yarn/fabric. This can be achieved with plastic curtains or mosquito nets.


Some companies prefer part changing technique to mend the defects in fabric. Part changing is done in finishing stages; in this process only the damaged parts of garments are changed by using good components from other products. However, even with these techniques chances are that defect will be passed down to the final product.


Defects are a reluctantly accepted by-product of textile production and more than often irregular loom operation during manufacturing process in textile mills results in excessive, reduced-price, second-grade merchandise all around the world. No organisation would ever appreciate product recall; it is an unpleasant experience that can even besmirch the organisation's image. In case of textile industry, the chances of a flawed fabric going unnoticed are high, as several companies still prefer manual checking process over machine process. However, a product recall is every company's nightmare and in textile companies the fabric flaws and faults can easily be detected or even avoided. The fabric faults in manufacturing processes vary, as the faults can occur anytime during knitting, yarn manufacturing, machine setting, dyeing or finishing et al.

 

Complete evasion of fabric faults is impossible, but a little alertness during manufacturing can mean production of perfect fabrics. The signs of fabric faults must be taken seriously at the initial stages, as it will ensure that the problem is solved before it becomes monstrous.


References:


1.      Textlielearner.in

2.      Indiantextilejournal.com

3.      Onlineclothingstudy.com

4.      4.comp.poly.edu.hk


Image Courtesy:


1.      Uster.com

2.      Primeasiantextile.blogspot.com