  Total Texle Process at a Glance PROJECT ON Root Causes Analysis of knitted Fabric Faults & Their Remedies 3 3 Content  Introduction  Causes of Fabric faults due to yarn  Causes of Fabric faults due to knitting  Causes of Fabric faults due to Dyeing & Finishing  Conclusion 4 4 Introduction Due to increasing the demand for quality knitted fabrics, high quality requirements are today greater since customer has become more aware of “Non-quality" problems, in order to avoid fabric rejection, knitting mills have to produce fabrics of high quality, constantly. Detection of faults during production of knitted fabric with circular knitting machine is crucial for improved quality and productivity. Any variation to the knitting process need to be investigated and corrected. The high quality standard can be guaran teed incorporating appropriate quality assurance. Industrial analysis indicate that quality can be improved, and defect cost minimized, by monitoring of the circular knitting process. 5 5 Our aim of this project is to study on root causes analysis of knitted fabric faults. To do so we have collected various type of faults from many industries and classify them in a systematic manner 6 6 Causes of Fabric faults due to Yarn Almost all the defects appearing in the horizontal direction, in the knitted fabric are, yarn related.  These defects are mainly: I) Barriness II) Spirality III) Shrinkage IV) Thick & thin place 7 7 I). BARRINESS Definition: Barriness defect appears in the Knitted fabric, in the form of horizontal stripes of uniform or variable width. 8 8 Fig:Barriness Causes Of Barriness: factors which may cause or contribute to barre are listed as follows:  Raw material/fiber  Yarn formation /supply  Knitting machine 9 Raw Material/Fiber:  Failure to control fiber diameter (micronaire or denier) from lay down to lay down.  Too high a C.V. of micronaire in the lay down for a given mill's opening line blending efficiency.  Failure to control the fiber color in the mix (grayness Rd, yellowness +b). 10 [...]... in fabric Fig: Thick Thin Place 19 Causes of Fabric faults due to Knitting  Almost all the defects appearing in the vertical direction, in the knitted fabrics, are as a cause of bad Knitting Elements And some defects appear randomly in the knitted fabrics, due to the wrong knitting machine settings & that of the machine parts  About Different type of faults are discuses bellow 21 Cracks Or Holes... 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 Calendaring machines 18 (IV) Thick & Thin Places It causes due to yarn problem If thick & thin places remain in yam & fabric is knitted with that yarn, then, this problem found in fabric Fig:... twisted garment, after washing The seams on both the sides of the garment displace, from their position & appear on the front & back of the garment Fig: Spiraility 14 Influencing Factors: A) Influence of yarn properties  Count  Twist  Blend B) Influence of fabric properties:  Fabric Stitch length:  Fabric Structure  Fabric Tightness 15 (III) SHRINKAGE  A dimensional change resulting in a decrease... Fig: Stain or oil line 29 Remedies:  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 30 Fabric Press Of  Fabric press off appears, as a big or small hole in the fabric, caused due to the... causes this fault Remedies:  Sinker has to be clean  It should be checked that the sinker having correct thickness and depth  Replacement of defected sinkers Fig: sinker mark 28 Stains or Oil Lines Stains appear as spots or patches of grease, oil or dyes of different color, in a neat & clean finished fabric surface Causes:  Grease & Oil stains from the unguarded moving machine parts  Fabric touching... mainly due to yarn swelling and the resulting crimp increase during washing in case of cotton fabrics 16 Causes of Shrinkage:  Twi s t factor: twist factor increases so that shrinkage will be increases,  Stitch length: stitch length increases so that shrinkage will be increases,  GSM: GSM increases so that shrinkage will be increases 17 Remedies of Shrinkage  Keep the Grey Fabric in loose plated form,...  Fail to catch the Lycra yarn by needle Remedies:  Ensure the feed of lycra yarn to every needle  The tension of lycra yarn should be uniform 34 Slub Causes:  Usually caused by a thick or heavy place in yarn or by ling getting onto yarn feeds Remedy:  By using Good quality yarn Fig: Slub 35 Causes of Fabric faults Due To Dyeing & Finishing 37 The Dyeing and finishing related defects are, as follows... the needles Fig: Press off 31 Remedies:  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 32 Lycra out Causes:  Fail to catch the Lycra yarn by needle  Low tension of Lycra yarn  Lycra yarn breakage  Faulty auto stop motion Remedies:  Ensure the feed of... Dyeing Fig: Fly contamination 25 Remedies  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 26 Needle Broken Causes:  High Yarn Tension  Bad Setting of the Yarn Feeders  Old & Worn out Needle set Remedies:  Ensure uniform &... properly set,  Poorly lubricated yarn Fig: Hole 22 Remedies:  Use of flat knots  Yarn regularity control  Yarn consumption & coulier re-adjustment  Precise yarn - guide resetting  Air humidification  guide blowing  Use of protective filter creel 23 Pin Hole Causes:  Improper tension  Same drive for both knit & tuck stitch  Curved needle latch Remedies:  Different drive have to maintained Needle . Analysis of knitted Fabric Faults & Their Remedies 3 3 Content  Introduction  Causes of Fabric faults due to yarn  Causes of Fabric faults due to knitting  Causes of Fabric faults due. causes analysis of knitted fabric faults. To do so we have collected various type of faults from many industries and classify them in a systematic manner 6 6 Causes of Fabric faults due to Yarn Almost. appearing in the vertical direction, in the knitted fabrics, are as a cause of bad Knitting Elements. And some defects appear randomly in the knitted fabrics, due to the wrong knitting machine