Faults in the Knitted Fabrics (part 7)

WetSqueezer Marks
Definition:
The fabric on the edges of the fabric tube gets permanent pressure marks due to the hard pressing by the squeezer rolls. These marks appear as distinct lines along the length of the fabric & can’t be corrected.

Causes:

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

Remedies:

• 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.

FoldingMarks
Definition:
Fold marks appear as distinct pressure marks along the length of the fabric.

Causes:

• 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.

Remedies:

• 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.

CreaseMarks
Definition:
Crease marks appear in the knitted fabric, as dark haphazard broken or continuous lines.

Causes:

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

Remedies:

• 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.

HighShrinkage
Definition:
The original intended measurements of the Garment go, haywire, during storage or after the very first wash.

Causes:

• 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

Remedies:

• 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.

GSMVariation
Definition:
The fabric will appear to have a visible variation in the density, from roll to roll or within the same roll of, the same dye lot.

Causes:

• 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.

Remedies:

• 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.

FabricWidth Variation
Definition:
Different rolls of the same fabric lot, having difference in the finished width of the fabric.

Causes:

• 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.

Remedies:

• 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.

Measurement Problems
Definition:
The measurements of the garments totally change after, a few hours of relaxation & after the first wash. The arm lengths or the front & back lengths of the garments may vary, due to the mix up of the parts.

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