Fabric Defects

                                                             Fabric Defects

Definition:-  Defects in the fabric are the major problem in weaving. Defect will reduce the quality as well as appearance o the fabric.

Some major or frequently occur defects  in the fabric are explaining here:-

1.     Starting  mark :

An isolated narrow bar running parallel with the picks, starting abruptly & gradually shading away to normal cloth. This is due to abrupt change in the pick spacing followed by a gradual coming back to normal pick spacing.

   Cause:

·         Restarting wvg. M/c after pick finding.

·         Reed (loom) stops ahead from the place where it should stop (generally loom stops at 40⁰),so that sufficient moment is not generated during the next pick beating and results in starting mark.

2.     Weft Bar :

A bar due to difference in material, count, twist, lusture or shade of the adjacent     groups of weft yarns.

3.      Reed Marks :

Irregular spacing between the groups of warp yarns across the width of the fabric.   The defect may be caused by a damaged or defected reed, i.e. dent opened or gap is more than normal between two dents.

4.     Missing ends / Ends out / Chira :

This most commonly characterized by a gap of one or more warp end in the fabric.

The main causes are:-

• The weaver is careless, not mends broken ends immediately.
• Missing ends in the beams.

                                         

5.     Patti :

Take up roller jammed or move slowly in between the regular process due to some   mechanical fault than a thick place or closer pick spacing results known as Patti or thick bar.

6.     Thin : 

Due to some mechanical fault take up roller moves little bit faster, gives a fault known as thin bar.

7.     Double pick :

In plane weave if after loom stops due to pick breaking, loom is not turned back to its initial position than two pick are comes in the same shed, resulting the defect named double pick.

8.     Design Cut :

If the above defect occurs in the dobby design, design gets disturbed & defect is known as design cut. Clean Fluffs & use thicker dobby card (250 Microns) for Sulzer.

9.     Temple mark :

Holes or surface disturbances along the selvedge of a fabric due to bad or improperly adjusted temples

10. Slub :

Fly accumulated at drop pin or heald wire goes along with the warp in the fabric create slub in the fabric, gives defect in finishing if not removed.

11. Wrong Weft Pattern :

Hole is not punched properly for weft colour selection or some mechanical mistake is selection needle, result something wrong weft to be inserted thus give defect known as wrong weft pattern.

12. Pattern Break :

    Shed not opened properly due to some mechanical fault, gives pattern break.\

13. Broken pattern :

This defect may be due to wrong drawing of threads,inserting a pick                                       in the wrong shed, incorrect lifting of warp threads.

14. Cracks :

A narrow streak parallel to the weft due to the pronounced opening between two adjacent yarns. Any loom condition that permits erratic operation of the sley or yarn of its parts will create cracks in the fabric.

A loosed-reed, that is, one that has excess freedom in the sley, will also caused this defect. A take-up motion which is sticking may produce cracks in the fabric.