Defects in woven fabric inspection can be categories as imperfections relating to yarn, imperfections occurring in the Warp direction, imperfections occurring in the Filling direction, dyeing faults, printing faults as well as finish fault according to their causes. Because defects in woven fabrics can be a result of imperfections in the yarn, incorrect weaving, improper dyeing or printing, or mistakes occurring in the finishing operation. There are many different types of defects that can exist in a fabric. The following are some examples of woven fabric imperfections:
Imperfections relating to yarn
Slub or Slug: an abruptly thickened place in a yarn caused by the inclusion of “fly” or waste with the regular fibres when the yarn was being spun
Imperfections occurring in the warp direction
Broken End or End out: space in the fabric caused by a end wholly or partially missing from the fabric.
Mix End: End used in the fabric that is different than what is being used in the rest of the fabric. It could be a difference in yarn count/titre, twist, colour or number of plies.
Tight End, Slack End: one or more ends woven under excessive or insufficient tension.
Reed Marks: spaces or cracks between groups of warp yarns. They may be caused by yarns being too crowded or improperly spaced as they pass through the reed. Also the warp tension may be improper.
Warp Streak: Narrow bands or bars running warpwise. It may be caused by ends having different dye affinities, resulting in sections of yarns slightly different colour or shade. It may also be caused by rough mechanical parts of the loom abrading the warp yarns.
Wrong Draw or Misdraw:a section where one or mor dends have been incorrectly “drawn” through a harness or the reed.
Tight Selvage: warp yarns in selvage are under abnormally high tension, producing a pucker or wavy surface.
Imperfections occurring in the Filling direction
Broken Pick or Missing Pick: space in the fabric caused by a Pick wholly or partially missing from the fabric.
Mix Pick: Pick used in the fabric that is different than what is being used in the rest of the fabric. It could be a difference in yarn count/titre, twist, colour or number of plies.
Tight Pick, Slack Pick: one or more Picks woven under excessive or insufficient tension.
Barre Mark or Filling Band: a striped effect which repeats at intervals across the width of the fabric. It is caused by various conditions, including mechanical fault of the loom and yarn variations in lustre or dye absorption.
Filling Bar: a band across the width of the fabric. It is caused either by picks of different count/titre being used in this section of the fabric or the section having different picks per cm/inch than the rest of the fabric(usually from improper starting of the loom after it has been stopped).
Mispick: filling yarn not interlacing properly. Caused by starting the loom on the incorrect pick after the loom has been stopped.