Fabric defect · Woven fabric - Filling bars and weft bars in fabric

ConductVision Textile is designed to flag each defect with its place on the roll, its size, its points and a still image. Your inspector names the defect and confirms or dismisses it.

On the defect map in the roll report, a filling bar crosses the width, so its place along the roll marks where the band starts.

A U.S. federal glossary of fabric imperfections defines the heavy filling bar as "a fillingwise band or bar either across the full width of the cloth or a portion of it," with picks thicker than normal or more of them, and the light filling bar as the same band with finer picks or fewer of them ¹. Filling that differs from the rest, such as the wrong twist, color or yarn lot, it calls mixed filling or a shade bar ¹.

Goldberg's 1950 casebook calls a wide band a filling band, "generally at least several inches in width with a different appearance in shade or luster," sometimes one or more whole bobbins of yarn ². A filling change is a band that starts at a knot or a filling-bobbin transfer and gradually fades ².

Some bars hide in the greige goods. Goldberg notes that uneven pickage is not always easy to see before dyeing; once the goods are dyed and finished, the dye penetrates unevenly and narrow bands show where the fabric is denser ².

A filling bar runs across the width, across all of it or part of it ¹. Its place along the roll is where the yarn or the loom changed. A band of mixed filling runs from one shuttle change to the next, a filling change starts at a knot or a bobbin transfer, and a set mark sits where the loom stopped ².

A bar across the full width is longer than 9 inches, so it gets 4 points, and one buyer manual gives each full-width defect a maximum of 4. A band that runs on along the roll for more than 9 inches gets up to 4 points in each linear yard it covers, and no linear yard gets more than 4 points, however many defects it holds ⁵.

A 1968 analysis of warp tension on the loom proposed that thick and thin places come mainly from swings in warp tension set up by the movement of the tension rollers. It also found that tension at a start or a stop differs from steady running, which it suggested shapes set marks ⁴.

A 2015 conference paper traced start-up marks to the cloth fell creeping out of place while the loom stood, and found that longer stops, finer yarn and stretchier yarn moved the fell further ³.