Calculating Loom State Thread Spacing and Finished Density Relationships
Finished fabric density derives directly from loom reed spacing and total length shrinkage across wet processing.
Starch Size Add On
Sizing Quantity
Percentage weight increase of dry yarn after sizing has been applied represents a critical parameter in prepare-for-weaving operations. This value, called the starch size add on, must be kept within tight tolerances to ensure that the warp yarns survive the abrasive action of the loom. It varies depending on the yarn count and weave density.
Weaving Efficiency
Insufficient chemical coating results in yarn hairiness that leads to clinging and breakage during shedding. When starch size add on is too low, the protective film cannot withstand the rapid abrasion of the reed, which increases machine downtime and ruins the fabric quality. An optimal coating balance must be achieved for high productivity.
Laboratory Extraction
Chemical analysis of a dry sized yarn sample involves washing the starch away with enzymes and weighing the residue to calculate the exact treatment level. To obtain a true starch size add on value, technicians dry the yarn to its standard moisture regain before and after the desizing process to avoid weight inflation from moisture. This test is done on every batch before weaving starts.
Desizing Impact
Excessive amounts of starch on the woven fabric require larger volumes of water and enzymes to wash out during finishing. High starch size add on increases the chemical load of waste water. This requires thorough effluent treatment.