Calculated Cover Factor Metrics for Heavy Cotton Twills in Batch Dyeing
Heavy twill cover factors above twenty-two impede jet dyebath penetration, requiring lowered heating rates and increased anti-crease lubrication.
Yarn Tex
Linear Density
A metric unit defines the mass in grams of one thousand meters of a specific filament or spun yarn. Using yarn tex provides a universal way to express the thickness of textile materials regardless of the fibre type or the spinning system used. It is a direct numbering system where a higher number always indicates a heavier and thicker yarn.
Precision in this measurement is vital for calculating fabric weight.
Standard Calculation
The weight of a known length of yarn is measured on a precision scale and then scaled to the one-kilometer standard. For example, if one thousand meters of a polyester yarn weigh twenty grams, the yarn tex is twenty. This system replaces older indirect units in international trade.
Manufacturing Control
Spinning mills monitor the consistency of the output to ensure the final fabric meets the customer specifications for strength and opacity. Variations in the yarn tex can lead to visible bars or stripes in the finished cloth (a defect known as barre). Adjustments to the draft ratio in the spinning frame are used to correct any drift in the density.
High-quality production requires tight tolerances on this value.
Measurement Condition
Testing must occur after the material has reached moisture equilibrium in a standard atmosphere to ensure the weight is accurate. Results are often reported as an average of multiple samples.