They are used to qualify or quantify the various elements of textile.
Units to qualify the yarns
The metric number (Nm) is widely used for (staple) fibers. It represents the number of meters of yarn per gram. The higher the Nm, the finer the yarn.
The DeciTex (Dtex) is the standardized unit. It is defined by the weight in grams of 1000m of yarn.
Denier (Ds) is still used for silk yarns as well as for determining the opacity of pantyhose. It is the weight per 9000m of yarn.
For knitting machines, this is the number of needles present on 1 inch (2.54 cm). This determines the approximate size of the yarn accepted in the machine as well as the fineness of the knitted fabric that comes out of the machine.
The English use different units :
The English cotton number (Ne.c) is expressed as the number of skeins of 840 yards (768.1 m) in an English pound (453.6 g).
The English linen number (Ne.l) is expressed by the number of skeins of 300 yards (274.32 m) in an English pound (453.6 g).
The English wool number (Ne.w) is expressed as the number of skeins of 560 yards (512.06 m) in an English pound (453.6 g).
Units to qualify the resistance
The centi Newton / Tex is a unit allowing to qualify the elastic capacity of a textile or a thread. This measurement is taken with a dynamometer. The elastic limit of a material is defined by the force in cN/Tex that it is able to support and then return to its initial shape, without deformation.
Mega Pascal is a pressure measurement used to determine the breaking stress of a textile or yarn. This means how much force the material is able to withstand before breaking.
The units to qualify the weight
GSM are grams per square meter. This measurement is commonly used to characterize a textile.
It is the unit of measurement of ounces, an English measure to qualify the weight per square meter. It is still commonly used today for denim (jeans). (1 Oz = 28.35 g).
The units to qualify the thermal resistance
Unit for measuring the thermal resistance of textiles. It is widely used for fireproof textiles such as firefighters’ equipment for example.
European unit for measuring the thermal resistance of textiles. 1 tog = 0.645 clo (European unit).
This is the limiting oxygen index, the measure of flammability. This unit is expressed in percentages (%) and defines the oxygen level of the atmosphere. This parameter is used to calculate the capacity of a textile to ignite when exposed to a flame.
The unit to qualify the hydrophilicity
This is the percentage of a material’s moisture recovery. Simply put, it is the percentage of its own weight that the material is able to absorb. For example, 100 grams of wool can absorb 18.25 grams of water, so it has an RH of 18.25%.
Conversions of length units
- Feet : x 0,3048= m
- Inches : x 2,54 = cm
- Miles : x 1,6093 = km
- Yards : x 0,9144 = m
Mass unit conversions
- Ounces (Oz) : x 28,35 = g
- Pounds : x 0,4536 = kg