Most Important Textile Fibers and Their Densities

Density:
Fibers with different densities but of equal diameter will have different covering power that is the ability to cover a surface. Fabrics made with fibers of different densities will have difference in fabric appearance, flexibility, air permeability and cover. The linear density of a fiber is commonly measured in units of denier or tex

The density, also called volumic mass or mass density, is the mass per unit volume and has ρ as its symbol. It is usually expressed in grams per cubic centimeter. Another term is specific gravity, which is the ratio of the mass of a fiber material and the mass of an equal volume of water (density 1g/cm3). The specific gravity of a substance vis-a-vis water equals the numerical value of the (absolute) density of this substance if it is expressed in g/cm3. Every fiber is characteristics by its density, which can be measured in various ways.
Different textile fiber
Fig: Different textile fiber
Measurement of density can be carried out with a gradient column, where the liquid in the tube has a density which varies in height. If a fiber is dropped in the tube, it will sink to the point at which the fiber density equals the liquid density, and remain suspended there.

This experiment is based on the fact that a fiber which is submerged in a liquid with the same density will sink nor drift but float, and that the density of a liquid can easily be measured. Treatments for finishing fibers can influence the results. Foreign substances on or in the fibers must be removed before doing the experiment.

The list below gives an overview of the most important fibers and their densities.
Textile Fibers
Fiber densities in g/cm3
Commercial name
Cotton
1.55
Raw
Cotton
1.54
Mercerized
Flax
1.50

Jute
1.50

Wool
1.30
No brand
Silk
1.33
Natural
Silk
1.60
Weighted
Silk
1.32
Tussah
Polyester
1.22
Kodel, vestan
Polyester
1.38
Teryleen, Dacron
Viscose
1.53

Cuprammonium
1.53

Polyurethane
1.15
Lycra
Polypropylene
0.90
Meraklon
Polyethylene
0.92
Courlene
Polyethylene
0.95
Courlene X3
Nylon 6
1.13
Perlon
Nylon 66
1.14
Tri-nylon
Acrylic
1.14-1.17
Orlon (staple/filament)
Polyvinyl alcohol
1.30
Kuralon, vinal