Material Density
A physical property of a material represents the ratio of its density to the density of water at a specified temperature. For textile designers, fiber specific gravity determines the weight and drape of a yarn or finished fabric. This value is used to calculate the cover and yield of different fibers, allowing developers to predict fabric thickness before weaving begins.
The ratio does not change with yarn twist or fabric construction.
Buoyancy Test
Testing laboratories measure this property by submerging the fibers in a liquid of known density. Low-density fibers like polypropylene float or require less force to submerge, while high-density fibers like cotton sink quickly. The measurement must be conducted at a constant temperature to ensure accuracy.
Yarn Yield
Fibers with low density provide high warmth and volume without adding weight to a garment. This characteristic is valuable in activewear and thermal blankets where low weight is preferred. The specific gravity values vary from light synthetics to dense natural fibers.
Structural Effect
Spinners use these density values to calculate the required yarn count for a specific fabric thickness. A fabric made from a low density fiber will be thicker than a fabric of the same weight made from a high density fiber. This physical property assists in selecting the appropriate raw materials for specific fabric designs.
