COTTON GRADING
The textile sector is highly profitable and competitive. Cotton fiber quality must meet
minimum standards. To remain competitive in the marketplace, the product quality must be
maintained.
Cotton is graded based on a number of different factors.
Cotton fibers are graded primarily based on the following quality criteria:
Typical fiber length
The mean fiber length is calculated after ginning. This distance is expressed in either
millimetres (mm) or inches. This is how mean fiber length is categorised.
Span size
Utilizing a computerised fibrograph, the 20% span length and 50% span length are
examined. It is a standard measure of cotton fiber length that is recognised globally. It can
be measured in inches or millimetres. Span lengths over 2.5% are categorised as follows:
Classification of a span length of 2.5%
Fineness fiber
Weight per unit of fiber length determines fiber fineness. Weight and fiber fineness per unit
length are inversely proportional to one another. The basis for categorising the fineness of a
fiber is its micronaire (Microgrammes/inch) grading.

fiber tenacity
fiber maturity-coefficient
The maturity of the fiber is influenced by cotton development. Compound microscopes are
used to determine the maturity of fiber. 100 to 200 fibers are placed on a slide and
moistened with an 18% caustic soda solution to calculate the maturity co-efficient. The
maturity co-efficient is categorised as follows:

x
Uniformity Ratio
This trait indicates the consistency of cotton fiber length. The ratio of 2.5% span length to
50% span length, presented as a percentage, is the uniformity ratio of cotton fiber. Following
is a classification of uniformity ratio:
Colour appearance of cotton
Classification of cotton colour is based on the yellow colour present in cotton. In India
according to colour cotton is classified as follows:

• White
• Gray
• Pearly