Definition: Cotton yarn is derived from the spinning of fibers extracted from the hairs covering the seeds of the plant genus Gossypium.
Classification of Cotton
The classification of cotton is crucial as the name and value of the fiber depend on its place of origin. Each cotton type has a specific nomenclature based on variety. The main commercial classifications include:
Sea Island Cotton:
Origin: North America
Description: Features a silky fiber, making it the highest quality cotton; used for refined processing.
Fiber Length: Varies from 3.8 cm to 6.3 cm.
Color: White.
Egyptian Cotton (Makò):
Description: Characterized by a very white color.
Fiber Length: Ranges from 3.1 cm to 3.8 cm.
American Cotton (Upland):
Description: Known for its short fibers, named according to its origin (e.g., Texas, Mississippi).
Fiber Length: 1.9 cm to 2.5 cm.
Indian Cotton:
Varieties: Include 'Madras' and 'Surat'.
Description: Typically possesses even shorter fibers and is considered to be of poorer quality.
Usage: Only the best types are used for thick yarns; otherwise, they are not suitable for spinning.
Properties of Cotton Fiber
Origin: Cotton is of vegetable origin.
Durability: Highly resistant to boiling and ironing.
Moisture Absorption: Exhibits a high capacity to absorb moisture, making it a good conductor that facilitates body heat dispersion.
Flaws:
Low elasticity.
High shrinkage potential.
Tendency to crease easily.
Behavior Under Humidity: Unlike other fibers, cotton's toughness increases with humidity, making it more resilient.
Degradation Temperature: Cotton deteriorates only at high temperatures (above 150°C), maintaining its elasticity at lower temperatures.
Washing:
Can be washed by hand or machine without issues.
Resistance increases when the fiber is wet.
Recommended Washing Temperature: Can be washed at high temperatures (up to 90°C) using strong alkali detergents.
Caution: Direct sunlight during drying should be avoided, as it may cause the fiber to yellow.
Types of Cotton Yarn
Virgin Cotton:
Definition: Fibers are worked for the first time.
Regenerated Cotton:
Definition: Obtained by reprocessing already used fabric.
Mercerized Cotton:
Definition: Cotton treated in a caustic soda bath, resulting in a yarn with a better hand, increased shine, and improved dyeing affinity.
Gassed Cotton:
Description: This type undergoes an industrial process involving passing the yarn over flames. The burning of protruding fibers results in a more uniform, smooth texture with a dry feel.
Combed Cotton:
Description: Involves the removal of short fibers and impurities, producing yarn with parallel fibers of consistent length.
Note: Approximately 28% of the initial raw material is discarded during this process.
Makò Cotton:
Description: Composed of twisted and mercerized Egyptian cotton, known for its quality.
Summary
Cotton is a widely used natural fiber with various classifications depending on its origin and manufacturing processes. It offers distinct properties and imperfections that make it unique compared to other fibers. Understanding these classifications and properties is essential for textile production and fashion design.