Cotton Fibres Characteristics Consider For Spinning Process
Fibre length is one of the most important fibre characteristics.
- Yarn strength.
- Yarn evenness.
- Handle of the product.
- Lusture of the product.
- Yarn hairiness.
Different stable length of Cotton:
Short staple —- 1 inch Or Less.
Medium stable —- 1 1/32 inch to 1 1/8 inch.
Long stable —- 1 5/32 inch to 1 3/8 inch.
Extra long stable —- 1 13/32 inch to Above.
Fibre Fineness is one of the most important fibre characteristics. It determines how many fibre are present in the X-section of a yarn of given thickness.
Fineness is usually specified by the relation of mass (weight) to length (Km).
\Tex = mass/length
The Fineness scale is as follows:
MIC value Fineness
Up to 3.1 Very fine
3.1 to 3.9 Fine
4.0 to 4.9 Medium
5.0 to 5.9 Slightly Course
Above 6 Course
The minimum strength for a textile fibre is approximately 6 CN/Tex. In relation to cotton the strength of fibre bundles is measured and stable as the pressley value.
\Pressley Index = Breaking strength in lbs / Bundle weight in gm.
Pressley Index Strength
93 – Above Excellent
87 – 92 Very strong
81 – 86 Strong
75 – 80 Medium
70 – 74 Fair
Under 70 Weak
Fibre maturity means the thickness of cell wall. The more thickness, the maturity. Unripe fibres have neither adequate strength nor adequate longitudinal stiffness.
They therefore lead to:
- Loss of yarn strength.
- A high proportion of short fibres.
- Varying dye ability.
- Processing difficulties mainly at the card.
It is a very important factor for spinning. Without this fibre could not be spinned. Elongation of cotton fibre 6-10%.
Cleanliness & Trash content:
Generally many types of foreign matter may contain in cotton stocks.
Vegetable matter Mineral matter Other foreign matters
- 1.Husk 1. Soil 1. Metal fragments
- 2.Seed 2. Sand 2. Cloth fragments
- 3.Stem 3. Dust 3. Packing fragments
- 4.Leaf fragments
- 5.Wood fragments
As spinning process is sensitive to impurities. So the fibre should be main taired clean as far as possible. The reason for fibre containing such foreign matters are:
Modern high performance plucking system
- Hard ginning, cleaning & pre-drying
- Cleanliness, handling, during transportation & pack.
The scale below represents the degree of contamination:
Up to 1.2% ——————— Very fine
1.2 to 2.0% ——————— Clean
2.0 to 4.0% ——————— Medium
4.0 to 7.0 % ———————- Dirty
7.0 to Above ———————- Very dirty
Effect of unclean fibre:
Additional stress on personal.
- Environment problem.
- Effect on the production.
- Stressing of the machine.
Brand Name Country
Pima, Arizona & SJV ———– USA
Eluna, Parvee & Ronda ———– CIS
Giza ———– Egypt
Andy ———– Australia
Suvin ———– India
Delta ———— Bangladesh
Barakat ———— Sudan