Botanical Names of Cotton Fibre

1. Gossypium Herbaceum:  - Fibre length: 20mm – 26mm  - Producing country: India, China, Bangladesh	3. Gossypium Arboreum: - Fibre length: 15mm – 30mm - Producing country: India, Russian, Pakistan, China, America
2. Gossypium Hirsutum: - Fibre length: 25mm – 30mm - Producing country: Pakistan, India, China, Russian, South America	4. Gossypium Barbedense: - Fibre length: 30mm – 60mm - Producing country: Egypt

Types of Impurities Found in Raw Cotton

The types of impurity found in raw cotton are: 

• Seed: this is the largest type of impurity found in raw cotton. It may consist of un-ginned seeds, with fibres still attached, ginned seeds or under-developed seeds and part of the seed.
• Chaff: A collection of vegetable fragments, most of them consisting of leaf, bract, and stalk. A bract is a form of small leaf growing beneath the cotton ball. 
• Dirt: Sand and soil which originates from the cotton field. 
• Trash: The term trash is often applied to the combination of all the above impurities.

Chemical Composition of Different Fibres

Chemical composition of cotton fibre:

Cellulose	94%
Protein	1-1.5%
Pectic Acid	1%
Mineral substances	1%
Acids, Sugars, Pigments	2%
Waxes	0.5%

Chemical composition of Jute fibres:

Cellulose	65.2%
Hemi-cellulose	22.2%
Lignin	12.5%
Water Soluble matter	1.5%
Fat and Wax	0.6%

What are the by-products of cotton fibre manufacturing?

Ginning: is a process of separating the cotton fibres from cottonseed. During cotton fibre manufacturing (or producing or separating from seed), there has some other things being produced as the by-products as below- 

Cotton linters: Linters are short, fuzzy fibres that remain on the seeds after they have been separated from the fibre in the cotton gin. They are used in the manufacturing of rayon and acetates, plastics and photographic film.

Hulls: These are the outside portion of the cotton seeds rich in nitrogen and used as fertilizers, paper cattle feed.

Inner seed: It yields cottonseed oil which is used as cooking oils and in the manufacturing of soap.

Impact of Fiber Properties on Yarn and Fabric Quality

Fibre is the foundation of all textile products. To achieve the target fabric specifications, we must begin with the appropriate fibre properties. Different fibre properties have a significant influence on yarn as well as fabric quality. Let’s have a look as below- 

Fibre Quality	Definition	Yarn Impacts	Fabric Impacts
Micronaire value	The fineness and maturity of the fibre	Evenness/imperfections, spinning efficiency, strength etc.	Dye-ability, white specs, appearance, strength, etc.
Staple length	The length of the fibre reported as the average length of the longer one-half of the fibre (upper half mean length).	Evenness/imperfections, spinning efficiency, strength, hairiness, etc.	Appearance, strength, pilling, etc.
Length uniformity	The length variation of the fibres and the best indicator of short fibre content.	Evenness/imperfections, spinning efficiency, strength, hairiness, etc.	Appearance, strength, pilling, etc.
Strength	The amount of force required to break a bundle of fibre.	Spinning efficiency, strength, etc.	Strength
Colour grade	The fibre reflectance and yellowness of the fibre.	-	Dye-ability and appearance.
Trash grade	The amount of leaf, plant, and other non-lint material in the cotton fibre.	Spinning efficiency	Dye-ability, white specs and appearance, etc.

Difference Between Fibre and Textile Fibre

Fibre is the constituent unit of a material whose length is a thousand times longer than the diameter or thickness. Fibre may be spinnable or not. 

Textile fibre is that fibre, which can be further converted into yarn and then fabric through various subsequent processes like weaving, knitting, braiding, felting, and so on. So textile fibre is also one type of fibre but all fibres are not textile fibre. Fibres must have some characteristics to be textile fibres.

Classification of Textile fibres?

Different types of textile fibres can be classified as below diagram. 

Fiber Characteristics Being Influenced by Staple Length

Staple Length of fibre: The average spinnable length of fibre is termed as the staple fibre. For example, short-staple cotton fibre is up to 1 1/8" long. A long-staple fibre is between 1 1/8" and 1 1/4 "long. The extra-long staple fibre is between 1 3/8" and 2" long.

Staple length influences the following fibre characteristics:

i. Spinning limit.

ii. Yarn evenness.

iii. Handle of the product.

iv. The lustre of the product.

v. Yarn hairiness.

vi. Productivity.

How to calculate Lycra percentage in Elastic Core Spun Yarn

Md. Bashar Uddin 

Lecturer, Department of Yarn Engineering, Bangladesh University of Textiles 

Core Spinning: Core spinning is a process by which fibres are twisted around an existing yarn, either filament or staple spun yarn, to produce a sheath-core structure in which the already formed yarn is the core. The production of Core-spun yarns are done successfully by most of the spinning system with or without any additional attachments.

Bi-Component Fiber

Emdadul Haq

Lecturer, Department of Textile Engineering, Primeasia University; Bangladesh

Bi-component Fibres

Bi-component fibres are filaments made up of two different polymers that are extruded from the same spinneret with both polymers contained within the same filament but separated by a fine plane. The two polymers differ in chemical nature or physical properties such as molecular weight.

Why Bi-component Fibres?

The conventional fibres may not have all the desirable properties. By the use of bi-component fibres, the functional properties of both the components can be exploited in one filament. Further, the fibres can be produced in any cross-sectional shape or geometry. The properties of these bi-component fibres are governed by:

• Nature /properties of two materials.
• Their arrangement in the fibre.
• Relative proportion of the two.
• Thickness of the fibre.

Types of Bi-component Fibres

These fibres can be produced in many geometrical arrangements. On the basis of cross section, these can be classified as:

Comprehensive Viva Preparation | Smart Fibre Technology

Hemp Fiber and its Prospects for Sustainable Textiles

Md. Reajul Islam
PhD Candidate (Textile Engineering), Çukurova University, Turkey and Assistant Professor (Study Leave); Department of Yarn Engineering, BUTEX

Introduction  

Fibre from the industrial hemp plant is one of nature’s wonders – it is used in everything from stuffing furnishings to high-quality textiles. Hemp is a bast fibre extracted from the stalk of hemp plants that grow well in the soils, which are well-drained, rich in nitrogen, and nonacidic. Hemp is called a fibre of a hundred uses. True hemp is a fine, light-coloured, lustrous, and strong bast fibre, obtained from the hemp plant, “cannabis Sativa.” The bark of the hemp stalk contains bast fibres, which are among the earth’s longest natural soft fibres and rich in cellulose.

Chemical composition

Composition	Hemp	Cotton
Cellulose	60 - 70%	88 – 95 %
Hemicellulose	15 – 20%	--------
Lignin	2 – 4%	---------
Pectin	2 – 4%	0.7 – 1.2%
Oil and  wax	1- 2%	0.5%
Proteins, pectose and colouring matter	---------	1- 2%

Comprehensive Viva Preparation | Synthetic Fibre Technology

Comprehensive Viva Preparation | Textile Fibre & Polymer Chemistry

What is winding? | Elements of a winding unit | Yarn Splicing

Winding is the process of transferring yarn or thread from one type of package to another to facilitate subsequent processing. The re- handling of yarn is an integral part of the fibre and textile industries.

Elements of a winding unit

1. Lower yarn sensor
2. Gripper arm tube with shutter
3. Electromagnetic yarn tension sensor
4. Yarn splicer
5. Electronic yarn clearer

What is Zoning Sampling Technique?

Zoning technique: When bulk is not homogeneous, a number of sub-samples must be taken at random from different places in the bulk. Question is how much and how many times should be taken from the different position of the bulk of loose fibres like cotton. It certainly depends on the heterogeneity of the bulk/fibre bales. 

A comparatively large sample (2 ozs bulk) is drawn from the bulk and then divided into four parts. 16 small tufts are taken from each part randomly and after that, each tuft is halved four times. Each tuft is halved and one half is discarded at random; the retained half is again divided into two and half of that discarded. This process is repeated until getting 16 wisps from each part. Next, these wisps are combined to form a tuft and each tuft is again divided into four parts. A new tuft is obtained by combining a part of each of four tufts. The sample is mixed again by doubling and drawing and a quarter of the sample is taken out from each tuft to form the final sample. Zoning technique has been graphically illustrated as below-

Fibre Moisture Measurement | Importance

The moisture content of cotton makes significant changes in the physical properties of cotton and hence moisture content has to be known. High moisture content increases flexibility, toughness, elongation and tensile strength. If the moisture content is too high it causes difficulty in processing due to the tendency of the stock to lap-up on drafting rolls. Low moisture, on the other hand, facilitates cleaning but increases the brittleness of the fibre and results in fibre breakage during ginning, cleaning and mill processing. Low moisture also increases fly waste and may cause manufacturing difficulties due to static electricity.

Reference: A Practical Guide to Textile Testing by K. Amutha (Woodhead Publishing)

What is moisture content and moisture regain?

Moisture Regain: Moisture regain is defined as the amount of water (or moisture) expressed as the percentage of oven-dry weight.

Moisture regain, MR = (W / D) × 100%,  where W = weight of moisture; D = Oven dry weight of the sample

Moisture Content: Moisture content is defined as the amount of water expressed as the percentage of the original weight of the sample. 

Moisture content, MC = [W / (W+D)] × 100% 

                                     = MR / [1 + (MR/100)], where W = weight of moisture; D = oven dry weight of sample, W + D = original weight of sample.

Oven-dry weight: It is the weight of the sample after removing all water or moisture by heating in an oven at 105℃ to constant weight. The weight of the water is the difference in the weight of the sample before and after drying. 

Yarn Numbering System | Count

Count: It is a numerical expression of yarn fineness or coarseness and also indicates the relationship between length and weight (the mass per unit length or the length per unit mass) of that yarn. Another term ‘linear density’ is also used to express the yarn fineness or coarseness. We can have an idea about the yarn diameter by yarn count. 

Classification of Count:

1. Direct Count system (weight per unit length)

2. Indirect Count system (length per unit weight)

Direct Count system (weight per unit length): In this system, the weight of a fixed length of yarn is determined and the weight per unit length is the yarn count. The common feature of all direct count systems is the length of yarn fixed, and the weight of yarn varies according to its fineness. The following formula is used to calculate the yarn count: 

N= W / L

where, 

N = Yarn count or numbering system 

W = Weight of the sample at the official regain in the unit of the system 

L= Length of the sample

General Properties of Yarn

Various types of yarn properties according to the yarn classification have been summarised in the following table:

Yarn Types and Their Properties
Sl	Yarn Types	General Yarn Properties
1	Staple yarns - Combed cotton - Carded cotton - Synthetic and blends - Worsted - Woollen	Good hand, cover, comfort and textured appearance. Average strength and uniformity.
2	Continuous filament yarns - Natural - Man-made or synthetic	High strength, uniformity and possibility for very fine yarns. Fair hand and poor covering power.
3	Novelty Yarns - Fancy - Metallic	Decorative features and characteristics.
4	Industrial Yarns - Tyre cord - Rubber or elastic core - Multiply coated	Functional; designed and produced to satisfy a specific set of requirements.
5	High-bulk Yarns - Staple - Continuous filament (Taslan)	Great covering power with less weight, high loftiness or fullness.
6	Stretch Yarns - Twist-heat set-untwist - Crimp heat-set - Stress under tension - Knit-deknit - Gear crimp	High stretchability and cling without high pressure, good handle and covering power.

Spun yarn can be classified as either short-staple spinning or long-staple spinning. Staple fibre has a length of between 10 and 500 mm. Short staple fibre has a maximum length of 60 mm (cotton fibre is a short-staple at about 25–45 mm). Long-staple fibre has a length of more than 60 mm (wool fibre is a long-staple at about 60–150 mm).

Yarn Twist । Zero Twist Yarn

Yarn twist

The twist is given into the yarn to hold the fibres together in order to develop yarn strength. Amount of twist also determines the softness or hardness of the yarn that may be important for particular end-use. Strength of spun yarn increases with the increase of twist to a certain limit. After that, decreases the strength. Twist reduces the filament strength directly.