Textile & Fashion World

A manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed of at least 85% by weight of acrylonitrile units [-CH2-CH(CN)-] (FTC definition). Acrylic fibers are produced by two basic methods of spinning (extrusion), dry and wet. In the dry spinning method, material to be spun is dissolved is a solvent. After extrusion through the spinneret, the solvent is evaporated, producing continuous filaments which later may be cut into staple, if desired. In wet spinning, the spinning solution is extruded into a
liquid coagulating bath to form filaments, which are drawn, dried, and processed.

Acrylic fibers are synthetic fibers made from a polymer (polyacrylonitrile) with an average molecular weight of ~100,000, about 1900 monomer units. To be called acrylic in the U.S, the polymer must contain at least 85% acrylonitrile monomer. Typical comonomers are vinyl acetate or methyl acrylate. The Dupont Corporation created the first acrylic fibers in 1941 and trademarked them under the name "Orlon".

Acetylene + Hydrogen cyanide --> Acrilonitrile

2nd Method
Ethylene--Air Oxidation--> Ethylene oxide + HCN--> Ethylene cyanahydrin--Dehydration at 300 deg C (catalyst)--> Acrylonitrile

Production Process of Acrylic Fiber
The acrylic process is a "one step technology", with the following main characteristics:

1. polymerization in solution
2. direct feeding of the dope to spinning
3. wet spinning
4. DMF as solvent for both polymerization and spinning

Milk fiber

Glass fiber is a material consisting of numerous extremely fine fibers of glass. Fiberglass is a strong and lightweight reinforcement used in composites, communication, data transfer, or decorative purpose. Glass fibers able to transfer light, ray and radiation inside its subtle hole. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. 

Glass fiber fabric

Dyeing of Glass Fiber:
Dyeing of glass fiber filaments, fabrics or fabric is not so easy. In this case, it must be taken into consideration that, under normal circumstances, there is no affinity between glass fiber and dye and that no penetration of the dye into the glass fiber is possible, only surface dyeing or coloration is possible.

The following overview includes patented processes of glass fiber dyeing or coloration which must be regarded as being legally protected:

1. Fused mass coloration or dyeing
2. Dyeing of activated surfaces of glass fibre
3. Direct dyeing methods of glass fibre
4. Pre-mordanting dyeing methods
5. Bonding-agent dyeing methods

Stated of these process are given below:

1. Fused mass coloration or dyeing: Using coloured metal oxides yielding weak dyes only as the colour intensity inevitably decreases with the cross section of the filament.

2. Dyeing of activated surfaces of glass fiber: Predominantly older processes of relatively little practical importance and usually yielding weak coloration, deficient in crocking fastness and, almost without exception, having a tendency to damage the fibers surface.

3. Direct dyeing methods of glass fiber: Without pre-treatment, using conventional dyeing techniques and, in this case, yielding surface coloration or dyeing which is barely acceptable. Methods involving the deposition of water-insoluble dyes are exceptions to this but usually only weak coloration can be achieved, e.g., when using sulphur or vat dyes.

4. Pre-mordanting dyeing methods: 

a) metal-salt process gives strong colours in some cases but almost always with insufficient crocking fastness, b) cation active process gives very strong colorations which, with the right choice of dye, can have good fastness properties against water and light but only moderate crocking fastness.

5. Bonding-agent dyeing methods: Coating with dyeable or dyed films: 

a) Pigment dyeing methods are the most elegant and simplest to use. Pale to medium shades are possible with maximum light, water and crocking fastness (with the right choice of dye) while the properties of the dark colours (marine and black) are frequently much worse. The principle consists of fixing the pigment using synthetic resins. 

b) Other bonding-agent dyeing methods are to some extent still very inconvenient and unsatisfactory (especially with regard to crocking fastness). Exception: Õ Corona discharge process with good overall fastness but crocking fastness and grease resistance are not completely satisfactory. No dark full shades obtainable. 

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The sequence of the treatments undergone by wool fibres in various forms (staple, sliver, yarn, woven and knitted fabric) varies according to the modification process of the fibre structure, according to the type of processing system used and according to the experience of the operator (these criteria are valid for all fibres).
Therefore the wool processing cycle can vary accordingly: an example is shown in the following. 

Worsted Cycle:

 

Flowchart of worsted wool finishing process

 

Flowchart of woollen wool finishing process

The preparation process of long staple fibers allows to transform the sliver produced by the hackling machine into a 2 - 4 g/m roving through a series of drawing passages and a high number of doublings, which ensure the high blending rate necessary for heterogeneous fibers like hemp. The flow chart is similar to that used for flax processing and the machines employed are practically the same. At the delivery from last drawing passage, the sliver can be subjected to one of two alternative processes:

• Wet spinning, the typical process used for bast fibres, with bobbin drying and winding. As for flax, the roving can be degummed and bleached before spinning.
• Dry spinning directly from sliver through the same spinning frames used for flax tow spinning.

Tow spinning, as also dry spinning of long staple yarns, follows the same criteria as wool spinning on machines characterized by wider pitches and by more rigid and firm opening points, which can stand the high stresses caused by extremely hard and stiff fibers.

We point out that the card sliver has not the cleanness degree which is necessary to produce a regular yarn, therefore it requires a hackling operation on machines very similar to wool combers.

Tows can be dry or wet spun. For dry spinning, two kinds of spinning frames are used:

• With drafting cylinder systems which operate according to the typical criteria of the semi-worsted system, with settings suited to the high length of these fibres
• With gill-bars, i.e. with needle bars placed in the drafting fields assigned to the guide of the fibres, which are similar to those used for long fiber dry spinning. 

As already for flax, the prospects for a widening of hemp use are conditioned by the finishing operations. In fact the fibre can undergo some important changes, if the order and the crystalline lay-out of the fibrous cells are adequately varied ; moreover, if full advantage is taken of the inner channels (lumens) for fluid diffusion by preparing them for a more efficient migration of fluids capable of modifying the fiber’s physical properties, completely new handle and appearance effects, even adjustable by the finisher, can be obtained. 

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Rayon is the oldest commercial manmade fiber. It is a manufactured fiber composed of regenerated cellulose, as well as manufactured fibers composed of regenerated cellulose in which substituents have replaced not more than 15% of the hydrogens of the hydroxyl groups. Rayon fibers include yarns and fibers made by the viscose process, the cuprammonium process, and the now obsolete nitrocellulose and saponified acetate processes. Generally, in the manufacture of rayon, cellulose derived from wood pulp, cotton linters, or other vegetable matter is dissolved into a viscose spinning solution. The solution is extruded into an acid-salt coagulating bath and drawn into continuous filaments. Groups of these filaments may be made in the form of yarns or cut into staple.

Characteristics of Rayon Fiber :

1. Highly absorbent
2. Soft and comfortable
3. Easy to dye
4. Drapes well

The drawing process applied in spinning may be adjusted to produce rayon fibers of extra strength and reduced elongation. Such fibers are designated as high tenacity rayons, which have about twice the strength and two-thirds of the stretch of regular rayon. An intermediate grade, known as medium tenacity rayon, is also made. Its strength and stretch characteristics fall midway between those of high tenacity and regular rayon.

Types of Rayons

Rayon fibers are engineered to possess a range of properties to meet the demands for a wide variety of end uses. Types of rayon fiber are given below:

1. High wet modulus rayon
2. Polynosic rayon
3. Specialty rayons
4. Super absorbent rayons
5. Tencel rayon
6. Lyocell

Manufacturing Process of Viscose Rayon:

While there are many variations in the manufacturing process that exploit the versatility of the fiber, the following is a description of the procedure that is used in making regular or viscose rayon.

Regardless of whether wood pulp or cotton linters are used, the basic raw material for making rayon must be processed in order to extract and purify the cellulose. The resulting sheets of white, purified cellulose are then treated to form regenerated cellulose filaments. In turn, these filaments are spun into yarns and eventually made into the desired fabric.

The process of manufacturing viscose rayon consists of the following steps mentioned, in the order that they are carried out: (1) Steeping, (2) Pressing, (3) Shredding, (4) Aging, (5) Xanthation, (6) Dissolving, (7)Ripening, (8) Filtering, (9) Degassing, (10) Spinning, (11) Drawing, (12) Washing, (13) Cutting. The various steps involved in the process of manufacturing viscose are explained below.

1. Steeping: 

Cellulose pulp is immersed in 17-20% aqueous sodium hydroxide (NaOH) at a temperature in the range of 18 to 25°C in order to swell the cellulose fibers and to convert cellulose to alkali cellulose.

(C6H10O5)n + nNaOH ---> (C6H9O4ONa)n + nH2O
 

2. Pressing: 

The swollen alkali cellulose mass is pressed to a wet weight equivalent of 2.5 to 3.0 times the original pulp weight to obtain an accurate ratio of alkali to cellulose.
 

3.  Shredding: 

The pressed alkali cellulose is shredded mechanically to yield finely divided, fluffy particles called "crumbs". This step provides increased surface area of the alkali cellulose, thereby increasing its ability to react in the steps that follow.
 

4.  Aging: 

The alkali cellulose is aged under controlled conditions of time C) in order to depolymerize the°and temperature (between 18 and 30 cellulose to the desired degree of polymerization. In this step the average molecular weight of the original pulp is reduced by a factor of two to three. Reduction of the cellulose is done to get a viscose solution of right viscosity and cellulose concentration.
 

5. Xanthation: 

In this step the aged alkali cellulose crumbs are placed in vats and are allowed to react with carbon disulphide under controlled temperature (20 to 30°C) to form cellulose xanthate.

(C6H9O4ONa)n + nCS2 ----> (C6H9O4O-SC-SNa)n

Side reactions that occur along with the conversion of alkali cellulose to cellulose xanthate are responsible for the orange color of the xanthate crumb and also the resulting viscose solution. The orange cellulose xanthate crumb is dissolved in dilute sodium hydroxide at 15 to 20 °C under high-shear mixing conditions to obtain a viscous orange colored solution called "viscose", which is the basis for the manufacturing process. The viscose solution is then filtered (to get out the insoluble fiber material) and is deaerated.
 

6.  Dissolving: 

The yellow crumb is dissolved in aqueous caustic solution. The large xanthate substituents on the cellulose force the chains apart, reducing the interchain hydrogen bonds and allowing water molecules to solvate and separate the chains, leading to solution of the otherwise insoluble cellulose. Because of the blocks of un-xanthated cellulose in the crystalline regions, the yellow crumb is not completely soluble at this stage. Because the cellulose xanthate solution (or more accurately, suspension) has a very high viscosity, it has been termed "viscose".
 

7. Ripening: 

The viscose is allowed to stand for a period of time to "ripen". Two important process occur during ripening: Redistribution and loss of xanthate groups. The reversible xanthation reaction allows some of the xanthate groups to revert to cellulosic hydroxyls and free CS2. This free CS2 can then escape or react with other hydroxyl on other portions of the cellulose chain. In this way, the ordered, or crystalline, regions are gradually broken down and more complete solution is achieved. The CS2 that is lost reduces the solubility of the cellulose and facilitates regeneration of the cellulose after it is formed into a filament.

(C6H9O4O-SC-SNa)n + nH2O ---> (C6H10O5)n + nCS2 + nNaOH
 

8.  Filtering: 

The viscose is filtered to remove undissolved materials that might disrupt the spinning process or cause defects in the rayon filament.
 

9.  Degassing: 

Bubbles of air entrapped in the viscose must be removed prior to extrusion or they would cause voids, or weak spots, in the fine rayon filaments.
 

10.  Spinning - (Wet Spinning): 

Production of Viscose Rayon Filament: The viscose solution is metered through a spinnerette into a spin bath containing sulphuric acid (necessary to acidify the sodium cellulose xanthate), sodium sulphate (necessary to impart a high salt content to the bath which is useful in rapid coagulation of viscose), and zinc sulphate (exchange with sodium xanthate to form zinc xanthate, to cross link the cellulose molecules). Once the cellulose xanthate is neutralized and acidified, rapid coagulation of the rayon filaments occurs which is followed by simultaneous stretching and decomposition of cellulose xanthate to regenerated cellulose. Stretching and decomposition are vital for getting the desired tenacity and other properties of rayon. Slow regeneration of cellulose and stretching of rayon will lead to greater areas of crystallinity within the fiber, as is done with high-tenacity rayons.

The dilute sulphuric acid decomposes the xanthate and regenerates cellulose by the process of wet spinning. The outer portion of the xanthate is decomposed in the acid bath, forming a cellulose skin on the fiber. Sodium and zinc sulphates control the rate of decomposition (of cellulose xanthate to cellulose) and fiber formation.

(C6H9O4O-SC-SNa)n + (n/2)H2SO4 --> (C6H10O5)n + nCS2 + (n/2)Na2SO4

Elongation-at-break is seen to decrease with an increase in the degree of crystallinity and orientation of rayon.
 

11. Drawing: 

The rayon filaments are stretched while the cellulose chains are still relatively mobile. This causes the chains to stretch out and orient along the fiber axis. As the chains become more parallel, interchain hydrogen bonds form, giving the filaments the properties necessary for use as textile fibers.
 

12.  Washing: 

The freshly regenerated rayon contains many salts and other water soluble impurities which need to be removed. Several different washing techniques may be used.
 

13.  Cutting: 

If the rayon is to be used as staple (i.e., discreet lengths of fiber), the group of filaments (termed "tow") is passed through a rotary cutter to provide a fiber which can be processed in much the same way as cotton . 

Major End Uses of Rayon Fiber :

1. Apparel: Accessories, blouses, dresses, jackets, lingerie, linings, millinery, slacks, sportshirts, sportswear, suits, ties, work clothes 

2. Home Furnishings: Bedspreads, blankets, curtains, draperies, sheets, slipcovers, tablecloths, upholstery 

3. Industrial Uses: Industrial products, medical surgical products, nonwoven products, tire cord 

4. Other Uses: Feminine hygiene products

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Carbon Fiber:

Carbon fiber is a high-tensile fiber or whisker made by heating rayon or polyacrylonitrile fibers or petroleum residues to appropriate temperatures. Fibers may be 7 to 8 microns in diameter and are more that 90% carbonized. 

Carbon fiber Weave

This fibers are the stiffest and strongest reinforcing fibers for polymer composites, the most used after glass fibers. Made of pure carbon in form of graphite, they have low density and a negative coefficient of longitudinal thermal expansion.
Carbon fibers are very expensive and can give galvanic corrosion in contact with metals. They are generally used together with epoxy, where high strength and stiffness are required, i.e. race cars, automotive and space applications, sport equipment.

Depending on the orientation of the fiber, the carbon fiber composite can be stronger in a certain direction or equally strong in all directions. A small piece can withstand an impact of many tons and still deform minimally. The complex interwoven nature of the fiber makes it very difficult to break. 

Characteristics/Properties of Carbon Fibers

1. Physical strength, specific toughness, light weight.
2. Good vibration damping, strength, and toughness.
3. High dimensional stability, low coefficient of thermal expansion, and low abrasion.
4. Electrical conductivity.
5. Biological inertness and x-ray permeability.
6. Fatigue resistance, self-lubrication, high damping.
7. Electromagnetic properties.
8. Chemical inertness, high corrosion resistance.

Classification of Carbon Fiber:
Based on modulus, strength, and final heat treatment temperature, carbon fibers can be classified into the following categories:

1. Based on carbon fiber properties,
2. Based on precursor fiber materials, 
3. Based on final heat treatment temperature,

1. Based on carbon fiber properties, carbon fibers can be grouped into:

• Ultra-high-modulus, type UHM (modulus >450Gpa)
• High-modulus, type HM (modulus between 350-450Gpa)
• Intermediate-modulus, type IM (modulus between 200-350Gpa)
• Low modulus and high-tensile, type HT (modulus < 100Gpa, tensile strength > 3.0Gpa)
• Super high-tensile, type SHT (tensile strength > 4.5Gpa)

2. Based on precursor fiber materials, carbon fibers are classified into:

• PAN-based carbon fibers
• Pitch-based carbon fibers
• Mesophase pitch-based carbon fibers
• Isotropic pitch-based carbon fibers
• Rayon-based carbon fibers
• Gas-phase-grown carbon fibers

3. Based on final heat treatment temperature, carbon fibers are classified into:  

Application/Uses of Carbon Fiber
The two main applications of carbon fibers are in specialized technology, which includes aerospace and nuclear engineering, and in general engineering and transportation, which includes engineering components such as bearings, gears, cams, fan blades and automobile bodies. Recently, some new applications of carbon fibers have been found. Such as rehabilitation of a bridge in building and construction industry. Others include: decoration in automotive, marine, general aviation interiors, general entertainment and musical instruments and after-market transportation products. Conductivity in electronics technology provides additional new application.

Application Carbon Fiber are given as Shortly:

• Aerospace, road and marine transport, sporting goods.
• Missiles, aircraft brakes, aerospace antenna and support structure, large telescopes, optical benches, waveguides for stable high-frequency (GHz) precision measurement frames.
• Audio equipment, loudspeakers for Hi-fi equipment, pickup arms, robot arms.
• Automobile hoods, novel tooling, casings and bases for electronic equipments, EMI and RF shielding, brushes.
• Medical applications in prostheses, surgery and x-ray equipment, implants, tendon/ligament repair.
• Textile machinery, genera engineering.
• Chemical industry; nuclear field; valves, seals, and pump components in process plants.
• Large generator retaining rings, radiological equipment.

Carbon fibre is sometimes used in conjunction with fiberglass because of their similar manufacturing processes, an example of this would be the Corvette ZO6 where the front end is carbon fibre and the rear is fibreglass. Carbon fiber is however, far stronger and lighter than fiberglass.

Carbon fibre can be found in a wide range of performance vehicles including sports cars, superbikes, pedal bikes (where they are used to make frames), powerboats and it is often used in the tuning and customising industry where attractive woven panels are left unpainted to 'show off' the material. 


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A bast fiber used for sacking, burlap, and twine as a backing material for tufted carpets. Jute is one of the most affordable natural fibres and is second only to cotton in amount produced and variety of uses of vegetable fibres. Jute fibres are composed primarily of the plant materials cellulose (major component of plant fibre) and lignin (major components of wood fibre).

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

Rooty Jute: in these jute the lower parts of jute fires contain barks.

Specky jute: this defects occur because of insufficient washing which causes the outer barks to adhere in some places

Croppy Jute: this is a defect where the top end of the fibre become rough and hard. It is usually caused by careless steeping.

Knotty jute: the jute fibres contain knots in places and it is caused by insect bite or punctures.

Dezed or Dead fibres: due to over retting in moist condition, the fibre becomes dull, lose strength and becomes inferior for spinning.

Runners: this is a defect where long and hard barky ribbon of fibres remains in jute fibre.

Hunka: defects caused by non-removal of dried up base and hard bark from the fibres.

Mossy jute: fibres from short plants that cannot be properly stripped and cleaned contain broken piece of jute sticks etc.

Flabby or Fluffy jute: due to careless stripping, fibre loses firmness and becomes flabby and hairy

Heart damage: These defects occur when jute fibre contains excess moisture when baled. The centre of the bale becomes badly tendered and in some cases fibres are reduced to powder.

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Among the seed and fruit fibres, cotton has grown in stature as the most important textile fibre in the world. In fact, cotton is the backbone and basic foundation of the world’s textile trade and industry. Cotton is a natural vegetable fibre produced in the cotton plant in many countries of the world even in Bangladesh also.

Properties of Cotton Fibres:

 
Properties of cotton fiber can be divided into two parts, one is according to physical structure and another is using process.

A. According to physical structure:

Length of cotton fiber:
Physically the individual cotton fibres consist of a single long tubular cell. Its length is about 1200-1500 times than its breadth. Length of cotton fibre varies from 16mm to 52 mm depending upon the type of cotton.

1. Indian cotton- 16-25 mm
2. American cotton- 20-30 mm
3. Sea Island- 38-52 mm
4. Egyptian cotton- 30-38 mm

Fineness of cotton fiber:
Longer the fibre, finer the fibre in case of cotton fibre. It is expressed in term of decitex and it varies from 1.1 to2.3 decitex.

1. Indian= 2.2-2.3dtex
2. American= 2.1-2.2 dtex
3. Egyptian= 1.2-1.8 dtex
4. Sea Island= 1.0-1.1 dtex

Fineness may be more in case of immature fibre. So it is necessary to express maturity with fineness.

Strength and extension of cotton fiber:
Cotton fibre is fairly among natural fibres in relation to tenacity which is 3-3.5g/dtex. Its tensile strength is between wool and silk fibre but disadvantage is low extension at break which is 5-7%.

Elastic properties of cotton:
Recovery from deformation of cotton fibre, yarn or fabric from applied load is very low. By applying heat it can’t be achieved. This property can be achieved by -1.Chemical treatment to improve crease recovery, but the problem is the materials become harsher due to chemical treatment 2. blending or mixing of cotton with elastic fibre, e.g. polyester, blend ratio depends on the end use of the fabric. The initial modulus is fairly high=0
5 g/dtex (wool=0.25 g/dtex)

Cross-section:
Cross-section of cotton fibre is some what ribbon like. The cell wall is rather thin and the lumen occupies about two-third of the entire breadth and shows up very prominent in polarized light. Fibre cross-section becomes round when mercerized.

Appearance:
Cotton fibre is fairly short, fine and creamy white color. Color of the fibre depends on soil of growth. By adding chemicals in the soil, color of the cotton fibre may be varied.

Crimp:
Cotton fibre is more or less twisted on its longitudinal axis which cab not be seen from out side is called convolution. The twist in the fibre does not to be continuous in one direction i.e. if at first right direction, then left direction. This property of cotton fibre helps in spinning.

B. According to using process:

Comfortable: 

Cotton fiber has large amorphous portion and this is why the air can be in and out through cotton fiber. So, the fabric made by cotton fiber is quite comfortable to use. 

Soft Hand: 

 Cotton fiber is too much regular fiber and if properly ginned; this fibre can be the best soft hand feeling fibre amongst the others. 

Absorbent: 

Cotton fiber has high absorbency power and this is why this fiber can be died properly and without any harassment. 

Good Color Retention: 

If the printing is applied on cotton fiber, it seems it doesn’t spread the color outside the design. So printing efficiency is good on cotton fibre. 

Machine Washable & Dry Cleanable: 

It is seen that some fibers can’t be dried or washed due to it’s sensitivity and weak fastness properties but in case of Cotton fiber you will have large number of options to choose. You can easily wash the cotton made fabric by machines and even you will be able to dry this fiber by using electronic drier. 

Good Strength: 

If you want to seek an average strength which might be enough for you; then cotton fiber can be your ultimate choice. The strength of cotton fiber is quite good. 

Cotton Fibre Drapes Well: 

The drape-ability of cotton fibre is awesome. You can use the cotton fibre made fabric in any kind of wear which needs more flexibility and drapes. 

Sewing & Handling Is Easy: 

 The sewing efficiency on Cotton made fabric is easier and comfortable than other fiber. This is why the demand of cotton made fabric is higher in all over the world.

Uses of Cotton Fiber:

Cotton fiber is a versatile fibre which has wide variety of uses. But the Cotton fibre is mostly used on the Apparel Industry to make the wearing cloth like Sweaters, Skirts, Shirts, Swimwear, Kids wear, Blouses, Pants, Hosiery and to make other type of dresses.

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Jute is a natural biodegradable fiber with advantages such as high tensile strength, excellent thermal conductivity, coolness, ventilation function et al.1-2. Recently, due to the improvement of people’s living standards and need for environmental protection, the demand of natural biodegradable and eco-friendly fibers is rising worldwide day by day. Ramie, flax, hemp and some other vegetable fibers have been used as textile materials, but jute fiber is basically used for traditional purposes such as manufacture of sackings, hessian, carpet backing and the like. Taking account of the costliness of ramie and the shortage in sources of flax, and the challenges from the synthetic fibers in the traditional jute products market, if jute could be used to replace ramie and flax partially as textile material, not only the cost could be reduced but also a new market would be provided for jute products.

Jute fiber is a bast fiber obtained from the bark of jute plant containing three main categories of chemical compounds namely cellulose (58~63%), hemicellulose (20~24%) and lignin (12~15%), and some other small quantities of constituents like fats, pectin, aqueous extract, et al. Jute fiber is composed of small units of cellulose surrounded and cemented together by lignin and hemi-cellulose10-11. The low cellulose content, coarseness, stiffness, low extensibility, low grip performance and some other disadvantages seriously restrict the raw jute fiber from spinning. So a series of wet chemical processing sequences are needed to improve the spinnability of jute. The qualities of the fiber and yarn mostly depend on the degumming effect. So degumming is one of the most important sequences in the chemical processing of jute.

Generally, there are three methods for degumming, i.e., mechanical, chemical and biological methods. The mechanical methods such as steam explosion2,14, microwave and ultrasonic 15 have very limited effect on improving the spinnability of jute fiber. Biodegumming is an eco-friendly method has some advantages viz. mild conditions and high efficiency. However, the application of enzymes for degumming is hindered by some factors such as high substrate specificity, low activity stability, high cost, and low total gum decomposition16-18. The chemical method is the most commonly used method for degumming, but this traditional method has some major disadvantages like serious environmental pollution, lengthy time required and high cost 19. Taking account of these problems, it is urgent to improve the degumming method for natural fibers.

In our previous study, the pre-chlorite treatment of jute fiber before degumming has been reported to lighten the burden of degumming and enhance delignification20. In this paper, we report the chemical degumming of the pre-chlorite treated jute fiber. Both the gum decomposition and the spinnabilities viz. fineness, breaking strength and breaking extension were tested to optimize the conditions for degumming. Changes in the constituent content of the treated jute fiber were also analyzed.

Materials and Method:
Materials
Jute:
Lightly combed and dewaxed raw jute fiber.

Chemicals:
Sodium chlorite and sodium silicate, Acetic acid, sodium acetate, sodium hydroxide and sulphuric acid , Penetrating agent TF-107B and degumming agent TF-125A .

Methods
Pre-chlorite treatment
The samples were treated in a bath with sodium chlorite 1.5g/L, pH 3, liquor ratio 1:10, and kept at 30℃ for 30 min. and then thoroughly washed.

Scouring
The pre-chlorite treated jute fiber was treated with sodium hydroxide 5-30g/L, sodium silicate 1.0-5.0g/L, TF-107B 0.5-6.0g/L, TF-125A 1.0-8.0g/L, and kept at 60-100℃ for 60-240 min. with fiber to liquor ratio 1:10-1:40. At the end of the desired treatment, the fibers were neutralized with sulphuric acid, and then thoroughly washed with distilled water.

Testing
Breaking strength and breaking extension were tested using a XQ-1 fiber breaking strength machine in a constant 20℃ temperature and 65% relative humidity room (in accordance with ASTM Method D-5035). The fineness was tested according to GB/T12411.3. The constituent contents were tested according to GB/5889–86.

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Jute yarn is generally available in single and multiple twists. Available in various specifications, these cater to needs of developing market. Winding in cylindrical, conical and cone less spools or hanks is done as per prerequisites of our customers. This excellent jute yarn finds extensive application in carpet industry.

Now we will discuss about the types of jute yarn and batch selection technique of jute yarn.

1. Hassian Warp: 

These types of yarn are good, clean and free from specks with high lusture. For manufacturing this type of yarn, clean and defect free jute is required. To make this type of yarn clean and defect free jute is required. 

Batch Selection: 

Hard jute .......................................70%
Soft jute ........................................30%

Example: For 8 lbs/spyndle hassian warp

White C........................................40%
White X ...................................... 40%
Tossa ...........................................20%

2. Hassian Weft: 

Hassian weft yarn is cleaner and softer than hassian warp yarn. So for hassian weft clean fibre is required, but fibre of lower strength can be used to hassian weft yarn.

Batch Selection: 

For Heavy Yarn

Hard jute..................................30%
Soft jute ...................................70%

For Light Yarn

Hard jute .................................50%
Soft jute ...................................50%

Example: For 8.5 lbs/spyndle hassian weft

White C ...................................40%
White X ...................................40%
Tossa ........................................20%

3. Sacking Warp: 

Sacking warp jute yarn is good and strong. Specks and colour is not important when manufacturing this type of yarn. So, 70 to 80% Tossa jute can be used.

Batch Selection: 

Hard jute ................................... 60%
Soft jute .....................................40%

Example: For 8 lbs/spyndle sacking warp

X bottom ..................................67%
S M R ......................................33%

4. Sacking Weft: 

Sacking weft yarns are low quality yarn. It is coarse and is made from low grade jute fibre. It may contain line cuttings, bale cuttings, soft and hard waste, rope waste, jute dust, habijabi and entangled jute.

Example: For sacking weft

NC .......................................................70%
S M R ..................................................15%
Caddis ..................................................5%
Thread waste and gunny cuttings............10%

5. C.B.C (carpet breaking cloth):

Batch Selection: 

Hard jute ................................... 100%

Example: For 8 lbs/spyndle C.B.C warp

B.W.B ....................................... 40%
B.W.C ...................................... 60%

Example: For 8 lbs/spyndle C.B.C weft

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Linen is a cellulosic fibers derived from the stem of the flax plant or a fabric made from these fibers. Linen fibers are much stronger and more lustrous that cotton; they yield cool, absorbent fabrics that wrinkle easily. Fabrics with linen-like texture and coolness but with good wrinkle resistance can be produced from manufactured fibers and blends.

Linen Fiber

Properties/Characteristics of Linen Fiber:
Linen is comfortable, good strength, twice as strong as cotton, hand-washable or dry-cleanable, crisp hand tailors, well absorbent dyes and prints, well light weight to heavy weight, no static or pilling problems, fair abrasion resistant etc. Basically there are two types of properties of linen fibers. One is physical properties and another is chemical properties.

Physical Properties of Linen: 

Physical properties of linen fibers are given below:

1. Tensile Strength: Linen is a strong fiber. It has a tenacity of 5.5 to 6.5 gm/den. The strength is greater than cotton fiber.
2. Elongation at break: Linen does not stress easily. It has an elongation at break of 2.7 to 3.5 %.
3. Color: The color of linen fiber is yellowish to grey.
4. Length: 18 to 30 inch in length.
5. Lusture: It is brighter than cotton fiber and it is slightly silky.
6. Elastic Recovery: Linen fiber has not enough elastic recovery properties like cotton fiber.
7. Specific Gravity: Specific gravity of linen fiber is 1.50.
8. Moisture Regain (MR %): Standard moisture regain is 10 to 12%. 
9. Resiliency: Very poor.
10. Effect of Heat: Linen has an excellent resistance to degradation by heat. It is less affected than cotton fiber by the heat.
11. Effect of Sun Light: Linen fiber is not affected by the sun light as others fiber. It has enough ability to protect sun light.

Chemical Properties of Linen: 

Linen is a natural cellulosic fiber and it has some chemical properties. Chemical properties of the linen fiber are given below:

1. Effect of Acids: Linen fiber is damaged by highly densified acids but low dense acids does not affect if it is wash instantly after application of acids.
2. Effects of Alkalis: Linen has an excellent resistance to alkalis. It does not affected by the strong alkalis.
3. Effects of Bleaching Agents: Cool chlorine and hypo-chlorine bleaching agent does not affect the linen fiber properties.
4. Effect of Organic Solvent: Linen fiber has high resistance to normal cleaning solvents. 
5. Effect of Micro Organism: Linen fiber is attacked by fungi and bacteria. Mildews will feed on linen fabric, rotting and weakling the materials. Mildews and bacteria will flourish on linen under hot and humid condition. They can be protected by impregnation with certain types of chemicals. Copper Nepthenate is one of the chemical.
6. Effects of Insects: Linen fiber does not attacked by moth-grubs or beetles.
7. Dyes: It is not suitable to dye. But it can be dye by direct and vat dyes.

Major End Uses Linen Fabric:
Apparel:

• dresses, 
• suits, 
• separates, 
• skirts, 
• jackets, 
• pants, 
• blouses, 
• shirts, 
• children's wear etc.

Home Fashion :

• curtains, 
• draperies, 
• upholstery, 
• bedspreads, 
• table linens, 
• sheets, 
• dish towels etc.

Glass fiber also called fiberglass. It is material made from extremely fine fibers of glass Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes. Glass is the oldest, and most familiar, performance fiber. Fibers have been manufactured from glass since the 1930s.



Types of Glass Fiber
As to the raw material glass used to make glass fibres or nonwovens of glass fibres, the following classification is known:

1. A-glass: With regard to its composition, it is close to window glass. In the Federal Republic of Germany it is mainly used in the manufacture of process equipment.

2. C-glass: This kind of glass shows better resistance to chemical impact.

3. E-glass: This kind of glass combines the characteristics of C-glass with very good insulation to electricity.

4. AE-glass: Alkali resistant glass.

Generally, glass consists of quartz sand, soda, sodium sulphate, potash, feldspar and a number of refining and dying additives. The characteristics, with them the classification of the glass fibres to be made, are defined by the combination of raw materials and their proportions. Textile glass fibres mostly show a circular

Properties of Glass Fiber
Glass fibers are useful because of their high ratio of surface area to weight. However, the increased surface area makes them much more susceptible to chemical attack. By trapping air within them, blocks of glass fiber make good thermal insulation, with a thermal conductivity of the order of 0.05 W/(mK).

The strength of glass is usually tested and reported for "virgin" or pristine fibers those which have just been manufactured. The freshest, thinnest fibers are the strongest because the thinner fibers are more ductile. The more the surface is scratched, the less the resulting tenacity. Because glass has an amorphous structure, its properties are the same along the fiber and across the fiber. Humidity is an important factor in the tensile strength. Moisture is easily adsorbed, and can worsen microscopic cracks and surface defects, and lessen tenacity.

In contrast to carbon fiber, glass can undergo more elongation before it breaks. There is a correlation between bending diameter of the filament and the filament diameter. The viscosity of the molten glass is very important for manufacturing success. During drawing (pulling of the glass to reduce fiber circumference), the viscosity should be relatively low. If it is too high, the fiber will break during drawing. However, if it is too low, the glass will form droplets rather than drawing out into fiber.

Glass Fiber Manufacturing Processes
After the initial process of melting glass and passing it through spinnerets, continuous filaments or staple fibers of glass are manufactured by two different methods.

Continuous Filament Process
In this process, continuous filaments of indefinite length is produced. The molten glass passes through spinnerets having hundreds of small openings. These strands of multiple filaments are carried to winder revolving at very high speed of more than 2 miles per km. This process draws out the fibers in parallel filaments of the diameter of the openings. A sizing or a binder is applied to facilitate the twisting and winding process and to prevent breakage during yarn formation. After winding, filaments are further twisted and plied to make yarns by methods similar to those for making other continuous filament yarns. The sizing is removed through volatizing in an oven. These yarns are used for making such items as curtains and drapes.

Staple Fiber Process
Fibers with long-staple qualities are manufactured through staple fiber process. There are many methods for producing such fibers.

In one of such methods, the molten glass flows through the small holes of bushing, where jets of compressed air shake the thin streams of molten glass into fine fibers. These fibers vary in length ranging from 8 to 15 inches. The fibers fall through a spray of lubricant and a drying flame onto e revolving drum where they form into a thin web. These fibers in the form of web are gathered from the drum into a sliver. Yarn is then made from this sliver by similar methods that are adopted for making cotton or wool yarns. These yarns are used for fabrics for industrial purposes where insulation is required.

In yet another method, the ends of the glass rods are melted from which drops of glass fall away drawing off glass filaments after them onto a speedily revolving cylinder where they are wound parallel to each other. A web of sliver is formed if the cylinder moves sideways. Sometimes, the staple may be thrown off the cylinder onto a stationary sieve where it forms a sliver. In either conditions, the sliver is then converted into spun yarn.

The staple fiber, if subjected to oven, is compressed to the desired thickness and the binder which was earlier applied, is cured. This permanently binds the fibers.

Production:
The subsequent manufacture of glass fibres may be executed to the direct melting process. However, in most cases glass rods or balls are made first which then may undergo a variety of further processes.

Nozzle-Drawing:
As can be seen in Fig. 1-50, the glass fed in is melted in a heated melt tub at 1250–1400oC. Then, it emerges at the bottom of the melt tub from nozzle holes of 1–25 mm diameter and it is taken off and drawn. The filaments solidify and are finished and wound. One can find them in the shops as various kinds of “glass silk”. To make them into webs, the filaments are cut to length (mostly, between 6 and 25 mm).

Manufacture of glass melt

Nozzle-Blowing:
The same as with nozzle-drawing, glass balls are melted in the tub. The melt emerging from the nozzle holes is then taken by pressed air, which draws the liquid glass so as to make fibres of 6–10 um diameter. A fluttering effect is caused by the flow of pressed air, which results in fibres of lengths from 50 to 300 mm. A lubricant is put on and the fibres are laid down on a sieve drum which sucks them in. The dry web received is held together by the long fibres, the short ones lying in between them as a filling material. Then, the slivers of glass fibre material are cut.

Rod-Drawing:
By means of a burner, bundles of glass rods are melted at their bottom ends. This results in drops which, as they fall down, draw filaments after them. The filaments are taken by a rotating drum, a squeegee laying them down onto a perforated belt. Thus, a dry web is received which can be wound as glass fibre slivers. – Machine performance being limited by the number of glass rods fed in, the rotating drum may be combined with nozzle-drawing, which results in drum-drawing. This multiplies machine performance. The dry web is again laid down onto a perforated belt and solidified or, after winding it so as to receive slivers, cut for further processing on machines producing wetlaid nonwovens. Using and processing glass fibres is not without any problems. For example, fine pieces of broken fibres may disturb if the work place is not well prepared for the purpose. Using the nonwovens to manufacture glass-fibre reinforced plastics, it is important the surface of the plastic material is fully even. Ends of fibre looking out may be pulled out or loosened by outward stress (temperature, gases, liquids), which may influence material characteristics. In some cases, it is
advisable to cover up such layers of glass fibre with suitable chemical fibres.

Uses of Glass Fiber or Glass Yarn
Glass fiber is manufactured in a wide range of fine diameters. Some of them are so fine that they can be seen only through a microscope. This quality of fineness contributes greatly to the flexibility of glass fibers. Various manufacturers produce different types of glass fibers for different end uses. Glass fibers them are used for various purpose.

1. For making home furnishings fabrics;
2. For making apparels and garments; and
3. For the purpose tires and reinforced plastics.

There are certain glass fibers that can resist heat upto 7200oC and can withstand forces having speed of 15,000 miles per hour. These types of glass fibers are used as

1. Filament windings around rocket cases;
2. Nose cones;
3. Exhaust nozzles; and
4. Heat shields for aeronautical equipment

Some other types of glass fibers are embedded into various plastics for strength. These are used in

1. Boat hulls and seats;
2. Fishing rods; and
3. Wall paneling

Some other types of glass fibers are used for reinforcing electrical insulation. Yet other types are used as batting for heat insulation in refrigerators and stoves.

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