Manufacturing Worsted Yarns | Manufacturing Woolen Yarns

Manufacturing Worsted Yarns: Now, we would learn the steps involved in manufacturing worsted yarns. In the manufacturer of worsted yarns, the Different steps involved are:

• Carding


• Gilling and combing


• Drawing


• Roving


• Spinning

Carding: The carding process for worsted yarn production is intended to disentangle and lay them as parallel as possible. The fibres are passed between rollers covered with fine wire teeth. Since worsted yarns, however, should be smooth, the fibers are made to lie as parallel as this process will permit. Following this operation, the wool goes to the gilling and combing processes.

Gilling and Combing: Gilling is carried out before (preparative gilling) and after (finisher gilling) combing. The preparative gilling is mainly to align the fibers in a parallel direction, further blend the wool through doubling and to add moisture and lubricants. Whereas finisher gilling is mainly aimed to remove the mild entanglement introduced to the combed sliver. The carded wool, which is to be made into worsted yarn, is put through gilling and combing operations. The gilling process removes the shorter staple and straightens the longer fibers. This process is continued in the combing operation, which removes the shorter fibers of 1 to 4 inch (25 – 100 mm) lengths (called combing noils), places the longer fibers (called tops) as parallel as possible, and further cleans the fibers by removing any remaining loose impurities.

Drawing : Drawing is an advanced operation which doubles and redoubles slivers of wool fibers. The process draws, drafts, twists, and winds the stock, making the slivers more compact and thinning them into slubbers. Drawing is done only for worsted process.

Roving : This is the final stage before spinning. Roving is actually a light twisting operation to hold the thin slubbers intact.

Spinning : The type of spinning explained here is applicable both for woolen and worsted yarns. In the spinning operation, the wool roving is drawn out and twisted into yarn. There are two main methods used to produce woolen-spun yarns. These are:

• Ring spinning


• Mule spinning

Mule-spun yarns generally are superior to ring-spun yarns but they tend to be much more expensive due to the slow production rates and high labor input.

Worsted yarns are spun on any kind of spinning machine – mule, ring, cap, or flyer. The two principle systems of spinning worsted yarns are the English system and the French system.

· In the English system (Bradford), the fiber is oiled before combing, and a tight twist is inserted. This produces smoother and finer yarns. The more tightly twisted yarn makes stronger, more durable fabrics.

· In the French system, no oil is used. The yarn is given no twist; it is fuzzier, and therefore suitable for soft worsted yarns.

Manufacturing Woolen Yarns: In the manufacture of woolen yarns, the fibers are passed through two stages such as:

• Carding


• Spinning

The objective of carding process is to disentangle the fibers. In this process the wool fibers are passed between rollers covered with thousands of fine wire teeth. The wool fibers are disentangled by the action of the wires and are arranged in parallel fashion. This makes the woolen yarns smooth. Since the production of woolen yarns is intended to be rough or fuzzy, it is not desirable to have the fibers too parallel. By use of an oscillating device, one thin film, or sliver, of wool is placed diagonally and overlapping another sliver to give a crisscross effect to the fibers. This process helps in obtaining a fuzzy surface on the yarn.

The next stage is spinning which is similar to that of worsted production process. We would learn the spinning process is the next section.

Manufacturing Processes for Wool Based Yarns | Production Processes for Wool Yarns

Wool is the fiber derived from
the hair of domesticated animals, usually sheep. Wool is classified
according to the source from which it is obtained. The fleece or the
wool which is collected is kept to the different stages of manufacturing
process which starts with the preparation of the fiber. The different
stage through which it is taken depends upon whether the fiber is intended for worsted or woolen yarns. The flow chart for the manufacturing process is as follows:

Preparation Wool

Fleeces
vary from 6 to 18 pounds (3-8 kg) in weight. The best quality wool is
obtained from the sides and shoulders and is treated as one fleece.
Similarly, the wool obtained from the head, chest, belly, and shanks is
treated as a second fleece.

Preparation Wool

The
raw wool or newly sheared fleece is called grease wool because it
contains the natural oil of the sheep. When grease wool is washed, it
loses from 20 to 80 percent of its original weight. The wool obtained
should be carefully sorted into different grades.

Sorting and Grading: In
sorting, the wool is broken up into sections of different quality
fibers, from different parts of the body. The best quality of wool or
one fleece is used for clothing; the lesser quality or second fleece is
used to make rugs. Each grade is determined by type, length, fineness,
elasticity, and strength. The wool may be graded according to the type
of merino sheep or according to fineness or diameter which is otherwise
called as United States System and British System.

The
classification according to the United States System or according to the
type of merino sheep from which it is obtained is as follows:

• First quality wool is identified as fine and is equivalent to the
  quality of wool that could be obtained from a full-to
  three-quarter-blood Merino sheep.


• Second quality is equivalent to the kind of wool that could be obtained from a half blood Merino.


• The
  poorest qualities are identified as common and braid; they are coarse,
  have little crimp, relatively few scales and are somewhat hair like in
  appearance.


• The grading system on the world market is based upon
  the British numbering system, which relates the fineness, or diameter,
  of the wool fiber to the kind of combed, or worsted, yarn that could be
  spun from 1 pound of scoured wool.


• The first in quality would be
  that wool which is fine enough for and capable of being spun into the
  highest wool yarn counts of 80s, 70s, and 64s (No. of 560 yards in 1 
  pound).


•  The second quality is fine enough to be capable of being spun into yarn counts of 62s, 60s, and 58s.
  
  


• The poorest grade is capable of being spun into yarn counts of only 40s and 30s.

TableComparative Wool Grading Table

United States System	British System
Fine (full-to-three-quarter-blood)	80S, 70S, 64S
Half – blood	62S, 60S, 58S
Three – eights – blood	56S
Quarter – blood	50S, 48S
Low – quarter – blood	46S
Common	44S
Braid	40S, 36S

Scouring: Wool taken
directly from the sheep is called “raw” or “grease wool.” It contains
sand, dirt, grease, and dried sweat. The weight of these contaminants
accounts for about 30 to 70 percent of the fleece’s total weight.
Wool
scouring is the first step in the conversion of greasy wool into a
textile product. It is the process of washing wool in hot water and
detergent to remove the non-wool contaminants and then drying it. The
scouring machine contains warm water, soap and a mild solution of soda
ash or other alkali. They are equipped with automatic rakes, which stir
the wool. Rollers between the vats squeeze out the water. If the raw
wool is not sufficiently clear of vegetable substance after scoring, it
is put through the carbonizing bath of dilute sulfuric acid or
hydrochloric acid to burn out the foreign matter.

Drying: Wool
after scouring should not be allowed to become absolutely dry. About,
12 to16 percent of the moisture is left in the wool which would enable
handling of the fibers in further processing.

Oiling: Wool
is unmanageable after scouring and hence the fiber requires to be
treated with various oils to keep it from becoming brittle. Oiling of
the fibers also helps to lubricate it for the spinning operation.

Carding:
From this stage, further processing depends on whether woolen or
worsted yarns are to be produced. The main objective of carding is to
disentangle and to open the scoured wool. Carding also forms a web of
disentangled fibers that are formed into sliver.

Wool Fiber | Properties of Wool Fiber | Classification of Wool

Wool Fiber

Wool fiber is the natural hair grown on sheep and is composed of protein substance called as keratin. Wool is composed of carbon, hydrogen, nitrogen and this is the only animal fiber, which contains sulfur in addition. The wool fibers have crimps or curls, which create pockets and give the wool a spongy feel and create insulation for the wearer. The outside surface of the fiber consists of a series of serrated scales, which overlap each other much like the scales of a fish. Wool is the only fiber with such serration’s which make it possible for the fibers to cling together and produce felt.

Wool fiber

Properties of Wool Fiber
The characteristics of Wool fiber or protein fibers are as follows:

• They are composed of amino acids.
• They have excellent absorbency.
• Moisture regain is high.
• They tend to be warmer than others.
• They have poor resistance to alkalis but good resistance to acids.
• They have good elasticity and resiliency.

Classification of Wool
The quality of wool fibers produced is based on the breeding conditions, the weather, food, general care etc. For example, excessive moisture dries out natural grease. Similarly the cold weather produces harder and heavier fibers. The wool could be classified in two different ways:

1. By sheep from which it is obtained
2. By fleece

Classification by Sheep
The wool is classified according to the sheep from which it is sheared as given below:

Merino Wool: Merino sheep originated in Spain yields the best quality wool.

• These fibers are strong, fine and elastic fiber which is relatively short, ranging from 1 to 5 inches (25 – 125 mm).
• Among the different wool fibers, merino wool has the greatest amount of crimp and has maximum number of scales. These two factors contribute to its superior warmth and spinning qualities.
• Merino is used for the best types of wool clothing.

Class – Two Wool: This class of sheep originates from England, Scotland, Ireland and Wales.

• The fibers are comparatively strong, fine, and elastic and range from 2 to 8 inches (50 – 200mm) in length.
• They have a large number of scales per inch and have good crimp.

Class – Three Wool: This class of sheep originates from United Kingdom.

• The fibers are coarser and have fewer scales and less crimp when compared to earlier varieties of wool fibers and are about 4 to 18 inches long.
• They are smoother, and are more lustrous.
• These wool are less elastic and resilient.
• They are of good quality, used for clothing.

Class – Four Wool: This class is a group of mongrel sheep sometimes referred to as half-breeds.

• The fibers are abour 1 to 16 inches (25 – 400 mm) long, are coarse and hair like, and have relatively few scales and little crimp.
• The fibers are smoother and more lustrous.
• This wool is less desirable, with the least elasticity and strength. It is used mainly for carpets, rugs, and inexpensive low-grade clothing.

Classification by Fleece
Shearing, is the process by which the woolen fleece of a sheep is removed. Sheep are generally shorn of their fleeces in the spring, but the time of shearing varies in different parts of the world. Sheep are not washed before shearing. They are sometimes dipped into an antiseptic bath as prescribed by law. The classification by fleece is as follows:

Lamb’s Wool: The fleece obtained by shearing the lamb of six to eight months old for the first time is known as lamb’s wool. It is also referred to as fleece wool, or first clip. As the fiber has not been cut, it has a natural, tapered end that gives it a softer feel.

Hogget Wool: Hogget wool is the one obtained from sheep about twelve to fourteen months old that have not been previously shorn. The fiber is fine, soft, resilient, and mature, and has tapered ends. These are primarily used for warp yarns.

Wether Wool: Wether wool is the one obtained from the sheep older than fourteen months. The shearing is not done for the first time and in fact these fleeces are obtained after the first shearing. These fleeces contain much soil and dirt.

Pulled Wool: Pulled wool is taken from animals originally slaughtered for meat. The wool is pulled from the pelt of the slaughtered sheep using various chemicals. The fibers of pulled wool are of low quality and produce a low-grade cloth.

Dead Wool: This is the wool obtained from the sheep that have died of age or accidentally killed. This type of wool fiber known should not be confused for pulled wool. Dead wool fiber is decidedly inferior in grade; it is used in low-grade cloth.

Cotty Wool: This type of wool is obtained from the sheep that are exposed to severe weather. As discussed; the severe weather conditions hamper the qualities of the fleece obtained. The cotty wool is of a poor grade and is hard and brittle.

Tag locks: The torn, ragged, or discolored parts of a fleece are known as tag locks. These are usually sold separately as an inferior grade of wool.

What is Modacrylic fiber | Properties of Modacrylic Fiber | Uses of Modacrylic Fiber | Application of Modacrylic Fiber

Modacrylic fiber

Modacrylic fiber is a manufactured fiber in which the fiberforming substance is any long chain synthetic polymer composed of less than 85% but at least 35% by weight of acrylonitrile units. (-CH2CH[CN]-)x. A modacrylic is a synthetic copolymer. Modacrylic fiber is inherently flame resistant. Although it burns when directly exposed to flame, it doesn’t melt or drip and is self-extinguishing when the flame is removed. Modacrylic is widely used in high performance protective clothing, such as firefighting turnout gear, because flame resistance is combined with other desirable textile properties such as durability and good hand feel. Modacrylics are soft, strong, resilient, and dimensionally stable. They can be easily dyed, show good press and shape retention, and are quick to dry. They have outstanding resistance to chemicals and solvents, are not attacked by moths or mildew, and are nonallergenic. Among their uses are in apparel linings, furlike outerwear, paint-roller covers, scatter rugs, carpets, and work clothing and as hair in wigs.

Modacrylic fiber is chemical resistant. It retains its strength in concentrated acid/alkaline environments, which is useful for certain types of industrial filtration. Modacrylic is also on the extreme negative end of the triboelectric scale, and when combined with another more positive fiber such as polypropylene, results in a triboelectric media with improved filtration efficiency.

Modacrylic fibers are made from resins that are copolymers (combinations) of acrylonitrile and other materials, such as vinyl chloride, vinylidene chloride or vinyl bromide. Modacrylic fibers are either dry spun or wet spun.

Characteristics of Modacrylic Fiber 

• Soft 
• Resilient 
• Easy to dye to bright shades 
• Abrasion resistant 
• Flame resistant 
• Quick drying 
• Resistant to acids and alkalies 
• Shape retentive

The low softening temperatures of modacrylic fibers allow them to be stretched, embossed and molded into special shapes. The fibers may be produced with controlled heat shrinkage capacities. When fibers of different shrinkages are mixed in the surface of a pile fabric, the application of heat develops fibers of different lengths, producing a surface that resembles natural fur.

Properties of Modacrylic Fiber

General Properties
Chemistry	35% acrylonitrile / 65% vinylidene chloride
Size	3 denier x 51mm cut length
Crimp Level	3.8 crimps/cm
Moisture	3.5% (typical)
Thermal Properties
LOI	28 to 32
Mechanical Properties
Strength	2.6 cN/den (dry)
Elongation	28% (dry)

Application of Modacrylic Fiber

Apparel: Deep-pile coats, trims and linings, simulated fur, wigs and hair pieces, children’s sleepwear, career apparel 

Fabric: Fleece, knit-pile fabric backings, nonwovens 

Home Furnishings: Awnings, blankets, carpets, flame-resistant draperies and curtains, scatter rugs 

Other Uses: Filters, industrial fabrics, paint rollers, stuffed toys.

Precaution for Modacrylic Fiber

Dry-cleaning or fur-cleaning process is suggested for deep-pile garments. For washable items:

• Machine wash in warm water and add fabric softener during the final rinse cycle. 
• If dryer is used, use low setting and remove articles as soon as tumbling cycle has stopped. 
• If ironing is required, use low setting. Never use a hot iron. (For specific instructions, refer to garment’s sewn-in care label.) 

What is Elastoester Fiber | Properties of Elastoester Fiber | Uses of Elastoester Fiber

Elastoester is an official FTC generic fiber type defined as: At least 50% by weight aliphatic polyether and at least 35% by weight polyester. Elastoester is similar to polyester, but different enough physically to warrant a new generic name under the FTC’s Textile Labeling Rules. According to a notice the FTC placed in today’s Federal Register, elastoester is stretchy like spandex, readily washable, and can withstand high temperatures when wet. As a result, it retains dyes better than fabrics made of nylon and spandex and is less likely to be discolored or adversely affected by chlorine, an important characteristic for swimming suits.

Characteristics of Elastoester Fiber

• Possesses polyester-like qualities. 
• Excellent elongation qualities (stretchability). 
• Washable/easy care. 
• Can withstand high temperatures when wet. 
• Excellent dye retention. 
• No adverse discoloring or yellowing when exposed to chlorine. 

Uses of Elastoester Fiber

Apparel - 

• sweaters,
• hosiery and socks
• foundation garments, 
• knitwear, 
• dresses, 
• swimwear, 
• activewear, 
• athletic wear, 
• ski pants,

Sportswear-

• swimsuits, 
• cycling shorts and 
• ski pants.

Melamine Fiber | Properties of Melamine Fiber | Manufacturing Process of Melamine Fiber | Applications of Melamine Fiber | Uses of Melamine Fiber

Melamine fiber is a manufactured fiber in which the fiber-forming substance is a synthetic polymer composed of at least 50% by weight of a cross-linked melamine polymer. Melamine fiber is a cost effective heat resistant fiber based on melamine chemistry, with a 400°F (200°C) continuous operating temperature. Melamine fibers are flame resistant, have outstanding heat/dimensional stability, and are self-extinguishing. EFT’s WF series of melamine fibers have a fiber length distribution tailored for use in wet-laid nonwovens. Typical fiber lengths are in the 1-12mm range, and they show excellent dispersion and formation in wet-laid processes. 

Flame Resistance of Melamine Fiber

Characteristics of Melamine Fiber 

• Chars without shrinking 
• Naturally flame retardant 
• Low thermal conductivity 
• Non-toxic / No VOC release
• White and dyeable 
• Flame resistance and low thermal conductivity 
• High heat dimensional stability 
• Processable on standard textile equipment

Typical Properties of Melamine Fiber

Measurement	Units	Typical Values
Color		Ivory white
Average Diameter	µm	15
Average Denier	g/9000m	2.4
Specific Gravity		1.4
Tensile Strength	ksi	36
Tenacity	g/den	2.0
Modulus	Msi g/den	1.0 55
Elongation at Break	%	11
Moisture Regain (23°C, 65% RH)	%	5
Shrinkage at 200°C (1hr exposure)	%
Limiting Oxygen Index	%	32
Maximum Continuous Operating Temperature	°C	200
Melting Temperature	°C	Does not melt or drip
Resistance to Mildew, Aging, Sunlight		Excellent
Resistance to Solvents, Alkalis		Excellent

Production Process of Melamine Fiber

The production process is proprietary. It is based on a unique melamine chemistry that results in a cross-linked, non-thermoplastic polymer of melamine units joined by methylene and dimethylene ether linkages. In the polymerization reaction, methylol derivatives of melamine react with each other to form a three-dimensional structure. This structure is the basis for the fiber’s heat stability, solvent resistance, and flame resistance.

Applications of Melamine Fiber

• Mattresses, Home Furnishings / Nonwovens
• (Compliant with 16CFR1633)
• Specialty flame resistant papers
• Firefighting apparel
• Electrical papers
• Transmission / friction papers
• Filtration media
• Engineered materials / Short-fiber composites
• Adhesives / Fillers
• Tire sealants
• Truck / Rail brakes

Besides Melamine fiber has Potential use which are given below :

Fire Blocking Fabrics: Aircraft seating, fire blockers for upholstered furniture in high-risk occupancies (e.g., to meet California TB 133 requirements)

Protective Clothing: Firefighters’ turnout gear, insulating thermal liners, knit hoods, molten metal splash apparel, heat resistant gloves.

Filter Media: High capacity, high efficiency, high temperature baghouse air filters.

Aramid Fiber | Manufacturing Process of Aramid | Properties of Aramid Fiber | Uses of Aramid Fiber | History of Aramid Fiber

Aramid Fiber:

Aramid ia a manufactured fiber in which the fiberforming substance is a long-chain synthetic polyamide in which at least 85% of the amide (-CO-NH-) linkages are attached directly between two aromatic rings.

Technically, aramid fibers are long-chain synthetic polyamides. Aramid fibers have extremely high tensile strength, which is why they are commonly used in armor and ballistic protection applications. With a distinctive yellow color, aramid fibers are frequently used in advanced composite products which require high-strength and light-weight properties.

Structure of Aramid

Also Known As: Kevlar (Trademark of DuPont), Twaron (Trademark of Teijin)

History of Aramid Fiber | Aramid Fiber History
Aromatic polyamides were first introduced in commercial applications in the early 1960s, with a meta-aramid fiber produced by DuPont under the tradename Nomex. Aramid fiber, which handles similarly to normal textile apparel fibers, is characterized by its excellent resistance to heat, as it neither melts nor ignites in normal levels of oxygen. Aramid is used extensively in the production of protective apparel, air filtration, thermal and electrical insulation as well as a substitute for asbestos. Meta-aramid is also produced in the Netherlands and Japan by Teijin under the tradename Teijinconex, in China by Yantai under the tradename New Star and a variant of meta-aramid in France by Kermel under the tradename Kermel.

Manufacturing Process of Aramid
World capacity of para-aramid production is estimated at about 41,000 tons/yr in 2002 and increases each year by 5-10%. In 2007 this means a total production capacity of around 55,000 tons/yr.

Spinning:
After production of the polymer, the aramid fiber is produced by spinning the solved polymer to a solid fiber from a liquid chemical blend. Polymer solvent for spinning PPTA is generally 100% (water free) sulfuric acid (H2SO4).

Appearances of Aramid Fiber

• Fiber
• Chopped fiber
• Powder
• Pulp

Aramid Fiber Characteristics

• Good resistance to abrasion
• Good resistance to organic solvents
• Nonconductive
• No melting point, degradation starts from 500°C
• Low flammability
• Good fabric integrity at elevated
• Sensitive to acids and salts
• Sensitive to ultraviolet radiation
• Prone to static build-up unless finished

Uses of Aramid Fiber

• Flame-resistant clothing
• Heat protective clothing and helmets
• Body armor[competing with PE based fiber products such as Dyneema and Spectra
• Composite materials
• Asbestos replacement (e.g. braking pads)
• Hot air filtration fabrics
• Tires, newly as Sulfron (sulfur modified Twaron)
• Mechanical rubber goods reinforcement
• Ropes and cables
• Wicks for fire dancing
• Optical fiber cable systems
• Sail cloth (not necessarily racing boat sails)
• Sporting goods
• Drumheads
• Wind instrument reeds, such as the Fibracell brand
• Speaker woofers
• Boathull material
• Fiber reinforced concrete
• Reinforced thermoplastic pipes
• Tennis strings (e.g. by Ashaway and Prince tennis companies)
• Hockey sticks (normally in composition with such materials as wood and carbon) 

 

What is Spandex Fiber | Properties of Spandex Fiber | Production Process of Spandex Fiber | Manufacturing Process of Spandex Fiber | Uses of Spandex Fiber

Spandex is a manufactured fiber in which the fiber forming substance is a long-chain synthetic polymer comprised of at least 85% of a segmented polyurethane. Spandex or elastane is a synthetic fiber known for its exceptional elasticity (stretchability). It is stronger and more durable than rubber
, its major plant competitor. It was invented in 1959, and when first introduced it revolutionized many areas of the clothing industry.Spandex is the preferred name in North America, while elastane is most often used elsewhere. A well-known trademark for spandex or elastane is Invista’s brand name Lycra; another trademark (also Invista’s) is Elaspan.

Characteristics of Spandex Fiber 

• Can be stretched repeatedly and still recover to very near its original length and shape 
• Generally, can be stretched more than 500% without breaking 
• Stronger, more durable and higher retractive force than rubber 
• Lightweight, soft, smooth, supple 
• In garments, provides a combination of comfort and fit, prevents bagging and sagging 
• Heat-settable — facilitates transforming puckered fabrics into flat fabrics, or flat fabrics into permanent rounded shapes 
• Dyeable 
• Resistant to deterioration by body oils, perspiration, lotions or detergents 
• Abrasion resistant 
• When fabrics containing spandex are sewn, the needle causes little or no damage from “needle cutting” compared to the older types of elastic materials 
• Available in fiber diameters ranging from 10 denier to 2500 denier 
• Available in clear and opaque lusters.

Spandex Fiber Production 

The polymer chain is a segmented block copolymer containing long, randomly coiled, liquid, soft segments that move to a more linear, lower entropy, structure. The hard segments act as “virtual cross-links” that tie all the polymer chains together into an infinite network. This network prevents the polymer chains from slipping past each other and taking on a permanent set or draw. When the stretching force is removed, the linear, low entropy, soft segments move back to the preferred randomly coiled, higher entropy state, causing the fiber to recover to its original shape and length. This segmented block copolymer is formed in a multi-step proprietary process. It is extruded into a fiber as a monofilament threadline or for most products into a multiplicity of fine filaments that are coalesced shortly after they are formed into a single threadline.

Uses of Spandex Fiber 

Garments where comfort and fit are desired: hosiery, swimsuits, aerobic/exercise wear, ski pants, golf jackets, disposable diaper, waist bands, bra straps and bra side panels. 

Compression garments: Surgical hose, support hose, bicycle pants, foundation garments 

Shaped garments: Bra cups

Flax Fiber | Properties of Flax Fiber | Histroy of Flax Fiber | Applications of Flax Fiber | Uses of Flax Fiber

Flax is also called Linen. The fibre is obtained from the stalk of a plant (Linum Usitatissimum - A literal translation is “linen most useful.” ) which is from 80 to 120 cm high, with few branches and small flowers, of a colour which varies from white to intense blue, which flowers only for one day. Common flax was one of the first crops domesticated by man. 

Flax is thought to have originated in the Mediterranean region of Europe; the Swiss Lake Dweller People of the Stone Age apparently produced flax utilizing the fiber as well as the seed. Linen cloth made from flax was used to wrap the mummies in the early Egyptian tombs. In the United States, the early colonists grew small fields of flax for home use, and commercial production of fiber flax began in 1753. However, with the invention of the cotton gin in 1793, flax production began to decline. Presently the major fiber flax producing countries are the Soviet Union, Poland, and France.

Common flax (also known as linseed) is a member of the Linaceae family which includes about 150 plant species widely distributed around the world. Some of them are grown in domestic flower beds, as flax is one of the few true blue flowers. Most “blue” flowers are really a shade of purple.

Properties of Flax Fiber

70% is composed of cellulose, it cannot provoke allergies, absorbs humidity and allows the skin to breathe: therefore it is very indicated in the manufacture of summer articles. Very resistant, above all if wetted it can be washed many times without alteration, rather it becomes softer, something very important for articles of clothing and for daily use which require frequent washing such as shirts. Having very low elasticity, linen cloths do not deform themselves. 

European linen fabrics today are luxurious, elegant, comfortable and practical. Linen is thermo regulating, non-allergenic, antistatic and antibacterial. Because it can absorb up to 20 times its weight in moisture before it feels damp, linen feels cool and dry to the touch. It is not by accident that the world’s oldest and most useful fiber is still in great demand.

Flax History | Histroy of Flax Fiber

Flax fibres are amongst the oldest fibre crops in the world and the use of flax for the production of linen goes back 5000 years. Pictures on tombs and temple walls at Thebes depict flowering flax plants. The use of flax fibre in the manufacturing of cloth in Northern Europe dates back to pre-Roman times. In the USA flax was introduced by the Pilgrim fathers. Currently all flax produced in the USA and Canada are seed flax types for the production of linseed oil or flaxseeds for human nutrition.Flax fibre is soft, lustrous and flexible. It is stronger than cotton fibre but less elastic. The best grades are used for linen fabrics such as damasks, lace and sheeting. Coarser grades are used for the manufacturing of twine and rope. Flax fibre is also a raw material for the high quality paper industry for the use of printed currency notes and cigarette paper.

The major fibre flax producing countries are the former USSR, Poland, France, Belgium and the Czech Republic

Applications of Flax Fiber

• Table wear 
• Suiting 
• Clothing apparel 
• Surgical thread 
• Sewing thread 
• Decorative fabrics 
• Bed linen 
• Kitchen towels 
• High quality papers 
• Handkerchief linen 
• Shirting 
• Upholstery 
• Draperies 
• Wall coverings 
• Artist’s canvases 
• Luggage fabrics 
• Paneling 
• Insulation 
• Filtration 
• Fabrics for light aviation use 
• Automotive end uses 
• Reinforce plastics and composite materials. 
• Flax could conceivably be mixed with excess grass seed straw or softwood fiber in composite boards 

Consumers around the world buy linen because they like the way it looks, feels and performs. With new varieties of flax; new processing techniques; and new ways of spinning, weaving and finishing, the European linen industry has reinvented itself. And all of the links in the supply chain are working together through the European flax and linen organization, Masters of Linen, Paris, to market linen globally to a new and growing trade of niche players.

The flax plant has also a couple of other important end uses 

Industrial Uses:

Flax is still produced for its oil rich seed. Linseed oil has been used as a drying agent for paints, varnishes, lacquer, and printing ink. Unfortunately these markets have eroded somewhat over the years with the production of synthetic resins and latex. One bright spot in the market has been the use of linseed oil as an anti-spalling treatment for concrete where freezing and thawing effects have created problems on streets and sidewalks. Occasionally the straw is harvested and used to produce some paper products. 

Livestock Feed:

Linseed oil meal is an excellent protein source for livestock containing about 35% crude protein. Flax straw on the other hand, makes a very poor quality forage because of its high cellulose and lignin content. 

Human Food:

Recently there has been some interest in seed flax as a health food because of its high amount of polyunsaturated fatty acids in the oil.

Nylon Fiber | Nylon Fiber Production Process | Characteristics of Nylon Fiber | Uses of Nylon Fiber

Nylon is a manufactured fiber in which the fiber forming substance is a long-chain synthetic polyamide in which less than 85% of the amide-linkages are attached directly (-CO-NH-) to two aliphatic groups.

Nylon is a synthetic polymer, a plastic, invented on February 28, 1935 by Wallace Carothers at the E.I. du Pont de Nemours and Company of Wilmington, Delaware, USA. The material was announced in 1938 and the first nylon products; a nylon bristle toothbrush made with nylon yarn (went on sale on February 24, 1938) and more famously, women’s stockings (went on sale on May 15, 1940). Nylon fibres are now used to make many synthetic fabrics, and solid nylon is used as an engineering material.

Nylon Fiber Production — The term nylon refers to a family of polymers called linear polyamides. There are two common methods of making nylon for fiber applications. In one approach, molecules with an acid (COOH) group on each end are reacted with molecules containing amine (NH2) groups on each end. The resulting nylon is named on the basis of the number of carbon atoms separating the two acid groups and the two amines. Thus nylon 6,6 which is widely used for fibers is made from adipic acid and hexamethylene diamine. The two compounds form a salt, known as nylon salt, an exact 1:1 ratio of acid to base. This salt is then dried and heated under vacuum to eliminate water and form the polymer.

In another approach, a compound containing an amine at one end and an acid at the other is polymerized to form a chain with repeating units of (-NH-[CH2]n-CO-)x. If n=5, the nylon is referred to as nylon 6, another common form of this polymer. The commercial production of nylon 6 begins with caprolactam uses a ring-opening polymerization. For a detailed production flowchart, go here.

In both cases the polyamide is melt spun and drawn after cooling to give the desired properties for each intended use. Production of nylon industrial and carpet fibers begins with an aqueous solution of monomers and proceeds continuously through polymerization, spinning, drawing, or draw-texturing.

Characteristics of Nylon Fiber

• Exceptionally strong 
• Elastic 
• Abrasion resistant 
• Lustrous 
• Easy to wash 
• Resistant to damage from oil and many chemicals 
• Can be precolored or dyed in wide range of colors 
• Resilient 
• Low in moisture absorbency 
• Filament yarns provide smooth, soft, long-lasting fabrics 
• Spun yarns lend fabrics light weight and warmth

Some Major Nylon Fiber Uses

Apparel: Blouses, dresses, foundation garments, hosiery, lingerie, underwear, raincoats, ski apparel, windbreakers, swimwear, and cycle wear .

Home Furnishings: Bedspreads, carpets, curtains, upholstery 

Industrial and Other Uses: Tire cord, hoses, conveyer and seat belts, parachutes, racket strings, ropes and nets, sleeping bags, tarpaulins, tents, thread, monofilament fishing line, dental floss.

Termal Properties of Textile Fibers

The property which is shown by a textile fiber when it is subjected to heating is called thermal property. Thermal properties are including:

1. Thermal conductivity

2. Heat of wetting or heat of absorption

3. Glass transition temperature

4. Melting temperature

5. Heat setting

6. Thermal expansion

 

Thermal conductivity: 

Thermal conductivity is the rate of heat transfer in degree along the body of a textile fiber by conduction. Higher the thermal conductivity indicates the fiber more conductive. Thermal conductivity is measure by co-efficient of thermal conductivity.

 

Heat of wetting: 

When a textile fiber absorb moisture or water it gives of some amount of heat which is called heat of wetting or heat of absorption. Heat of absorption resulting from changes in moisture regain rather than the thermal conductivity. If 1gm of dried textile fiber is completely wetted then heat in calory/gm is involved which is known as heat of wetting for that fiber.

Glass transition temperature(Tg): 

The temperature up to which a fiber behaves hard as like glass and after which it behaves soft as like rubber is called Glass transition temperature and it is denoted by Tg. The range of Tg is lies between -100˚C to 300˚C

 

Melting temperature: 

A temperature at which fiber melt completely is called melting temperature. At melting temperature fiber losse its identity and convert it into a viscous liquid. At melting temperature fiber also losse its strength and some molecular weight.

 

Thermal expansion: 

Thermal expansion can be measured by co-efficient of thermal expansion and which is defined as the fractional increase in length of a specimen to rise in temperature by 1˚C. Co-efficient of thermal expansion ═ Length increased / initial length of specimen ═ ∆L / L ═ L2-L1 / L1

 

Heat setting: 

Heat setting is the process of stabilizing the form of fibers, yarns, fabric or garment by means of successive heating or cooling in dry and wet condition.

Static Electricity

 

If two surfaces come in close contact with each other, then charge is created due to friction between them. The produced charge remains enclosed and static in those surfaced. They can not move from one place to another place. Here only charges are exchanged between two surfaces. This type of electricity is called static electricity.

Problem caused by static electricity in textile:

 

1. Similar charge repel each other:

a) The filament in a charged warp will blow out away from one another.

b) This causes difficulties in handling materials.

c) There will be ballooning of a bundle of sliver.

d) Cloth will not fold down neatly upon itself when it comes off a finishing machine.

 

2. Different charge attracts each other:

a) Difficulties in the opening of the parachute.

b) Different parts of garments may be stick together.

3. Attraction between charged particles & charged textile materials:

a) Roller lapping may occur.

b) Dust, Dirt’s etc may be attracted by the textile material as a result materials become dirt.

c) Soiling of cloth may occur.

d) Fibers may stick to the earthed parts of the machine.

Methods of minimizing static electricity: 

1. By using conducting liquids like emulsion, oil, friction between the materials ca be reduced as a result, static electricity will be minimize. 
2. By increasing relative humidity of the atmosphere, static electricity can be minimized.
3. By using anti-static agent on the materials static problem may reduce.
4. By ear thing the metallic part of the machinery static electricity can be minimized. By blending conductive materials with non conductive materials, static electricity can be minimized.

Fiber migration:

Migration occurs during spinning both in staple and filament yarns. The effect of migration is more pronounced in staple yarn than in filament yarn. The migration of fiber affect on many properties of fiber as like elongation and strength. According to the textile institute “The change in the distance of a fiber or filament form the axis of a yarn during production is called fiber migration.

Structure of Textile Fiber | Physical Structure of Textile Fiber | Molecular Structure of Textile Fiber

Requirement of fiber formation or fiber forming polymer:

1) Polymer should have long & linear chain molecules.

2) They must be chemically resistance.

3) Molecular chain must be parallel to each other.

4) They should have attractions.

5) Some measures of freedoms of molecules movement due to give required extensibility.

6) Lateral forces to hold the molecules together and gives cohesion the structure.

Methods of fiber structure investigation:

1) X-ray diffraction method

2) Infra-red radiation method

3) Electron microscopic method

4) Optical microscopic method

5) Thermal analysis

6) Nuclear magnetic resonance methods

7) Density

8) General physical properties

9) The chemistry of fiber material

Properties of x-ray diffraction method:

1) Determination of chemical groups

2) Determination of molecular spacing

3) Determination of chemical bonding

4) Determination of degree of crystallinity & orientation

5) Determination of water absorption

Properties of Infra- red radiation absorption method:

1) Determination of spiral turns or convolution of cotton fiber

2) Determination of molecular spacing

3) Determination of chemical bonding

4) Determination of degree of crystallinity & orientation

5) Determination of molecular packing

6) Determination of cross-sectional shape of fiber

7) Identifications of fiber

Crystallinity:

Crystallinity is the arrangement of fiber molecules in the molecular chain.
Properties of crystallinity:

1) More dense 

2) More stiff

3) More strength

4) More rigid

5) Less water absorbent

Measurement of crystallinity:

1) X-ray diffraction method

2) Infra-red radiation absorption method

3) Density measurement methods

Orientation: Orientation is the arrangement of molecular chain of fiber.
Properties of Orientation:

1) More dense 

2) More stiff

3) More strength

4) More rigid

5) More water absorbent

6) More lustrous

7) Less elastic as less extension

Measurement of Orientation:

1) X-ray diffraction method

2) Infra-red radiation absorption method

3) Density measurement methods

Effects of structural factors on fiber properties:
1) Chemical bonding:

a) Single bond-More strength, less flexibility 

b) Double bond - Less strength, more flexibility

2) Character of polymer chin: 

a) Long chain, such as [-CH2-CH2-CH2-CH2-CH2-CH2-]n-More strength, less flexibility
b) Sort chain, such as [-CH2-CH2-]n-Les strength, more flexibility 

c) Long side chain-More strength, less flexibility
d) Sort side chain-Less strength, more flexibility 

 

3) Molecular packing: 

a) Regular packing: More strength, less flexibility
b) Irregular packing: Less strength, more flexibility 

 

4) Crystallinity: High crystallinity, higher strength and less flexibility 

 

5) Orientation: High Orientation, higher strength and less flexibility

6) Nature of monomer:

a) Same monomer (Homopolymer) -More strength, less flexibility
b) Same monomer (Co-polymer) -Less strength, more flexibility

7) Internal structure of fiber polymer: 

a) For ring structure -More strength, less flexibility 

b) For normal structure -Less strength, more flexibility

Torsional Properties of Fiber | Torsional Properties of Textile Materials

It is the property of fibre or material when a Torsional force is applied on it. Here Torsional force is a twisting force that is applied on the two ends of the material in two opposite direction. The behaviors which are shown by a textile material when it is subjected to a torsional force is called torsional property.

1. Torsional rigidity

2. Breaking twist 

3. Shear modulus

1. Torsional rigidity:  

Torsional rigidity can be defined as the torque required against twisting is done for which torque is termed as torsional rigidity.Mathematically, torsional rigidity = ηET2/ρ

Where, 

η = shape factor, 

E = specific shear modulus (N/tex)

Specific torsional rigidity: Specific torsional rigidity can be defined as the torsional rigidity of a fiber of unit linear density.Mathematically, specific torsional rigidity = ηE/ρ

Unit: N-m2 /Tex

2. Breaking twist:  

The twist for breaking of a yarn is called breaking twist. It also can be defined as the number of twists required to break a yarn. Breaking twist depends on the diameter of fiber and it is inversely proportional to its diameter.That is, Tb ∞ 1/d

Where, 

Tb = Breaking twist, 

d = diameter of fiber

Breaking twist angle: This is the angle through which outer layer of fiber are sheared at breaking. Mathematically, α = tan-1(πdTb)

Where, 

α = breaking twist angle, 

d = diameter of fiber, 

Tb = breaking twist per unit length 

Frictional Property of Textile Fiber

When the textile materials are processed, then friction is developed between the fibers. The properties which are shown by a textile material during friction is known as frictional property. This properties are shown during processing. Too high friction and too low friction is not good for yarn. Therefore it is an important property when yarn manufacturing and processing.

Frictional properties depend on-

1. Composition of the material

2. State of the surface of the material

3. Pressure between the surfaces

4. Temperature

5. Relative humidity %

Co-efficient of friction:  

Frictional force is proportional to the normal or perpendicular of a material due to its own weight.That is, F ∞ N Or, F = μ N Or, μ = F/NWhere, F = Frictional force, N = Normal / perpendicular forceHere, μ is the proportional constant known as “co-efficient of friction”.So, co-efficient of friction can be defined as the ratio of frictional force and perpendicular force.

Methods of measuring co-efficient of friction:  

Capstan method is most commonly used to measure co-efficient of fraction. Capstan method can be classified into two classes-

1. Static capstan method

2. Dynamic capstan method

Other methods- 

1. Buckle & Pollitt’s method

2. Abboh & Grasberg method

3. Gutheric & Olivers method

Influences of friction on textile material:

Friction holds the fibers in a sliver and hence the sliver does not break due to its’ own weight. Friction helps in drafting and drawing.· Uniform tension can be maintained during winding & warping because of friction.· Friction helps to make yarn by twisting during spinning.· Friction increases lusture and smoothness of the yarn and the fabric.· Friction makes more clean material. 

Demerits of friction on textile material:· 

Friction causes nap formation.· High static friction causes high breakage of yarn during weaving.· If the frictional force is high, the handle properties of fabric will be low.· Friction generates temperature and therefore static electricity is developed which attracts dust, dirt etc. and the materials become dirty.· Sometimes due to over friction materials may be elongated.· Friction increases yarn hairiness.· Friction worn out parts of machine.

Minimization of friction intensity:  

1. Sizing is done in warp yarn before weaving to reduce frictional intensity. As a result, yarn damage will be reduced.

2. Emulsion, oil, lubricants etc. are specially applied on jute fiber to reduce friction.

3. Chemical treatment is done on wool fiber to reduce scale sharpness and thus reduce friction during processing.

4. By calendaring frictional intensity of cloth is reduced.

5. Sometimes resin finish is applied on fabric to reduce friction.