Protein fibers are fibers of moderate strength, resiliency, and elasticity. They have excellent moisture absorbency and transport characteristics. They do not build up static charge. While they have fair acid resistance, they are readily attacked by bases and oxidizing agents. They tend to yellow in sun Iight due to oxidative attack.

Silk fibers

BOMBYX MORI-commonly called the SILKWORM

SILK

Preparation of silk fiber from the larvae.Silk moths lay eggs on specially prepared paper. The eggs hatch and the caterpillars (silkworms) are fed fresh mulberry leaves. After about 35 days and 4 molting, the caterpillars are 10,000 times heavier than when hatched and are ready to begin spinning a cocoon. A straw frame is placed over the tray of caterpillars, and each caterpillar begins spinning a cocoon by moving its head in a "figure 8" pattern. Two glands produce liquid silk and force it through openings in the head called spinnerets. Liquid silk is coated in sericin, a water-soluble protective gum, and solidifies on contact with the air. Within 2–3 days, the caterpillar spins about 1 mile of filament and is completely encased in a cocoon. The silk farmers then kill most caterpillars by heat, leaving some to metamorphose into moths to breed the next generation of caterpillars. Harvested cocoons are then soaked in boiling water to soften the sericin holding the silk fibers together in a cocoon shape.

Silk fiber

TYPES OF SILKWILD SILK

A variety of wild silks, produced by caterpillars other than the mulberry silkworm have been known and used in China, South Asia, and Europe since ancient times. However, the scale of production was always far smaller than that of cultivated silks. There several reasons for this: one, they differ from the domesticated varieties in color and texture and are therefore less uniform, secondarily, cocoons gathered in the wild have usually had the pupa emerge from them before being discovered so the silk thread that makes up the cocoon has been torn into shorter lengths, and thirdly, many wild cocoons are covered in a mineral layer that stymies attempts to reel from them long strands of silk. Thus previously the only way to obtain silk suitable for spinning into textiles in areas where commercial silks are not cultivated is by tedious and labor intensive carding.

CULTIVATED SILK

Cultivated silks originate from reared silkworm pupae which are killed by dipping them in boiling water before the adult moths emerge or by piercing them with a needle, and have been bred for a white color and no mineral on the surface, factors all contributing to the ability of whole cocoon to be unravelled as one continuous thread. This permits a much stronger cloth to be woven from the silk. Wild silks also tend to be more difficult to dye than silk from the cultivated silkworm. A technique known as demineralizing allows the mineral layer around the cocoon to be removed, leaving only variability in color as a barrier from creating a commercial silk industry based on wild silks in parts of the world where wild silkmoths thrive, such as Africa and South America.

From SILK FIBER to SILK YARN.

Silk is a staple fiber and is naturally in filamentous formThe fibers are unwound to produce a continuous thread. This continuous long filament fiber is shortened into small pieces to form fine threads. Since a single thread is too fine and fragile for commercial use, anywhere from three to ten strands are spun together to form a single thread of silk. It is called the spun silk or silk yarn.

SILK YARN

SILK FABRICSilk yarn is woven to make the Silk Fabrics. The longer the length of the silk Yarn better is the quality of the silk fabric. Quality of the silk fabric is determined by the fineness and strength of the fabric. Best quality silk fabrics are very expensive.Silk fabrics were meant for the rich and powerful in India since the ancient times. Ancient texts and mythological tales tell us that for a long time, silk fabrics were specially cultured and developed for the use of the royalty. Times have changed, and anybody who can buy silk products can use them without reservation. However, silk still remains one of the most sought after and expensive fabrics and even now, most of the common masses cannot afford silk fabrics.Silk fabrics are valued chiefly due to their luster and drapability. It is used not only in garments, but

also in draperies, ribbons and head gear.

Silk fabric

Silk dress

APPERANCE OF SILK FABRIC.Silk fibers from the Bombyx mori silkworm have a triangular cross section with rounded corners, 5-10 µm wide. The fibroin-heavy chain is composed mostly of beta-sheets, due to a 59-mer amino acid repeat sequence with some variations. The flat surfaces of the fibrils reflect light at many angles, giving silk a natural shine. The fiber having sharp edges reflect light in several angles giving the fabric the glossy lustrous appearance.The cross-section from other silkworms can vary in shape and diameter.

Cross section of silk fiber.Glossy appearance of

silk fabric

Surface contour.Silk has a smooth, soft texture that is not slippery, unlike many synthetic fibers.

ElasticityIts elasticity is moderate to poor: if elongated even a small amount, it remains stretched

PHYSICAL PROPERTIES OF SILK FABRIC

Moisture contentIt has a good moisture regain of 11%

StrengthSilk is one of the strongest natural fibers but loses up to 20% of its strength when wet and retains wet spots.Hence it is preferably sent for dry cleaning.

LengthSilkworm silk was used as the standard for the denier, a measurement of linear density in fibers. Silkworm silk therefore has a linear density of approximately 1 den, or 1.1 dtex.

Light sensitivitySilk is very sensitive to light. It can be weakened if exposed to too much sunlight.

Chemical resistance

Silk is resistant to most mineral acids, except for sulfuric acid, which dissolves it. It is yellowed by perspiration

Effect of insects

It may also be attacked by insects, especially if left dirty.

Silk yarns.

Wool fiber Wool is the textile fiber obtained from sheep and certain other

animals, including cashmere from goats, mohair from goats, from vicuña, alpaca, and camel from animals in the camel family, and angora from rabbits. It has several qualities that distinguish it from hair or fur: it is crimped, it is elastic, and it grows in staples(clusters). The term wool is usually restricted to describing the fibrous protein derived from the specialized skin cells called follicles in sheep.

Long and short hair wool 

Characteristics Wool's scaling

and crimp make it easier to spin the fleece by helping the individual fibers attach to each other, so that they stay together. Because of the crimp, wool fabrics have a greater bulk than other textiles, and retain air, which causes the product to retain heat. Insulation also works both ways; Bedouins and Tuaregs use wool clothes to keep heat out.

Clothes worn by Bedouins

Shearing Sheep shearing is the process by which the woolen fleece of a

sheep is cut off. After shearing, the wool is separated into four main categories: fleece (which makes up the vast bulk), broken, bellies, and locks. The quality of fleeces is determined by a technique known as wool classing.

Merino shearing

ScouringWool straight off a sheep, known as "greasy wool" or "wool in the grease", contains a high level of valuable lanolin, as well as dirt, dead skin, sweat residue, pesticide, and vegetable matter. Before the wool can be used for commercial purposes, it must be scoured, a process of cleaning the greasy wool. Scouring may be as simple as a bath in warm water, or as complicated as an industrial process using detergent and alkali, and specialized equipment.

Wool is made by cutting or tearing apart existing wool fabric and respinning the resulting fibers. As this process makes the wool fibers shorter, the remanufactured fabric is inferior to the original. The recycled wool may be mixed with raw wool, wool noil, or another fiber such as cotton to increase the average fiber length. Such yarns are typically used as weft yarns with a cotton warp. This process was invented in the Heavy Woollen District of West Yorkshire and created a micro-economy in this area for many years.

Wool yarn

Wool fabric is equipped with different characteristics like warm, resists to wrinkle, wear and tear, it is light weight and durable which also absorbs moisture. Have been largely used in blankets and carpets, today almost every wardrobe contains garment made of woolen fabric.

Wool fabric and its uses

Wool fabric

Types of wool Ragg is a sturdy wool fiber

made into yarn and used in many rugged applications like gloves.

Worsted is a strong, long-staple, combed wool yarn with a hard surface.

Woollen is a soft, short-staple, carded wool yarn typically used for knitting. In traditional weaving, woollen weft yarn (for softness and warmth) is frequently combined with a worsted warp yarn for strength on the loom. Worsted wool suit

• Angora

• Camel

• Rabbit

• Goat

ANGORA FIBER Angora wool or Angora

fiber refers to the downy coat produced by the Angora rabbit. While their names are similar, Angora fiber is distinct from mohair, which comes from the Angora goat. Angora is known for its softness, thin fibers, and what knitters refer to as a halo (fluffiness). It is also known for its silky texture. Good quality Angora fiber is around 12-16 micrometers in diameter, and can cost around $ 10 - 16 per ounce. Angora fibers are hollow, which gives them their characteristic floating feel.

Angora

Fur ProductionAngora fur is

produced in Europe, Chile, China and the United States. Harvesting occurs up to three times a year (about every 4 months) and is collected by plucking, shearing, or collection of the molting fur.

Angora rabbits being sheared

Quality The premium first quality wool is

taken from the back and upper sides of the rabbit. This is usually the longest and cleanest fiber on the rabbit. There should not be hay or vegetable matter in the fiber .

Second quality is from the neck and lower sides, and may have some vegetable matter.

Third quality is the buttocks and legs and any other areas that easily felt and are of shorter length..

Fourth quality is totally unsalvageable, and consists of the larger felted bits or stained fiber. 

Premium quality garment

MOHAIR Mohair usually refers to a silk-

like fabric or yarn made from the hair of the Angora goat. It is one of the oldest textile fibers in use. It is both durable and resilient. It is notable for its high luster and sheen, and is often used in fiber blends to add these qualities to a textile. Mohair also takes dye exceptionally well. Mohair is also warm as it has great insulating properties. It is durable, and resistant to moisture-wicking, stretch, flame and creases. It is considered to be a luxury fiber, like cashmere, angora and silk, and is usually more expensive than most wool that comes from sheep.

Angora goat

Red mohair fabric

Camel hair fiber Camel hair is, variously,

the hair of a camel; a type of cloth made from camel hair; or a substitute for authentic camel hair; and is classified as a specialty hair fiber. When woven into haircloth, using the outer protective fur called guard hair, camel hair is coarse and inflexible. However, other varieties of camel hair cloth—especially those that blend camel hair with wool— or from the pure under coat are soft and plush. Pure camel hair, frequently used for coats, is gathered when camels molt in warmer seasons. This undercoat is very soft, and is separated from the dense, coarse guard hair for cloth use.

• A camel can produce around 5 pounds of hair a year. The specialty animal fiber is collected by a number of methods including combing, shearing, and collecting the hair shed naturally during the molting season. During the molting season the hair falls off first from the neck, then the mane and lastly the body hair. The molting season occurs in late spring and is a process that takes six to eight weeks.

•There are five primary steps to the production of camel hair; collection, sorting, dehairing, spinning, and weaving or knitting. After collecting the hair either through shearing or collecting during the molting season the hair goes through a sorting method. In this process the coarse hair is separated from the fine, soft hairs. Then sent to be spun into yarn and used for either weaving or knitting.

Uses Of Camel Hair The fine fur of the camel hair are often blended with fine

wool to create fabrics for men's and women's coats, jackets and blazers, skirts, hosiery, sweaters, gloves, scarves, mufflers, and caps and robes. The long coarser hair removed in the dehairing process is also used which can be made into carpet backing as well as waterproof coats that are very warm for colder climates.

Coat made of camel hair

Camel hair blanket

Rabbit hair fiberRabbit hair (also called rabbit

fur, cony, comb, convey or lapin) is the fur of the common rabbit. It is most commonly used in the making of fur hats and coats, and is considered quite valuable.

The hair of a rabbit can be divided into three types:

guide hairs: external hairs, long and rough

guard hairs (also called "barbes“) four guard hairs surround each guide hair, sealing the coat

down: there are around sixty down hairs for each guide hair; they are very short and barely visible, and serve to insulate the rabbit.

Rabbit hair

QualityRabbit hair is commonly considered a

byproduct of the ordinary process of breeding rabbits for meat, and as such is manufactured in vast quantities in England and France; more than seventy million pelts a year in France alone. However, the quality of fur from these rabbits tends to be low, as the rabbits are slaughtered before reaching twelve weeks old and still have the infant coat. In temperate climates, the highest quality furs are obtained in winter from rabbits over five months old, when the thickness of the fur is even; at other times of year, varying degrees of hair shedding causes uneven patches in the fur. The coat is also at its thickest at this time of year. The highest quality pelts are suitable for clothing, and typically constitute less than half of all pelts collected.