Fabrics, history and usage - SILK June 27 2013, 0 Comments
Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and produced by certain insect larvae to form cocoons. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity (sericulture). The shimmering appearance of silk is due to the triangular prism-like structure of the silk fiber, which allows silk cloth to refract incoming light at different angles, thus producing different colors.
Silks are produced by several other insects, but generally only the silk of moth caterpillars has been used for textile manufacturing. There has been some research into other silks, which differ at the molecular level. Many silks are mainly produced by the larvae of insects undergoing complete metamorphosis, but some adult insects such as webspinners produce silk, and some insects such as raspy crickets produce silk throughout their lives. Silk production also occurs in Hymenoptera (bees, wasps, and ants), silverfish, mayflies, thrips, leafhoppers, beetles, lacewings, fleas, flies and midges.
The entire production process of silk can be divided into several steps which are typically handled by different entities. Extracting raw silk starts by cultivating the silkworms on Mulberry leaves. Once the worms start pupating in their cocoons, these are dissolved in boiling water in order for individual long fibers to be extracted and fed into the spinning reel.
Silk's absorbency makes it comfortable to wear in warm weather and while active. Its low conductivity keeps warm air close to the skin during cold weather. It is often used for clothing such as shirts, ties, blouses, formal dresses, high fashion clothes, lingerie, pajamas, robes, dress suits, sun dresses and Eastern folk costumes. Silk's attractive luster and drape makes it suitable for many furnishing applications. It is used for upholstery, wall coverings, window treatments (if blended with another fiber), rugs, bedding and wall hangings. While on the decline now, due to artificial fibers, silk has had many industrial and commercial uses, such as in parachutes, bicycle tires, comforter filling and artillery gunpowder bags.
A special manufacturing process removes the outer irritant sericin coating of the silk, which makes it suitable as non-absorbable surgical sutures. This process has also recently led to the introduction of specialist silk underclothing for people with eczema where it can significantly reduce it. New uses and manufacturing techniques have been found for silk for making everything from disposable cups to drug delivery systems and holograms. To produce 1 kg of silk, 104 kg of mulberry leaves must be eaten by 3000 silkworms. It takes about 5000 silkworms to make a pure silk kimono. The construction of silk is called sericulture. The major silk producers are China (54%) and India (14%).
HISTORY OF SILK
According to Chinese tradition, the history of silk began in the 27th century BC. Its use was confined to China until the Silk Road opened at some point during the later half of the first millennium BC. China maintained its virtual monopoly over silk for another thousand years. Not confined to clothing, silk was also used for a number of other applications, including writing, and the colour of silk worn was an important indicator of social class during the Tang Dynasty.
Silk cultivation spread to Japan in around 300 CE, and by 522 the Byzantines managed to obtain silkworm eggs and were able to begin silkworm cultivation. The Arabs also began to manufacture silk during this same time. As a result of the spread of sericulture, Chinese silk exports became less important, although they still maintained dominance over the luxury silk market. The Crusades brought silk production to Western Europe, in particular to many Italian states, which saw an economic boom exporting silk to the rest of Europe. Changes in manufacturing techniques also began to take place during the Middle Ages, with devices such as the spinning wheel first appearing. During the 16th century France joined Italy in developing a successful silk trade, though the efforts of most other nations to develop a silk industry of their own were unsuccessful.
The Industrial Revolution changed much of Europe’s silk industry. Due to innovations in spinning cotton, it became much cheaper to manufacture and therefore caused more expensive silk production to become less mainstream. New weaving technologies, however, increased the efficiency of production. Among these was the Jacquard loom, developed for silk embroidery. An epidemic of several silkworm diseases caused production to fall, especially in France, where the industry never recovered. In the 20th century Japan and China regained their earlier role in silk production, and China is now once again the world’s largest producer of silk. The rise of new fabrics such as nylon reduced the prevalence of silk throughout the world, and silk is now once again a rare luxury good, much less important than in its heyday.
The Silk Road or Silk Route is a historical network of interlinking trade routes across the Afro-Eurasian landmass that connected East, South, and Western Asia with the Mediterranean and European world, as well as parts of North and East Africa. The Silk Road includes routes through Syria, Turkey, Iran, Turkmenistan, Uzbekistan, Kyrgyzstan, Pakistan and China.
Extending 4,000 miles (6,437 kilometres), the Silk Road gets its name from the lucrative Chinese silk trade which was carried out along its length, and began during the Han Dynasty (206 BC – 220 AD). The central Asian sections of the trade routes were expanded around 114 BC by the Han dynasty,[not in citation given] largely through the missions and explorations of Zhang Qian, but earlier trade routes across the continents already existed.
Trade on the Silk Road was a significant factor in the development of the civilizations of China, the Indian subcontinent, Persia, Europe and Arabia. Though silk was certainly the major trade item from China, many other goods were traded, and various technologies, religions and philosophies, as well as the bubonic plague (the "Black Death"), also traveled along the Silk Routes.
The main traders during Antiquity were the Indian and Bactrian traders, then from the 5th to the 8th century the Sogdian traders, then afterward the Arab and Persian traders.
• Gently handwash silk items using very cold water.
• Apply a very mild detergent (this soap will help preserve the garment’s natural oils).
• Rinse the item in cold water until all soap residue has been removed.
• Add a few drops of hair conditioner to the rinse water to keep the silk soft and flexible.
• Press the water out of the fabric by rolling it in a towel. Do not twist or wring, as this will damage the fabric.
• Hang the wet garment and allow it to air dry completely.
• Do not hang silk garments in the sun to dry.
• Iron only when absolutely necessary. Use a cool iron with a press cloth between the iron and the fabric.
In general, machine washing is the worst way to clean silk, as the agitator and other garments can damage the fabric. However, if the instructions for your washing machine state that the machine is safe for silk, there should be no serious problem washing your silk garments in it. Before washing, make sure there's no soap or dirt on the inside of the machine that might stain the silk garment. Place the silk item in a mesh bag or a pillowcase loosely tied closed. Use a small amount of a very mild appropriate detergent and wash on a gentle cycle, such as a wool cycle, at a temperature of no more than 86°F / 30°C.
If you use a spin cycle, keep it as short as possible.
Even if you machine wash, never use a machine dryer to dry silk, as the friction and lack of humidity will likely damage the fabric. Instead, roll the silk item up in a bath towel and gently press the water out. Never wring silk. When most of the water is out, hang your garment up to dry. Keep the garment away from heat sources or direct sunlight, both of which can discolour silk.
Silk should be pressed while still damp, never when completely dry. If the item has dried, dampen it with water from a mineral water spritzer bottle before ironing. To avoid damage, turn the item inside out and iron on the reverse side of the fabric on a cotton-covered ironing board. Use a low setting and don't use steam, which can leave watermarks. Take care not to apply pressure to the seams of the garment.
For long-term storage, keep silk in a cotton pillowcase or other material that can breathe. Avoid plastic, which traps moisture and can cause yellowing and mildew. Silk, like other natural fibers, is a favorite with moths, so store cedar chips or balls with your silk to keep the bugs away.
STAIN REMOVAL TIPS
• Remove any spilled material from silk immediately to prevent it from setting. Remove food or sauce by scraping it off with a clean knife. Blot liquids on silk with a clean cloth dampened with cold water. Treat remaining oil or grease spots by sprinkling with cornstarch or talcum powder and gently patting it into the spot. Leave the powder on overnight to absorb the grease. Brush off the powder; repeat if necessary.
• Sponge lukewarm water onto coffee and tea stains. Gently rub commercially available glycerin into the stain. Leave the glycerin on the stain for a half-hour, then rinse the garment thoroughly in warm water.
• Add 1 tsp. of salt to 1 cup of cold water; dab a clean washcloth into the salt mixture and gently dab on blood stains. Rinse with cold water and repeat if needed. If the salt treatment doesn't work, make a paste with meat tenderizer and just enough water to moisten it. Work the paste into the stain with your fingers; follow with a cold-water rinse.
• Remove perspiration and makeup stains from silk using diluted ammonia. For perspiration stains, use equal parts cool water and ammonia on a clean cloth to dab at the stain. For makeup, mix one part ammonia to three parts water and apply with a clean cloth. Increase the ammonia proportion if needed, to a maximum concentration of equal parts ammonia and water. Follow all ammonia applications with repeated rinsing in cold water.
• Treat wine stains by sprinkling a little cornstarch on the stain to absorb the wine. Brush off the powder. Using a clean cloth, apply a commercial spot-removal product designed for silk directly to the spot. Follow with cool-water rinses.
• Apply a commercial spot-removal product designed specially for silk fabrics for all other stains. Apply as directed on the label and follow up with hand-washing in a gentle liquid detergent and rinsing in cool water.