The History and Development of Silk and Natural Silk
(I)Natural Silk——Oldest Pride of Chinese
All Chinese know the Silk Road in history and most people know the natural silk is originated from China, fostered and enhanced in Europe and America. It is even regarded as valuable treasure by Japanese in modern times. But now few people know why the natural silk is the oldest pride of the Chinese. Dating back to the ancient Chinese goddess who started to feed the silkworm, the Chinese has a close connection with the silk- the Bo in the Zhou and Qin dynasty, Hui in the Han dynasty, silk in the Tang dynasty and the Hangzhou silk and Sichuan figured satin in nowadays. In the development history of human civilization, the silk products have always been closely linked up with human life.
(II) Silk--The Unique Product of China
Before the opening of the Silk Road in 206BC, there was no silk in other places except China. The Silk Road was built in the Han dynasty (139 BC). It started as the emperor sent Zhang Qian to Yuezhi in the western regions. And it slowly spread to the west till 105 BC. It took a whole year for the silk to leave China and finally be sold in Rome after a 9600-kilometer journey. The silk transported to Rome through the Silk Road had the same value of gold, while the women in Rome still raced to wear it as a fashion. Chinese exported silk without telling the process of producing, which made a famous writer from Rome, Virgil, always believe that silk grew on trees in 100 BC.
China's secrets of silkworm breeding and silk weaving had been kept for 3000 years. It was not until 522 AD, when two Nestorians from Rome stole 550 silkworm eggs from China to win the reward offered by the emperor Justinian and incubated them on the silkworm trees in Constantinople until them cocooning, that the westerners began to know the secrets of silk.
(III) Silk-- The fiber nearest to human skin in the world
The conformation and feature of silk:
Silkworm is a kind of insect belonging to the order Lepidoptera. After peeling off their skin four times, the larva of silkworm would eject silk from mouth and fix it on the ground before put up the false work, which was used as the framework of cocoons, and the project of making cocoons need two to three days. Each mature silkworm has a pair of silk gland which consists of more than 900 gland cells.
At first, the silk protein which was secreted by the silk gland was liquid, and then hardens to silk fiber as soon as it exposes to air from the silk tube.
The silk fiber consist of inside and outside organizations--fibroin (about 75%）and sericin ( about 25%).
The fibroin itself still possesses 35% interval from the volume and the sericin outside also has the Amino Acids that is a hydrophil lateral chain, which make silk has a great function of absorption of moisture and still keep its comfort and coolness in spite of torridness.
Silk fiber can bear 35-44Kg/cm² pulling force in a unit of cross-sectional area and it can still restitute after elongating the 1/7 length of itself, which has excellent flexibility and is light, soft and fluffy.