silk

—silklike, adj.

/silk/, n.

1. the soft, lustrous fiber obtained as a filament from the cocoon of the silkworm.

2. thread made from this fiber.

3. cloth made from this fiber.

4. a garment of this cloth.

5. a gown of such material worn distinctively by a King's or Queen's Counsel at the English bar.

6. silks, the blouse and peaked cap, considered together, worn by a jockey or sulky driver in a race.

7. Informal. a parachute, esp. one opened aloft.

8. any fiber or filamentous matter resembling silk, as a filament produced by certain spiders, the thread of a mollusk, or the like.

9. the hairlike styles on an ear of corn.

10. Brit. Informal.

a. a King's or Queen's Counsel.

b. any barrister of high rank.

11. hit the silk, Slang. to parachute from an aircraft; bail out.

12. take silk, Brit. to become a Queen's or King's Counsel.

adj.

13. made of silk.

14. resembling silk; silky.

15. of or pertaining to silk.

v.i.

16. (of corn) to be in the course of developing silk.

[bef. 900; ME (n.); OE sioloc, seol(o)c (c. ON silki), by uncert. transmission < Gk serikón silk, n. use of neut. of serikós silken, lit., Chinese, deriv. of Sêres the Chinese (Russ shëlk, OPruss silkas (gen.) "silk" appear to be < Gmc); cf. SERIC-]

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Animal fibre produced by certain insects as building material for cocoons and webs.

In commercial use it refers almost entirely to filament from cocoons produced by the caterpillars of several moth species of the genus Bombyx, commonly called silkworms. Silk is a continuous filament around each cocoon. It is freed by softening the cocoon in water and then locating the filament end; the filaments from several cocoons are unwound at the same time, sometimes with a slight twist, to form a single strand. In the process called throwing, several very thin strands are twisted together to make thicker, stronger yarn. Silk was discovered in China sometime before 2700 BC, and the secret of its production was closely guarded for millennia. Along with jade and spices, silk was the primary commodity traded along the Silk Road beginning about 100 BC. Since World War II, nylon and other synthetic fibres have replaced silk in many applications (e.g., parachutes, hosiery, dental floss), but silk remains an important luxury material for clothing and home furnishings. More than 50% of the world's silk is still produced in China.

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▪ fibre

Introduction

      animal fibre produced by certain insects as building material for cocoons (cocoon) and webs. In commercial use it is almost entirely limited to filament from cocoons produced by the caterpillars of several moth species belonging to the genus Bombyx and commonly called silkworms.

History.

      The origin of silk production and weaving is ancient and clouded in legend. The industry undoubtedly began in China, where, according to native record, it existed from sometime before the middle of the 3rd millennium BC. For many centuries the Chinese zealously guarded the source and methods of production of silk, but by the 1st millennium BC they had begun trading silk cloth abroad. Within a few centuries, caravans were regularly carrying silk to India, Turkistan, and Persia. According to legend, in about 140 BC, sericulture as well as silk spread overland from China to India. By the 2nd century AD India was shipping its own raw silk and silk cloth to Persia. (Japan, too, acquired and developed a thriving sericulture a few centuries later.)

      Persia became a centre of silk trade between East and West under the Parthians (247 BC–AD 224). Silk dyeing and weaving developed as crafts in Syria, Egypt, Greece, and Rome. The workers used some raw silk from the Orient, but they derived most of their yarn by unraveling silk fabrics from the East. Silk culture remained a secret of Asia.

      Eventually a strong demand for the local production of raw silk arose in the Mediterranean area. Justinian I, Byzantine emperor from 527 to 565, persuaded two Persian monks who had lived in China to return there and smuggle silkworms to Constantinople in the hollows of their bamboo canes (c. AD 550). These few hardy silkworms were the beginning of all the varieties that stocked and supplied European sericulture until the 19th century.

      Silk culture flourished in Europe for many centuries, especially in the Italian city-states and (from 1480) in France. In 1854, however, a devastating silkworm plague appeared. Louis Pasteur, who was asked to study the disease in 1865, discovered the cause and developed a means of control. The Italian industry recovered, but that of France never did. Meanwhile Japan was modernizing its methods of sericulture, and soon it was supplying a large portion of the world's raw silk. During and after World War II the substitution of such man-made fibres as nylon in making hosiery and other garments greatly reduced the silk industry. Still, silk has remained an important luxury material and remains an important product of Japan, South Korea, and Thailand.

Sericulture.

      Production of silk involves (1) the care of the domesticated silkworm (silkworm moth) (Bombyx mori) from the egg stage through completion of the cocoon and (2) the production of mulberry trees that provide leaves upon which the worms feed. The silkworm caterpillar builds its cocoon by producing and surrounding itself with a long, continuous fibre, or filament. Liquid secretions from two large glands within the insect emerge from the spinneret, a single exit tube in the head, hardening upon exposure to air and forming twin filaments composed of fibroin, a protein material. A second pair of glands secretes sericin, a gummy substance cementing the two filaments together. Because an emerging moth would break the cocoon filament, the larva is killed in the cocoon by steam or hot air at the chrysalis stage.

      Silk is a continuous filament within each cocoon, having a usable length of about 600 to 900 m (2,000 to 3,000 feet). It is freed by softening the binding sericin and then locating the filament end and unwinding, or reeling, the filaments from several cocoons at the same time, sometimes with a slight twist, forming a single strand. Several silk strands, each too thin for most uses, are twisted together to make thicker, stronger yarn in the process called throwing, producing various yarns differing according to the amount and direction of the twist imparted.

      Silk containing sericin is called raw silk. The gummy substance, affording protection during processing, is usually retained until the yarn or fabric stage and is removed by boiling the silk in soap and water, leaving it soft and lustrous, with weight reduced by as much as 30 percent. Spun silk is made from short lengths obtained from damaged cocoons or broken off during processing, twisted together to make yarn. The thickness of silk filament yarn is expressed in terms of denier, the number of grams of weight per 9,000 m (9,846 yards) of length. Silk is sometimes—in a process called weighting—treated with a finishing substance, such as metallic salts, to increase weight, add density, and improve draping quality.

      The degumming process leaves silk lustrous and semitransparent, with a smooth surface that does not readily retain soil. Silk has good strength, resisting breakage when subjected to weights of about 4 g (0.5 ounce) per denier. Wetting reduces strength by about 15–25 percent. A silk filament can be stretched about 20 percent beyond its original length before breaking but does not immediately resume its original length when stretched more than about 2 percent. Silk, lower in density than such fibres as cotton, wool, and rayon, is moisture-absorbent, retaining as much as a third of its weight in moisture without feeling damp, and has excellent dyeing properties. It is more heat-resistant than wool, decomposing at about 170° C (340° F). Silk loses strength over a long period of time without appropriate storage conditions and tends to decompose with extensive exposure to sunlight but is rarely attacked by mildew. It is not harmed by mild alkaline solutions and common dry-cleaning solvents. Friction imparts a static charge, especially in low humidity. The rustling sound, or scroop, associated with crisp silk fabrics is not a natural property of the fibre but is developed by processing treatments, and it does not indicate quality, as is sometimes believed.

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