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As a textile, the history of silk goes hand-in-hand with that of the human race. Some new uses of silk were described at the beginning of this article; but let us consider uses of silk in fields other than the apparel industry, all of which take advantage of its excellent affinity with the natural world.
It is well known that silk thread has been used for many years worldwide for intricate surgical and ophthalmological operations. Silk is suitable for this purpose because of its fine, soft fibers, and tensile strength, and because it is easy to tie and difficult to untie, and its protein composition makes it compatible with the human body. In other medical fields, anti-hay fever masks, gauze pads, and bandages for dermatological disorders made from silk have been commercialized. The development of technology to dissolve silk fibers and make film from silk protein has opened the way for research and development into its use in artificial skin, blood vessels, and tendons; contact lenses; catheters for surgical procedures; and anticoagulants. All these applications exploit silk's biocompatibility and permeability.
Other uses are constantly being developed, such as in membranes and filter material, which draw on silk's ability to absorb or filter out specific substances (e.g., oxygen and carbon dioxide), and in biosensors using silk enzyme-fixing membranes that trap enzymes.
Environment-friendly fishing lines are also being developed from silk. Silk is a natural material and is highly biodegradable, so it promises to play a role in solving the problem of fishing lines polluting waterfowl habitats. |
A technique for mixing silk powder in a coating substance has also been developed. Known as "silk leather," it is used for the steering wheels of luxury cars, consumer electronics products like video players, watches and stationery such as ball-point pens. The silk leather product range boasts a soft, smooth texture and sheen that gives it a luxury feel, and is expected to extend into other areas.
Ancient wisdom that fruit and vegetables keep longer if they are wrapped in silk has been substantiated by tests that demonstrated how ethylene gas emitted by plants adheres to silk. This led to the development of an nonwoven cloth called the Silk Sheet, a combination of silk and polyester which helps to keep fruit and vegetables fresh, with a significant economic benefit.
Attempts are now being made to use silk to clean rivers polluted by household and industrial waste water. The purpose of the experiment is to absorb and break down pollutants with bacteria cultured in gaps between scrap cocoons. Says Katsuno, "It is our future dream to be able to use silk to trap expensive metals like uranium and carcinogens like dioxin. To make that happen, we have to undertake further studies into the nature of the proteins in silk."
Silk has been treasured over the centuries as the mysterious thread of the East. In the next century it will become an essential substance for mankind, thanks to its infinite appeal and potential.
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| Silk products are also finding their way into medical fields. In addition to professional applications such as artificial tendons (an Achilles' tendon) and large bandages used in the clinic, a number of home-use products are also on the market. |
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| The editors would like to thank The Japan Silk Association, Inc. and Kinkame Shigyo Co., Ltd., for their cooperation in preparing this article. |
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| Source of the Dream: Original Silkworm Races (Eggs),a Valuable Genetic Resource |
Up to the World War II, silk was a quintessential Japanese export, and Japan was even known as the "land of cocoons"; but in the past six years, imports have outpaced domestic silk production. Cheap silk floods in from China and other countries, and Japan has become a net silk consumer rather than producer. Considered from another perspective, however, this means that silk consumption and demand are diverse, and the user base is clearly expanding.
As appropriate for the "land of cocoons," Japan carefully preserves the original silkworm races (eggs). These eggs have infinite usage value, e.g., for developing new silkworm races for creating new silk materials.
Eggs of more than 800 silkworm races are currently preserved in three refrigeration facilities in Japan. Once a year eggs are hatched, worms are allowed to spin cocoons, threads are taken, and their constituents analyzed to check whether their performance is stable. Some of the worms are obviously grown to adulthood so eggs can be taken from them and stored. This complex and time-consuming process is repeated every year.
These preserved original silkworm races are a valuable asset as they are the starting point for all selective breeding. Indeed, as long as these eggs exist, any kind of silkworm can be created by selective breeding to suit particular requirements. |
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