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Asbestos



1. Asbestos has been known and used as a textile since the earliest times. The first written evidence of asbestos was recorded by Pliny in the first century A. D.

2. It is told that one of the Emperors of Rome delighted guests by throwing a tablecloth made of asbestos into fire and then removing it unchanged from the flame. A few centuries later Marco Polo told his friends in Italy about a substance he observed in Siberia. He told that it could be woven into attractive textiles which did not burn even in direct flame.

3. Asbestos is one of the strangest of all the naturally occurring fibers. It is a rock which has been subjected to unusual treatment during its formation. Asbestos is the only mineral substance used as a textile fiber in the form it is obtained from natural sources. There are many varieties of asbestos rocks but only chrysotile is widely used for textile products. Chrysolite is mined in many countries of the world. The soft, long, white fibers of this mineral can be spun into yarn by the usual processes. Pure asbestos being very difficult to spin, a proportion to cotton fiber is usually added to help to bind the asbestos fibers together. The strangest characteristic of asbestos fibers is their resistance to heat and burning. This property determines the ways in which they are used.

4. Early uses for asbestos included such articles as handkerchiefs and table coverings. The Chinese used asbestos to make false sleeves which could be cleaned by putting them in the fire. All the dirt was burned off, leaving the asbestos clean. We know commercial development of the fiber to have started in the 19th century. Asbestos was used in flame-proof clothing of many kinds, for laboratory, industrial and military purposes.

5. Fabric made of asbestos have good strength. Today the main applications are those in which non-inflammability is essential such as conveyor belting for hot materials, industrial packing, fireproof clothing, etc. Asbestos is sometimes used with glass fiber in making decorative fabrics for curtains for hospitals, theatres and other buildings where the public assembles. Asbestos is also used for electrical winding and insulation.

Note:

A. D. – нашої ери

chrysotile – хризотил

flame-proof clothing – вогнезахисний одяг

strength – міцність

winding – обмотка

rock - скеля





Дата публикования: 2015-10-09; Прочитано: 496 | Нарушение авторского права страницы | Мы поможем в написании вашей работы!



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