Although not a true synthetic, Rayon is the first man-made fibre. It's
made from naturally occurring cellulose (usually from specially
processed wood pulp). Because of the chemical processes involved in its
production it is classed as a semi-synthetic or artificial fibre, and is
generally considered the precursor to all true synthetic fibres.
History
Rayon
can claim a heritage dating back to the 1850s, when Swiss chemist
Georges Audemars invented the first crude artificial silk by dipping a
needle into a solution of mulberry bark pulp and gummy rubber to make
threads. Other chemists developed further techniques over the next few
decades, but none were efficient enough to make the new fibre a
financially viable alternative to real silk.
In 1894, British
inventor Charles Cross, together with Edward Bevan and Clayton Beadle,
patented a practical method of making artificial silk. They named their
product "viscose" because their processing of the cellulose gave a
highly viscous solution, which was then passed through a spinneret to
form fine filaments (the scientifically minded can read a more detailed
description of the
manufacturing process).
This chemical-intensive process is not very environmentally sound,
unfortunately, though steps have been made in modern production to
reduce the impact.
An alternative method of processing natural
cellulose into a man-made fibre using acetone was developed by Swiss
brothers, Doctors Camille and Henri Dreyfus. In 1905, Camille and Henri
developed a commercial process to manufacture cellulose acetate. The
brothers initially focused on cellulose acetate film, which was then
widely used in celluloid plastics and film. By 1913, Camille and
Henri's studies and experiments had produced excellent laboratory
samples of continuous filament acetate yarn. In 1918 acetate (a.k.a.
cellulose acetate or acetate rayon) fibre was first manufactured in
quantity at the British Celanese plant in Derbyshire, England.
The first commercial viscose rayon was produced in the UK by Courtaulds
in 1905, and in America in 1910 by the American Viscose Company. DuPont
Chemicals acquired the rights to the process in the 1920s and quickly
turned rayon (The term "rayon" was first used in around 1924) into a
household name.
There are two varieties of viscose rayon fibre. Filament rayon is
produced in the form of a continuous thread and can be used for fabrics
to resemble silk. Spun rayon consists of short filaments twisted (spun)
together into a yarn similar to cotton or linen, and is turned into
fabrics to resemble these.
By the 1930s rayon was available in a
profusion of different fabrics - plain satin, shadow print satin,
crepes, velvet, Jacquard, taffeta, shantung, chamois, sharkskin, pique,
boucle, gabardine, chiffon, voile, faille - rayon could do anything the
natural fibres could.
Rayon in both filament and spun forms has a beautiful soft drape, which
helped cement its popularity in the drape-loving 1930s through the early
40s Swing era.
Acetate rayon is particularly suited to satins and taffetas, so really
came into its own in the 1950s when fabrics with more body were required
for the full-skirted silhouette of Dior's New Look.
Properties
Rayon is the most absorbent of all cellulose
fibers, even more so than cotton and linen. Because of this, rayon
absorbs perspiration and allows it to evaporate away from the skin,
making it an excellent summer fabric. Its high absorbency applies
equally to dyes, allowing beautiful, deep, rich colours.
Rayon is a good conductor and poor insulator, furthering its usefulness in hot climates.
It
loses a great deal of strength when wet. Because of this it must be
handled carefully when washed, and it is also more prone to stretching
and shrinkage than cotton. Spun Viscose rayon fabrics shrink more with
repeated laundering than fabrics made of the filament yarns.
Rayon lacks the elasticity and resilience of wool and silk and tends to crease easily.
Identification
Fiber Identification (information from
swicofil.com)
In
the burning test, rayon most resembles cotton. It ignites rapidly,
sometimes even faster than cotton, burning with a large, bright, yellow
flame. Burnt rayon leaves an odour like burnt paper, similar to cotton.
The ash is also like cotton: light and feathery gray, which
disintegrates rapidly.
In the feeling test, rayon is more
difficult to identify. The variety of processes, modifications of
technique and various treatments can make rayon look and feel like silk,
cotton, wool or linen. In general, however, rayon has the smooth
felling of silk. It is slippery because of the smoothness of the
filaments, and has an almost brittle-feeling quality due to the fiber's
inelasticity.
The breaking test can differentiate between rayon,
cotton and linen yarns. Because of its inelasticity, rayon will tend to
break shortly, with a short, uneven breaking pattern. It is even easier
to distinguish when wet, as it breaks very easily then.
Article from:
http://tuppencehapennyvintage.blogspot.com/2011/02/history-of-synthetics-rayon.html
