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History
of Plastics:
This short history of the development of the modern
plastics industry is taken from SPI’s annual statistics
report, Facts & Figures of the U.S. Plastics Industry.
Today’s plastics are one of the most used materials on a
volume basis in U.S. industrial and commercial life. Plastics
are broadly integrated into today’s lifestyle and make a
major, irreplaceable contribution to virtually all product
areas. Although the plastics industry in the United States is
now in its second century, the most important developments
have occurred since 1910. However, the roots of these modern
developments go back not only to the research of cellulose
nitrate by John Wesley Hyatt in the 1860s, but also to the
plastic-like compositions used by man through the centuries.
Origin
of Plastics
One
can go as far back as the Old Testament to find references
about natural materials used as fillers, adhesives, coatings,
and the like. These materials were the precursors of modern
plastic materials. Historians continue to differ as to the
exact year or decade that the plastics industry began because
the definition of “plastic” is a matter of interpretation.
Certainly, the history of the rubber industry has a bearing
on plastics. This is because ebonite, or hard rubber,
discovered in 1851, was the first thermosetting material to be
prepared and the first material that involved a distinct
chemical modification of a natural material. But ebonite was
not exploited commercially for some years after its discovery;
for that reason, its historical importance has become somewhat
blurred.
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European
Developments
While
the basic processes of rubber technology were developing,
other important discoveries were taking place in Europe.
Following work by Pelouze, Schonbein established conditions of
controlled nitration of cellulose. The product soon became of
interest as an explosive and in the manufacture of collodion,
a cellulose solution in an alcohol-ether mixture. In the
1850s, the English inventor Alexander Parkes observed that the
solid residue left after the evaporation of the solvent of
photographic collodion was a “hard, horny elastic and
waterproof substance.” In 1856, he patented the process of
waterproofing woven fabrics by the use of such materials.
In 1862, at the Great Exhibition in London, Parkes
introduced a new material named for himself- Parkesine.
Parkesine was obtained by dissolving cellulose nitrate in a
minimum of solvent. The mixture was then put on a heated
rolling machine from which some of the solvent was then
removed. While still in the plastic state the material was
then shaped by dies or pressure. In 1866, Parkes organized the
Parkesine Company to manufacture products from his new
material, but the company failed in 1868. This appears to be
due, in part, to Parkes’ attempt to reduce production costs
that resulted in the production of inferior items.
One year after the failure of the Parkesine Company, an
associate of Parkes, Daniel Spill, formed the Xylonite Company
to manufacture products similar to Parkesine. Once again,
economic failure resulted and Spill’s company went bankrupt
in 1874. Undaunted, Spill moved to a new site, established the
Daniel Spill Company, and continued production of his
material, Xylonite.
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First
Plastics in the U.S.
In
the United States during the 1860s, John Wesley Hyatt
experimented with cellulose nitrate. In 1865, Hyatt became
involved in devising a method for producing billiard balls
from materials other than ivory. Originally using mixtures of
cloth, ivory dust, and shellac, he patented in 1869 the use of
collodion for coating billiard balls. The patent came one year
after his collodion material was introduced commercially.
John W. Hyatt and his brother Isaiah took out U.S. Patent
105,338 in 1870 for a process of producing a horn-like
material using cellulose nitrate and camphor. Although Parkes
and Spill had mentioned camphor in their work, the Hyatt
brothers recognized the value of camphor as a plasticizer for
cellulose nitrate. In 1872, the term “celluloid” was
coined by Isaiah Hyatt to describe the Hyatts’ commercially
successful product.
The validity of Hyatts’ patents was challenged by Spill,
and a number of court actions took place between 1877 and
1884. In the final action, it was found that Spill had no
claim on the Hyatt brothers’ patents, the judge ruling that
Parkes was the true inventor of the process because he had
mentioned the use of camphor in his patents. Thus, there was
no restriction on the use of these processes and any company,
including the Hyatts’ Celluloid Manufacturing Company, was
free to use them. After that decision, the Celluloid
Manufacturing Company prospered, changed its name to the
American Cellulose Chemical Corporation, and eventually was
absorbed by the Celanese Corporation.
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Formaldehyde
Resins
Next
to cellulose nitrate, the most important material in the early
history of plastics was formaldehyde. Around 1897 there was a
demand in German schools for a white chalkboard. Efforts to
obtain such a product resulted in the discovery of casein
plastics, produced by reacting casein (milk protein) with
formaldehyde. The material soon became established under the
trade names of Galalith and Erinoid. Today, casein still is
used by the button industry.
In 1899, Arthur Smith took out British Patent 16,275, the
first dealing with phenol-formaldehyde resins for use as an
ebonite substitute in electrical insulation. During the next
decade, the phenol-formaldehyde reaction was investigated
mainly for academic interest. In 1907, however, Leo Hendrik
Baekeland discovered techniques to control and modify the
reaction so that useful products could be made from it. Thus,
phenolics were the first fully synthetic resins to become
commercially successful.
Prompted by the success of phenolic moldings, research
began on reacting other materials, such as urea and thiourea,
with formaldehyde. These materials were used to manufacture
molding powders. Unlike phenolics, they could be molded into
light-colored articles and rapidly achieved commercial
success. Today, these urea-based resins are used for molding
powders, adhesives, and textile and paper finishing, while the
related melamine-formaldehyde resins are used in decorative
laminates.
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Growth
of Modern Plastics
Cellulose
acetate, a thermoplastic, was developed about the same time as
the urea-based resins. Similar in structure to cellulose
nitrate, it was found to be safer to process and use.
Cellulose acetate was introduced as a molding compound in
1927.
The period 1930-1940 saw the initial commercial development
of today’s major thermoplastics: polyvinyl chloride, low
density polyethylene, polystyrene, and polymethyl methacrylate.
The advent of World War II in 1939 brought plastics into great
demand, largely as substitutes for materials in short supply,
such as natural rubber. In the United States, the crash
program leading to large-scale production of synthetic rubbers
resulted in extensive research into the chemistry of polymer
formation and, eventually, to the development of more plastic
materials.
The first decade after World War II saw the development of
polypropylene and high density polyethylene and the growth of
the new plastics in many applications. Linear low density
polyethylene was introduced in 1978 and made it possible to
produce polyethylenes with densities ranging from 0.90 to
0.96. Large-scale production of these materials reduced their
cost dramatically. The new materials began to compete with the
older plastics and even with the more traditional materials
such as wood, paper, metal, glass, and leather. The
introduction of alloys and blends of various polymers made it
possible to tailor properties to fit certain performance
requirements that a single resin could not provide. The demand
for plastics has increased steadily; plastics are now accepted
by designers and engineers as basic materials along with the
more traditional materials. The automotive industry, for
instance, relies on plastics to reduce weight and thus
increase energy efficiency.
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