Page 450 - Handbook of Properties of Textile and Technical Fibres

Tensile failure of polyester fibers 423

HO–(CH 2 ) 2 –OH
HOOC COOH

Terephtalic acid Ethyleneglycol
Figure 13.2 Structure of polyethylene terephthalate basic components.

melting point of about 260 C, capable of crystallization and which could be spun into
fibers. In 1940, Whinfield and Dickson, at the laboratories of the Calico Printers
Association in the UK, prepared fiber-forming polyester from ethylene glycol and
TPA (see Fig. 13.2).
The first patent application was filed on Jul. 29, 1941 (Whinfield, 1953). The patent
was sold to ICI and then licensed to DuPont (Scheirs and Long, 2003). In 1944 ICI
produced the first PET fibers on a laboratory scale. The first information about the fiber
was released in Oct. 1946, when ICI launched a pilot plant for the production of the
fiber. The basic patents expired in 1966. Use of TPA and 1,4-butanediol for the devel-
opment of polyester fibers was investigated almost at the same time by Schlack (see
Ludewig (1971)). In 1944, Izard from DuPont independently developed PET (Scheirs
and Long, 2003).
Based on an ICI license, the commercial production of PET fibers under the trade
name “Dacron” was started by DuPont in Kinston, N. C. USA in 1953. In Europe com-
mercial production of PET fibers (ICI “Terylene”) began in 1955. In 1960 the share of
polyester fibers in the world production of synthetic fibers attained the level of 17%. In
1974 it was 41% and in 1980 the level of 50% was attained. In 2006, the 22 largest
companies in the world, including Sinopec (China), Reliance (India), NanYA
(Taiwan), Huvis (South Korea), Invista (USA), Teijin (Japan), etc., produced more
than 11 million tons of polyester fibers and yarn, including 5.5 million tons of staple
fiber, 5.4 million tons of textile, and 0.5 million tons of industrial fibers (Aizenshtein,
2007). Of this volume, approximately 7.0 million tons was produced by 10 Chinese
companies.
Many other types of polyester and modified PET were investigated after the inven-
tion of PET. In general the intermediates were more expensive and the polymers were
not commercialized at that time. The first patents covering the preparation of a modi-
fied PET fiber using isophthalic acid were filed to get around the patent protection of
Terylene. ICI filed a patent covering improved dyeability and water absorbing capacity
of PET fibers through modification with alkylene oxides (Mark et al., 1968). Filed
nearly at the same time were a number of other patent applications that proposed
replacing part of the TPA with another dicarboxylic acid or part of the ethylene glycol
with another diol.
There are numbers of patents and processes covering chemical, physical, and
combined modifications of PET (Militký et al., 1991). One of the first purely physical
modifications was based on a shortening of the PET polymer chains to reduce the
pilling tendency in the fiber (Sharova et al., 2002). Furthermore, physical modification