FROM CAR fittings to washing-machine parts and from tennis racquets
to space stations, engineering plastics are rapidly becoming important in
a variety of areas of life.
These materials are the tough, strong plastics that are sold in low
volumes and at high prices. Their characteristics can be changed relatively
easily by altering manufacturing conditions or by mixing in other substances.
They include many types of plastic reinforced with glass or carbon fibres,
for instance. These composite materials are being used increasingly in aircraft
wings and in other products of the aerospace industry.
Engineering plastics are among the group of substances known as 鈥榓dvanced
materials鈥�. This catch-all category also includes silicon-based electronic
chemicals, novel metal alloys and strong, heat-resistant ceramics. Engineering
plastics stand out largely because of the ease with which they can be used
in established, straightforward manufacturing processes. This makes them
appealing to production engineers: it is also one reason for the relatively
high growth rate in their use. Consumption of these plastics is especially
high in the car industry, where companies such as Ford, General Motors,
Toyota, BMW and Volkswagen are using more of them to produce body panels,
axles and smaller fittings, such as bumper parts and wing-mirror brackets.
Advertisement
Chemically, engineering plastics are similar to the ordinary plastic
materials used in packaging and building products. Engineering plastics,
which have annual sales worldwide of about $25 billion, add up to only a
small part of the world鈥檚 chemicals sector, which has revenues around 50
times as big. But for many of the world鈥檚 giant chemicals groups, including
BASF, Bayer and Hoechst of West Germany, ICI of Britain and Du Pont and
Dow Chemical in the US, engineering plastics promise to be an enormous market
in the 1990s. While many areas of the chemicals business, including the
ordinary plastics used in high volumes in non engineering applications,
are growing at an annual rate of just a few per cent in sales terms, growth
rates for many engineering plastics are between 8 and 10 per cent. Tempted
by the possibilities, the chemicals giants, together with a number of the
smaller fry in the sector, are sinking billions of dollars into increasing
their involvement in this potentially lucrative field.
Another group that views engineering plastics as highly important is
General Electric, the American electrical engineering and electronics company.
In 1988, the company paid $2.3 billion for Borg-Warner, an American plastics
company, in a move that catapulted General Electric into the top position
in the industry. It was the culmination of a 20-year spending spree that
saw General Electric splashing out $3 billion in Europe alone on its big
engineering plastics factory and development laboratory at Bergen op Zoom
in the Netherlands. Since the early 1970s, Dow has sunk around $130 million
into building up its engineering plastics business, while Bayer is currently
getting through nearly $600 million with the aim of increasing its worldwide
capacity in engineering plastics by half by 1994.
The prospects in this field of materials appear rosy enough to have
tempted a large number of groups into the business from Japan and the rest
of the Far East. Many Western industrialists say that engineering plastics
might be the route that Japan in particular takes to build up a bigger stake
in chemicals internationally. Among the Japanese companies investing heavily
in engineering plastics are Idemitsu, Mitsubishi Gas Chemical, Asahi Glass,
Daicel, Kureha, Sumitomo and Toso. Companies from other parts of the Far
East that have become significant suppliers of engineering plastics include
Lucky in South Korea and Chi Mei in Taiwan. Several of the Japanese companies
are forming joint ventures with groups from Europe and the US. For example,
Idemitsu plans to build an engineering plastics factory in the Netherlands
with the help of DSM, the big Dutch chemicals business. Dow and General
Electric have formed joint ventures in engineering plastics with Sumitomo
and Toso, while Hoechst has joined Kureha.
Expertise in partnership
Engineering plastics attracts the interest of the chemicals industry
because the business combines two of its favourite and most developed technologies
鈥� processing and manufacturing. Suppliers must know how to mix materials
at the right concentrations and production conditions to make plastics of
the correct quality. They must also know how to convert these plastics into
usable parts, which could be anything from a child鈥檚 toy to a helicopter
blade. Companies in the field need to have a broad range of engineering
expertise, including knowledge of computer-aided design and the latest automated
machining and moulding systems. They must also work closely with their customers
from the engineering sectors, a collaboration that is not seen in many areas
of production industries.
Already, users of engineering plastics are establishing both formal
and informal links with manufacturers. In Europe, for example, General Electric
works closely with Renault and Volkswagen and also with Electrolux, the
big Swedish consumer goods manufacturer that is interested in using engineering
plastics in items such as washing machines.
Engineering plastics account for only about 10 million tonnes (one-tenth)
of the annual output of the plastics industry. About four-fifths of that
output are the everyday plastics used as packaging or building materials,
mainly polystyrene, polyvinyl chloride (PVC), polyethylene and basic grades
of polypropylene.
Researchers in West Germany and Britain invented the first three during
the golden decade of plastics development in the 1930s; polypropylene is
the relative newcomer, developed in Italy in the late 1950s. Plastics as
a whole have grown in use over the past 50 years faster than any structural
material, much faster than older substances such as steel, timber and glass.
During the 1990s, however, the plastics industry is likely to expand
at an annual rate of no more than a few per cent a year as economic growth
in the developed world slows down and as concern about the environmental
problems of disposing of plastic increases. By contrast, sales of engineering
plastics should grow, mainly in applications where they are replacing traditional
materials, mainly metals. 鈥楪reenness鈥� is one of the material鈥檚 advantages;
engineering plastics are technologically easy to recycle and their high
cost tends to make recycling them economic. BMW and Volvo are well aware
of this trend. They are already planning how to recover and reuse the engineering
plastics in the cars they produce after the vehicles have been scrapped.
Defining the plastics that should be categorised as engineering materials
is not always easy; sometimes, quite legitimately, different manufacturers
describe the same plastic as both an engineering material and as a cheap
wrapper. Generally, the distinction depends on the material鈥檚 manufacturing
process and whether additives were used to impart strength or some other
special characteristic.
Three key characteristics help to define engineering plastics: application,
quality and cost. The material is an engineering plastic if it is used as
a structural component that must be accurately made and finished. The material
is also likely to display strength or toughness or some other special L
characteristic such as heat resistance. The third aspect is price. Most
standard plastics sell for between $700 and $2000 per tonne; engineering
plastics usually cost at least $3000 per tonne, and as much as $30 000 per
tonne for some highly specialised varieties.
Materials defined as engineering plastics include L polycarbonate, polyacetyl
L and most grades of polyamide plastics, which are better known as nylon.
Also under this heading come other types such as acrylonitrile butadiene
styrene (ABS); some specialist grades of polypropylene, one of the high-
volume standard plastics; and a variety of esoteric plastics, which include
polyphenylene oxide, polybutylene terephthalate (PBT), some grades of polyethylene
terephthalate (PET), polyethersulphone and polyphenylene ether alloys.
All these materials belong to a family known as thermoplastics; they
can be hardened and resoftened by a reversible process of cooling and heating.
Epoxy resins, which can be strengthened with glass or carbon fibres to form
composite materials for aircraft wings or fishing rods, are among the traditional
thermoplastics. Also in the family are some grades of polyurethanes, which
are often used for non-engineering components in footwear. There are other
engineering plastics, known as thermosets, that become irreversibly hard
during manufacture. While this is a useful attribute for applications involving
high temperatures, it does mean that thermosets cannot be reshaped by remelting,
as thermoplastics can, and so they cannot be recycled easily.
Made to measure
One of the major advantages of engineering plastics is the way they
are suited to automated manufacturing methods in which components can be
moulded or extruded more quickly and cheaply than those made from traditional
materials such as steel or aluminium. Because manufacturers can easily change
the characteristics of engineering plastics 鈥� by altering the formulation
or reaction conditions during processing in the chemical plant 鈥� the materials
suit the growing trend in production towards more customised parts that
are, to a large degree, tailored to meet individual needs.
Several new automation techniques make the most of the advantages of
engineering plastics and of those reinforced with fibres to make composite
materials. Pultrusion, one of these techniques, involves pulling a bundle
of continuous fibres through a bath of molten plastic, which could be either
a thermoplastic or thermoset, and on through a heated die. Cooling, or reaction
with another chemical in the case of thermoset epoxy resins, produces a
composite material. Engineers use this process to make parts for bridges
and for aircraft wings. For instance, Airbus Industrie uses pultruded components
in the wing struts of the A320 aircraft it builds. On another scale, pultruded
plastics are popular in France as supports for grapevines.
Another automation technique is resin transfer moulding, a variation
on standard injection moulding used throughout the plastics industry. Manufacturers
apply pressure to a fibre- reinforced plastic in a mould and inject resin
to make the material take the shape of the mould as it cures. Computer-
aided design can help to define the shape of the mould and, in particularly
advanced factories, manufacturers can link several stages of moulding in
a series of manufacturing steps under the control of a computer.
The car industry, meanwhile, wants manufacturers of fibre- reinforced
engineering materials to be able to tailor the surfaces of the material
to its individual requirements. This has led General Electric in the US,
in a joint venture with PPG, a large American glass fibre maker, to investigate
what mixtures of engineering plastics and strengthening agents will give
shiny plastics that can replace metals in body panels. The car industry
will not be the only beneficiary. In Britain, ICI has come up with a technique
for adding silica to acrylic resins to produce materials for kitchen sinks
that resemble a hard surface. Other companies are looking more broadly at
how additives and blending change the nature of the finished plastic. The
resulting materials offer slightly different characteristics, such as density,
strength, heat resistance and ease of processing and recycling, which can
extend the range of use of the components. Car manufacturers, for instance,
use alloys of polycarbonate and acrylonitrile butadiene styrene with up
to 10 different resins or other organic additives.
Sometimes manufacturers use liquid crystals to reinforce their conventional
engineering plastics. The advantage of liquid crystals over fibres is that
manufacturers can put the mixture into a mould without going through the
separate operations of formulating the plastic and then adding the fibre
afterwards. Bayer is one of the companies investigating this approach to
the production of high strength plastics.
For all the promise of engineering plastics, however, there are still
clouds on the horizon for companies in the industry. The high cost of the
material makes many potential customers think twice about using them while
cheaper alternatives, such as metals, are available. This may hold up their
development as manufacturers turn downmarket, away from aerospace and cars
where engineering plastics have made their biggest mark so far. The problems
for the manufacturers of engineering plastics are high development costs
and the need to have experience of technologies that are not relevant to
other sectors of chemicals production. While the growth of the industry
may be good during the 1990s, some analysts say it will not be as profitable
as many industrialists had been hoping.
鈥斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌�
World Production of engineering plastics 1989 鈥斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌�
Type Production Leading suppliers (million tonnes)
鈥斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌�
Polpropylene (1) 4 Himont, ICI, DSM Acrylonitrile
butadiene sytrene (ABS) 2 General Electric, Dow,
Monsanto, Lucky, Chi Mei Polyamide (nylon) 1 Du Pont,
Hoechst, BASF, ICI, Toray Polycarbonate 1 General
Electric, Dow, Bayer, Mitsubishi Gas Chemical Thermoset epoxy resins
1 Shell, Ciba-Geigy, Dow Polyacetyl 0.5
Du Pont, Hoechst, BASF Other thermoplastics (2) 0.5 Various
鈥斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌�
(Source: Financial Times. (1) Engineering grades only; (2) Includes polyphenylene
oxide, polybutylene terephthalate, some grades of polyethylene terephthalate,
various alloys and other materials.) 鈥斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌斺赌�
Peter Marsh is a journalist on the Financial Times.