For more than 5,000 years, composites have been used in applications such as building materials, plastics, insulation, communications, automobiles, and safety and protection.
Man-made composite materials date to ancient times, when straw and mud were combined to create bricks used in construction. These brick-making methods were documented in Egyptian tomb paintings. Around 3400 B.C., the ancient Mesopotamians began gluing wood strips at different angles to create plywood. Later (around 2182-2055 B.C.), the Egyptians developed Cartonnage, layers of linen and papyrus soaked in plaster to form death masks. Additionally, concrete (which was described in 25 B.C. in Vitruvius’s The Ten Books on Architecture) was used widely in ancient times and researchers have shown that in some ways the concrete used by Romans is superior to today’s Portland Cement.
In the late 1800’s, polymerization caused a revolution in chemistry and materials development. New synthetic resins (including celluloid, melamine, and Bakelite) could be transformed from liquid to solid in a cross-linked molecular structure. Continuing into the early 1900’s, new plastics were being developed astonishingly quickly. However, these early plastics were not nearly as capable as modern plastics as they lacked the strength and rigidity required for many demanding applications.
The 1930’s were arguably the most important decade in the history of composites. Owens Corning launched the fiber reinforced polymer (FRP) industry in 1935 by developing the first glass fiber. Just one year later, unsaturated polyester resins were patented and because of their curing properties would become the dominant resin choice in manufacturing even today. By 1938, more high-performance resins like epoxies would also become available.
World War II catalyzed the jump from research to production for the FRP industry. Fiberglass composites boast a high strength to weight ratio, and are transparent to radio frequencies. Therefore, they were used in radar domes and with other electronic equipment and by 1945, 7 million pounds of fiberglass were used, mostly for military purposes. By 1947, an automobile with a fully composite body had been built and tested. Its reasonable success then influenced the 1953 Corvette, which was largely fiberglass and manufactured using new, more efficient, molding techniques.
Nearly a decade later, in 1961, the first carbon fiber was patented. However, it would be several years before carbon fiber composites would become commercially available. Carbon fiber opened up even more applications for composite materials with its improved stiffness to weight ratios. Just five years later, in 1966, a DuPont chemist invented a para-aramid fiber known as Kevlar, which is used today in advanced composites and body armor.
The rise of composites have already transformed most of the world’s industries and will continue to grow in the years to come. In 2015, the U.S. Department of Energy announced the Institute for Advanced Composites Manufacturing Innovation. This organization is a $259 million public-private partnership that will focus on making advanced composites less expensive and energy-intensive to manufacture. It will also focus on making composites easier to recycle and develop new fibers and resins to open up even more applications for composite materials. In the future, the composites industry will continue growing into more applications and markets. Environmentally friendly composites will incorporate recycled plastic and bio-based polymers to feed the growing demand for stronger, lighter, and more environmentally friendly materials.