About Composites

On the road to Olympic and Paralympic Games

Composite materials, also widely known to “composites,” are materials composed of at least two components with significantly different physical or chemical properties that, when combined, form a new material with superior performance and with properties different from the individual components.

Etymology: Borrowed from Middle French composite, from Latin compositus, past participle of compōnō (“put together”)

Composition:

Composite materials are microscopic or macroscopic combinations of two or more distinct engineered materials, non-miscible. The physical and chemical properties of each of the constituent materials remain distinct in the new material. The materials are separated by a distinct interface.

These constituent materials work synergistically to produce a composite material that has different properties when compared with the individual constituent materials. In essence, composite materials are heterogenous, combining a “matrix” and “fibers” as a reinforcement:

• As matrix, polymer resins are the most significant, in volume and value terms.
• The fibers have a considerable length-over-diameter ratio (or “aspect ratio”), excluding spherical or ellipsoidal “inclusions” (when these are added to polymers, the resulting materials are called “particle reinforced” materials). Continuous fibers have an infinite aspect ratio, discontinuous or short fibers have finite aspects ratios (ranging from 10 to many thousands); higher aspect ratios result in higher stiffness and strength of the composite.
• The “reinforcement” indicates that this phase has mechanical properties superior to those of the matrix in terms of stiffness, strength and toughness

Manufacturing & Technologies

Composites are usually made with a combination of the following materials:

• Reinforcement fibers such as glass fibers, carbon fibers, aramid, basalt, or natural fibers like flax, hemp, bamboo…
• Matrix materials such as polymer resins, bioresins, concrete, ceramic…
• Additives and finishes enabling this combination and/or providing additional properties

Polymer composite products are manufactured using various processes and technologies, such as resin transfer molding, infusion, pultrusion, filament winding, fiber placement and more recently 3D printing. Simulation, automation and testing also play an important role in optimizing the development and manufacturing processes and in ensuring the highest levels of quality and performance.

The various combinations of materials, manufacturing processes, finishes and all the technologies involved in the composites industry offer an almost unlimited range of possibilities for end-users in all markets.   

History of Composites

Since 2020, JEC has decided to celebrate the expansion of the composites industry as a whole with brochures describing the progress of composites, from Pre-history to the early day of our century, “10 Milestones in the history of composites” (Volume 1) and over the past 50 years and the years to come, “The last 50 years and the future” (Volume 2) reviewing the evolution of the materials, the processes and various application sectors.

For this, JEC commissioned Ignaas Verpoest, Emeritus Professor at the Composite Materials Group of the Department of Materials Engineering, Katholieke Universiteit Leuven, to document both volumes.

While preparing this document, with the collaboration of Nelly Baron (VP Content, Marketing & Communication at JEC), Ignaas Verpoest received feedback and additional information from several composites’ professionals and specialists in specific areas. In fact, Stepan Lomov and Yentl Swolfs at KU Leuven, and former collaborator Bart Vangrimde (now at Huntsman, also VP of SAMPE Europe) have reviewed the text and provided essential feedback. For specific subjects, he required the input of Prof. Jim Thomason (University of Strathclyde, Scotland) on glass fibres, Fumihiko Tanaka and Ichiro Taketa (Toray) on carbon fibres, Hans Lilholt (retired from Risoe-Denmark) and Frans Van Hulle (retired from ECN-Petten, The Netherlands) on wind turbines, and Prof. Karel Van Acker (KU Leuven) on sustainability.

Readers will be able to journey through different eras of the composites industry, gaining a deeper appreciation of the market trends and technological advances which have brought us to this point.

Continual innovation is advancing the performance, efficiency and sustainability of the composites industry in the drive for solutions to the challenges posed by the megatrends transforming our world.