A composite product provides a designed solution that surpasses the performance of the starting materials.

What Are Composites?

Composites are engineered products made from two or more different materials.  A composite product provides a designed solution that surpasses the performance of the starting materials.  While there are many variations of composites, the most common engineered composite materials are fiber reinforced polymers (FRP).

What are the Advantages of FRP Composites?
The benefits of using composite materials include:

• High Strength
• Light Weight
• Corrosion Resistance
• Dimensional Stability
• Design Flexibility
• Durability

Where are composites found?
Composites are used to raise performance levels, address traditional material design limitations, and enable the development of new product solutions.  Composite materials are found in many of the products used in our daily lives, such as cars and trucks, bath tubs and counter tops, boats and windmills.  Composites are also used in many critical industrial, infrastructure, aerospace, and military applications.

What are composites made from?
The term composite can describe many types of engineered materials, but the most common engineered composite materials are fiber reinforced polymers (FRP).  FRP is often comprised of a reinforcing fiber in a polymer matrix.

• The reinforcing fiber is commonly glass fiber, although high strength aramids, plant based fibers and carbon fibers are used in some applications.
• The polymer matrix is typically a thermosetting binder resin.  Polyester, vinyl ester, and epoxy chemistries are the most predominately utilized binders.  Polymer selection is driven by end use application characteristics, such as corrosion considerations, cosmetic requirements, operating temperatures, and fabrication requirements.
• Pigment, filler and granule materials can also be used to modify cost, performance and appearance characteristics of the composite part.

How are composite products made?
To form a composite part, the liquid polymer binder resin is combined with the fiber and filler materials.  The polymer is then converted from a liquid to a solid during a heat and chemistry driven molding process, encapsulating the fibers and fillers into a specific shape.

There are many processes available for fabricating composite parts.  The fabrication methods range from very simple and low cost direct molding operations to complex processes and equipment operations.  The process selected to fabricate the composite part is dependent upon factors such as the quantity of parts to be produced, the design requirements, part complexity and surface appearance.

Composites offer high strength, low weight, durability and design flexibility

Why Use Composites?

Composites, especially Fiber Reinforced Polymer (FRP) composites, offer many advantages compared to traditional materials:

• High strength:FRP composites are very effective in providing high strength components. They can be designed to provide a specific range of mechanical properties, including tensile, flexural, impact and compressive strengths.  Composite parts designed with oriented reinforcement can provide additional strength, directional strength, or flexural properties at desired locations within a single part.
• Lightweight:FRP composites have a higher specific strength than most materials used in similar applications.  They can deliver more strength per weight than most metal alloys.
• Corrosion Resistance:FRP composites do not rust or corrode.  There are various resin binder systems available which provide long-term resistance to most chemical and temperature environments.  Properly designed FRP composites parts have long service life and minimum maintenance compared to traditional building materials.
• Durability:How long do composites last? Often, over fifty years and still counting.  FRP composite technology is “new” compared to the materials that it often replaces, such as concrete, steel and wood, so the full life span for many composite components is still being developed.  However, there are many cases of FRP composite boats, tanks and other products that are in use after more than 50 years of service life!  (Composite Durability overview)
• Design Flexibility:FRP composites can be fabricated into virtually any shape.  An application can be complex in configuration, large or small, structural, decorative, or a combination of these.  Composites free designers to try new concepts, from prototype to production.
• Parts Consolidation:Because of the design and fabrication flexibility of composites, single composite parts can replace complex assemblies units of multiple fasteners/parts that are produced with traditional materials such as wood, steel and aluminum.
• Dimensional Stability:FRP composites maintain their shape and functionality even under severe mechanical and environmental stresses.  FRP composites typically do not exhibit the “cold-creep” characteristics of thermoplastics.
• High Dielectric Strength:FRP composites have excellent electrical insulating properties, making them an obvious choice for components in current carrying applications.
• Low Thermal Conductivity: FRP composites are naturally poor conductors, which makes them great for applications such as window lineals, door skins, exterior cladding and other products where insulation is important.  However, thermally conductive or electrically conductive materials can be incorporated into the composite part if high thermal or electrical conductivity is required.
• Elevated Temperature Service:Composite parts fabricated utilizing appropriate polymer binder and filler technology perform very well in high temperature applications.

Composites reduce environmental impact by direct applications and through functional applications.

Composites & Sustainability

Many of the properties that make FRP composites the preferred material of choice for performance reasons also result in a more sustainable material.  These properties include:

• Durability, requiring less frequent maintenance and replacement
• Resistance to rot and corrosion, resulting in a longer service life
• Low weight, resulting in lower impact transportation and/or installation by reducing the size of equipment needed for installation
• Insulating, providing energy savings during use

Composites can contribute to reducing environmental impact by direct application and through functional applications.

Direct contribution can be seen in applications that reduce energy requirements, such as:

• Fiberglasswindow lineal and doors do not rot, rust or swell – resulting in fewer air leaks and better seals than wood and steel products.  Also FRP components provide inherent insulation value that far exceeds aluminum and steel products.
• Theheavy truck industry has moved to predominately composite bodies.  This move from steel to FRP reduces truck weight and allows for more freight to be carried, so fewer trips are required, and also provides for significant fuel savings when the truck is pulling empty.

Functional contribution can be seen in applications such as:

• Wind turbines, where the composite blades allow significantly longer length than traditional wood blades and facilitate the production of clean energy.
• Scrubbers and stacksthat can resist the corrosive nature of flue gas desulfurization and other scrubbing operations allow industrial operations to remove air contaminants under conditions that would fail traditional metals very quickly.

The Future of Composites
The composite industry is driving to improve in the area of sustainability, including:

• Generation of more life cycle analysis studies. The American Composite Manufacturers Association has recently led an industry wide effort to develop Life Cycle Inventory data for the major raw materials and processes used in composite products.   This will make future LCAs easier to perform, more accurate and lower cost.  Similar efforts to develop European LCI data sets are underway.
• The use of alternative materials. The use of alternatives is not limited to composites replacing traditional materials.  The composite industry has been aggressively identifying and utilizing recycled materials as fillers and in the binder resins.  There has also been significant work to replace petroleum based raw materials with bio based materials.  This trend is expected to continue.
• The use of natural fiber reinforcements. Natural fibers, such as flax, hemp, and jute, have been significantly studied and improved and are now being used as a partial or full replacement for the traditional fiber reinforcement in reinforced composite parts.
• Improved logistics for recycling composite materials. Composites are durable, and this makes recycling composites a challenge.  As the industry develops improved means of recycling, there is a larger need for lower cost and more consumer friendly means of collecting, handling and shipping composite materials for re-use.  An improvement in the recycling options available is a key industry objective.