Recycling

< ------------------------------------------------------------------------------------------------------------------->

Composites

(Current Recyclable Materials)

Go to Page 2

Introduction to Current Composite Materials  (Page 1)

Composite materials, also known as fibre-reinforced plastics, are light and strong materials that can withstand damp and corrosive environments better than many other materials.  Composite materials have the favorable characteristics of being low weight, high corrosion-resistance, long life, high specific rigidity, high specific strength, and high fatigue resistance.  With the demand for lighter and stronger components increasing in many industries, composite materials’ role in society expanding.  This section is devoted to introduce to you the type of composite materials available today.  Not all of the following composite materials are recyclable.  For a complete list of today’s recyclable composite materials, please visit our section Current Recyclable Materials – Composites – Thermoset Resins or Current Recyclable Materials – Composites – Thermoplastics.  If you are interested in how some composites can be recycled, please visit our section Current Recycling Process – Composites. The following information is extracted from the works of Dr. Pichai Rusmee of University of Utah and Dr. Bill Jordan of Louisiana Tech University. What is a Composite? From an engineering point of view, a composite is technically any material resulted from physical assemble of a variety of materials.   A composite should still have components identifiable.  The real advantage of having composite is the utilization of all the positive characteristics of the combined materials. The Two Components of Composite… Usually, composite materials will consist of two separate components, the matrix and the filler.  The matrix is the component that holds the filler together to form the bulk of the material.  It usually consists of various epoxy type polymers but other materials may be used.  Metal matrix composite and thermoplastic matrix composite are some of the possibilities.  The filler is the material that has been impregnated in the matrix to lend its advantage (usually strength) to the composite.  The fillers can be of any material such as carbon fiber, glass bead, sand, or ceramic. Composites Categorized Base on Filler Types… Composites can be classified into roughly three or four types according to the filler types: • Particulate – Particulate composites are composites in which the filler materials are roughly round. An example of this type of composite would be the un-reinforced concrete where the cement is the matrix and the sand serves as the filler.  Lead particle in copper matrix is another example where both the matrix and the filler are metals. • Short fiber – Short fiber composites are composites in which the filler materials has a ~100 length to diameter ratio.  An example of fillers used in short fiber composite would be the fiber glass filler for boat panel. • Long fiber – Long fiber composites are composites in which the filler materials has a ~ ? length to diameter ratio.  An example of fillers used in long fiber composite is carbon fiber. • Laminate – Laminate composites uses filler materials in form of sheet instead of round particles or fibers.  An example of fillers used in Laminate composite would be glass. GENERAL TYPES OF COMPOSITES 1. Macroscopic Composites   Macroscopic composites contain individual components that are large enough to be seen without the use of microscope. Examples of Macroscopic Composites: • Concrete • Steel reinforced concrete • Laminated wood 2. Microscopic Composites Microscopic composites contain individual components that are microscopic in scale, but still larger than the size of an atom.  Following are different types of microscopic composites.

_________________________________________________________________________________________

QUICK LINKS (Specific Table of Contents): Section I: Introduction Section II: Present (YOU ARE CURRENTLY IN THIS SECTION) Section III: Future

Links:

Home Complete Table of Contents Reference