Some times, when two or more materials are mixed together in a special way… magic happens! This synergy is called a “composite!” They’re neat, and EC! is all about exploring their properties and making stuff out of ’em.
Mostly we think of common industrial combinations: concrete and re-bar, polyester resin and fiberglass, polyetheretherketone and carbon fiber… peanut butter and jelly! People have known for thousands of years how to mix materials together to make something that is more than the sum of its parts. By using one material to complement another, different materials “team up” to make more effective and efficient structures.
From mud and straw, concrete and steel – and on to plastics and refined fibers, people have evolved these material “teams”. In the last century or so we have learned to combine materials to exceed the properties of structures frequently found in nature. The main way we do this is by applying huge quantities of energy to make very highly-refined materials and then carefully controlling their combinations and chemistry. This refining, engineering and careful combining of reinforcements and polymers is composites!
Polymer Matrix and Fiber Reinforcement
For our purposes, we’re going to talk about the magic mix of a polymer (plastic / resin) combined with a reinforcement fiber. The resin is weak and/or brittle without the fibers and the fibers are floppy and, “directionless” without the resin matrix to keep them aligned and pulling together. Depending on the relative volumes of resin and reinforcement, you can think of the fiber as reinforcing the resin – or the resin bonding the fiber together. Like in concrete and steel in a bridge or a building – it’s hard to say if the steel is supporting the concrete or the concrete is supporting the steel. One is good at compression and the other at tension – so it really is a team effort!
Broad ranges of polymer matrices are available with an incredible variety of mechanical and processing properties. The same goes for fibers: from flax to high modulus carbon – the range allows you to tailor your mix to meet performance, price and manufacturing requirements. Some of these combinations result in the strongest and stiffest materials that people know how to make. Some are tough and fire resistant. Some are shiny and hard and cheap. These combinations and how to work with them are the focus of Explore Composites!
Art and Science
The practice of building with composite materials is a mix of art and science. It is about designing combinations of polymer matrix and reinforcement materials. It is also about designing the way that they are combined, the way they are molded to desired shapes and fiber orientations. The part about resin chemistry, laminate design and tooling process are mostly science. The parts about process optimization, tooling design and managing manufacturing organizations are mixes of art and science. There are lots of variables and it’s not always obvious what will work and what won’t.
My goal with EC! is to help explain the basics and develop a growing body of knowledge of the art, the science, and the gray areas in between.
