Check out Part 4 of our educational series on Composite and Fiberglass Terms. This installment sheds light on carbon fiber, thermoset plastic resin, milled fibers and more. Whether you’re a DIY enthusiast, a student entering the field of material sciences, or just curious about how these advanced materials shape our world, this is for you.

Carbon fiber-Also called graphite. It is known for its' strength, being light weight and for its' good looks.  It is commonly used in the automobile, sporting goods and aerospace industry.  A yard of carbon fiber cloth has millions of microscopic filaments all bundled together.   For instance, in a 3k fiber fabric, each tow (or bundle) of fiber has 3000 filaments in it.  The bundles are woven together to form a fabric. This is what makes it so strong.  Each filament carries part of the load.

Solvent- A substance (usually a liquid) used as a dissolvent or cleaning material during reinforced plastics operations. It is also often flammable or toxic. It should be handled in accordance with safety instructions.

Acetone- A commonly used wipe solvent. Also known as 2-propanone and Di-methylketone. It is used for cleaning composite surfaces prior to bonding and also metal surfaces prior to other treatments. It can be used to remove uncured epoxy resin from tools and other items. It is classed as “Seriously Flammable”.

Plain weave- A weaving pattern in which the warp and fill fibers alternate, that is, the repeat pattern is warp/fill/warp/fill, etc. Both faces of a plain weave are identical.

Thermoset Plastic Resin- A plastic that goes from liquid to solid following a chemical reaction. The solid cannot be melted back into a liquid.

Milled fiber- Continuous glass strands hammer milled into very short glass fibers. They come in a variety of lengths such as 1/32″, 1/8″ and 1/4″.   Milled fibers are glass filaments coated with a specific sizing to enhance resin compatibility and milled to a specified bulk density. Useful as inexpensive filler or anti-crazing reinforcing fillers for adhesives.

Blister-  A de-bond of paint or other coating from part surface. It is an undesirable rounded elevation of the surface of a plastic with boundaries that are more or less sharply defined, resembling in shape to a blister on the human skin. The blister may burst and become flattened.

If you want to see a comprehensive list of composite/ fiberglass definitions, all in one place, you can check it out here- Composites Glossary.