Carbon fiber

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Page for stuff with carbon fiber, more specifically Carbon-fiber-reinforced polymer, in the makerspace.

Theory

Composites are created from two or more dissimilar materials that act together as one. While concrete and plywood are technically composites, the term composite in industry has come to refer to reinforcement fibers held together in a resin matrix and formed in a mold. Carbon fiber is one of several textiles used in this class of materials. When joined together through a procedure called a layup, the fiber and the resin form a material with properties that exceed those of either constituent material.

As a rule of thumb, composites offer their greatest strength in the direction the fibers run — similar to how wood is strongest along the grain. Because of this, you can “tune” a composite’s strength characteristics by controlling and combining the directions of the fibers. If you want strength over the length of a part, simply align the fibers lengthwise. Likewise, if you’re making a tube that needs torsional (twisting) strength, it’s best to arrange the fibers helically, like springs, weaving them together with opposite rotations.

The bulleted section below describes the three most common forms of manufactured fibers: woven, unidirectional, and filament. Each general type can be produced from carbon, fiberglass, aramid (Kevlar), boron, basalt, and several other materials, which are chosen according to their particular physical properties.

  • Woven (aka “cloth”)
    Comes in rolls and resembles the thick nylon fabric used in trampolines. Weave styles vary according to the fibers’ directional alignment, drape (how well the cloth conforms to mold surfaces), and wet-out (how easily the fibers can be infiltrated by resin).
  • Unidirectional
    Comes in rolls and resembles a very fine, wide paintbrush. Composed of parallel fibers that are intermittently joined over their width by thin resin-coated fibers that keep the strands aligned into an easily usable form.
  • Filament (aka “roving” or “tow”)
    Comes on reels as continuous strands of fibers, loosely gathered into a thread. It can be easily unwound and placed wherever necessary in a layup.

Resin is available in hundreds of different types, each with its own chemical and physical characteristics. In general, polyester, epoxy, and vinylester liquid resins are the most widely used in composite constructions.

Taken from this Make article.

Uses

Materials

For example, you can get a square meter of carbon fiber, with shipping, for 26 usd. You will also need resin and mould making equipment.