What is Carbon Fiber?
- Carbon fiber or Graphite fiber are fibers 5-10 micrometers in diameter and composed mostly of carbon atoms. Carbon fibers have several advantages including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion.
How is it Made?
- Carbon fiber is produced by using a high temperature process that bonds carbon atoms together in crystals aligned parallel to the long axis. Several thousand carbon fibers are bundled together forming a TOW. These bundles are then weaved together to form carbon fiber fabric.
What are the types of weaves?
Plane Weave
- Plain weave fabric is the second most widely used of the woven carbon fabrics. In this weave the weft goes over one warp and under the next, creating a grid-like pattern. Plain weave is a slightly tighter weave pattern that 2/2 twill and therefore easier to handle without distorting, however it is not as drape-able as 2/2 twill and therefore it is not the first choice for compound contours.
Twill Weave
- The most commonly used weave pattern for carbon fiber is '2/2 Twill'. In this pattern the weft goes over two intersecting warps and then under two (hence 2/2) to create a woven fabric with a predominantly diagonal pattern to it. Twill weave allows for bi-directional strength.
Uni-directional
- Unidirectional carbon fiber is a reinforcement where all of the carbon fibers are aligned in the same direction. The only thing holding the fibers together will be occasional strands of either carbon or polyester running across the fibers at 90 degrees. Unidirectional material is used in applications where all of the forces on a part will be in one direction.
What is TOW?
- TOW represents the total number if filaments in a strand. The strands are then weaved together to make fabric. Ex: a 1K TOW has 1000 carbon filaments in a strand. 12K-12,000 filaments and so on.
What does weight mean?
- The weight is typically for a square meter of fabric. A fabric that is 400g means that 1 square meter weighs 400 grams, 200 weight = 200 g/m2. A heavier fabric weight will have a higher TOW.
What is Kevlar?
- Kevlar is simply a super-strong plastic.There are literally hundreds of synthetic plastics made by polymerization (joining together long chain molecules) and they have widely different properties. Kevlar's amazing properties are partly due to its internal structure (how its molecules are naturally arranged in regular, parallel lines) and partly due to the way it's made into fibers that are knitted tightly together.
What is Kevlar aramid Fabric?
- Kevlar aramid fabric is Kevlar weaved with Carbon Fiber. Each TOW strand is alternated with Carbon Fiber creating a weave of Kevlar-Carbon Fiber.
What are Kevlar properties?
- Unlike most plastics it does not melt: it's reasonably good at withstanding temperatures and decomposes only at about 450°C (850°F).
- It's strong but relatively light. The specific tensile strength (stretching or pulling strength) of both Kevlar 29 and Kevlar 49 is over eight times greater than that of steel wire.
Do I have to apply an epoxy coating?
In short yes..uncoated the fabrics will fray very easily, Kevlar is especially prone to fraying. The fabrics gain their strength when the epoxy surrounds the fibers and hardens.
How do I cut the fabric?
You can cut the fabrics with a good pair of scissors. The scissors should be very sharp. Electric scissors work better as less fraying occurs.
