Materials

The CompoTech process has been developed using all grades of Carbon Fibre, Aramid Fibre, and Glass Fibre.
The Ultra High Modulus Graphite Fibre (also known as Pitch Fibre) is a particular specialty and is proposed where it is beneficial.
CompoTech use only Epoxy resin for the composite matrix, but there are many types of epoxy resin which are appropriate.
Epoxy with dispersed Carbon Nanotubes has been proven to be especially effective with the CompoTech process.
The inclusion of damping material in the composite has been pioneered by CompoTech and the resultant big improvement in damping properties of machine components is particularly useful.

Pin Winding

CompoTech developed an automated “Pin” winding method of manufacturing composite tubes in 1994 and have been developing the process ever since.

The CompoTech process is now known as “Axial Fibre Placement”

axial-fibre-modulus-graph

By placing fibres along the axis of a tubular component it is possible to get a higher volume fraction, i.e. more fibres relative to the volume of material. More fibres in the composite gives:-

  • 10% – 15% greater stiffness
  • 50% better bending strength

Axial Fibre Placement enables more of the performing fibres to be placed to advantage in the section. Here are some examples:-

Some Simple Sections

251-example-80mm-sections-2
A circular tube is the simplest product. With the CompoTech process fibres can be placed at any angle to the axis from 0˚ – 90˚. A simple tube with true 0˚ fibres will always be better in bending and stability than any other process.
All tubes with a variable thickness have to be made by adding axial fibres in an automated process.
Adding axial fibres in the thicker places is always better for bending properties in that plane.
If sharp corners or dimensional accurate outside section shapes are required, then outside tooling is required.
CompoTech have specialised in developing the process to make these sections accurately, repeatably and as economically as possible.
Of course CompoTech have many other sections and examples of other possibilities.

Additive Manufacturing

The CompoTech process is additive manufacturing. Most of the material added during manufacture is needed for the final part.  Carbon Fibre is an expensive material and very little is wasted. It is possible to be cheaper than a metal equivalent part by saving on the cost of post processing and/or building in features in the tooling.

Tooling and production volumes

Tooling can range from the experimental one time use, to long lasting high volume production tooling.
One tool may have multiple uses and for this reason all tooling is owned by CompoTech and used where appropriate.  A tooling contribution charge is made when a new tool is needed, but it does not give ownership or control to the customer who made that contribution. Every new tool that is made is used in combination with other tools that are already existing, paid for by contribution from other customers.

Production volumes can vary from 1 – 1000s depending on the customer needs.
Some experimental parts can be made from existing tooling or made from very cheap “one time” tools.

Volume production, and consequently pricing, will depend on the required lead time and batch sizes. This will dictate the number of tools needed and how many parts are made on one tool.