Carbon Fibre

Mar
2012
08

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Carbon Fibre RoofToday the Prindiville team have been focused in the Carbon Fibre Workshop. Many of our customers ask us about the technical process of manufacturing in Carbon Fibre material.
Below we explain how carbon Fibre parts are made using F1 as a working example.

In the early sixties, Colin Chapman, chief designer of Lotus, introduced the monocoque to formula one by placing thin plates around the bars of the vehicle. This new technology increased the stiffness of the chassis.

In the seventies, aluminium was mostly used for these constructions, but when these structures proved not to be resistant enough for the wings down force; John Barnard from McLaren examined and produced a first, the self-supporting chassis from carbonfibre. By 1981, the McLaren drivers proved the safety and advantages of Carbon fibre. John Watson finished first and second twice during that season. Andrea De Cesaris also demonstrated the importance of Carbon fibre, given the number of crashes he survived that season.

Properties

Carbon fibre is a non isotrope material. Which means that all the fibres have to point in the same direction throughout the material as the force lines. To clarify, wood is also not isotrope, aluminium and copper are too.

Carbon fibres are 3 times stronger and more than 4 times lighter than steel!

Tensile strength Density Specific strength
Carbon fibre 3.50 1.75 2.00
Steel 1.30 7.90 0.17

Building in F1

F1 teams use carbon fibres, a pre-impregnated epoxy resin and an aluminium honeycomb layer, which is sandwiched between two layers of carbon fibre.
The chassis is usually the first part of the car to be built, due to the amount of time required. The main chassis usually comprises of about 8 parts (panels). The first stage of the manufacturing process is to build a solid (computer cut) pattern, from which a mold for the panel is produced. The molds are constructed by laying a total of 10 layers of pre-impregnated (with resin) carbon fibre on top of each pattern to produce the mold. The production of the mold takes place in several stages, involving vacuum treatments, debulking and heating processes. The mold then has to be thoughly cleaned and prepared for use.
The next phase is the actual fabrication of a car part, made from sheets of pre-cut, pre-impregnated carbon fibre, which are carefully laid inside the molds. It is therefore vital to orientate the carbon fibre sheets in pre determined directions in order to achieve the desired strength. A total of 5 layers of carbon fibre are laid, forming the outer skin of the chassis (to achieve a final, cured thickness of 1mm, a total of 3-4 layers of carbon fibre must be laid down).

The next stage of the process is to cure the carbon fibre in an autoclave. This exposes the carbon fibre to a number of temperature / pressure cycles according to the specific requirements of the materials and components being processed. During this treatment, the resin impregnated in the carbon fibre flows into the surrounding fibres and is activated, thereby curing the carbon fibre. Once the outer skin has been cured and cooled down, a honeycomb layer of aluminium is fixed onto the outer skin by a sheet of resin to ensure the materials stick strongly together. The chassis panel then returns to the autoclave for curing. After having cooled down again, one more layer, consisting of a number of pre-impregnated carbon fibre sheets is placed on of top the existing skin, and again treated in the autoclave for a final time.

When the part is completely produced, it is sent to the evaluation department, and when proven good, it can be used for racing.

The picture you see here is of our very own Prindiville Aircraft Grade Carbon Fibre Roof Skin….

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