Carbon composite is one of the most important materials in the modern-day era of Formula 1. Pretty much everything you see on the car is made of it; from the wings, to the bodywork, the suspension and the driver’s survival cell, the chassis tub. That’s approximately 80% of the total F1 car – a monumental responsibility for Force India’s composites department.
Carbon composite is used specifically for its unique properties as a material. A composite is a substance made of two or more materials to get the most of their respective properties in the final product. Carbon is already one of the toughest materials found in nature, but its strength is, in this case, combined with an epoxy resin for flexibility and a light weight.
With so much of the VJM cars made from the material, Force India carbon composites’ workshop is a busy place. Comprising just over 30 members, the department has responsibility for making sure the carbon composite parts of the car are produced to size, time and, most importantly, strength.
The department includes two different sections; the laminating shop, where the actual composites are laid up and cut to size, and the trim shop, where the parts are fine-tuned and assembled. The majority of carbon arrives in rolled sheets, which are kept in chilled cabinets – freezers to you and I – to prolong their life. This carbon is pre-pregnated with the resin so it’s still flexible enough at this stage to be moulded into the shapes we see every other Sunday, but doesn’t yet have the rigidity needed to be raced. This will happen at a later stage.
The process involved in making the parts is a finely-tuned one. When a part is designed and signed off by the team’s drawing office, it is released to the pattern shop. This department will make the mould for the part, making a template from a tooling block to ensure each part is produced identically. This template, or pattern, is then machined exactly to size before it is sent to the laminating shop for sealing and releasing. This process prevents the parts from ‘sticking’ to the side of the mould, making it easier and quicker for each part to be manufactured.
This mould is then transferred to the laminating shop and production of the parts will start. Some of the carbon parts, such as the chassis tub, larger parts of the bodywork and the floor underneath the car, are produced off-site but the smaller carbon parts are laboriously crafted within the Force India factory.
Each part is then laid up in the laminating shop according to a manual. This manual is really a guidebook on how each part should be put together and look, ensuring each and every part is uniformly constructed and its properties exactly the same. After this process the carbon part is then packed into a vacuum bag and the air sucked out and put into an autoclave, or huge oven that produces high temperatures and pressures. A nosecone for instance will be heated to 135 degrees celsius and 35 PSI for two to three hours.
Different parts have different ‘cooking’ instructions, all dependent on their eventual usage. Heat shields for instance, the carbon parts that go underneath the bodywork and will be subject to exceptionally high temperatures, will be cooked for two to three hours at 135 degrees and 75 PSI. Following this, each shield would then be ‘post-cured’ for 20 hours at 180 degrees celsius.
Similarly the glue used to fix each part together will be a bespoke type to endure the high temperatures and weight constrictions.
When finally trimmed to size and inspected, the carbon parts will be used in race conditions. Of course you know what can happen to the carbon if the driver touches the gravel or the wall, so to maintain the carbon two composites’ technicians will travel to each race.
After use each part is checked for any cracks and proof-loaded to verify if it can be used again. Even a remote sign of damage means the part is shelved – the team just can’t take a risk that a part will fail at high speed. That’s not to say there haven’t been late nights trying to manufacture new carbon parts when the car has had a big smash.
‘There have been times when the carbon parts have been completely destroyed,’ explains Brian Snooks, Composite Trim and Assembly Manager. ‘In these situations you can’t repair the parts as it would take too long and ultimately be too weak, so we have had to completely remanufacture and send out to a race weekend. Under these circumstances you have to be prepared to work long hours and have a good sense of humour!’
Source: Force India
