| Carbon Fiber: What exactly is it?? | | | | past 20 years to create better products with |
| January 2005 | | | | more predictable results. In this method the fibers |
| Who out there has heard of carbon fiber? Do you | | | | are pre-impregnated with resin at the factory. It |
| even know what it is? It has become apparent to | | | | is then rolled onto spools and then frozen to |
| me over the past few months that almost | | | | prevent the material from curing too quickly. |
| everyone in the sport compact scene is aware of | | | | Materials made by this method are typically |
| carbon fiber as it explodes in popularity. It is being | | | | 20-30% stronger than "wet" laminate of the |
| used to manufacture everything from the popular | | | | same thickness. Pre-impregnated lay-up materials |
| hoods to even fenders and interior pieces now. | | | | can be cured in one of two ways: vacuum bag |
| But another thing that became apparent is that | | | | compaction and also vacuum bag compaction plus |
| although many enthusiasts are aware of it, very | | | | an auto clave. The composite is placed under |
| few actually know what it is. Well in this month's | | | | vacuum bag compaction and is placed into an |
| column we will discuss where carbon fiber came | | | | oven. The resin will then solidify or "glass." When |
| from, the properties of the material, and how it is | | | | the autoclave is used it essentially pressure cooks |
| used. | | | | the fibers. The maximum allowable temperature |
| Carbon fiber has been around for over fifty years | | | | of the cured laminate is used and the continuous |
| with its earliest history in the aerospace and | | | | temperature is lower. It is normally is between |
| military industries. It was normally reserved to | | | | 250 and 350 degrees. |
| these industries as the costs of manufacturing | | | | Automakers first began experimenting with |
| carbon fiber were sky high, and cost consideration | | | | carbon fiber in the 1970s. Ford even built an entire |
| is low in these two industries. Only in recent years | | | | car out of carbon fiber composites in 1977. In the |
| has production of carbon fiber climbed, therefore | | | | 1990s GM manufactured a concept car out of |
| lowering the price and making its use more | | | | carbon fiber that got 100mpg. The motivation for |
| widespread. | | | | automakers is to produce vehicles with lower |
| Carbon fiber can be produced in one of two | | | | emissions, lighter weight, lower cost and better |
| ways. These are "wet" lay-up and | | | | fuel economy. The problem carbon fiber has |
| pre-impregnated lay-up processes. The "wet" | | | | presented though in the past is its astronomical |
| process has been used since the beginning of | | | | price compared to other materials. At one point, it |
| composites. It creates molded shapes from glass | | | | cost $100 per pound versus .40 cents for steel. |
| or carbon fiber and resin. Do-it-yourselfers use | | | | Nowadays though, the prices are hovering |
| this practice extensively as it is the least labor | | | | somewhere in the $5-$10 price range and it is |
| intensive and expensive money wise. When | | | | making many other industries experiment with |
| manufactured in the "wet" lay-up, dry fibers are | | | | the material. Many enthusiasts purchase carbon |
| laid into a mold and resin is poured onto them. | | | | fiber products solely for the looks, but they offer |
| The resin is then brushed over the fibers in a | | | | other benefits as well. Carbon fiber reinforced |
| relatively uncontrolled manner. Resin is added in | | | | materials perform at higher rates for strength |
| layers and layers until the desired thickness is | | | | versus steel and aluminum. |
| achieved. If this process is not performed | | | | So the next time you think about purchasing a |
| correctly the fibers can become saturated with | | | | carbon fiber hood or other products, you will |
| resin which causes added weight, and reduced | | | | know how to investigate the manufacturing of |
| strength and stiffness. This method can also | | | | the product to make sure you are getting what |
| create inconsistent products as certain areas are | | | | you are paying for. Carbon fiber is just getting |
| saturated and others are not thick enough. | | | | started with a bright future ahead. |
| Pre-impregnated lay-up has been refined over the | | | | |