Prepreg is a common term for a reinforcement fabric that is PREimPREGnated with a resin system, sandwiched between two layers of protective foil. This resin system (typically epoxy) already includes the right curing agents. At room temperature this resin systems shows low reactivity but at elevated temperatures it becomes more and more reactive. This gives the possibility to store the Prepreg material at low temperature (or even in a freezer) for a longer time (the out-life). A carbon prepreg material is fully ready to be put into the mold without the addition of any more liquid resin. For curing the laminate it is necessary to use a combination of pressure and heat.

Advantages of carbon prepreg materials compared to hand lay-up are:

• prepreg material gives maximum strength properties due to the controlled resin ratio.
• high product uniformity and repeatability. Curing process variation is reduced to a low level.
• less mess and less waste: no liquid resins to be used.
• less curing time: after completion of the curing cycle the part is ready for service.
• better cosmetics: less air bubbles, less fabric distortion, easy to obtain a smooth, glossy surface.

Disadvantages of using carbon prepreg material are:

• cost: prepregs are more expensive.
• shelf life: prepregs are best being stored at low temperature. Some types have outlife of about 1 year, but freezing will extend shelf life significantly.
• necessary heat (and pressure) curing: need of controlled heat source and vacuum bagging at minimum. Some fabricators use an autoclave.

Typical applications of carbon prepreg can be found in aerospace, sporting goods, pressure vessels and commercial products.

Our carbon prepregs are available in a wide range of fabrics (90 to 600 g/m2), plain and twill and in a variety of resins systems depending on the required end-use of the product.