Jon,
Don’t be too hard on Joey I would say that the amount of technical detail written above is sufficient for the purposes of this article, since this is more of a news article that should serve only as an brief introduction to a couple carbon fiber composite manufacturing processes. If I, as a reader, wanted to learn more about this subject, I would search elsewhere for that knowledge. There are a multitude of different manufacturing processes that can be used with pre-preg. carbon fiber material, some of which don’t necessarily require high autoclave pressures. Depending on the part, such as for a non-structural, single-layered item (i.e. engine cover), a relative pressure delta of 4 atmospheres at 140 C (284 F) is more than enough pressure and temperature to speedily cure and produce a high-quality part. For example, there may only be 2 atmospheres (approx. 29 psi) absolute pressure within the autoclave environment, plus 0.5 atmospheres absolute pressure inside the vacuum bag that encompasses the part (created via a tube that connects the vacuum bag to a vacuum generator outside the autoclave). This would produce the specified 4 atmospheres of relative pressure needed for such a part. Higher autoclave pressures and temperatures may very well be needed on a different type of part that’s used in a different application. Sometimes, sufficient relative pressure and high temperatures are produced without an autoclave at all Anyway, the idea here is that there isn’t a “standard” pressure or temperature range that is used during these processes, and many factors need to be considered (i.e. resin material, application of end product, dimensions of part, etc.) in order to determine the optimum pressure and temperature values needed.