Sage-Tips

Can you do carbon fiber without vacuum?

Absolutely. The only time they use vacuum and heat on carbon fiber is when it is a structural piece which utilizes heat activated resin to cure it up solid. Carbon fiber sheets are a bit more expensive than fiberglass, but it lays down about the same.

Can you cure carbon fiber in an oven?

Absolutely! Many carbon fiber parts made out there are done using an out of autoclave process (yes, there is even a name for it!). The appropriate matrix systems will cure in a regular oven or even room temperature.

What does an autoclave do for carbon fiber?

Autoclaving is a process that ensures the highest quality of carbon fiber reinforced polymer (CFRP) composite structures used in aviation. During the autoclave process, consolidation of prepreg laminas through simultaneous elevated pressure and temperature results in a uniform high-end material system.

Do you need autoclave for prepreg?

We, at Dexcraft, always recommend autoclave composites over OOA prepreg composites because they are capable of providing ultra-light weight prepreg carbon fiber components that offer excellent aesthetics with zero air voids, which can only be achieved using the autoclave manufacturing method.

Why do you vacuum bag carbon fiber?

First, it removes trapped air between layers. Second, it compacts the fiber layers for efficient force transmission among fiber bundles and prevents shifting of fiber orientation during cure. Finally, and most important, the vacuum bagging technique optimizes the fiber-to-resin ratio in the composite part.

Is carbon fiber strong without epoxy?

Carbon fiber truly shines with respect to its tensile strength. As raw fiber it’s only slightly stronger than fiberglass, but becomes incredibly strong when combined with the right epoxy resins. In fact, carbon fiber is stronger than many metals when fabricated the right way.

Can I make carbon fiber at home?

Yes, DIY fabrication is entirely possible. It is true that carbon fiber and similar composites are complex materials with a lot of science behind them. But you don’t have to go through the expensive and labor-intensive process of creating carbon fiber for your own layouts.

Can you hand lay carbon fiber?

The first technique is the simplest and the most economical one of the three. The reason that it is called hand-layup is that the resin is laid upon the Carbon fiber weave by hand typically with a brush, squeegee or a roller, but hand nonetheless.

Can you make a splice in the autoclave?

Manufacturers who autoclave their tube sections can not construct the splice in the autoclave. They can either use a vacuum bag cured scarf splice or a sleeve splice. Either will work well if properly engineered.

Why do parts fail in autoclaves?

Impacts can cause delamination that may lead to failure. Recent scientific studies have shown that autoclave produced parts are more subject to delamination than oven cured. One of these studies cited below was done by Baral, Davies, Baley and Bigourdan; a group from French Universities and Industry.

What are the disadvantages of compacting in autoclaving?

As compacting pressure is applied through the bag, it tends to be concentrated at any corner. The higher the pressure the greater the chance that the fibers will be pushed away from the corners during cure, which can and has been a problem for autoclaved parts. It is interesting that even aerospace companies are moving away from the autoclave.

What is the difference between autoclaved and vacuum bagged parts?

The autoclaved part has a bit lower resin content. It is thinner. Mechanical properties are about the same. The autoclaved part is less than 3\% stronger and stiffer in tension and compression prior to taking wall thickness into account, while the vacuum bagged part is better in shear.