First off, we don’t condone reverse engineering or duplicating somebody else’s product. Having said that, in my opinion, That insole will use a special resin system and or proprietary process to achieve the desired flex in the right places, while creating support where flex isn’t wanted. If they are as flexible as they say, then it won’t be a standard epoxy prepreg as those materials are designed for stiffness rather than flexibility. By using a more elastic resin system, they can get good flex, but stiffness is compromised. 

Hi you can google vktry carbon fiber insole to exactly know what is in my mind.i wanna make an insole like that.then u can help me better

18 hours ago, maede said:

Hi.i need a carbon prepreg for carbon fiber insoles.is there any prepreg available for it?the prepreg should remain flexible after final curing because we want the insoles to be strong while flexible to help the athletes restore energy,jump higher and run faster.if there is no prepreg for it I will make it myself but I don't know what epoxy resin is best suitable for this project.

Depends what characteristics you're looking for! If you have a basic design figured out Rock West Composites can definitely help you out with a layup to dial in the amount of flex you want 👍

1 bar is equivalent to 29 inhg. This can be achieved at sea level, but nothing more. 3 bar is not achievable with vacuum. This is equivalent to ~42 psi. This can only be achieved with mechanical pressure (press or clamp) or a vacuum bagged and autoclave cure process. Even cello wrapped parts, like the video above, will have limits on external pressure and is entirely controlled by the number of wraps you can put on the part and the tension of the cello tape. 

If I understand what you're trying to do correctly, this is essentially how cello wrapped carbon fiber tubes are made.

Check out this video: