Talk Composites - The Forum for Advanced Composites

How to choose it? Easy-Preg or Vari-Preg PrePreg

http://www.talkcomposites.com/Topic18706.aspx

By wangyuewwl - 7/8/2015 3:20:18 PM

I am the new coming for this area. Trying to buy some carbon fiber materials but being confused about so many options.. what is the different between these two and how to choose it based on the application?

Easy-Preg Surface Layer PrePreg Carbon vs Vari-Preg PrePreg Carbon Fibre 215g 2/2 Twill Wide

And what's the CFM for the vacuum pump sold in website? How much CFM is desired? 

Thank you
By Dravis - 7/17/2015 12:09:34 PM

The principal difference between "out of Autoclave" and "autoclave CF work is that the Pre-preg CF used for Autoclave work, relies on the autoclave being able to produce a pressure on the CF layers in the mould that is higher than +1 Bar/Ato.   Heating cycles and Ramping up of temperatures is needed in both cases .. using more then two layers of prepreg most often requires "bebulking" of the first layers, before adding more layers. often Autoclave Prepreg uses (or can use) a higher curing temperature ... The ramping up is required in order to first get the resin in the prepreg to flow and the CF layers to compress. If you go to full cure temperature too fast the resin will not have time to flow and the CF layes may not consolidate properly.

IMHO successfull "Out of Autoclave" prepreg work requires a properly controllable oven, with vacuum feed-through connectors.

Starting CF work using "out of Autoclave" Prepreg is perfectly possible, You will just have to accept wasting quite a bit of expensive Prepreg in geting to know the niggles with vacuum bagging, layup and mould work, without the the benefit of experience with the "wet" methods ..