I’ve seen some layup for prepreg that use both release film and peel ply then breather. My question is, can you just use peel ply without release film? will it soak up too much resin during baking and cause void?
check your datasheets. you probably need release film. (and it’s a lot easier getting your breather off!)
Typically you always need a release film with or without perforations otherwise too much resin will be drawn out of the material. Pre preg materials/carbons usually have just the right amount of resin already in them so only a minimal can afford to be lost.
So you should always have a release film or barrier (could be silicone sheet) and you can go with or without a peel ply.
I use normal dry peel ply with pre pregs and no problems, this peel ply is already drawing out resin too. Some will use pre preg peel ply which is the usual peel ply that is supplied already wet through just as any other pre preg fibre is. This way your peel ply will not remove any further resin from the job. It may in fact add resin??
Voids may not be due to having no release film. I find it very difficult to achieve a void or porosity free finish using pre pregs in composite moulds with vaccum and oven only process. Real autoclaves with more pressure work great$$ and metal moulds in a vacuum only process are quite good too.