Hello mates, I have a problem with carbon prepreg.
I have to do a piece, and I have to make a mold carbon epoxy prepreg, the problem is that I have never used this material.
I ask for help with some explanation, image gallery, or a video.
I appreciate any help.
A greeting
Here’s a useful starting point:
http://www.hexcel.com/Resources/DataSheets/Brochure-Data-Sheets/Prepreg_Technology.pdf
Thank you very much. I find it very useful.
Any video or image of a prepreg molding process?
Thanks.
I have studied the information.
I have to see how it develops a mold or a piece Prepreg.
Help Please.
Do you have experience in making molds or in composites work in general? Trying to figure out what you meant in your last post on developing a mold or pre preg part. If you are new to this kind of work I wouldn’t recommend jumping into prepregs at first.
If not you will need an oven if your using ETC prepregs. Any description of what your trying to to exactly?
Thanks for your reply.
If I have experience in composites, infusion work.
I also make molds in sections, vinylester.
Now I have to learn to work with Prepreg, to improve part quality.
I’m making an oven that comes to work at 150*C, vacuum connections are, and 5-10bar pressure.
I do not know how to make a mold and a piece of prepreg.
Greetings
What type of Pre Preg will you be using? What temperature will you be curing at? Your tooling can be made the same as what you have done in the past but working with elevated temperatures you to choose a resin system to make your molds that can withstand the curing and post curing of your laminate. You will also want to post cure your mold.
I also use prepregs and my highest cure temperature is about 100-120C. My Molds can withstand higher temperatures but the resin system used in my prepreg doesn’t need any higher than 100C.
Are you asking how to use prepreg in the mold? If so I would highly recommend using a semi permanent release agent. I use one made by SOLE . Be sure to follow the directions as far as application goes. Many people have problems because they don’t follow the directions or wait enough time between coats or apply enough.
Advanced composites have quite a documentation on how to work with prepregs, including mould building.
I have made moulds for using with prepregs in different techniques. A prepreg would probably be faster, without the need for a long post cure process. My choice would be to start with a fine surface fibre, a 12K weave, bulking up with a 12K-syntactic, and end again with a 12K weave and a fine weave, to prevent deformation. You can build quite fast that way, creating thickness fast without the need of a core, wich can and probably will give print in the surface.
Master models build from wood/foams take a long way to heat up. temp. sensors in your bag or mould sensors can give you an idea. cure cycle temperatures are part temperatures, not air temperatures. Using different materials(metals/plastics/woods) in your master can be done, but only if you can control the surface temperatures very precisely.
Thank you. I am looking for information to make the oven.
I will use the advanced compositores prepreg. Low temperature curing.
Do not like the oven to 150 degrees.
Are you building an autoclave or oven?
I’m designing a furnace, and an autoclave.
I have not decided which to build, because need for information and advice.
A greeting.
Oven need special prepreg (OaA)If you want excellent surface without pinholes.
Oven is a lot of cheaper than autoclave and easier to build.
Information Construction oven please?
A do it yourself autoclave build is not a good idea.
But there are many ways to build an oven for curing at elevated temperatures.
The autoclave is a job for professionals and is not safe to try building even with skilled hands.
You need the box. Frame from steel or aluminium covered rockwool or something like this.
- Fan inside
- heat controller
- vacuum line inside
-vacuum pump outside
That’s all what you need
I saw many DIY autoclaves. It’s not complicated if you have necessary all construction data.
ok, thanks. any link ovens?
Here is a link to a diy oven building forum for powder coating. This particular thread details a complete oven build with pics, but there are many more entries throughout the forum detailing diy builds. Hope this helps!
Jon
http://forum.caswellplating.com/oven-building-forum/13191-my-new-oven-build.html
I’m also thinking on building my own oven, but there’s two things that still take my sleep away.
I’m concern about the temp. rise “speed”. For what i understand, it’s not very good for the epoxy resin to heat very fast.
I think it has to be a gradual temp increase, over some hours/min.
In the example of the other forum, he states that he got 400 ºF in 11 min. I think its too fast, but i’m not sure. If some one could help with this, it would be nice.
The other thing i’m very afraid is to set fire to my garage!
On the other hand, a industrial oven is very expensive.
If your wiring is ok, and the insulation of the oven is, and there are no combustible materials in your oven construction, you’re pretty much ok.
For curing prepregs it’s usually 2 degrees/ minute ramp, for freestanding postcuring 10 degrees/ hour. Faster may couse deformation or exothermic reactions (may couse fire… )
I looked in to computer control, with a PID controller. But getting a controller is a bit of a pain in the ass around here. That way you can set ramp and dwell periods, without the need for control and adjusting. And an alarm for overshoot temp. and errors 
Keep in mind this oven building forum has powder coating in mind specifically. There are many box designs and ideas within the forum to use as is or modify to your own needs for composites curing. Properly constructed with electric heating ellements would not pose a fire risk in my opinion. Controls are a mystery to me however, and I would like to find a system to easily control ramp and soak temps. Any ideas?
If you live in the states, there is a small fab shop north of me a couple of hours that build a pretty decent looking oven for powder coating. If I can figure out the control system I might just have them build one for me. For the time it would take me to round every thing up and construct it, I think it well worth my while just to purchase one of these. Seems like a reasonable price. Here is a link to their site. http://www.powdercoatovens.com/index.php
Jon