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Steve Broad
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+xTo be fair not that much more. Put a vernier on a piece of uncurred umaterial an that's the thickness you will get cured,be it 15psi or 90 Just loose a little bit on a ply stack with multiple layers as one layer fits into another Don't really need 90psi,but your 100% it's in the corners Even 30psi will give you 99% success So, crucial for very high end stuff but not for the rest of us.
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f1rob
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To be fair not that much more.
Put a vernier on a piece of uncurred umaterial an that's the thickness you will get cured,be it 15psi or 90
Just loose a little bit on a ply stack with multiple layers as one layer fits into another
Don't really need 90psi,but your 100% it's in the corners
Even 30psi will give you 99% success
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Steve Broad
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+xFor a fair while back in the old days most curing was done in oven,not a autoclave in sight. Lot of invention then with cures,release film,breather ect to get a good part All the parts we are doing at the moment (4/500 a week) are autoclave but we are using OOA material An a 90psi cook Just as easy as normal material So, there is quite a lot of BS floating about. That's a fair squeeze, 6 times atmospheric :-) How much extra does that compress the material compared to 15psi?
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f1rob
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For a fair while back in the old days most curing was done in oven,not a autoclave in sight.
Lot of invention then with cures,release film,breather ect to get a good part
All the parts we are doing at the moment (4/500 a week) are autoclave but we are using OOA material
An a 90psi cook
Just as easy as normal material
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Steve Broad
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+x+x+xThere isn't such a thing as a "autoclave" resin system. Thou resin can be applied to carbon to make it OOA material,it's the same resin Most systems are the same an as Steve said experiment "Most" will start to flow at 30,most start to "gel" at 80 but will take 5/10 minutes to actually take a set at that temp Cook it long enough at 80 an it will cure but not have the best tg Most materials will be 120-130 cure Final hr at 135 usually covers all bases Remember KISS lots of people doing lots of really long complicated programs to cure their materials and it's not needed You have 3 states with your resin Liquid, gelled an cured so gently ramp up to just below your gel temp 1/2 hr dwell,if the resin hasn't done what it needs to in 30 mins it Isn't ever doing it Once your dwells over an your temp rises an you cross the gel point after a few minutes your resin isn't going to flow any more so any more dwells are totally pointless Up to your cure temp an hold P.S sorry Steve I will give you a bell an head over one evening but soon as I got your number we have had a mental few weeks at work an no spare time,hardly had a chance to pop on here I meant carbon fibre composite designed for autoclave :-) If the resins are the same, what is the difference between OOA and Autoclave composites? In order to use the autoclave composite I had to debulk after each layer of material was added and use the up to 80, hold for 30 minutes then up to 120 and hold for 2.5 hours method. It also had a 38% resin as opposed to 42% No problem, whenever you can make it will be fine by me as I am almost always here :-) OOA just has the resin applied a different way "Traditional" pre preg goes through a resin bath,the cloth is totally saturated an then it goes through essentially a giant mangle. That squeezes out a lot of the resin an depending how it's set gives you your resin percentage. OOA is "hot rolled" the material goes into the machine dry,the resin is squeezed out in a measured way (to get your resin percentage) onto a warm roller which the carbon passes under. As it compresses the carbon the resin film on the roller transfers to the carbon. The idea being you already have a good resin a surface when you lay up,an any air escapes a lot easier through the dry fibres as the resin bleeds through to the back. There is no "autoclave" pre preg Debulking the 1st ply is good practice but after that putting 4/5 down without a debulk fine So, let's see if I have got this :-) Prepreg is the original and required an Autoclave so is simply called prepreg. OOA was developed as an alternative so needs the OOA tag to differentiate it from the original. The resins are the same, The original pregreg is saturated but OOA prepreg is only coated on one side and relies on heat and vacuum to transfer the resin throughout the carbon. Why not use OOA in an Autoclave, getting the best of both worlds and only needing to make one type of prepreg? Apologies for the thread hijack :-)
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f1rob
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Group: Forum Members
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+x+xThere isn't such a thing as a "autoclave" resin system. Thou resin can be applied to carbon to make it OOA material,it's the same resin Most systems are the same an as Steve said experiment "Most" will start to flow at 30,most start to "gel" at 80 but will take 5/10 minutes to actually take a set at that temp Cook it long enough at 80 an it will cure but not have the best tg Most materials will be 120-130 cure Final hr at 135 usually covers all bases Remember KISS lots of people doing lots of really long complicated programs to cure their materials and it's not needed You have 3 states with your resin Liquid, gelled an cured so gently ramp up to just below your gel temp 1/2 hr dwell,if the resin hasn't done what it needs to in 30 mins it Isn't ever doing it Once your dwells over an your temp rises an you cross the gel point after a few minutes your resin isn't going to flow any more so any more dwells are totally pointless Up to your cure temp an hold P.S sorry Steve I will give you a bell an head over one evening but soon as I got your number we have had a mental few weeks at work an no spare time,hardly had a chance to pop on here I meant carbon fibre composite designed for autoclave :-) If the resins are the same, what is the difference between OOA and Autoclave composites? In order to use the autoclave composite I had to debulk after each layer of material was added and use the up to 80, hold for 30 minutes then up to 120 and hold for 2.5 hours method. It also had a 38% resin as opposed to 42% No problem, whenever you can make it will be fine by me as I am almost always here :-) OOA just has the resin applied a different way "Traditional" pre preg goes through a resin bath,the cloth is totally saturated an then it goes through essentially a giant mangle. That squeezes out a lot of the resin an depending how it's set gives you your resin percentage. OOA is "hot rolled" the material goes into the machine dry,the resin is squeezed out in a measured way (to get your resin percentage) onto a warm roller which the carbon passes under. As it compresses the carbon the resin film on the roller transfers to the carbon. The idea being you already have a good resin a surface when you lay up,an any air escapes a lot easier through the dry fibres as the resin bleeds through to the back. There is no "autoclave" pre preg Debulking the 1st ply is good practice but after that putting 4/5 down without a debulk fine
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Steve Broad
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Group: Forum Members
Posts: 408,
Visits: 4.1K
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+xThere isn't such a thing as a "autoclave" resin system. Thou resin can be applied to carbon to make it OOA material,it's the same resin Most systems are the same an as Steve said experiment "Most" will start to flow at 30,most start to "gel" at 80 but will take 5/10 minutes to actually take a set at that temp Cook it long enough at 80 an it will cure but not have the best tg Most materials will be 120-130 cure Final hr at 135 usually covers all bases Remember KISS lots of people doing lots of really long complicated programs to cure their materials and it's not needed You have 3 states with your resin Liquid, gelled an cured so gently ramp up to just below your gel temp 1/2 hr dwell,if the resin hasn't done what it needs to in 30 mins it Isn't ever doing it Once your dwells over an your temp rises an you cross the gel point after a few minutes your resin isn't going to flow any more so any more dwells are totally pointless Up to your cure temp an hold P.S sorry Steve I will give you a bell an head over one evening but soon as I got your number we have had a mental few weeks at work an no spare time,hardly had a chance to pop on here I meant carbon fibre composite designed for autoclave :-) If the resins are the same, what is the difference between OOA and Autoclave composites? In order to use the autoclave composite I had to debulk after each layer of material was added and use the up to 80, hold for 30 minutes then up to 120 and hold for 2.5 hours method. It also had a 38% resin as opposed to 42% No problem, whenever you can make it will be fine by me as I am almost always here :-)
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f1rob
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Group: Forum Members
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There isn't such a thing as a "autoclave" resin system.
Thou resin can be applied to carbon to make it
OOA material,it's the same resin
Most systems are the same an as Steve said experiment
"Most" will start to flow at 30,most start to "gel" at 80 but will take 5/10 minutes to actually take a set at that temp
Cook it long enough at 80 an it will cure but not have the best tg
Most materials will be 120-130 cure
Final hr at 135 usually covers all bases
Remember KISS lots of people doing lots of really long complicated programs to cure their materials and it's not needed
You have 3 states with your resin
Liquid, gelled an cured so gently ramp up to just below your gel temp
1/2 hr dwell,if the resin hasn't done what it needs to in 30 mins it Isn't ever doing it
Once your dwells over an your temp rises an you cross the gel point after a few minutes your resin isn't going to flow any more so any more dwells are totally pointless
Up to your cure temp an hold
P.S sorry Steve I will give you a bell an head over one evening but soon as I got your number we have had a mental few weeks at work an no spare time,hardly had a chance to pop on here
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Steve Broad
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Group: Forum Members
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+xThere is no way to figure it out, you need to contact the supplier. This is in no way a criticism, but it depends on the use the material is being put and the surface finish required. If the part being made is strength critical then, yes, you need the resin manufacture's curing data. However, if the part is cosmetic or non structural, then a little experimentation will suffice. I am assuming here that the resins used in fibreglass prepreg are similar to those used in carbon prepreg. Lay up a small sample and cure at around 120 deg C as most resins will cure at this temp (bring to this temp at 3deg C a minute) for around 3 hours. If the surface is pinhole free enough for your purpose, then carry on. If not, then try a lower temp for a longer time or a two stage cure - bring up to 80 deg C, keep here for 30 minutes, then continue to 120 and leave for 2-3 hours. At 120 deg C you can't really over cure. I have used resins designed for Autoclave only in my normal oven, using a method suggested by the supplier, so there is some flexibility to the curing process. This is in no way scientific, but has worked for me. I'm not making strength critical parts and I am painting them to hide the fact that they are carbon. Having said all this, the simplest way (as Hanaldo says), assuming that you know the origin of the material, is to ask the resin manufacturer :-)
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f1rob
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Group: Forum Members
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She or solway
9o gm satin weave
120g
200g
285g
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