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Hanaldo - 12/4/2018 2:15:24 AM

Yes, if you're worried about time then epoxy moulds are the way to go. For one-offs, I think vinylester moulds are still the way to go. For production moulds, epoxy all the way. 

I've tested co-curing VariPreg and XC110 together, and I dont believe them to be compatible. Cosmetically they look fine, but structurally the interlaminar bond and peel strengths are very poor and the two materials delaminate if flexed. You can pull the layers apart like peel ply.

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Matt (Staff) - 12/10/2017 9:26:12 AM

I've just published our latest video tutorial. This is the third and final part of the latest series which now covers the making of a carbon fibre engine cover from CAD model to prepreg carbon fibre part.



In this final video we're using our new XC110 prepreg which replaces the Easy-Preg that we've used and sold for many years. The decision to move away from the Easy-Preg system was a very big one and is something that we've been working towards for a very long time. Easy-Preg worked fantastically and was a great product but there were a number of drawbacks which we hope to have overcome with the new XC110 system. Namely, these were that the Easy-Preg system was limited to a specific surface ply (a 240g 3k) which could not be substituted for any other weight or weave (so finely balanced was a the behaviour of the material) and, to be perfectly honest, the very high price of the material (owing to the difficult manufacturing process).

Therefore, we hope to have achieved a number of things with the new XC110 prepreg:

Firstly, we now have a range of out-of-autoclave materials, including a 3k 210g, a 12k 450g (both of which could be used as the surface ply), as well as compatible unidirectional (UD) material and  an adhesive film. Having such a comprehensive offering means that even the most complex structural projects can be undertaken 'out-of-autoclave'. 

Secondly, by controlling the production of these materials from creel-set to freezer we have been able to significantly reduce the price of these materials so that they now compete with just about any prepreg system, let alone a high performance out-of-autoclave system. Of course, due to the extra admin and overheads of handling prepregs there is still quite a bit extra to pay on very short rolls (1m, 2m etc.) but, as an indication, a 25m roll of either the surface or backing is available from us at around £30 (34 euro, $40 usd) with further discounts available for larger orders. Download our full prepreg price list here.

There are however some significant differences between the Easy-Preg system and the new XC110 system so I thought this topic might be a good place to discuss them and take any questions people have. The most significant differences are:

1. XC110 is far more sensitive on the cure cycle. To get good results it's really important to follow a two-stage post cure with carefully controlled temperature. Full details of the recommended cure cycle can be found in the XC110 Out-of-Autoclave Complete Processing Guide PDF.
2. XC110 doesn't really seem to like vinylester mould surfaces (such as Uni-Mould). Obviously this is a huge disappointment to us because we have previously stated that Uni-Mould moulds can be used to for relatively low curing of prepregs. Although - at a push - the XC110 system can be cured in a vinylester mould it does seem to increase the chances of surface imperfections (pin holes) due to a combination of reaction with the vinylester and the fact that the preferred cure cycle for the XC110 (which finishes at 120'C) cannot be used because the Uni-Mould tools cannot take this temperature. Therefore we now suggest moulds made using either epoxy tooling prepreg or moulds made using high temperature epoxy gelcoat backed up with either high temp epoxy paste or high temp epoxy resin.
3. Bagging method: Better results are achieved with this prepreg system by not putting breather on the back of the release film where it is over the laminate (as can be seen in this video).

I hope you enjoy the new tutorial and would be happy to answer any questions anyone may have on this new system.