Corian mold for OOA application? CTE? Strength?

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#1

Using corian seems to like a very appealing way to cut down on fab time.

Here this guy even used an epoxy resin system with the corian ATH matrix to make a mold. http://www.rcgroups.com/forums/showthread.php?t=2165394

I’m wondering if anyone knows what the CTE is for corian? …If I was to use it as a mold in an oven along with internal platinum silicone intensifiers for compaction. My concern is the potential for 1) warping 2)cracking the corian due to stresses from heat along with the silicone intensifiers.

Here is a data sheet for the corian. http://www.dupont.ca/content/dam/dupont/tools-tactics/bi/surfaces-technical-library/documents/north-america/Performance_Properties_of_Corian.pdf How does the CTE relate to composites CTE’s? Does it show much greater expansion? would it be problematic for using it in a heated oven?

I’m really itching to make myself a all carbon electrical bicycle frame ( since I had a baby I’m really not riding my motorcycle street any more…)

The frame would be hollow in the main spar with access and space internally to place the battery and electronics. This would allow me to make use of split molds and place/retrieve the silicone intensifiers internally.

#2

Hi.

I’m not sure of the exact CTE of corian but it does expand quite a bit when heated. , also HDT is around 70 deg C. Most of the solid surfaces have HDT around the same and higher CTE comparing them to epoxies.

This was my theory when I started to research how they made corian. I just replaced the acrylic resin to make a stronger better product for quick moulds.

I’m literally just about to make a set of tail moulds for my planes , using my DIY corian but high temp casting resin. As I’m about to embark on making my tails with OOA pre-preg to speed up my process.

Tim.

#3

Thanks! Straight from the horses mouth so to speak:D

I saw our use of a different epoxy with the ATH, great idea.

It seems that things have been working out fine with it.

Please let me know how things go with the higher Tg resin.

I’m also curious if the cast molds are strong enough not to split under force from inside by an use of a silicone intensfier to increase laminate compaction?

#4

I doubt you would have any problems using a silicon intensifier. My PU. Foam cores are strong at so where around 600psi compressive strength and Are the same size as the tail moulds ( not undersize). So I get a lot of compaction and I use threaded rod and steel box type clamps across the mould. I put a lot of hurt on them and no moulds have failed.
The only problem I get is print through of fabric onto the mould tooling surface from the very high compression. Just goes to show the forces at play between laminate and carbon fabric.

Tim

#5

Great insight thanks.

Any way to remedy the print through you think? I imagine that it is the limitation of having a “solid cast mold” with potentially lower hardness and Tg than what is asked of it under pressure and heat.

#6

Yes

I think it’s just a combination of softish tooling coat and post curing at 50’C.
The epoxy tooling coat i used is probably a little soft as it has a shore D of 78. It was just what I had at the time.
Next moulds , the tooling coat will be around shore D of 90 , it’s hard to scratch with a screw driver :D. And will be able to handle 120’C. So I’m sure it will be fine.

Tim

#7

Great! Keep posted on the progress!