Infusion Resin's

[Guest]

Does anyone know of good resins that are available in NZ for infusion. I'm sick of wetting out, wana give infusion a shot. The nuplex resin I use at the moment is too viscous, I'm thinking international might be a good choice. Any experiences with different resins would be good.

[Guest]

Adhesive Technologies ADR resins

[chic014 0]

ADR246 or Prime 20 from high mod.

 

Infusion is great when you know exactly what you're doing but otherwise it can be a disaster.

 

Some key points:

 

Leak check is critical. Suitable leak rate depends on size but around 2mbar in 10 minutes is usually good. Use a digital gauge.

Make the distribution media end slightly shorter than the part, so the resin is forced to wet out the corners rather than racetracking to the vent.

Have a gap of around 50mm of peel ply between the end of the part and the vacuum line, this ensures complete wetout of the part if there is spatial variation in the permeability of the reinforcement, as the leading resin flow front will slow down when it hits the peel ply allowing the other parts to catch up before the vent is blocked.

Degass if you can, as this makes any lockout areas you may get not as voidy.

 

Lots of other things as well. Feel free to ask.

 

I'd recommended getting a sheet of window glass and making up some flat panels before you start on more complex geometry.

[Guest]

Cheers for the info. The ADR stuff looks good. Any ideas on price. I usually buy 4L at a time. And do you think I will have to post cure? I can go to about 40-50 degrees but not really any higher with my current set up.

 

Yeh I'll definitely have a play with some flat panels first. Having flat plate lying around the garage is always handy anyway.

[Guest]

Definitely post cure around 60 deg for 12 hours.

[chic014 0]

Yea most post cure is around 65deg for 7 hours.

 

Although if you can only get 40-50 deg that will get you to about 80% cure which will be all right for ambient temperature use. Not getting to 100% cure will mean your Tg will be lower but still sufficient.

 

If you're postcuring off the mould make sure you ramp the temperature slowly so that the Tg always stays above the cure temperature so the part doesn't distort. Around 1 deg per min should be OK.Don't put the part into hot oven if you're post curing off the mould.

[Guest]

Ok so they really need cooking to get the glass temp up, and if its a bit lower then it wont handle high temps. Do you tend to post cure under vacuum?

This is really helpful stuff.

Have you ever tried infusion with different resins and struck problems with them?

[chic014 0]

Yea post curing primarily helps bring up the glass transition temperature, although it does help to improve the ambient temperature mechanical properties also, so if you can do it I would even for ambient temp use.

 

There are some cases where boat's built in NZ weren't postcured, then went to the islands and started to become floppy.

 

You can post cure under vacuum but isn't really necessary. Do it on the mould though if you can for reasons I mentioned previously.

 

I've used ADR246 a bit and Prime 20 from High Mod extensively, including a lot of cure kinetics and rheology characterisation.

 

Generally speaking, you want a hardener fast enough that allows the laminate to cure enough so that you can demould it after 24 hours or so at ambient conditions(if you're not postcuring on the mould), but slow enough that you can mix it, degass it, infuse the part and allow for the thicknesses to settle out once you close the inlet(an invisible but important part of the process) before it gels. We use Prime 20 with a 90:10 mix of slow:fast hardeners and that seems suitable for NZ conditions. Generally speaking a temperature rise of 5DegC doubles the reaction rate, but halves the viscosity so things flow faster initially, but the viscosity increases at a faster rate.

[Guest]

Hey JuniorDave,

Give me a call when you are ready and we can jack you up some Prime 20 infusion resin in 4ltrs if thats what size you need. Can sort you data sheets and any other infusion additional materials you may need.

021676936 or call the SP High Modulus office at 09 4156262

[Guest]

Cheers Grape, that would be great. I was a bit worried I wouldn't be able to get something that small. Takes me a year or so to work through 4L, so theres no point in me getting anymore. I've had a look through the data sheets on the website, they're very informative.

To me, making composite parts is a bit of a hobby, but I still want to be able to make them as high tech and strong as possible, so I'm looking forward to the challenge of trying to master infusion.

 

It will probably be after winter when I get round to buying some more stuff, especially because its pretty hard for me to cure things down here in the winter.

[Kiteroa 8]

Resin confusion?

 

It's a good process for training, mainly cause you end up doing the job twice. But it's good for complying with emission standards, which was why the process was invented.