Hi Matt,

The data sheet for your IN2-Infusion Resin gives the following schedule of times@temperatures for post curing:

24hrs @ room temperature
6hrs @ 40C
6hrs @ 50C
12hrs @ 60C

The Maximum Tg (glass transition?) temperature for the IN2 Infusion Resin is given as 94C - 100C for the slow cure mix. Is this the maximum temperature that this resin can be post cured to or should it be post cured to a lower temp? Ideally I would like to post cure to as high a temperature as possible as the parts are structural and will be subject to intense solar heating at times.

Can you suggest a post curing time@temp schedule beyond the one given above (say to 80 - 100C)? I understand the temperature ramp-up rate can be critical to the finished part's strength.

I am using both 5mm and 10mm thick closed cell PVC foam core material in my laminates - what temperature can this foam board take before it starts to degrade - can it withstand the higher post curing temperatures?

Thanks,

Phil.

Hi Phil.

The post-cure schedule that you have specified will provide the maximum HDT (Heat Distortion Temperature), running the post-cure to higher temperatures will not increase this figure, however, it is possible to reduce to post-curing times. An Alternative Schedule:

24hrs @ Room temp.
4hrs @ 40 Deg C
4hrs @ 50 Deg C
4hrs @ 60 Deg C
4hrs @ 80 Deg C

With regard to the PVC foam, as long as there is not significant pressure being applied to the core during heating you should not encounter any problems taking the core though to 80 Deg C, much beyond this and the structure of the foam may begin to deform and degrade.

Paul Statham
Easy Composites / Carbon Mods - Technical

Thanks Paul.

Hi Paul,

A further question about post curing IN2 Infusion Resin parts - can post curing be carried out at any time (weeks to months) after initial curing or must the parts be post cured directly after the initial 24hrs of curing at 25degC is completed? The IN2 data sheet isn't clear about this - only that post curing must be carried out for parts that will see higher than ambient operating temperatures.

My project involves hundreds of medium to small parts and I would prefer to post cure them in batches (as many as will comfortably fit in the oven) instead of post curing each part individually as soon as it is cured.

Thanks,

Phil.

Hi Phil,

Although it is best to run the post-cure fairly soon after initial cure as the polymers will be more reactive, you can certainly run a post-cure later, you should have no problem doing them in batches; a few weeks shouldn't have any major impact on the effectiveness of the post-cure cycle.

Paul Statham
Easy Composites / Carbon Mods - Technical

Thanks Paul.

Phil.