As with many post-cure cycles for resins, the post-cure cycle for our EL2 and IN2 Epoxy Resins is not too sensitive and a range of different post-cure cycles will produce good results, specifically improved mechanical performance and elevated HDT/operating temperature. Post-curing parts that will be used at or exposed to elevated operating temperatures (such as vehicle bonnets/hoods in direct sunlight, engine-bay parts, car interior parts etc.) is strongly recommended to prevent distortion of the parts when they are put into service and experience these higher temperatures.
Where possible, parts should be post-cured still inside the mould to reduce distortion and improve surface finish (i.e. reduce 'print-through'). When post-curing parts in the mould, it is important to post-cure them without demoulding at all (i.e. don’t demould and then put them back into the mould) otherwise you can get some strange patterns on the surface where some areas are post cured in direct contact with the mould surface and others are not.
A simple and very effective post-cure cycle with the IN2 Infusion Resin (or EL2 Epoxy Laminating Resin) is as follows:
CYCLE #1 SUITABLE FOR MOST SITUATIONS
- 24hrs at room temperature
- 6hrs at 60°C
If you’re encountering any surface finish issues (faint print-through) then you can experiment with a slower 'ramp rate' which sometimes improves things:
CYCLE #2 SUGGESTED FOR SUBTLE IMPROVEMENTS TO SURFACE FINISH
- 24hrs at room temperature
- 2hrs at 40°C
- 2hrs at 50°C
- 5hrs at 60°C
If you need to push the HDT of the finished part higher then you could increase post-cure up to a maximum of 80°C as follows:
CYCLE #3 SUGGESTED FOR HIGHEST POSSIBLE HDT/OPERATING TEMPERATURE
- 24hrs at room temperature
- 2hrs at 40°C
- 2hrs at 50°C
- 2hrs at 60°C
- 2hrs at 70°C
- 4hrs at 80°C
These are all just suggestions. Most situations just call for option #1; 6hrs at 60°C. Many customers also find that they can dispense with the 24hrs cure at ambient and simply load newly infused parts into the oven to begin the cure however this is something that you would need to experiment with yourself. A cure at ambient temperature before post-cure is generally favoured with most resin systems.