Resin calculation query

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#1

Hi. This is probably a stupid question but here goes.

Say im doing an infusion, with lower and upper tooling. The cavity between them is fixed and i have a fabric preform in this cavity. I want the Vf to be 60% so i will need to inject 40% resin by volume. When calculating the qty of resin i know the volume of the cavity, the volume of the fabric based on its weight and fibre density. To calculate the amount of resin should i use the uncured density which is its density when i am filling the void or use the cured density?

#2

if the cavity is fixed, then it would not matter. You pump resin into the mold and wait till it comes out the vent. You can not control the FVF of that. Now, if the mold halves were PRESSED, and you are using the fabric to control thickness, then you might be able to control the FVF a bit more. I think?

But, I work with the density of the cured resin no matter what.

#3

sorry i explained that wrongly. Its actually a toughened flexible bag on top of an alloy plate. theres a cavity built into the bag. resin is injected and the flexibility of the bag allows the resin to flow over surface. pressure is then put on the bag to force it down. thickness is very much dependent on the qty of resin injected. been doing calcs for well over a year, but seem to be going slightly wrong somewhere. the qty of resin in the racetrack is very difficult to calculate correctly. there are so many other variables which make the calcs difficult as well, was just wondering if i could be going wrong with the density of resin. i have been using the cured density