Have you heard about Boeing patented CAPRI infusion process? CAPRI means Controlled Atmospheric Pressure Resin Infusion. The point is in using of secondary vacuum pump for lowering pressure at the resin feed pot. In normal resin infusion pressure acting on resin is 1 atmosphere. So one atmosphere is forcing resin into the feed lines and whole part. If the resin under 1 atm pressure is inside laminate, there is an equilibrium of outside pressure and inside pressure so there is no pressure that compact the laminate. If you lower resin pot pressure to, for example 0,5 atm, than when resin is in the laminate the outside pressure of 0,5 atm is forcing plyes to the mould surface… Of course this will cause slower resin flow etc.
If Im correct, secondary pump is not needed if you have resin pot far bellow mould. The feed line vertical length can be easily calculated, so 0,5atm (for example) pressure will be needed just to ,pump, resin up to higher mould level…
In a fact, vacuum on resin pot can also have benefit of degassing of mixed resin…
Would there be significant difference for most applications, by continuing vacuum and clamping of resin inlet once infused, or nearly infused?
Maybe they name the process after my Mercury Capri 2 racer…
I haven’t the patience to set all that up, and wait longer for the laminate to infuse.
cool idea though.
If you try to make high performance structural parts you need that patience 
But I really think it can be done without secondary vacuum pump just with vertically long tubing…
this method must be used because of the large size of the parts…
How do you mean it? This method is worse for large parts because of slower infusion speed. It is used because better resin/fiber ratio can be achieved (comparable to autoclave prepreg).
Whilst I don’t fully understand CARPI yet, let’s say you are trying to acheive some sort of resin pressure to infuse faster by having the bucket above thepart yes? Wouldn’t the resin pressure change decreasingly, as less resin is in the bucket? Got 10lbs of resin in the bucket, and 2 in the tube. Once it’s half way done, you only have that 5lbs of resin putting on pressure? Once your bucket is done, you only have 2lbs of resin force.
or something like that.
Wait…is that circled “pump” a vacuum pump, or air compressor?
Its a vacuum pump. So you lower the pressure acting on resin from 1 atmosphere (standard infusion - resin pot on free air) to for example 0,5 atmosphere. Whole resin infusion will be slower because there is only 0,5 atm gradient between inner vacuum and resin ,surface, in the pot (in standard infusion gradient is 1atm).
My idea was to use long tubing with resin pot far below part, so the resin must flow long path vertically and than it will reach part. Pressure in the feed line on mold level will be reduced by rogh.
BUT I calculated what vertical length of tube will be needed to reduce pressure to 0,5atm and the result for my epoxy resin is 5m long vertical tubing LOL Thats BIT unpractical…
huh. Guess it makes sense.
or just use membrane
I sense Mikey is trying to avoid using an autoclave:D
compression mold man!
I just want to make composites at the highest possible quality with infusion technologies… and my holy grail is to make infused monocoque carbon frame
Seems as though with resin supply under pressure, feeding part that the vacume applied on part might be greater than actual guage readings. If the guage relates to atmosephere/vacume not vacume/ pressure. Am I following correctly?
Very cool system.
Now, would this also have the effect of de-gassing the epoxy before it’s infused? I’m sure Boeing already mixes the stuff very gas-free, and probably already has an additional degassing process of their own, but to my eye, this should pull any trapped air out of the epoxy, or at least encourage it to go away.
I would guessit would degass the epoxy as long as the resin feed line is clamped off and you let the vacuum pump run for a few minutes.
Also mix your resin with a round stick when possible; less bubbles.