Pipe requirements for ratio application

[TravPump]

Its been a while since I had to do any fluid applications designing or calculation and I am struggling to remember some of the basics.

I am looking to apply a resin and hardener to a surface, from different outlet ports of differing sizes (prefer to bead the hardener ontop of the resin). I know my mixing ratio required and my expected flow rate required, but if i am pumping one fluid at 1/4 inch diameter and another at 1 inch diameter, each at their correct flow rates by ratio, would i also need the outlet sizes to be the same? Or would they also need to be sized in ratio with the application requirements?

I hope this is clear. If not let me know.

 

[LittleInch]

Resins are not the easiest of substances to deal with as they are viscous and sometimes no newtonian.

All depends on how the resin is being pumped.

My best idea would be that you would be using some sort of PD pump so that you control the flow rate and hence mixing ratio that way. Then the size of the nozle is more about how you control the two "streams"

I thought you needed to mix the two together? Not just lay two beads down?
This must be some sort of proprietary mixing gun already developed?

A diagram always helps. There are a couple of people here who are very experience din resins and polymers, but you might get better luck in the chemical process forum.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[TravPump]

Thanks LittleInch,

Seen you on a few of these threads and seems like you are usually the go to person.

The resin and hardener have relatively low viscosities, +-400cps for the hardener, still waiting on the datasheet for the resin. I am planning on using a diaphragm pump for the resin, and a dosing pump for the hardener, my mix ratio is 170:12 by weight.

Although I originally wanted to go with mixing in the applicator, or even simpler, mixing in a drum and then just dispensing from there, the supplier of the resin and hardener has said they have had succesful testing of beading the hardener onto the resin, and they would prefer if we attempted this as it means cleanup after application is easier since you wont have product hardening all through the applicators piping.

Mixing guns are not really an option as this is for a large surface area application, and most of those that I could find would be using a spray type application for large areas.

I have included an image of the resin dispenser that was developed (or at least half of it, this is an open view, it would get a top half as well), and the hardener dispenser would look similar to this and typically just be placed right above the resin applicator and pour directly onto the resin beads. But if the hardener applicator has the same size outlets, and runs at a different flow rate, would that not just apply a non-uniform bead on top? My brain doesnt seem to want to reconcile this.

 

[LittleInch]

I know when I don't know... Compositepro is much better than me at this sort of stuff.

But if it was me I would want the two to be coming out at the same actual velocity. So work out the volume per second from your flows and then based on one orifice or opening size, size the other so that the two beads come out at the same speed. Maybe it doesn't make any difference, but wouldn't hurt to try.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[TravPump]

Thanks LittleInch,

Hopefully Compositepro is looking out for new threads and sees this one. Will give that a try first and see what I can figure out.