Metering Pumps and Meter Mix Dispensing

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Good luck with your quest.

I think that.04 mL is an impossible requirement for any but the tiniest pump.

Like this: PAR 2-P - Metermix

Talk to the people who make dosing/metering pumps.

This is nothing new to them.

There's a big difference between a dispensing pump and a meter mix system, which implies the a catalyzed shot is dispensed.

Metering Pumps from Cole-Parmer - coleparmer.com‎

Oh, a penny dropped. So, if I attempt to use answer my own question: The valve has to have an automatic open and close. It will open when a metered pump squeezes out the fluid, and close when the pump is sucking in fluid from the fluid hopper. I think that is right.

I guess the point Lyn and I were trying to make is why build your own if you can buy one already manufactured?

Unless you are a manufacturer who wishes to get into this market, it's almost always more cost effective to buy a tool/equipment, than build your own (provided of course you can purchase a unit that meets your requirements).

The valve is pneumatically actuated.

Read this:

Metering pump - Wikipedia

Why?

You need to be talking to companies like these:-

http://www.metermix.co.uk/par_two-part-product.htm

http://www.nordson.com/en/divisions/efd

Hope this helps.

Look at pharmaceutical manufacturing equipment OEMs. Particularly, metering of liquid into vials or cartridges for injection devices, would be a similar application.

At my facility, we use very small gear pumps manufactured by Jetter for liquid dosing. In the past I have had very good results by dosing with progressive cavity pumps, though have not tried such small dosing. Seepex is a good manufacturer, but you'd have to check on dosing limits.

Nordson is excellent for adhesive dispensing as someone else recommended.

Thanks for the replies. The Meter Mix PAR 2P is a nice piece of kit, but no doubt pricey and beyond my budget. I've contacted Cole-Palmer, see what they advise. Rich

Did you mean 0.4mL to 1.6mL instead of 0.04mL to 1.6mL?

Miinimum a volume of 2mm x 2mm x 1mm; maximum 40mm x 40mm x 1mm. I think, 0.04mL and 1.6mL. The higher dosage shots can be achieved by repeat shots if need be.

This?:

If so, then it would seem there are ample ports on the valve to send parts A and B back where they came from before mixing them.

Do you have a cell phone? You should call them and chat for a spell.

Yes, that is a valve I have been looking at. I belivee you need a metered pump in the system, because it is simply an open/closed type of valve. I should check with the seller whether it could be used to dispense as low as 0.04 mL.

The type of valve you're looking at, is what you're going to need. But not sure it will be able to apply the lower volume. Typically the volume dispensed is done on a time basis i.e. time valve is open. The two parts of the glue are feed to the valve from two separate pressurised vessels. A metering pump is not necessary, as the metering is done by the pressure imparted onto the adhesive/hardener in the pressure vessels and, the amount of time the valve is open. This is pretty much a suck it and see application. You could feed the hardener and adhesive from two separate valves and, bring them together via some sort of manifold. This would give you better control over the mix %.

One thing has dawned upon me since I started the thread: For maximum precision, you would employ a metered valve. The material would be drawn into the valve and then dispensed direcftly, without passing through piping. This is the system with Meter Mix PAR 2P.

The issue you have to deal with, with small doses, is change of viscosity with heat, or simply change in viscosity between batches. And temperature can change from day to day, unless the ambient temperature can be kept stable. I see that a metered valve system or any positive displacemt system / volumetric system (such as a metered pump system) will tend, I think, to have the edge over time/pressure systems for small doses, if the viscosity changes to such a degree that the dosage varies outside limits.

If I had my druthers, I'd go for a metered valve systyem, or a metered pump system, but that may turn out to be too expensive for me, and if so, I must seriously consider the time/pressure systems. I think I know who to talk to. I'm in UK by the way.

One thing that's not been asked, how big are you expecting the production runs going to be?

I've been working on the notion, that it's large scale production runs. But if it's only small scale, you could probably employ the positive displacement syringe type, dispensing equipment. These are far more accurate, but the syringes will require changing on a regular basis.