Improvements in Static Mixing

[ArgoMix]

Hi!

 

I'm researching disposable static mixers at the University of Wisconsin-Madison. I was wondering where a mixer with a reduced L/D ratio would be the most useful. Currently, the research is in disposable mixing components such as those used in 2 part resins, epoxies and polyurethanes. These mixtures are then used in construction, marine, and automotive manufacturing applications. Where would a shorter mixer (that reduces product waste) be the most beneficial? In what application within these industries? Where else might I look for an answer to this?

 

Thanks a ton!

 

Brian

Edited July 23, 2015 by ArgoMix

[studiot]

I'm not sure I follow the importance of L/D ratio

 

Is this length to depth?

 

Please expand a bit.

 

[ArgoMix]

Sure thing! The L/D ratio is the ratio of a mixer's length (L) to the diameter of the pipe it's set in (D). The idea being that if you can reduce the L/D in one application, you're effectively decreasing the overall length of necessary piping. This, in turn, reduces the amount of waste of whatever you are mixing that would be stuck in the mixing segment after it has been dispensed.

 

Does that help?

[Enthalpy]

It would be most useful in none of the cited construction, marine and manufacturing applications, but for the one-shot users. They waste product in the mixer and get exhausted by hand-pumping the components through the mixer. We had some such mixers at an engineering subcontractor company where we produced in single unit amounts, and mixers requiring less pressure would have been very useful.

[ArgoMix]

What application was that in? What were you mixing? How many mixers/times a day did you have to do this?

[Enthalpy]

Epoxy, used occasionally as a glue and bought from the tinkerer's supermarket (where professionals buy too here). So the epoxy's and mixer's manufacturers make money over many supermarket customers.

 

Though, every users thinks first of these mixers that the paste is very hard to flow through and the mixers retain much or the components which are hard to clean, so an improvement on the pressure and on the dead volume would be very welcome. Do write it on the package, because users are repelled by the known drawbacks and prefer to mix by other means because of this.

[ArgoMix]

Are people using these for hours/day? I understand that the mixing is difficult to perform, but I can't imagine even a professional going through more than 5 tubes/mixers in a single day.

[Enthalpy]

Several hours would be just impossible. Someone having already used such a mixer for epoxy glue thinks "unuseable" when he sees it again, and decides either to buy a different product or to mix it with a bit of wood.

 

That's why I say, if you improve it, write it BIG on the package.

[Sensei]

Somebody tried to cover mixer by teflon to see how it works? It's widely used as non-sticking surface in other areas.

Edited August 8, 2015 by Sensei

[npts2020]

Teflon may work as suggested by Sensei but it might be impossible to reuse much of the equipment some resins and epoxies are mixed in. The best solution might be to have a disposable tip and design the applicator to mix components at the tip as they are being pumped out, thereby keeping them from hardening in the equipment being used. It will be interesting to see what you finally come up with.