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Low cost process automation for making emulsions

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That is analog! We are using digital to make analog materials not the reverse!!!!

If you need tubes, I have boxes of them that I saved! :smile:

PE
 
I can contribute some hefty aluminum heat sink. Use a 5 amp three pole DC voltage regulator as a constant current source for your estimated 2 amps. Can source it from a old PC power supply 12 vdc side. Let me know, have many electronic goodies boxed and waiting for interesting projects.
 
I think the idea is to use easily sourced parts - that's why I've ordered the parts to make an easily assembled adjustable voltage regulator good from 0v to about 30 v at up to 5 amps (depending on input power source) based on an LM338T regulator.
 
Lachlan, thanks, but these are tiny compared with the pot we need. Ours is about the size of a tennis ball.

PE
 
Probably Thursday for me. Nick only has W and Th free and I have Th free.

Heck of a way to pass messages. Lets use PM or E-mail. :wink:

Ron
 
Don't keep us in the dark! Please keep this very interesting conversation going.
 
Nick has a workshop this week so we will not be able to work until next week at the earliest.

That would be the week of the 20th.

PE
 
Well? Any news?
 
Nick has a workshop this week and has nothing new to report. I have not gone to GEH since last week and there was nothing new.

We plan on reviewing information in one week.

I will post anything new ASAP.

PE
 
I see that the GEH folks have been quite busy. Good for them!

PE, one question if I may: are you guys using pumps to add reactants into the kettle or to circulate/mix the emulsion during ripening? I suppose both is an option, too.

Jason
 
Jason, pumps were only and are only used for addition of the reactants to the kettle. The circulation is done by a mixer or stirrer. In the case of a stirrer, this is either a magnetic bar or a propeller (often mistakenly calleed a mixer). By a mixer, I mean a true mixer such as a shrouded turbine. Using a blender as suggested by some, entrains too much air and also cracks grains causing fog. Blenders are used to disperse color couplers or other chemicals in gelatin.

PE
 
Thanks Ron, that's what I was thinking. The reason for my question, though, is that back when FPP had the Ilford plant tour on their podcast, the fellow at Ilford was talking about a "6 inch circuit" in their kettle. (This was for the Delta films) Unfortunately we didn't get pictures or video of this facility but I was envisioning a 6 inch pipe loop through which emulsion was pumped and somehow mixed along the way for some reason.

I am sure you know much more about this than me, I am just going by things I have seen in patents. If you understand what he was describing please feel free to elaborate!

Anyhow, I was wondering if you guys at GEH were getting into those sort of processes, especially with Nick making the FB posting about GEH making all their own emulsions now.

-- Jason
 
Jason, Ilford and Agfa used a prop mixer at one time, with a small recirculating nucleator at the bottom of the kettle. This is akin to the Kodak process outlined in Wey and Whiteley. This patent shows a nucleator above the kettle and any of these 3 can be, in effect, a shrouded turbine in regards to the result on the emulsion. That result is to constrain the emulsion for a short period for nucleation and then violently expelling it into a more dlute environment.

As for Nick on FB, IDK what you are referring to. Our goal is to get a medium speed, fine grained, orthochromatic emulsion and to get a small pump setup for about $100 to allow for process control with minimal computer skills. The process control will allow more uniformity within a batch and from batch to batch and could allow for more advanced making if desired.

I have been working with Nick on simplifying a formula to gain higher speed with less lab work. Right now we are at ISO 12 - 25, blue sensitive only, but have had higher speed. We are working on the repeatability.

Oh, and regarding mixers, it is quite definite that mixer (or stirrer) design and use must vary from the 100 ml make to the 1000 ml make! The speed must often be adjusted as well. There is a model for that, but only for the shrouded turbine (AFAIK).

PE
 
About the nucleation, I have seen the Kodak work you mention. So that is probably what the Ilford fellow was talking about.

In my current favorite, the second part of the silver is run in over a period of 30 minutes. To make this easier I picked up a used hospital IV syringe pump for a few bucks that can be adjusted in 2 minute increments. This runs the silver at a constant rate, of course. Pumps like you are using would allow the rates to be ramped up or down, right?

As far as Nick's posting, Nick showed a stack of boxes of 4x5 sheet films in an FB posting and said they were going to sell it off for $250 because they were now making their own emulsions and didn't need it any longer.
 
IDK about Nick's post. I will have to ask him as I don't follow FB.

As for making, the pumps we are using can be ramped up and down. I have used larger pumps to ramp over 3 hours and I hope to test these over the same time period. But I hope you realize that we are talking about older 15' to 1 hour makes versus modern 1 hour to 5 hour makes. These separate the men from the boys so to speak and also separate slow from fast speed and those who like to move into modern making from the older makes of the 20s to 50s.

They all have merit, but chacun a sa metier! Or more to the point chacun a sa gout! ( I hope I got that French right, my ancestors would be horrified with me! )

PE
 
All, I think we've found our barn. It's been sitting under our noses the whole time, and it's GEH. Not only that, but we don't have to chain PE there as he's working there willingly, and he has others working with him too! :laugh: And they're even developing equipment to do the job.

Joking aside, this is great that we've got PE and others working on ways to make emulsion making easier for those who wish to pursue it on a small scale. Long live PE, Nick, Mark, and all those others doing research on emulsion making at GEH.

I'm guessing you guys chose the Arduino for its inexpensiveness, and also because it probably suits your needs a bit better than the Raspberry Pi? I've got one of the Raspberry Pi model B's, and it's a nice set-up (I use it for a file and media server), but I'm guessing it's probably overkill as a pump controller. Not to mention, the display (a computer monitor) puts out way too much light to be hanging around a light-sensitive emulsion.
 
We may end up without a mini controller. We may just go with variable resistors. As for the Pi it has a proprietary bus and not many cards. The Arduino has a whole series of motor controllers, and if that is not enough, the PCduino 3 is compatible with the Arduino and can multitask. The Edison is not bad either but a bit pricey. It too is compatible with the Arduino bus.

I've got a 4 line LCD display sitting next to me that can do a good job in the dark (with safe flashlight I suppose) and I have a TFT up and running.

Between Mark, Nick, Fred and myself, we are moving forward within the constraints of their budget and workshop schedule.

PE
 
I really like the idea of variable resistors. Less to go wrong, and easier to trouble-shoot if something does. I'm capable with computers and FOSS, but resistors seem more robust and less complex.
 
Too much fooling with computers all day long. Resistors and pots are great!

-- Jason
 
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