Film coating machine (homemade) on Flickr

Photo Engineer · Dec 25, 2007

Yes, that is where the vacuum goes. It then allows a bead to form which helps to damp out chatter. It is shown in the EK patents that I have mentioned in another thread. There I've listed several patents on emulsions and coating.

PE

ben-s · Dec 25, 2007

PE;
I noticed something on this photo:
http://www.flickr.com/photo_zoom.gne?id=2043299804&context=set-72157603226919391&size=o
When I saw it, I wondered whether the perspex box under the front of the head and roller was for vacuum. There seems to be a hose running to it...

Dark Orange · Dec 25, 2007

Thanks for the interest. The only vacuum is for the splicing table, there is only the one tensioner, and the hose running from the coating head in the photo is a drain from the waste collection tray.

I will enquire about emulsion recipes, but I would guess that at this stage he is brewing a pretty standard analog of the commercial products. The final product is ISO 100, by the way.

One thing I forgot to take some photos of is his emulsion preparation equipment and tools. His reaction chambers especially look impressive.

I can't quite work out where the web goes after the tensioner.

It's difficult to get a whole photo now, but I'll see what I can whip up. In this case, the web goes straight across to the rollers on the left. All the extra rollers are there to aid the threading of the machine, but aren't used when coating.

PHOTOTONE · Dec 25, 2007

So, in this particular coating operation, does the fellow run the raw stock thru several times to build up a final product? Or is it one-pass, one coat?
You mentioned earlier that the base stock was spliced into a loop?

Dark Orange · Dec 25, 2007

Yes, the layers are added sequentially. The stock is threaded through the machine and spliced into a loop. The emulsion is added and primed and the 14m loop is coated with a single layer. At this point, either a new emulsion is plumbed into the system and a second coat applied, or the coated stock can be removed and stored and fresh stock run into the machine.

AgX · Dec 25, 2007

I still don't understand the idea of slicing the base/film into a loop.

You save on additional base for threading (for which you could use special leader tape to be reused if economical advantageous). But at the same your coating is limited to a fixed length (less than 14m due to loss until the coating runs stable).

Or am I again slow on the uptake?

Emulsion · Dec 25, 2007

Photo Engineer said:
Excellent work.

I might mention that this is a small scale version of a 12" coater at Kodak that was called P3. It resembles it even to the arched chill cabinet.

PE

PE,
Is it possible to obtain some photographs of the P3? Any manuals etc for the the P3 would also be of great interest! It seems that Kodak factories around the world are being destroyed at a rapid pace and all this information will be destroyed with them. (I have heard of Kodak plants in Australia, Canada and the US that are now demolished).

Is there a Kodak PR or Archives manager that might be helpful in preserving this technology?

Emulsion.

Photo Engineer · Dec 25, 2007

ben-s said:
PE;
I noticed something on this photo:
http://www.flickr.com/photo_zoom.gne?id=2043299804&context=set-72157603226919391&size=o
When I saw it, I wondered whether the perspex box under the front of the head and roller was for vacuum. There seems to be a hose running to it...

Ben;

That is the correct design for the vacuum attachment, but I didn't see any hose running to it, nor did I see any catch basin for underflow (or overflow, whatever....) as you tune the flow/vacuum combination. So I discounted it as being an in-use vacuum system. IDK.

PE

Photo Engineer · Dec 25, 2007

AgX said:
I still don't understand the idea of slicing the base/film into a loop.

You save on additional base for threading (for which you could use special leader tape to be reused if economical advantageous). But at the same your coating is limited to a fixed length (less than 14m due to loss until the coating runs stable).

Or am I again slow on the uptake?

This same loop method was used by Agfa in their experimental Geissmachin for research in which a continouous loop was used for making short lengths of coating with several layers.

PE

Photo Engineer · Dec 25, 2007

Emulsion said:
PE,
Is it possible to obtain some photographs of the P3? Any manuals etc for the the P3 would also be of great interest! It seems that Kodak factories around the world are being destroyed at a rapid pace and all this information will be destroyed with them. (I have heard of Kodak plants in Australia, Canada and the US that are now demolished).

Is there a Kodak PR or Archives manager that might be helpful in preserving this technology?

Emulsion.

AAMOF, the P3 machine looked (<- note past tense) much like what we see depicted here, but it was wider and had a front end bombardment setup for electrostatic bombardment of film and paper. It also had a takeup roller instead of a continuous loop.

There were other differences such as it having a different drying (hot) cabinet, but I'm not sure of the details now.

I only used this for prebombardment of support and my friends only used it for making single layer coatings for tests, so it is quite hazy in my mind. The only thing that stands out is the arched chill cabinet which was a design feature of the P3.

George Eastman House and RIT both have coating machines that are currently not on display but rather in storage.

PE

Dark Orange · Dec 26, 2007

I still don't understand the idea of slicing the base/film into a loop.

I assume it is because this is not a volume production operation, but an experimental coating machine. Having it in a loop allows for easy recoating for multiple layers, and 14m is more than enough to test the emulsion.

I'll confirm that however.

Photo Engineer · Dec 26, 2007

When coating film, it is not a good practice to roll it up before you put on an overcoat. The process of rolling it up can introduce scuffs and other abrasions including small fog spots where the emulsion is rubbed. This machine avoids that problem by having a continuous piece of film that can be doublecoated in one operation.

PE

rmazzullo · Dec 26, 2007

PE,

What components are in an overcoat? How is this different than adding hardeners, etc to the emulsion / coating formula itself?

Is an overcoat a customary (or preferred) step in film / paper making, even on a small scale?

Thanks,

Bob M.

Photo Engineer · Dec 26, 2007

Bob;

An overcoat is only needed if the film is rolled up on a takeup spool.

It can consist of anything you want to add such as antifoggants, hardeners, matting agents, antistatic agents, tints, dyes.... Well, you get the picture.

Generally, I coated an overcoat even at a small scale, but if we didn't mind the scuff marks and blemishes we just made one pass. Typically, Kodak machines could coat 2 layers with 2 hoppers and a takeup spool. The machine was T shaped with a hopper at each end of the - bar at the top and drying between. Then the film or paper looped down to the long | bar of the T and was wound up.

This is not true of the slide hopper machines or the very tiny machines. P3 was an example of the single ended machine such as in the post above, but there was no loop. The coating was rolled up at the end of the machine.

PE

rmazzullo · Dec 26, 2007

dark orange,

Can you shed some light on how the bubble trap is supposed to work? Do you know the order in which the bubble trap / inline filter / zenith pump are connected, and if there are more than one filter and trap placed in the emulsion 'plumbing'?

Thanks,

Bob M.

Dark Orange · Dec 26, 2007

There have been a couple of questions off-list that I will address here in the public area along with the other questions.

By the looks of things, many here may not be familiar with the workings of my image hosting site. I link to the image pages rather than the images themselves, which means you can get larger images by clicking on the little magnifying glass above the image and choosing the image size you want. This allows finer details (if any) to be read.

On my next visit, I shall attempt to document the emulsion manufacturing technique and equipment involved. While the builder has a top quality lab built for the task, with all the flasks and glass tubes and stuff, he is building special reaction chambers that sounds like it would be of interest to many of the posters and lurkers here. I'll put it in a new thread obviously.

I am not sure the bubble-trap and filter have actually been used yet. As for the bubble-trap, it is a simple chamber - emulsion/bubbles flow in, bubbles rise in the chamber, emulsion flows out. The screw in the top allows release of the air if too much accumulates. I'll make the assumption that they would go between the pump and the coating head, but shall get confirmation on that.

Finally, I wish to take this moment to thank Photo Engineer for filling in the details that I do not know. He is definately an asset to this forum.

PS. Did nobody notice the Kodachrome statement I made earlier?

Photo Engineer · Dec 26, 2007

I read it, and I know the problems having worked on it a very little bit.

PE

Dark Orange · Dec 26, 2007

All problems are surmountable if you try hard enough.

tim_walls · Dec 26, 2007

Dark Orange said:
PS. Did nobody notice the Kodachrome statement I made earlier?

I read it, and cool though it sounds, I must confess I sort of wondered "why?"

I mean, making your own reversal process sounds very cool, but why would you base it on Kodachrome style technology other than, say, E6? Kodachrome seems colossally complicated.

Or is a Kodachrome type emulsion actually easier to homebrew?

If it's some particular image characteristic of Kodachrome you were after (e.g. colour balance say,) is there no way of trying to reproduce that characteristic but using an E6 type approach?

Of course, I accept as a perfectly valid answer to the "why?" question "because he can." That's the best reason going as far as I'm concerned

Dark Orange · Dec 26, 2007

Of course, I accept as a perfectly valid answer to the "why?" question "because he can." That's the best reason going as far as I'm concerned

That's the whole reason behind the existance of this forum, innit?

PHOTOTONE · Dec 26, 2007

I don't think KODACHROME as an emulsion would be considered more difficult than E-6 emulsions to "make", rather the difficulty is in the processing, and the many more tightly controlled steps needed to successfully process it. Isn't Kodachrome actually three b/w emulsions (with carefully controlled characteristics) with filter layers in-between?

dmr · Dec 26, 2007

Dark Orange said:
PS. Did nobody notice the Kodachrome statement I made earlier?

Yes, I did.

Although I will probably never coat film (my times in a wet darkroom can be counted easily on your fingers) I find threads like this fascinating.

What impresses me is that while many attempts to coat film or paper seem to result in so-so quality at best, this magic machine seems to be at least an attempt to get a reasonable degree of quality and consistency.

Even before you mentioned Kodachrome, when I saw the remarks about different layers being coated, I thought "Color, maybe?"

What impressed me most about this thread and this magic machine is that maybe a few companies whose business is dwindling don't have the strangle-hold on film use that we think they have!

Photo Engineer · Dec 26, 2007

Kodachrome will require at least 9 emulsions and 6 layers to be coated. It will need either rem-jet on the back or AH under the emulsion layers. It is not a trivial task and will have to be built in groups of layers to get it right.

Good luck.

PE

Gatsby1923 · Dec 26, 2007

WOW I love this thread! I have been following it from day one. I almost want to build my own. I don’t have the know how but still this is a fun thread.

Dave M

Photo Engineer · Dec 26, 2007

Hey, I would park my car in the driveway and put this in the garage just to have one. But, since I cannot, I'm doing the best to do it in a way that everyone can use.

But I sure do miss the coating machines. Quality is so much better.

PE

Film coating machine (homemade) on Flickr

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