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Emulsion
12-29-2007, 09:46 PM
Dark Orange,

Thanks for your posts.

I'm sure everyone would be very interested to see the emulsion making equipment. If you get a chance to take some photos that would be great!

Any extra info is always appreciated!

Thanks from,

Emulsion.

Dark Orange
12-30-2007, 01:18 AM
Also, the comments about kodachrome were intriguing.

He asked me to somehow slip the info that he has perfected the method of developing kodachrome and he now has consistently perfect results - but that is for another thread if I manage to get him into here. ;)


Also, he does not have a current supplier for the film base. The stuff he uses he has had in his cupboard for many many years, and he cannot get any more. That is the obvious reason the machine is set up for a 5" web.

richard ide
12-30-2007, 01:42 AM
You should be able to buy 40" rolls of triacetate from a graphic arts supplier, It was a reasonable price when I was buying it 7 years ago. The slitting is an easy job.

Photo Engineer
12-30-2007, 09:14 AM
Developing Kodachrome is 'merely' following the published patent. ;) Coating it is another matter.

Support can be purchased from the Photographers Formulary, but IDK if they can supply it in the size you want. I have 1 roll of Kodak support given me by a friend who just happened to have a roll at home. I believe it is 100 ft x 5". I would have to check.

It would be a shame if projects like this fail due to lack of the film support or some such detail. I keep running into problems like this involving chemical supplies. The support problem looms on the horizon for me too.

PE

rmazzullo
12-30-2007, 02:06 PM
PE,

If clear polyester has been modified to accept toner (copier or laser printer) would this imply that it could accept an emuslion coat? Or, does this just mean that it would accept a subbing coat more readily than bare polyester?

Thanks,

Bob M.

Photo Engineer
12-30-2007, 02:12 PM
Bob;

Each material must be tested and evaluated. Some work and some do not.

PE

Steve Smith
12-30-2007, 03:20 PM
Polyester is also available with surface coatings and/or treatments to make them more receptive to ink coating (screen printing). It is possible that some of these would be suitable but they would have to be tested first.

We get most of our polyester from Autotype: http://www.macdermidautotype.com/autotype.nsf/webcategorieseurope/Industrial

This page shows a range of surface coatings for various applications. We purchase it through another company who either slit it to the widths we require or (more often) sheet it out to our required size.


Steve.

Photo Engineer
12-30-2007, 03:26 PM
Here is the best I can do for you:

Here are the problems that must be checked for.

1. Adhesion to the support during processing.
2. Effect on silver halide itself
3. Coatability with your selected method
4. Absorption of dyes
5. Absorption and reaction with process chemistry

I have one support that accepts a coating fine but is almost impossible to coat without having defects. Another coats fine, and processes fine, but due to the inkjet chemistry it turns brown within 24 hours. One absorbs all dyes and stays colored despite processing and so you end up with a colored image with a high dmin if any dyes are present. Some are just fine until they hit the developer/stop/fix/wash (you pick the solution) and then they either bubble up, slide off or reticulate.

PE

Dark Orange
12-30-2007, 09:29 PM
Talking of Printers, they use inkjet printers to print just about anything these days. I suppose it would be technically possible to design a printer head to handle a particular emulsion, and print it directly to the base.

You could design it to fit into a commonly available printer and you'd then just need some drivers written.

Are there any obvious reasons it wouldn't work?

Photo Engineer
12-30-2007, 09:33 PM
There is someone here who says he has done something like this.

PE

David A. Goldfarb
12-30-2007, 09:49 PM
If it's a gelatin based emulsion, you've got to keep it warm and then flush it out of the system before it sets. I think an inkjet printer is going to be too slow to do it without clogging.

AgX
12-31-2007, 12:18 AM
Yes, I remember reading about that inkjet-coating here too, but wasn't it about coating paper?

Anyway, reading in that Agfa coating head patent about the precision such a slit must have, and keeping in mind what PE is saying on coating precision, I doubt wether inkjet printing would gain sufficient eveness of the layer.

Emulsion
12-31-2007, 03:14 AM
A coating machine can of course use a trough coater. This is far less complex and therefore easier to construct. Baker describes a lab scale machine with a trough coater.

Trough coating is still used by some of the "boutique" film makers. It may be low tech but it works.

AgX
12-31-2007, 07:44 AM
In the literature Wofgang Schneider, the main person behind the early Agfacolor-type of films, a DIY-guy, is quoted to have built a coating machine in the late fourties in his private handicraft cellar which he could take under his arm…
...up to his R&D lab.

Photo Engineer
12-31-2007, 09:01 AM
Jim Browning has built a trough coater and a plate coater. I have used both of his coating machines and they work perfectly. In fact, I coated about 40 ft of cyanotype on paper with his trough coater. I let the paper air dry.

See the pictures and specifications on his web site.

PE

dyetransfer
12-31-2007, 01:35 PM
Jim Browning has built a trough coater and a plate coater. I have used both of his coating machines and they work perfectly. In fact, I coated about 40 ft of cyanotype on paper with his trough coater. I let the paper air dry.

See the pictures and specifications on his web site.

PE


See my site: www.dyetransfer.org . THere is a .pdf file there which has pictures of a simple trough coater assembled in a lucite box. It has 3 rollers which are made from aluminum,turned accurately, and plated with nickel. One is for supply, and has an adjustable slip clutch, and a hand crank. The film/paper is wound on the supply roller (with the clutch loosened), down under the coating roller, and up to an outfeed roller. The slip clutch is then tightened so that the film/paper will be held tightly to the coater roller to prevent emulsion from reaching the back as you pull the film out of the box.

The film/paper makes a 90 degree turn around the outfeed roller and exits the box. You pour emulsion into the 'trough' under the coater roller via a funnel on the side of the box, and then start pulling by hand. It takes 2 people to run it, one to keep topping of the emulsion level, and one to pull the paper out of the box at a steady speed. It works suprisingly well. You can cut off long sheets and hang them up to dry, and keep on going until you either run out of emulsion, or substrate. Very simple, makes pretty good 20" wide coatings. You can get the proper Melinex 582 film from PF if you are coating film, or you can tape 20 x 24" baryta sheet together for coating paper, or better yet, get a roll 20" wide.

Possible improvements would be a debubbling system and a pump controlled by a level switch, which would allow one person to operate it. Also, you could attach a leader, and attach it to a motorized windup system. This way, you could regulate the draw speed. You would wind up the leader, and stop before winding up the emulsion coating. You would then cut the coated sheet off, and hang it up on a track overhead for drying, and then reattach the leader for the next strip. My thinking was to operate the coater inside the dryer. The coater would be on a counter long enough to hold the strip. There would be clips on pullys which would be lowered from above, and you would just hoist the film up and out of the way, and slide it over to make room for the next sheet. You could make large amounts of film quickly with this system, without haveing to dry the film prior to windup, as the strips would dry in the space above the coating counter, and would be out of the way.

Regards - Jim Browning

snowblind
01-21-2008, 07:31 PM
Certainly a magnificent piece of work but, though I'm not saying I could build one (without plans), I did always expect it wasn't beyond the capabilities of someone with the right background. After all, there are several large-scale versions working away out there. Emulsions would be the really interesting part in my opinion. Like okto, one of my biggest worries (photography-related worries, that is) is the idea of 35mm film being no longer available. However, I don't worry so much about the future of B/W since it is readily available from numerous manufacturers and relatively cheaply at that. So, anyone any ideas for a high-quality colour slide emulsion? Colour negative even? I'd also like EIR back!! My real worry is not so much that 35mm won't be available but that I'll be restricted to monochrome. Now, I also wonder if this machine could be adapted to coat reel-to-reel tape for those of us ill enough to take our analog obsession over to audio? ;-)

P.S. (O.T.) This is my 3rd attempt to post this reply as, every time I come to this site, I seem to have to keep logging in every 2 minutes -- anything I'm doing wrong there?

Photo Engineer
01-21-2008, 07:51 PM
With regard to EIR, if someone can get me 1 gram of the IR dye, I can make a respectable IR film. The problem is that you can't get the dye.

As for coating machines, they can be built by anyone with the knowledge and the money. I have one but not the other. Your guess as to which.

Color can be done. I will be aiming first at a dye bleach print material like Ilfocolor.

PE

okto
01-22-2008, 12:40 AM
This is an exciting time to be into film.

Stephen Frizza
01-22-2008, 02:11 AM
I am thrilled to know that in my neck of the woods such developments are occurring!