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Photo Engineer
10-13-2007, 09:14 PM
Festooning went out in the 50s or earlier.

The two items above are obsolete.

Coating hoppers are extrusion, slide or curtain. Coating uses a chill cabinet and a series of heating/drying cabinents that condition the film or paper to the proper final conditions. Festooning causes coating defects based on the spacing of the top and bottom rods in the festoon.

AFAIK, EFKE is the only plant that uses festooning outside of the former Soviet Union. IDK about those within it.

PE

Emulsion
10-14-2007, 02:14 AM
Thanks PE,

Can you recommend any books or journal articles that describe coating and subsequent manufacturing processes of film? I have found some patents but nothing more. E.g. Patent 2620285 (Dupont).

Emulsion.

Ian Grant
10-14-2007, 03:11 AM
Emulsion, you really aren't trying hard enough !!!!!

Just try looking in the right places, here's an advert from 1954, I remember it well :)

http://www.lostlabours.co.uk/Uploads/dixons.jpg

Dixon's are still around, see here. (http://www.dixontechnologies.com/corpbro.pdf)

Ian

Philippe-Georges
10-14-2007, 03:21 AM
Just an little question of a non English speaker : what is festooning?
I could not find the word in my (Oxford) dictionary...

Philippe

Ian Grant
10-14-2007, 03:41 AM
Festoon, means decorate with strings of flowers, or hanging them

In this case festooning is the hanging system the paper is looped over as it dries.

Emulsion
10-14-2007, 05:23 AM
Thanks Ian,

Looks like some very large scale equipment!

Emulsion.

Photo Engineer
10-14-2007, 09:18 AM
Just an little question of a non English speaker : what is festooning?
I could not find the word in my (Oxford) dictionary...

Philippe


Look at the picture posted on the right above. It shows a 'festoon' of material drying.

PE

Photo Engineer
10-14-2007, 09:24 AM
Ian's post should give you an idea of the size and shape of Kodak equipment. Although this mentions trough and gravure coating, Kodak no longer uses these methods. And, the cabinets are totally enclosed on all machines to control temperature, humidity and to prevent dust and dirt from getting on the wet coating.

That pdf file shows some equipment. Also, there was a previous post that showed an Agfa animation of color coating. I don't have the reference, but I'm sure it can be located here on APUG if you want to see it.

I don't keep these things as I have seen the real thing in action. Sorry.

PE

dyetransfer
10-14-2007, 02:49 PM
AFAIK, EFKE is the only plant that uses festooning outside of the former Soviet Union. IDK about those within it.

PE


Here are some pictures I took at Fotokemika (Efke brand) while we were testing the new emulsion. There are pictures of the trough coater, the drying tunnel (first half) with the coating foreman (on left) and our customer rep. Also shown is the bull wheel which turns the corner, and the wind up station at the end. The drying tunnel is horseshoe shaped going out about 100 feet, around the bull wheel, and back to the windup station (Pictured with myself).

The trough coater picture shows a ultrasonic debubbling device on the wall. The emulsion is pumped through that, into the trough, and it overflows the trough continuously. The roller is lowered to the surface of the emulsion, and the web is started. Pictured is a rubberized cloth leader used for threading the coater. Up above is the chill station, and an over coater used for putting a hardening overcoat on - we didn't use this as the matrix film is unhardened. After that, a few people working on a cat walk gather the loops and attach them to clips on the overhead track. The loops travel slowly out to the the bullwheel, and then back to the windup station. Temperature and humidity are controlled along the way for ideal drying conditions as the film moves along.


I think they told me that the equipment was from Dupont, pre WWII. Fotokemika has a large 'campus' which was very busy during the soviet era, but has been greatly downsized more recently. It was a kick walking down long, long halls in the total darkness, and turning into a side room that you couldn't see which was very dimly lit with red safelights. Sort of like a halloween spook house, but without the suprises.

Also shown is a technician mixing the silver nitrate for the small test we ran, a vacuum filter, a large noodling press, and a sensitizing test. There is also a picture of a small mixer - used for precipitation during small tests such as we were doing. They had much larger temperature controlled mixing vessels. They had tubes running through the gelatin solution which controlled the temperature while precip was happening. They could match the temperature profile that I used while developing the formulation here in the US.


They would coat glass plates frequently while sensitizing, expose them while wet to a test pattern, and process them. They would run into the emulsion engineer's office with film boxes with the processed wet plates, and she would inspect it for a particular type of colored fog which indicated that the ideal sensitizing period had been exceeded.


It was a very interesting experience, and our Croatian hosts were very generous and entertained us by showing us around Zagreb. Samabor is a very nice small town about 1/2 hour out of Zagreb. We made 3 miles of matrix film, all of which has been sold. We had a good level of success partly because the techniques they used in production were similar to the techniques I used while developing the formulation. It translated to production quite well. Lots of dye prints are being made with this film these days.

Regards - Jim Browning

Ian Grant
10-14-2007, 02:59 PM
Jim, the equipment was definitely the Dupont/Adox plant which was dismantled and shipped from Germany. There's plenty been written about it over the years.

Ian

Photo Engineer
10-14-2007, 03:02 PM
And I can guarantee that Kodak does not use anything remotely resembling this equipment for making or coating.

It works, but is considered to be antique equimpent which is fully functional.

The post by Ian shows some modern equivalents of this type of equipment, which is still not in any way like Kodak methodology.

PE

Emulsion
10-15-2007, 03:16 AM
Excellent photos and description Jim! Thanks for posting these. Fascinating stuff!

That is very interesting about de-bubbling using ultrasonics. I guess this technique might also be used on a small scale. I have heard of a vacuum (low pressure) being used to de-bubble viscous liquids but not ultrasonics.

Emulsion.

Photo Engineer
10-15-2007, 09:36 AM
Kodak uses a mixture of filtration, vacuum and ultrasonics.

Each lab had a small ultrasonic setup to debubble coating melts prior to use.

PE