lab scale vs pilot scale coating

[rmazzullo]

Hello PE,

Can you please explain some of the capabilities / differences between a lab scale and a pilot scale coating setup? Can you shed some light (no pun intended) how both types were built while you were at Kodak?

Thanks,

Bob M.

 

[Ian Grant]

The pilot coating machine at Ilford, that APUG visitors have been shown, is a scaled down coating machine that emulates the larger coating machine. This is used for lab coatings of test emulsions etc. It isn't used for full scale batches as it's too narrow, and coating lengths aren't particularly long.

Kodak would have had more than one pilot machine, Ron would know how many but I'd guess that there were at least 2 or 3 because Kodak coated films & papers in at least 4 countries at one time, England, Canada, Hungary and of course the US.

Ian

 

[Photo Engineer]

Kodak uses (used) a variety of coating methods and machines. At the smallest lab scale, we used hand coating blades such as I have had built and shown here. At Kodak, we had 3 models of these, 1 mainly for paper and 2 mainly for film. Some came in sets of about 6 with different gaps for coating different quantities of emulsion while others had fixed gaps or undercuts as we called them. They came in 120 film size up to 5" for 4x5 sheets.

The next scale was a set of coating machines that coated about 5" wide and coated about 100 feet in 10 ft increments. It was called a Sample Coater, and therefore the coatings were stamped or punched with an SC -n-xxxx where n was the machine number, and xxxx was the coating number. When I left, there were 5 of these machines. There were comparable RC machines which coated solvent coatings such as thermal silver behenate coatings using a butvar polymer in a flammable solvent. Basically, these were beefed up RC machines. The widest was about 11" though. These all used extrusion hoppers. There were at least 4 of these in KRL and one pilot machine now used for production by another company for medical products.

Next up were the J-n machines where the capability went to 1000' and up to 11". They had just build J-9 when I started coating, and one of my first sets was about the 200th roll to be coated. Machines up to J-5 used extrusion hoppers, and J-6 - J-9 used slide or curtain hoppers capable of up to 11" width and high speed. J-7 was not in operation while I was there AFAIK.

There were P series machines used for old fashioned coatings with the dip and doctor blade. These were only used for putting on an electrostatic bombardment and a gelatin subbing while I was there. They were primitive. P-1 was torn down and given to RIT, and P3 was still in operation in the room next to my emulsion lab in the 70s.

All of the above were duplicated at each plant as well for R&D.

The next scale was the 21 machine series for plant pilot coatings. There was a set of them in Film manufacturing and a set in Paper Manufacturing and also sets at each plant world wide. They coated 21" film or paper in lengths up to 5000 ft and could use extrusion or slide or curtain coating. I'm not entirely sure of the latter as I never participated in any of these on the 21 machine.

The paper plant had 6 full width machines that did only slide or curtain coating at full speed in 5000 ft lengths. There were 4 machines in operation, 24/7/365 at one time while 2 were out for routine manintenance. This was duplicated in a smaller scale (number of machines) at Harrow and Chalon as well as in Australia, Canada and Brazil. Film manufacturing had a similar setup but IDK how many machines they had there. They were duplicated world wide.

The paper plant also had a set of older paper coaters mainly used for Baryta B&W due to the dirt and dust when coating FB papaers. They also had a huge paper mill that made all of their own paper support for RC and FB and this involved coating machines as well to apply baryta, Titanox and RC. Film had casting machines to make their own film, and a casting wheel is used as a display at the entrance to Kodak Park West (at least it was last time I went by, but things are changing).

At the time I last went through these areas, the Paper Manufacturing operation was more advanced and modern than the Film units until the new film machines were built in the new building on the corner of State and Lake. Then Film surpassed Paper.

The machines at Colorado were 72 or 78" wide, I forget the width OTOMH. They were the largest, and were sold along with the Health Sciences division back about 2 or 3 years ago. Kodak still rents time on them.

The film machines and paper machines had a different design based on the philosophy and wisdom of the respective divisions. This was held fast until a plant manager in the late 80s ordered a crossover between machines and showed no significant difference in sensitometry and defect rate and so at the current time Kodak engineers would design either a film or paper machine to the same specifications.

This spans the 32 years I was at EK. It is different now, of course. But, it is larger now than Ian speculates and was far far larger when I worked there. I'm sure that this is more than you ever wanted to know, but after Ian's response, I had to indicate how large it was and is.

PE

 

[rmazzullo]

PE,

Thank you for the background info. The detail you provide is never too much. It's probably a good thing you didn't build them, because I would have a lot more questions for you. Even so, can you please describe how the coated product was dried? On the sample coater and the J machines, how were the lengths of coated material handled before they were packaged?

Thanks again,

Bob M.

 

[Photo Engineer]

The coatings were first chilled to set the gelatin, and then once set they went through cabinets with increasing temperature and constant or lower humidity. Gentle air blowed on both front and back through a series of vents. The coating turned corners on either undercut rollers using the selvedge as safety to avoid touching the coating itself, or it turned on air bearings when it was dry enough. The final cabinet conditioned the coating to a standard value of temperature and humidity used at all plants.

After coating, each coating was slit and chopped to the specifications of the "customer". It was then packed accordingly. All sheet films or sheet papers went into blank yellow boxes or in the case of larger sizes of paper, into blank yellow envelopes. All of this packing was normal double envelope or box. The 35mm film was usually either packed in blank black casettes or chopped to 12" lengths and put into tubes. These tubes were the only thing that was never seen outside of Kodak AFAIK, all of the other packing was standard but unlabeled yellow or black. About 20 strips of 35mm came from 10 feet of coating giving us 20 experiments we could run. We got about the same 4x5 sheets. I never saw anyone get 120 done for some reason, but it was an option.

The 1 ft 35mm was never perfed, but the rolls in casettes was normal perf. The 1 ft 35mm had two holes punched in each end for holders that we used. All research film and paper had a punched ID number with coating machine and sequence number. Pilot coatings did not.

I coated every other week and ran about 10 coatings per set on average. I used all coaters but J-5. It was used exclusively for B&W films and for emulsion testing. Since my work was either product oriented or theoretical, I either used the SC machines, RC machines or the J-8 or J-9 machines. Some of my simple color work was J-4 or J-6 stuff using extrusion hoppers to prepare single color coatings. We did not coat on the plant machines. The plant Development Engineers did that work. It then went on to Product Engineering.

PE

 

[AgX]

PE,

How was that Sample Coater set up?

100feet of base were running through while 10 coating heads where successively coating in a sort of flying spice?

 

[Photo Engineer]

No, one head did all 10 coatings. One at a time on a roll of film or paper about 120 feet long. Each good coating was about 10 feet with in-between startup and shutdown defects and coaters markings for ID.

It looked like a continuous version of the machine shown here earlier in another thread. It took up a space about the size of a 2 car garage if you consider the coater and all ancillary equipment.

Just for a size comparison, J-9 took up about 2 floors that covered 1/2 of a large building about 1 block square. One floor above that was air conditioning equipment for it in addition. The machine was so big, you could open a drying cabinet and walk into it! BTDT! Me and my trusty safe-flaslight looking at coating as it zoomed by!

PE