Film Dryer - How hot can film go?

How much heat can film handle in the drying stage?

 

I searched around and found what looks like an interesting design for a home made film dryer, using PVC pipe with

a hair dryer at one end and your film, still on the reel, at the other. A lot of people say it works great to

keep dust off the film, which is my goal. Anyway, I made one and when I tested it I measured a temp of about

110-115 degrees F at the film end of the tube, and that is with the hair dryer set on "Cool." That's hotter than

I expected. What do you think? Is that too hot?

 

If anyone has a store bought film dryer, can you tell me how hot it gets?

 

Thanks,

Paul

 

PS. This isn't exactly what I did, but it's the same basic idea:

http://www.mediabaron.com/filmdryer.html

We had one that was a part of our traveling darkroom kit that was put together by a photographer. It looks just like the one you sent in the link. It worked great, but if you loaded too many rolls in it, the rolls near the hair dryer could get too warm. I would keep the drier on the lowest setting, and drill some extra holes in the side of the tube to dump off some of the air. I do not think 110 degrees is that hot, the professional tube dryers we had in the darkroom at the paper got at least that hot or more. The trick is to take them out of the dryer , and off the reels before they cook ,and lay them flat ,emulsion side down for a few minutes as they cool down. If you leave them on the reels they develop a curl that is hard to remove.

Just for laughs, I just googled "film melting point" and got the following link from Kodak:

 

http://www.kodak.com/eknec/documents/bb/0900688a802b35bb/ti2598.pdf

 

The second (right) column on the first page has data about "Temperature Effects", which leads me to believe that the temperature you're working with won't damage anything. They even have data about "distortion" in the temperature effects section.

 

Mr. Ging's advice above looks really good and is completely in line with what I just read.

 

Chalk this up as another instance where I'm amazed at Kodak! What a lot of great research they've done, eh? I just wish they'd bring Verichrome Pan 120 back....

Just stuck my Weston darkroom dial thermometer into my DSA/Phototech film dryer and it got up to 95F after about five minutes. This is a big wall mounted unit that can handle six or eight reels at a time. When I worked for UPI our photographers used home made units in the field that consisted of any old blow dryer gaffer taped to a piece of plastic clothes dryer venter exhaust tubing. Probably hotter but they put the film in only long enough to dry in a hurry on deadline.

The link that Michael Hendrickson provided refers to polyester film base. Most 35mm film is coated on acetate support. The real concern is the gelatin coating on the film base. The gelatin in modern color films is hardened and wont melt at any temperature you are likely to find in a dryer. Older B&W products like Tri-X are not hardened to the same degree. If the film temperature actually got up to 115 F, you might do some damage to unhardened films. The temperature of the film is generally lower than the air temperature unless you leave it in the dryer too long.

 

The bigger concern is the rate of drying. The gelatin is stronger if you dry it gradually. This is not a big deal unless some parts of the film dry much faster than others. Then you can get some distortion effects. The rate of drying is affected by the temperature, the humidity of incoming air, and the velocity of the air impinging on the film.

 

Having said all this, I know of color film dryers that range from 80 to 135 F.

<p>Would there be an adverse effect on film (35 and 120 black and white ilford and agfa) for drying in too cool a temperature? I dry in my garage and may get into the 30's (dry air). I hang it still wet from photo flo and just drip dry so it takes some time and stays wet for a bit.</p>