longer exposure times due to low temperatures

[Screen Dan]

i do know that if is below freezing our supplier will not ship it out as the emulsion will get too cold in UPS.  they wait till the temp at there shop is above freezing

Hmm.  My supplier drops off directly from their warehouse one town away...but some times they are left at the edge of our bay overnight or even an entire weekend.  Doors closed, sure...but it's been getting mighty cold out at night.

What symptoms would I get from an emulsion that got too cold and/or frozen?  Would it be obvious?  Does it have to freeze all the way to ruin it or does getting colder start to cause issues and the colder it gets the worse it gets?

[jvanick]

some emulsions are likely more freeze-stable than others.

I believe that Al from Murakami told me that SP1400 is freeze-stable...

The Saati guys told me that their emulsions were fine to be shipped in freezing conditions... so we actually tested it and put a quart of Saati PHU in the freezer over night, and while it didn't freeze solid, it defintely thickened up... after it warmed back to room temperature, no problems at all.. exposed just like a non-frozen batch.

[Rockers]

So here are my observations. The extended exposure times are  rather down to the exposure units. I did a couple of screens this morning. On our Vastex LED exposure unit we did not manage to make a screen that did not wash off even if we doubled the exposure times.
Then we burned the images on our MSP3140. Came out all fine. What I noticed while burning them on the MSP3140 was that at lamp start up the LTU were counting down extremely slow probably 3 sec per LTU. After a 10 sec that changed to around 1 sec per LTU. I assume the lamp needs to reach a certain temperature before max UV output is achieved.
Now on the LED units it seems low temperatures are much more of a problem as the lamps don`t really heat up a lot!?
But maybe I`m just barking up the wrong tree here.