I am finding that more than a few lip balms out of each batch I pour don’t wind down again once you have wound them up the first time. It seems quite random but say i do a batch of 50 lip balms, 10-15 won’t wind back down and the others will. Sometimes it’s more than 50% of the batch.
I have been putting the trays in the fridge to cool down.
We have never heard of putting trays in a fridge. We do have customers that have a large number of our trays, using a chiller line. This is basically a conveyor belt with a cold tunnel. However this only is maybe, 30 seconds. Enough to cool the perimeter of the tub and top.
As to temp or humidity, we have hundreds of customers all over the world and have not heard of anyone talking about this affecting pours. The range of formulae and products they put in the containers is astounding.
I suggest stopping the use of the cold time and see what happens.
It actually sounds to me that they are stripping out the plug. You see… all tubes have threads, or protrusions on the shaft that not only guide the elevator part of the tube up and down but also bind the plug by creating a nut/bolt like effect. This pulls the plug up or down as the elevator goes up or down. The plug can’t go down if the threads are stripped. Same as trying to tighten a stripped bolt. It just spins.
Something either in the formula is either binding too well to the tube or the cold doing something, but what that would be, I have no clue.
Call your container manufacturer. Their engineers may be able to help you. I would think there would be someone out there that has had the same issue.
End result… It was the cold time in the fridge.