“How hot can your barcode labels get?”
They had a requirement to attach labels to circuit boards which would briefly be exposed to high temperatures. After printing their own labels and having them turn almost black, they asked if we could solve their problem. Being a question that we do not get everyday, we decided to conduct some tests to find out.
We used our standard .003” white polyester barcode labels, with dimensions of 1.25 x 0.50 inches. Each tag was baked at 350°F at increasing periods of 10 minutes. The last label was baked for an hour at 350°F and then 10 minutes at 500°F.
The labels that baked from 10 to 50 minutes at 350°F showed no notable discoloration. The last label showed both a very slight discoloration and surprisingly, decreased in size approximately 6% both horizontally and vertically. All of these barcodes were still readable.
Next, we thought we might push our luck. We dialed the oven up to 500°F. Matching our customer’s conditions (two minutes at 500°F) turned out to have no affect on the label. What would more time do? After testing for up to an hour, the labels showed some serious discoloration, but were all still readable. One mistake we made was putting the label right next to the coil heating our oven. As you can see in the image, the barcode completely melted away. This isn’t going to be identified by anyone!
So the quick takeaway lesson from our little experiment is this:
- Printing your own barcodes for high temperature use is likely a bad idea.
- Exposing high quality polyester barcode labels to short bursts of high temperatures will be fine.
- The more a label discolors, the harder it will be to read.
- If you need a barcode that can be exposed for long durations of high temperatures, you should invest in either a laser engraved steel nameplate or a ceramic on steel nameplate.