How to bake paper labware

We bake full sheets of Ahlstrom 319 paper (8.5 x 11” size, 400 micron paper thickness) in a glassware drying oven set to 100-110C.   A design like the titrator or electrochemistry dogbones requires 6-10 minutes, although each oven must be tested to find its baking sweet spot.   

  • We test 100% of our pages after baking. To test that the wax has sealed properly, pull a sheet from the oven and use a Beral pipet to drop DI water onto several devices that are located in different regions of the page. We use plain water rather than food coloring because the water will just evaporate, and you can use the devices afterwards.  The water will make the paper translucent. Hold the paper up to a light to see if water is leaking through the wax barriers. If the wax has not sealed, just bake the sheet another few minutes and test again.   
  • If the paper lies directly on a metal grid or shelf you will get uneven melting of the wax. We place a layer of paper towels on the metal shelf or grid to even out heat transmission. The paper towels are not a fire hazard at the low temperatures used.  If your oven is sometimes used at higher temperatures, you must ensure that the paper towels don’t stay inside and create a fire hazard.