Why is my ink cracking?

June 17, 2014 by Robb Mears 2 Comments

When you are experiencing ink cracking, 99% of the time the ink is under-cured.  This is the time when you need to ask yourself how you are testing the temperature of your dryer.  There are only two acceptable ways to test your conveyor dryer.  First, try using Thermolabels.  These handy stickers will measure the ink at 290F up to 330F with a temperature indicator every 10 degrees.  Once the 320F indicator is completely black, the ink should be cured.  Place the Thermolabel next to the print for best results.  The second test is by using an Atkins heat probe.  This “donut” probe has two cross wires that are designed to be placed in the plastisol ink.  A hand-held device will give you the temperature readings as it goes all the way through the dryer.  Once the ink has reached 320F, it should be fully cured.  Please notice I did not mention a temperature gun.  This will only measure the surface temperature of the ink and this does not ensure the ink has been cured.  Other causes of ink cracking include printing the ink too thin for the fabric, over-curing (not common), and using the wrong ink for the job.  Screen printing stretchy fabrics may require a special stretchable ink.