One of two critical components in optimized substrate wetting is surface tension (the other being surface energy). Tension is what enables moving liquids to form a spherical shape as if they are surrounded by a tensile elastic membrane. Instead of breaking apart in the air, the molecules prefer to cling together. Everything you need to know about surface tension test ink, including its limits, is right here:
What Is the Function of Surface Tension Test Ink?
Still unsure of how to calculate surface tension? To begin with, because the goal of a flexo surface tension test is to measure surface wettability, test inks are available in a variety of surface tensions. That’s a good thing because surface wetness can be difficult.
If the ink emerges in drop form rather than even strokes, the tester advances to the next lower level of test ink until the surface tension is at least equivalent to that of the test ink.
What Materials Are Used to Make Surface Tension Test Ink?
Several types of ink may be used for a wetting tension test, depending on the surface being tested.
- Ethanol Test Inks: These are appropriate for the majority of typical surfaces.
- Formamide Test Inks: These perform well on warmer surfaces but are not suitable for PVC. Extra caution is essential because these inks are hazardous and necessitate a longer reading time to accurately identify findings.
- Methanol Test Inks: Again, these will work on most common surfaces, but these inks are hazardous, so use them with caution.
Surface Tension’s Importance in Flexographic Printing
The most important aspect of printing is ensuring that the ink spreads uniformly throughout the substrate. Because of the expanding usage of water-based inks and various substrate materials, more flexographic printers use this easy surface tension measurement to adapt the treatment procedure. Failure to use these procedures may result in:
- Lack of adhesive properties
- Poor print quality
- Production interruptions
- Dissatisfied clients
Ink Testing’s Potential Limitations
These are relative numbers, and the changes between surface tensions may be just marginally noticeable. Any lag time between surface wettability testing and printing could result in different results. To use ink tests successfully, industry experience and a critical thinking process are required.
No Surface Tension Measurement Is Completely Error-Free
While no surface tension ink test is completely foolproof, sending your materials out for testing can produce more reliable findings. A flexographic products supplier may already have surface tension measurement procedures and equipment in place to ensure a smooth testing process.