Dyne Pens Specialists

A quick and easy way of measuring surface wetting or surface energy

When a Dyne Pen is applied to a substrate, the ink will either form a continuous film on the surface or pull back into small droplets.

If the Dyne Pen ink forms a continuous film which is stable for three seconds, it indicates that the surface energy of the substrate is at least as high as the ink value, measured in mJ/m², mN/m, or dyne/cm – often known as “Dynes”.

If you apply a 38 Dyne Pen to a substrate, and the ink stays as a film for three seconds, the substrate has a surface energy of at least 38 dyne/cm. By using a range of Dyne Pens of various dyne levels, the surface energy of a substrate can be determined to a narrow range.  

Why measure surface energy?

In general, the ability of a substrate to anchor inks, coatings, or adhesives is directly related to its surface energy. If the substrate surface energy does not significantly exceed the surface tension of the fluid which is to cover it, wetting will be impeded and a poor bond will result.  Therefore, assessing surface energy before printing, coating or laminating is attempted is an important part of many industries’ manufacturing processes.

It is important to note that while surface energy is critically important to many converting operations, it is not the sole determinant of product suitability. Factors such as the surface topography, coating rheology and chemical incompatibility must also be considered. This is why broad-based communication with vendors and customers is so important but by systematically measuring surface energy, you will have a sound starting point from which to resolve other problems should they arise.

What is a Dyne?

The unit of measurement of surface energy is mJ/m², mN/m, or dyne/cm. For our purposes, these are the same, i.e. 1 mJ/m² = 1 mN/m = 1 dyne/cm. We commonly abbreviate this unit to just Dyne.

What materials can Dyne Pens be used on?

Dyne test marker pens perform well on most non-absorbent materials. It is critical that the test fluid does not alter the surface properties of the substrate. For example, if the test fluid permeates a fibre substrate (e.g. paper) and causes swelling, results will indicate unrealistically easy wetting. A chemical reaction between the test fluid and the substrate invalidates results altogether.