Dyne pen test principle

Dyne pen test principle
Using the surface tension test pen, it is easy to analyze the surface ability, hydrophilicity, wettability and other small changes of different solids. The analysis method is simple and effective, and the accurate result can be quickly known by only scratching a mark on the surface of the substrate. This is specially designed for production line testing and is carried out by trained operators in the factory.
During the test, an intermediate value should be selected as the starting point, such as 38mN/m. During the test, if the test pen wets the surface of the substrate within 2 seconds, the surface tension of the substrate is greater than the selected value or just right, then you need to select A test pen with a larger value is used for the second test, and so on, until the test result is reduced to a water droplet (spherical) within 2 seconds, the previous value of this test is regarded as the surface energy of the substrate. And use this for comparative analysis.
If it shrinks into water droplets (spherical) during the first test, replace the test pen with a smaller value for the second test until the surface is wet. This method can accurately measure the surface tension and surface wetness of the substrate and determine whether the surface factors of the substrate meet the requirements before work so that it can be adjusted to the needs of the work.

Analysis result
1. If the film that has been properly corona treated is evenly distributed without any beading, it means that the dyne on the surface of the film is higher than or equal to the index marked on the surface tension test pen.
2. If the film without proper corona treatment shrinks slowly by drawing a line, it means that the dyne on the surface of the film is lower than the index marked on the surface tension test pen.
3. If the film without corona treatment shrinks immediately after drawing lines and forms beads, it means that the dyne on the surface of the film is extremely lower than the index marked by the surface tension test pen.
In industrial practice, the surface energy (surface tension) of plastics is measured by testing the ink according to DIN ISO 8296, using inks with known different surface energies to brush about 100mm long ink strips on the film to be measured, and observe Whether more than 90% of the ink strips shrink and form ink droplets within 2 seconds. If so, change the ink with a lower surface energy and then brush the ink strips, and perform the same observation until there is no shrinkage and ink droplets appear. , The surface energy of the test ink corresponds to the surface energy of the film. This method can accurately measure the surface tension and surface wetness of the substrate and determine whether the surface factors of the substrate meet the requirements before working in order to adjust the ink, coating, and viscosity to the working needs.
Surface tension and surface wetness are very clear standards for accurately determining the bonding status of printing inks and other materials on the surface, but there are other factors that affect viscosity, such as static electricity and many additives. However, these factors are not often shown during the test, and even the test results are very good but actually unsatisfactory. This requires discussing these technical issues with the raw material supplier. Generally speaking, the above situation will not happen to them, and the surface value of 38-41mN/m can meet the viscosity requirements. When the surface tension is below 37mN/m, it will cause many white pages (no printed content). When the surface tension is below 35mN/m, the viscosity will be bad.
Generally speaking, the substrate forms ink droplets, and the coating and adhesion ability is related to the energy of the surface. If the energy of the surface of the substrate is lower than the tension of the surface of the applied test liquid, beads will be formed and the drawn line will shrink. Therefore, for most printing and plastic-based solvents, the test pen requires 36-40 dynes/cm. Some ink-based liquids require the test pen to be between 40-44 dynes/cm. Some rolling and coating applications require surface energy of 50 dynes/cm or more. Obviously, the energy of the surface needs to be estimated before printing, coating and rolling.
The surface tension test pen performs well on most non-adhesive materials. It is important that the test solution does not change the surface characteristics of the substrate. For example, if the test solution penetrates a fibrous substrate (such as paper) and causes it to swell, the result can indicate that it is prone to moisture. The biochemical reaction between the substrate and the test solution invalidated the results.
In order to ensure the repeatability of test results, the preparation of materials and the methods of testing must be standardized. The ASTM STD D6182 agreement specifies the test conditions and methods. Detection theory believes that it is important to standardize the surrounding environment, substrates and test methods. The trainer teaches the inspectors to minimize all changes. The relative humidity should not exceed the standard. Too high humidity will aggravate the variability of the data. Ultimately, the time for testing extrusion or coating (printing) needs to be controlled. It can accurately measure whether the surface tension of the film reaches the value of the test pen. Let users clearly understand whether this film is suitable for printing, laminating, vacuum aluminizing, etc. Effectively control the quality and reduce the loss caused by unqualified materials.

Matters
Before use, please ensure that the test surface is clean and avoid contamination of the pen tip.
After use, be sure to close the pen cap tightly.
When pen ink gets on your hands or skin, please rinse with water immediately.
Please avoid direct sunlight and keep it in a cool place.