Surface Tension Wetting Dyne Solutions and Pens
Wetting tension solution for the examination of polymer plastic surface energy.
For successful printing and adhesion to polyolefin materials, it is necessary to treat the desired area so the surface energy rises to a defined point. Surface energy is measured in dynes/cm (mN/m).
Untreated PE and PP have a surface tension of about 30 dynes/cm. After treatment for printing with solvent-based ink, PE and PP should have a value of approximately 38-40 dynes/cm. For printing with water-based ink, the surface should have a value of approximately 42-44 dynes/cm.
Polymer plastics with a surface tension of less than 37 dynes/cm have bonding difficulties. When performing the “Tape Test”, negative results are proof of these bonding problems.
For many coating and adhesion applications, however, a surface tension of between 48 to 56 dynes/cm is often required.
In general, the ASTM procedure D2578 covers the measurement of surface tension of various olefin substrates using specific testing solutions in the presence of air.
The value of treatment is tested, by brushing the solution onto the desired surface. The test solutions are graduated from 30 dynes/cm to 72 dynes/cm.
Both dyne test solution and dyne test pens are available from 3DT. The level of accuracy is plus or minus 1 dynes/cm.