Precisely formulated wetting tension test solutions are available from Enercon Industries Corporation. Used to determine surface tension of polyolefin film surfaces, Wetting Tension Test Solutions identify the ideal corona treat level setting for production of extruded film and for converting processes such as laminating, coating, extrusion coating, extrusion laminating, and printing.
Enercon wetting tension test solutions are available in dyne levels ranging from 30 through 70 dynes. Enercon solutions may be used in conjunction with CSD Corona Treat Level Test Kit or in conjunction with cotton swabs. The following test methods comply with procedures established by the American Society of Testing and Materials (standard D2578-79)
Test Procedures with CSD Corona Treat Level Test Kit
- Cut a test sample from the film to be tested and mount it on a clipboard.
- Select three bottles of Enercon wetting test solutions that bracket the desired treatment level. For example, if the surface treatment specification is 42 ± 2 dynes/cm, select wetting test solutions of 40, 42, and 44 dynes/cm for the draw down tests.
- Visually divide the test sample into three equal columns. Place three drops of the lowest dyne/cm test solution near the top center of the left hand column. Repeat using the midpoint solution in the center column and he highest in the right hand column.
- Place a DYNE-A-COAT rod (#6 wire wound Mayer rod) flat on the sample, just above the row of dyne solution test drops. With a smooth, continuous motion, draw the rod downward to produce a thin, accurate layer of each solution.
- Note the time it takes for each of the liquids to break into droplets.
- The solution that just begins to break into droplets in 2 seconds is the sample's dyne level
- If all three solutions take more than two seconds to break up, repeat the test using higher level solutions.
- It's recommended that film surface tension be 10 dynes/cm higher than ink, adhesive, or coating materials.
Test Procedure using Cotton Swabs
- Wet tip of applicator with test solution from calibrated bottle. A minimum amount of solution should be used because an excess can distort readings.
- Spread solution lightly over approximately one square inch of the material to be tested.
- Note the time it takes for the liquid near the center to break into droplets. If the liquid doesn't break into droplets after two seconds, repeat the test with the next higher surface tension solution. If the liquid breaks into droplets in less than two seconds, repeat the test with the next lower surface tension solution. Do not repeat the test in the same area of the film.
- NOTE: Use a clean cotton applicator for each test solution to avoid contamination of the solutions. Sever peripheral shrinkage of the liquid may be caused by placing too much liquid on the polyolefin film surface.
- repeat steps 1 through 3 until you find the solution that holds for exactly two seconds before breaking into droplets.
- It is recommended that film surface tension be 10 dynes/cm higher than ink, adhesives, or coating material.
Ask A Question