Simulation with Silicone - Wacker Chemie AG


Simulation with Silicone

“The paper quality available on the market is constantly changing. And new adhesives are continuously posing challenges, too.”

Dr. Hans Lautenschlager Head of Technical Support for Silicone Release Coatings at WACKER SILICONES

New Challenges

Technical service engineers measure the coating’s release force electronically with the aid of a peel-force measuring device. Different tests show how the coating behaves at a peel angle of 90 degrees or 180 degrees, for example.

The test results are illustrated graphically. The DEHESIVE® Coating Center’s database already contains 50,000 test results. However, if you think that this means that the Care & Coatings business team will soon have covered all conceivable material constellations, you are mistaken. “The paper quality available on the market is constantly changing. And new adhesives are continuously posing challenges, too,” explains Lautenschlager. He believes that, while the test results to date point the way ahead, they are by no means definitive.

Release coatings thus require further research, so that shampoo, melons, etc. will be optimally labeled in the future, too.

The highly branched star polymers of the DEHESIVE® SFX product family yield silicone layers with comparatively flat release-force profiles. For example, the release force of a DEHESIVE® SFX 250-based layer (red line) rises less at an increasing peel rate than the release force of a standard product such as DEHESIVE® 924 (blue line). Both silicones have a viscosity of around 200  mPa·s. The release force was measured with the aid of a Tesa A 7475 adhesive tape. In the diagram, the peel rates that are typical for slow peeling (0.3 m/min), machine labeling (10 m/min) and rapid matrix peeling (300 m/min) are marked.