When the Plastics Decorating editorial team needed a technical report on surface adhesion they turned to Enercon. Enercon responded with a new technical article called "Surface Activation for Optimizing Adhesion to Polymers."
This article discusses current atmospheric surface activation systems, appropriate measurements of wettability and adhesion, over-treatment effects, and surface analysis techniques relative to optimizing the adhesion of inks, paints, coatings, and adhesives to polymer surfaces. Recommendations for improved activation by substrate and application also will be addressed.
Substrates such as plastics are generally composed of non-polar, long-chain molecules. Polymeric surfaces have a small amount of free energy. Fluorocarbons, silicones and vinyls have particularly low free-surface energies.
As such, plastics have few available bonding sites due to low levels of charged ions on the surface. In addition to low surface energies, plastics have diverse levels of conductivity, may be composites in structure, and may be blended with processing additives.
All of these variables can have a negative impact on molecular attraction, causing liquids to fail to wet the surface. There are three primary types of atmospheric surface activation system for three-dimensional polymeric surfaces: air plasma, flame plasma, and atmospheric chemical plasma regimens.
Continue reading the full technical paper.
Originally appeared in eNews: 3D Surface Treating 2nd Quarter 2009.