Three manufacturing technologies are widely used for pressure sensitive adhesive (PSA) tapes: solution, emulsion and hot melt. A polymer dissolved in a solvent is known as a solution PSA, and a polymer emulsified or dispersed in water is know as an emulsion PSA. Some polymers can also be made to flow at elevated temperatures, therefore making it possible to coat without being dissolved or emulsified. These are known as hot melt PSAs. A fourth kind, UV/radiation, uses new and evolving technology to eliminate solvents or a dispersible medium from the tapes manufacturing cycle. The place of UV PSAs is depicted by the dotted line in Figure 1 and shows its relationship to the other PSA technologies.
UV PSA technology is subdivided into hot melt UV and room-temperature (RT)-coatable UV PSAs. Hot melt UV PSAs require heating to facilitate the coating process. UV-sensitive chemistry is built into the polymer of hot melt UV PSAs, aiding crosslinking and giving the PSA improved shear and high-temperature properties. RT-coatable UV PSAs are liquid with coatable viscosity at room temperature.