Most people in the adhesives and sealants industry are aware of viscosity and realize that it characterizes the way a material will flow. More technically speaking, viscosity refers to a material's resistance to flow; it can be measured in various ways, depending on the application.

Pressure-sensitive adhesives (PSAs) are used in applications ranging from labeling food packaging to assembling electronic devices to mounting graphics displays. Although they have been around for decades and their use is widespread, manufacturers, converters, and printers may not understand the key differences between the adhesive choices available, how they’re constructed, or which are best suited for a particular job.

Historically, fire resistance has not generally been a significant requirement when specifying adhesive systems. Recent incidents, however, indicate that this may soon change. These include events outside of the formulators’ arena, such as increased sensitivity to the performance of components in a fire, and events within the formulators’ arena, such as the development of flame-resistant additives.