Synthetic resin adhesives may be divided into the thermosetting types and the thermoplastic types. The thermosetting types undergo a chemical change in hardening and retain their strength much better at elevated temperatures. The thermoplastic types can be softened repeatedly by the application of heat and do not retain their bond strength under elevated temperatures.
Synthetic resin adhesives do not retain their bond strength under elevated temperatures. However, some of them display characteristics that make them useful below 180 degrees Fahrenheit.