Requirements for Adhesives

1. Regardless of its initial state, the adhesive should be in a liquid state when applied.
2. It should be able to fully spread and thoroughly wet the surface of the material to be bonded.
3. It must be able to transform from a liquid to a solid or gel state through certain means, forming a tough and stable adhesive layer.
4. After curing, it should have a certain degree of strength. It should be able to connect reliably, transmit stress, and resist breakage.
5. It should be resistant to temperatures above 0℃ and withstand the test of a certain period of time.

Classification of Adhesives

• Classification by Appearance: Solvent - based, Emulsion - based (water - based), Paste - like or 糊状，Solid - type, Film - type.
• Classification by Curing Method: Water - based Evaporation - type, Solvent - Volatilization - type, Hot - Melt - type, Chemical - Reaction - type, Pressure - Sensitive - type.