① Regardless of its state, the adhesive should be in a liquid state when being coated.

② It should be able to completely spread and fully wet the surface of the bonded object.

③ It must be possible to transform the liquid into a solid or gel state through a certain method to form a tough and stable adhesive layer.

④ After curing, it should have a certain strength, be able to connect reliably, transmit stress, and resist damage.

⑤ It should be able to withstand temperatures above 0°C and pass the test over a certain period of time.