There are many kinds of adhesives, different compositions and different uses. The classification methods are as follows. 1. According to the source, it can be divided into natural adhesives and synthetic adhesives. The raw materials of natural adhesives mainly come from nature, such as bone glue, shellac, fish glue, etc.; vegetable gum includes starch, rosin, etc. Synthetic adhesive is made of synthetic resin or synthetic rubber as the main raw materials. For example, thermosetting adhesives include epoxy, phenolic, acrylic acid, silicone, unsaturated polyester, etc. Rubber adhesive has chloroprene rubber, nitrile rubber, silicone rubber and so on. Thermoplastic adhesives are polyvinyl acetate, ethylene, vinyl acetate, etc.

2. It can be divided into general adhesive and special adhesive according to its application. General adhesive has certain bonding strength and can be used for bonding common materials, such as epoxy resin. Special adhesives include metal, wood, glass, rubber, polyethylene foam and other adhesives.

3. According to the bonding strength, it can be divided into structural adhesive and nonstructural adhesive
The shear strength of the joint bonded with structural adhesive can reach 7MPa, which not only has enough shear strength, but also has high uneven pull-off strength. It can withstand vibration, fatigue and impact load for a long time, and has certain heat resistance and weather resistance. Non structural adhesive has a certain strength at lower temperature, and the bonding strength decreases rapidly with the increase of temperature, so this kind of adhesive is mainly used for bonding unimportant parts or temporary fixation.

4. According to the curing temperature of adhesive, it can be divided into room temperature curing adhesive, medium temperature curing adhesive and high temperature curing adhesive. Room temperature refers to temperature less than 30 ℃, medium temperature refers to 30-99 ℃, high temperature refers to adhesive that can be cured above 100 ℃.

5. It can be divided into resin, rubber, inorganic and natural adhesives.

6. According to other special properties, it can be divided into conductive, magnetic, spot welding adhesive, etc.