1, the basic theory of epoxy adhesive:
Epoxy adhesive is generated by the two forces, one is the mechanical adhesion. When the binder is in liquid, clean bonding surface to penetrate pores, adhesive curing and forming the combination of a mechanical anchoring force; second, chemical bonding, because the molecular structure of epoxy resin containing aliphatic ether is very lively in the base and epoxy.
Because the polar hydroxyl and ether, electromagnetic force between molecules and the adjacent surfaces of epoxy resin and epoxy matrix containing active hydrogen of metal surface reacts to form chemical Gou Jian, both between the adhesive molecules between combined. This combination is called chemical bonding is generally believed to mainly due to chemical bonding adhesion of epoxy resin work.
2, epoxy bonding characteristics:
2.1 can bond various materials, metal to metal, metal and non-metal, non-metal and non-metal have a strong bond between.
2.2 has a high bonding strength and other physical properties (table 1)
2.3 bonding process is simple and easy to learn, and good economic results. If you have a 100m crack of tractor engine block, with only a few Yuan to repair and loading both use within two days. Repairing a pipeline just a few cents.
2.4 glued joints are not leaking, no oil leakage, watertight and resistant to chemical corrosion and other excellent features.
2.5 bonding surface can be machined.
2.6 bonded during high temperature processing is not needed on the workpiece and, therefore, no effect on the microstructure of parts.
2.7 less shrinkage, contraction rate of 1–2; such as adding the appropriate packing its shrinkage rate is 0.1-0.2%, good temperature resistance of epoxy resin, long work can be in the range 150-200 ° c temperature, its cold up to-55 ℃-50 ℃.
2.8 bonding surfaces more brittle, less erosion-resistant properties, adhesive curing drug.