1. Preparation of adhesive the performance of adhesive preparation will directly affect the practical performance of adhesive joint. Therefore, the preparation of adhesive should be scientific and reasonable, and the preparation should be carried out in a reasonable order.

There are many types of adhesives, such as single component, two-component and multi-component. One component adhesive can be used directly. When preparing two-component or multi-component adhesive, the quality of each component must be accurately calculated and weighed, and the quality error shall not exceed 2% - 5%. If the amount of curing agent is too much, the adhesive layer will become brittle; if the amount of curing agent is insufficient, the curing of adhesive will not be complete.

Before preparation, the adhesive should be placed in a sealed container with a temperature of 15-25 ℃ (except for special varieties), which is dark and opaque and has no destructive effect on the adhesive.

The preparation of adhesive depends on the dosage. When the dosage is small, manual mixing can be used; when the dosage is large, the electric mixer should be selected for mixing. The components must be uniform in mixing. For some adhesives with poor compatibility, more fillers and long storage time, they should be stirred again before use. The viscosity of the increased also need to add solvent dilution after stirring.

2. The coating of adhesive is to apply the adhesive on the surface of the bonding part with proper methods and tools. The coating methods include brush coating, dip coating, spraying and scraping.

According to the purpose of the adhesive, the viscosity of the adhesive and the properties of the adhesive, different gluing methods can be selected. If the temperature of preparation is too low and the adhesive is too dry, it can be heated in water bath or preheated in the oven.

The coating should be uniform. In order to avoid air in the adhesive layer after bonding, the coating should be applied from one direction to the other with a speed of 2-4cm / s. The thickness of adhesive layer is generally 0.08-0.15mm.

For solvent based adhesives and porous binders, it is necessary to apply the adhesive for 2-3 times. Before the second coating, it is necessary to accurately grasp the first layer of adhesive and then apply the second layer after the solvent has completely evaporated. If the residual solvent in the adhesive layer will reduce the bonding strength, but if it is too dry, the adhesive layer will lose its adhesion.

For the solvent-free thermosetting adhesive, it should be bonded immediately after coating to avoid absorbing moisture in the air for a long time or volatilization of curing agent (such as aliphatic amine curing agent of epoxy adhesive).