(1) Aluminum honeycomb panels produced using polyurethane and epoxy resin reactive curing adhesives are characterized by simple process and low energy consumption. Polyurethane adhesives are characterized by flexibility and resistance to temperature differences, but they are sensitive to moisture during gluing and have high requirements for the environment in which they are used; epoxy resin adhesives are characterized by good adhesion to aluminum, high temperature resistance, and little influence from moisture. The disadvantage is that the adhesive film is brittle , the peeling strength is not high.
(2) The bonding strength of aluminum honeycomb panels produced using the epoxy film process is low, measured for an aluminum honeycomb panel with a honeycomb core side length of 4mm, a panel thickness of 1mm, and a total thickness of 10mm. The 180° peel strength is about 4N/mm. However, its bonding performance and weather resistance are good, and its peel strength decreases very little after one year of use. The disadvantage is that the adhesive layer of the aluminum honeycomb panel is relatively brittle, and the aluminum honeycomb panel will delaminate after long-term vibration.
(3) The bonding strength of the aluminum honeycomb panels produced by the thermoplastic film continuous composite process is 3-5 times that of the aluminum honeycomb panels produced by the first two processes. For the edges of the regular hexagonal honeycomb core The measured 180° peel strength value of an aluminum honeycomb panel with a length of 4mm, a panel thickness of 1mm, and a total thickness of 10mm is about 18N/mm. It has good adhesion and weather resistance, and its peel strength decreases very little after one year of use. Because it is a continuous production, it is highly efficient and can meet short-term and large-volume supply requirements. The disadvantage of this process is that the flat continuous thermal laminating machine equipment used is expensive and requires huge investment. Thermoplastic adhesive film is a special hot-melt adhesive film. The adhesive film itself must have high cohesion strength and tensile strength, which can ensure the strong bonding of aluminum honeycomb panels. If a general hot melt adhesive film is used, its bonding strength is very low, with a 180° peel strength value of only 3N/mm. Oil, dirt and the naturally formed loose oxide layer on the aluminum surface will seriously affect the bonding effect of the aluminum honeycomb panels. Therefore, it must be cleaned and pre-treated. The aluminum surface can be phosphated or chromated to form a tight chemical conversion film on the aluminum surface. The treated aluminum has a good bonding effect.