Reasons for the Peel Strength of Aluminum Honeycomb Panels

1. Effect of adhesive on peel strength of aluminum honeycomb panel

(1) the use of polyurethane, epoxy resin room temperature curing adhesive production of aluminum honeycomb panel, the bonding strength is low, for the honeycomb core side length of 4mm, panel thickness of 1mm, the total thickness of 10mm aluminum honeycomb panel measured 180 ° peel strength is about 4N/mm. The adhesion and weather resistance of this aluminum honeycomb panel are poor, and the adhesion performance is greatly reduced after 1 year of use. The aluminum honeycomb panels produced by this process are not suitable for outdoor use, but can be used for indoor decorative partitions.

(2) The adhesive strength of aluminum honeycomb panel produced by epoxy adhesive film process is low. The 180 peel strength measured for aluminum honeycomb panel with honeycomb core side length of 4mm, panel thickness of 1mm and total thickness of 10mm is about 4N/mm. However, its adhesive performance is good in weather resistance, and its peel strength decreases little after 1 year of use. The disadvantage is that the bonding layer of the aluminum honeycomb panel is brittle, and the aluminum honeycomb panel will be layered after long-term vibration.

(3) The bonding strength of aluminum honeycomb panels produced by thermoplastic film continuous composite process is 3-5 times that of aluminum honeycomb panels produced by the first two processes. For aluminum honeycomb panels with regular hexagonal honeycomb cores of 4mm in side length, 1mm in panel thickness and 10mm in total thickness, the measured 180 peel strength is about 18N/mm. Its adhesion and weather resistance are good, and its peel strength decreases little after 1 year of use. Because it is continuous production, high efficiency, can meet the short-term mass supply requirements. The disadvantage of this process is the high price of the flat continuous heat composite machine equipment and the huge investment. Thermoplastic film is a special hot melt adhesive film, the film itself should have a high cohesive strength and tensile strength, so as to ensure the strong bonding of aluminum honeycomb panel. If the general hot melt adhesive film is used, its bonding strength is very low, and the 180 ° peel strength value is only 3N/mm.

2. Effect of production process on peel strength of aluminum honeycomb panel

The use of hot press production of aluminum honeycomb panels, due to the hot press pressure is larger, more difficult to control, in order to prevent the collapse of aluminum honeycomb core, often placed pad. If the pad is high, it will affect the applied pressure, resulting in low bonding strength. Such as the use of flat thermal composite machine, because the pressure is provided by the elastic force, can be adjusted by the height to control the applied pressure, therefore, the use of this process of production of aluminum honeycomb panel bonding strength is high, and very stable.

3. The influence of the surface condition of aluminum on the peel strength of aluminum honeycomb panel

The oil, dirt and naturally formed loose oxide layer on the aluminum surface will seriously affect the bonding effect of the aluminum honeycomb panel. Therefore, it must be cleaned and pretreated. The aluminum surface can be phosphated or chromized to form a close chemical conversion film on the aluminum surface, and the treated aluminum has a good bonding effect.