Abstract
Thickness of greasy layer and that of oxide film on aluminum as rolled were determined by means of ellipsometry, and the effects of surface layers on the peeling strength of polyethylene and aluminum were examined. Chemical properties of the greasy layer were also studied by Auger electron spectroscopy and infrared absorption spectroscopy. From these measurements, it was found that the greasy layer is depleted almost completely in the air at above 500°C, being replaced by the growth of oxide film. It was also found that the peeling strength of aluminum and polyethylene decreases with the increase in the oxide film thickness. This is interpreted that bond failure does not take place at the interface between aluminum and polyethylene, but is caused cohesively by the brittle fracture of the oxide film. On the other hand, the greasy layer had very little effects on the adhesion of hotmelt abhesives such as polyethylene, but a marked decrease in the peeling strength was observed, if the layer was oxidized during the heating process.
