Fuzzy set approach for fitting a continuous response surface in adhesion formulation

Two response surfaces covering overlapping subregions have been connected using a fuzzy set approach, which resulted in exactly one continuous response surface. The modeling of a fuzzy border was necessary to describe the failure of a bond in the region of either cohesive or adhesive failure. The interpretation of the result allows for both optimizing the response and classifying the failure mode. This new method was applied to a formulated hotmelt adhesive for primerless poly(propylene) bonding. With high reliability the adhesives composed of isotactic oligo(propene), tackifiers and thermoplastic elastomers achieved more than 3 MPa according to DIN 52383.