Process parameters of poly (ethylene-co-vinyl acetate) (EVA)-modified poly (ethylene-co-1-octene) (POE)-interpenetrating, double network blend was designed through Taguchi L9 orthogonal array as a novel approach for complete optimization of engineering and solvent-swelling properties. Influence of different factors like EVA and peroxide concentrations, blending temperature, and blending time on gel content, tensile modulus, tensile strength, ultimate elongation were statistically calculated. Results showed good correlation between mathematical and physical inferences. Stress relaxation, hysteresis and other physico-mechanicals like total elongation, solvent-swelling, etc., were interestingly depended upon the nature of dominantly crosslinked phase instead of net crosslinking of the network hybrids. Sorption, on the other hand, depended on the hydrophobic-hydrophilic property of the surfaces. The series of data produced finally helped to select the best process parameters under which a particular POE-EVA blend composition yielded most balanced physico-mechanicals. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012