The structure and properties of a spunbond fabric are determined by numerous process variables. The development of fiber morphology is influenced and controlled by extrusion and quenching conditions. The properties of the fabric are the result of the properties of the filaments, their arrangement in the web, and the bonding conditions. It is therefore critical to understand the relationship between the process conditions and the properties of the fabrics produced. This study was conducted to investigate the effects of some of the important process variables on the structure and properties of the filaments and ultimately on that of the fabrics. Process variables such as polymer throughput rate, cooling and suction air speed, web basis weight, and bonding temperature were investigated. Filament samples were collected before bonding and were analyzed for various properties such as crystallinity, crystallite size, birefringence, density, thermomechanical stability, and tensile properties. The fabric samples were analyzed for tensile properties, tear strength, stiffness, and crystallinity. Ruptured strips obtained from the tensile test were observed with a scanning electron microscope to understand the failure mechanism. The results were statistically analyzed to evaluate the effect of process variables on the properties and to predict the properties for different process conditions. The findings are helpful in determining the optimum processing conditions so as to achieve the desired properties. (c) 2005 Wiley Periodicals, Inc.