Development of structure and properties during spunbonding of propylene polymers

The production of a spunbond fabric involves the interrelation of numerous process variables. The development of fiber morphology is influenced and controlled by the extrusion variables. Fabric properties are greatly influenced by the properties of the filaments composing them, web structure and the bonding conditions. Understanding the relation between the process parameters and the properties is of utmost importance since the desired properties of the end product can be predicted and engineered by adjusting the process conditions. Two types of polypropylenes (PP) prepared using different catalyst systems were processed on our spunbond pilot line. Filament samples collected before bonding and the bonded fabrics were analyzed for aspects of structure and properties such as crystallinity, birefringence, density, thermo-mechanical stability and tensile properties. Structure and properties of the fibers produced from metallocene catalyzed PP were much better than that of the Ziegler Natta (ZN) catalyzed PP.