Evolution of Structure and Properties in a Spunbonding Process

摘要

The inherent properties of filaments are of utmost importance in spunbonded webs. A good understanding of structure and property development in individual filaments is helpful in better comprehending the whole process. A polypropylene homopolymer and a copolymer (PP/PE) are processed on the Reicofil~® spunbonding line at the Textiles and Nonwovens Development Center of the University of Tennessee. The properties of the filament samples taken before thermal bonding are determined through a variety of experimental techniques, such as differential scanning calorimetry, thermomechan-ical analysis, scanning electron microscopy, density, x-ray diffraction, and mechanical properties. The performance properties of the bonded nonwoven fabrics from the same set of filaments are evaluated and the structure and properties of the fibers are compared with those of the bonded fabrics. Primary air temperature and throughput have a strong influence on the structure and properties of both filaments (before bonding) and non-wovens (after bonding). As primary air temperature and throughput decrease, filament diameter tends to decrease, accompanied by a simultaneous increase in crystallinity, birefringence, tensile strength, initial modulus, thermal stability, and density.