Methods of making spunbonded fabrics from blends of polyarylene sulfide and a crystallinity enhancer
Spunbonded fabrics are formed by melt-spinning a blend comprised of a major amount of an uncured substantially amorphous polyarylene sulfide and a minor amount of a crystallinity enhancer to obtain a nonwoven mass of filaments, and thereafter passing the nonwoven mass of filaments through a nip of heated calendering rolls to form a spunbonded fabric therefrom having at last substantially crystalline surface regions. Preferably, blending minor amounts of a polyolefin (e.g., polypropylene) with an uncured polyarylene sulfide (e.g., polyphenylene sulfide) allows spunbonded nonwoven fabrics to be formed which do not suffer from the drawbacks noted above. More specifically, spunbonded fabrics formed of a blend of PPS and polypropylene may be calendered (bonded) at temperatures greater than between about 110 to about 125° C. (preferably greater than about 140° C.), and exhibit lengthwise and widthwise shrinkage after heatsetting at 120° C. for 3 minutes which is less than about 5%.