Abstract: A battery separator of a nonwoven substrate coated on at least one surface with a cellulose film made from a liquid cellulose or cellulose derivative solution with the substrate having at least 50% by wt. noncellulosic fibers having a noncircular cross-sectional perimeter which has a percentage cross-sectional area difference relative to a circumscribed circle according to the formula: ##EQU1## wherein A=Area of a noncellulosic fiber cross-section; and B=Area of a circle circumscribing said fiber cross-section and, preferably, having an absorption rate of at least 15, most preferably at least 30 mm/10 min. in an aqueous solution of 40 wt. % KOH.

Abstract: A curl resistant battery separator of a noncellulosic nonwoven substrate extrusion coated on at least one surface with a cellulose film and process for making such separator by contacting a nonwoven noncellulosic textile substrate with a cellulose or cellulose derivative solution on at least one side of said substrate; converting the solution to a solid cellulose or cellulose derivative, preferably having a degree of polymerization of at least 350, more preferably at least 600, to form a coated substrate; washing said substrate in an aqueous solution; drying the coated substrate under biaxial tension to provide a battery separator having a moisture content of from about 4 to 25 wt. % based on the bone dry gauge of the separator(BDG); and then holding the separator for at least 8 hours at elevated temperatures of at least 40.degree. C. in the presence of a controlled amount of moisture to produce a separator which is stabilized against curling and has a moisture content between about 4 to 25 wt.

Abstract: A battery separator of a noncellulosic nonwoven substrate extrusion coated on at least one surface with a cellulose film and process for making such separator by contacting a nonwoven noncellulosic textile substrate with a cellulose or cellulose derivative solution on at least one side of said substrate; converting the solution to a solid cellulose or cellulose derivative, preferably having a degree of polymerization of at least 350, more preferably at least 600, to form a coated substrate; washing and drying the coated substrate to provide a battery separator, preferably having a absorption rate of at least 6 mm/5 min. and a 30% KOH absorption of at least 200 g/m.sup.2.

Abstract: A battery separator of a cellulosic nonwoven substrate coated on at least one surface with a cellulose film and process for making such separator by contacting a nonwoven cellulosic textile substrate with a cellulose or cellulose derivative solution on at least one side of said substrate; converting the solution to a solid cellulose or cellulose derivative having a degree of polymerization of at least 500, preferably at least 600, to form a coated substrate; washing and drying the coated substrate to provide a battery separator having a absorption rate of at least 6 mm/5 min. and a 30% KOH absorption of at least 200 g/m.sup.2.