Papers Having High Average Specific Modulus and Ultimate Tensile Strength

A process for making a paper, comprising the steps of

• a) forming an aqueous slurry comprising 85 to 40 parts by weight polymeric fibers and 15 to 60 parts by weight binder, based on the combined weight of said polymeric fibers and said binder,
• wherein the polymeric fibers comprise first fibers and second fibers,
• the first fibers comprising a first polymer, wherein the first polymer is an aramid copolymer having a structure derived from the reaction of para-oriented aromatic diamine monomer and benzimidazole monomer with a para-oriented aromatic diacid monomer,
• the second fibers comprising poly(para-phenylene terephthalate) homopolymer, and
• the binder comprising a third polymer that is either an aramid homopolymer or aramid copolymer;
• and
• the polymeric fibers comprising 12.5 to 75 parts by weight first fibers and 25 to 87.5 parts by weight second fibers, based on the combined weight of said first and said second fibers;
• b) removing water from the slurry on a paper machine to form a wet paper composition;
• c) drying the wet paper composition to form a dried sheet;
• and
• d) thermally consolidating the dried sheet in one or more steps between nipped rolls heated to a surface temperature of 260° C. or more, using a nip pressure of 700 to 5000 lbs./inch (125 to 894 kg/cm);
• to form a paper having an ultimate tensile strength of 21 N-m/g or greater and average specific modulus of 4950 Pa-m3/g or greater.