Abstract: A composite media includes a stack with 20 or more layers, each layer including a substrate with a first major surface and an opposing second major surface; and a fiber layer deposited onto the first major surface of the substrate and including polymeric fibers with a diameter of 100 nm to 1.5 ?m. Each fiber layer independently has a thickness of 5 ?m to 100 ?m, and each layer independently has a pore size of 0.1 ?m to 10 ?m. A filter may include a housing and the composite media disposed within the housing. The filter may be a syringe filter.

Abstract: A process for making nanofibers includes preparing a fluid suspension of fibers, shear refining the fibers to create fibrillated fibers, and subsequently closed channel refining or homogenizing the fibrillated fibers to detach nanofibers from the fibrillated fibers. The shear refining of the fibers in the fluid suspension generates fiber cores having attached nanofibers. The closed channel refining or homogenizing of the fibrillated fibers is initially at a first shear rate and, subsequently, at a second, higher shear rate, to detach nanofibers from fiber cores and to create additional nanofibers from the fiber cores. The fiber suspension may flow continuously from the shear refining to the closed channel refining or homogenizing, and include controlling the rate of flow of the fiber suspension from the shear refining to the closed channel refining or homogenizing.

Abstract: A process for making fibrillated fibers includes preparing a fluid suspension of fibers, low shear refining the fibers at a first shear rate to create fibrillated fibers having a reduced CSF, and subsequently higher shear refining the fibers at a second shear rate, higher than the first shear rate, to increase the degree of fibrillation of the fibers. The refining at the first shear rate may be with a rotor at a first maximum shear rate and the refining at the second shear rate may be with a rotor at a second maximum shear rate, higher than the first maximum shear rate. The process may further include pre-treating the fibers by high shear refining with impact to stress the fibers prior to low shear refining.

Abstract: A process for making fibrillated fibers includes preparing a fluid suspension of fibers, low shear refining the fibers at a first shear rate to create fibrillated fibers having a reduced CSF, and subsequently higher shear refining the fibers at a second shear rate, higher than the first shear rate, to increase the degree of fibrillation of the fibers. The refining at the first shear rate may be with a rotor at a first maximum shear rate and the refining at the second shear rate may be with a rotor at a second maximum shear rate, higher than the first maximum shear rate. The process may further include pre-treating the fibers by high shear refining with impact to stress the fibers prior to low shear refining.

Abstract: A process for making nanofibers includes preparing a fluid suspension of fibers, shear refining the fibers to create fibrillated fibers, and subsequently closed channel refining or homogenizing the fibrillated fibers to detach nanofibers from the fibrillated fibers. The shear refining of the fibers in the fluid suspension generates fiber cores having attached nanofibers. The closed channel refining or homogenizing of the fibrillated fibers is initially at a first shear rate and, subsequently, at a second, higher shear rate, to detach nanofibers from fiber cores and to create additional nanofibers from the fiber cores. The fiber suspension may flow continuously from the shear refining to the closed channel refining or homogenizing, and include controlling the rate of flow of the fiber suspension from the shear refining to the closed channel refining or homogenizing.