A process for the preparation of a homogeneous spinning solution for the production of acrylic fibers, which includes: preparing an aqueous suspension of homopolymer or copolymer of acrylonitrile through the polymerization of monomers in aqueous suspension, removal of the unreacted monomers, filtration and washing of the aqueous suspension, obtaining a filtration cake; dispersing the filtration cake; and evaporating the dispersion of polymer or obtaining the homogeneous spinning solution.

The invention is contemplated for providing polyethylene-based fibers in which elution of metal from polyethylene is suppressed as much as possible. The invention relates to polyethylene-based fibers, composed of at least one kind of polyethylene resin, in which a total of content of metal elements such as Na, K, Ca, Fe, Cu, Mg, Mn, Li, Al, Cr, Ni and Zn contained inside the fibers is 40 ppm or less. Moreover, the invention relates to a nonwoven fabric using the polyethylene-based fibers.

A process is described for the preparation of a homogeneous spinning solution for the production of acrylic fibers, which comprises i) a preparation step of an aqueous suspension of homopolymer or copolymer of acrylonitrile through the polymerization of monomers in aqueous suspension, removal of the unreacted monomers, filtration and washing of the aqueous suspension, obtaining a filtration cake, ii) a step for dispersing the filtration cake and a step iii) for evaporating the dispersion of polymer or obtaining the homogeneous spinning solution.

A method for producing a carbon nanotube web includes a step of preparing a carbon nanotube array disposed on a substrate, the carbon nanotube array including a plurality of carbon nanotubes vertically aligned relative to the substrate; and a step of drawing a carbon nanotube web from the carbon nanotube array, the carbon nanotube web including a plurality of carbon nanotube single yarns arranged in parallel in a direction intersecting the direction carbon nanotube single yarns extend, and the carbon nanotube single yarns including a plurality of continuously connected carbon nanotubes. In the step of drawing a carbon nanotube web, the drawing position of the carbon nanotube web from the carbon nanotube array is kept at the same position in the drawing direction of the carbon nanotube web.