| 摘要 |
A pulp of synthetic polymer fibers useful for papermaking. The fibers have the appearance of rolled or folded sheets at a magnification of about 500X and are distinct from one another, being only mechanically intertwined. The fibers are of papermaking size, no more than about 10 percent by weight of the fibers being retained on a 20 mesh screen but at least about 25 percent by weight are retained on a 65 mesh screen. The pulp has a drainage factor greater than about 0.2 seconds/gram and a compressibility constant N greater than about 0.2. The pulp is preferably formed of high molecular weight polyethylene or polypropylene. Also, a process for forming polymer fibers comprising forming a solution of a crystalline polymer in a solvent at a temperature above the melt dissolution temperature of the polymer, passing the polymer solution through a precipitation zone into a region of reduced pressure whereby a portion only of the solvent is adiabatically vaporized and the polymer is precipitated as a highly swollen fibrous mass or gel, separating the solvent vapor from the gel, and subjecting the fibrous gel to attritional forces to liberate the individual, discrete polyolefin fibers therefrom. |
