Chip-free staple fiber process

Claim 1

A continuous process for the production of a staple fiber product, which process comprises: A. Spinning an equilibrium melt from a standard hydrolytic or anionic polymerization of caprolactam, the equilibrium melt containing methanol-extractable material including monomeric and oligomeric substances, the equilibrium melt being spun at a temperature of between about 230° and 270° C. through a spinnerette, the spinning take-away speed being less than about 250 meters/minute; the spinnerette having a multiplicity of holes spaced from each other in an asymmetric arrangement wherein the space between adjacent holes increases from each side of the spinnerette to the center thereof and from the front to the back thereof, the front being defined as that section proximate to the first entrance of quench gas, as set forth below, and the back being defined as that section proximate to the exhaust of quench gas, as set forth below; B. Quenching the molten polycaprolactam in two phases: (1) Directing gas at a temperature of less than 20° C. at a flow rate of between 200 and 500 cubic feet/minute for a polycaprolactam throughput of between about 0.25 to 1 gram/minute/spinnerette hole, to impinge upon the face of the spinnerette and molten polycaprolactam stands immediately adjacent thereto from a first entrance which is proximate to the section of the spinnerette referred to as the front thereof, and to be exhausted proximate to the section of the spinnerette referred to as the back thereof; and (2) Directing gas at a temperature of less than about 20° C. in an essentially countercurrent flow from a second entrance downstream from the first entrance with respect to the direction of movement of the filamentary polycaprolactam, at a rate which results in reducing the surface temperature of the polycaprolactam to a value between about 30° and 70° C. before drawing thereof as hereinafter defined; C. Applying a drawing and crimping lubricant and antistatic agent to the surface of the filamentary polycaprolactam; D. Drawing the filamentary polycaprolactam by conventional means at a total draw ratio between about 3 and 5; E. Crimping the drawn filamentary polycaprolactam by essentially conventional means; F. Cutting the crimped filamentary polycaprolactam into staple lengths by conventional means; G. Subjecting the filamentary polycaprolactam staple to a multiple stage washing procedure for removal of extractables; H. Drying the washed filamentary polycaprolactam staple by conventional means; and I. Packaging the dried filamentary polycaprolactam staple for subsequent use or sale.