Process for removing residual spin solvent from a gel spun filament, the filament, multi-filament yarn and products comprising the filament

摘要

Process for removing residual spin solvent from a gel spun, UHMwPE filament having an effective diameter of above 16 μm, comprising the steps of: removing residual spin solvent from the filament to a level of below 100 ppm at elevated temperature, while keeping the filament taut. The invention also relates to gel spun UHMwPE filament having an effective diameter of above 16 μm and a residual spin solvent residue of less than 100 ppm. Preferably the filament has a creep rate, measured at 50° C., under a load, so that the initial stress is 600 MPa, of less than 510−6 sec−1.

主权项

1. A process for removal of residual spin solvent from a gel spun ultrahigh molecular weight polyethylene (UHMwPE) filament comprising the steps of:
(a) providing a gel spun UHMwPE filament having an effective diameter of above 16 μm and a residual spin solvent content of between 100 and 2000 ppm, (b) winding the gel spun UHMwPE filament provided by step (a) around a frame so that the filament is taut around the frame at a tension of more than 0.15 g/dtex, and subsequently (c) placing the frame with the filament wound taut therearound according to step (b) in an autoclave and removing residual spin solvent from the filament by subjecting the filament taut to super critical CO2 extraction in the autoclave at a temperature between 80° C. and 147.5° C. and at a pressure between 50 bar and 400 bar for a time period between half an hour and 24 hours to thereby obtain a UHMwPE filament with residual spin solvent content of below 100 ppm.