| 摘要 |
<p>1518734 Recovering and re-use of scrap PVC insulation SOUTHWIRE CO 23 Jan 1976 [23 Jan 1975] 2647/76 Addition to 1432718 Heading C3L Polyvinyl halide insulation is recovered from mixed insulated wire scrap containing at least one other insulation material by: (a) selectively dissolving the polyvinyl halide insulation from the mixed insulated wire scrap with a solvent at a temperature at which the solvent is a specific solvent for the polyvinyl halide insulation and at which temperature the solvent has substantially no solvent effect upon the other insulations present in the mixed insulation wire scrap. (b) separating the undissolved portion of the insulated wire scrap from the dissolved polyvinyl halide insulation (c) recovering the dissolved polyvinyl halide from solution in a dry state suitable for reuse and (d) extruding the recovered polyvinyl halide upon wire as insulation therefore. The process may be carried out using a countercurrent extractor in which a mixture of copper and aluminium metals in combination with polyethylene, cross-linked polyethylene, nylon, PTFE, polyvinyl chloride, copolymers of polyvinyl chloride, chlorinated polyethylene ethylene propylene rubber and polypropylene is contacted with tetrahydrofuran, N-methylpyrrole, methylethylketone, cyclohexanone, dimethylformamide, N - methylpyrrolidone and mixtures thereof and the vinyl halide recovered from the charged solution by thin film evaporation.</p> |
