| 摘要 |
A long profile part (I) is claimed, with a core as substructure (A) and a silicone foam outer sheath (A), esp. for use at temps. from -80 to +300 deg. C; the novelty is that the sheath is crosslinked with the core. Also claimed is a process for the prodn. of (I), by (a) extrusion of (A) from a silicone or PTFE, (b) coating with silicone by extrusion and (c) crosslinking by cold- or hot-vulcanisation. More specifically, (A) is a complete cylinder or other extrudable profile with any cross-section, or a single- or multi-channel tube, made of silicone (pref. contg. heating wires) or PTFE; (A) contains a reinforcement, e.g, braiding, knitted fabric or a winding of monofils or filaments, synthetic or mineral fibres or metal wire (which can be used as an electrical conductor for control, heat conduction or energy conduction); (I) has an interlayer of compact silicone (C) between (A) and (B); pref., (A) consists of braiding or knitted fabric of glass fibre or Aramid; (A) and (B) are co-extruded; pref. process involves braiding or knitting glass fibre or Aramid to form (A), wetting with an aq. silicone-based medium, coating with silicone foam by extrusion, and crosslinking by vulcanisation. USE/ADVANTAGE - (I) are useful, e.g, for the thermal insulation of pipelines, electrical and thermal insulation of cables etc, transport of gases, liqs. and solids (e.g, flour), and as soft conveyor rollers etc. The invention provides long profiles with a core and sheath which are firmly bonded together, so that they do not move against one another and cannot be separated without destroying the whole system; system (I) also has improved usage properties, is easier to handle and is produced by a low-cost, continuous pro
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