| 摘要 |
1396304 Producing indicia tapes UNIDARE ENG Ltd 5 May 1972 [5 May 1971] 13374/71 Heading B5A [Also in Divisions F2 and H2] A polyvinyl chloride tape is made by slicing an extruding polyvinyl chloride tube longitudinally through its wall, and flattening out the extrusion to the tape form during passage over a cooled bar or roller. The slicing of the extruding tube is effected by a knife 6 at the face of the extrusion die 2, 3 and vertically intersecting the lowest point of the die orifice. The sliced tube is opened out and flattened during passage around a bar 8, from which it passes through a partial seal of rubber into and around rollers 10 in a water cooling bath 7. Water escaping through the rubber seal to a tray 9 is recirculated via cooling means. The tape may be laid underground, e.g. immediately below a pavement, to indicate the line of a pipe or electric cable conduit beneath the tape, and the tape may be printed with words or a code indicating the nature of the conduit. |
