| 摘要 |
<p>Thermoplastic tube production The extruded tube is (1) cooled by being passed over a pref. helically grooved cooling member, arranged in a coolant fluid bath, with coolant fluid flowing alont the helical groove; (2) successively flattened pref. between co-operating pairs of rollers (3) re-heated using pref. radiative heaters, and re-expanded by introducing heated air to the inerior of the tube, and (4) simultaneously pulled axially. The radial expansion of the tube is limited pref. by an annular air cushion arranged around it. The plastic is in a less crystallised form than plastic which is not so treated after extrusion.</p> |
