Process and apparatus for manufacturing optical cable elements

Apparatus for use in the manufacture of a tube of polymeric material comprising an extrusion machine for extruding a tube of polymeric material;

• means for drawing the extruded polymeric tube from the extrusion machine to reduce its internal diameter;
• at least one elongate oven downstream of said tube drawing means through which the drawn-down polymeric tube is adapted to pass;
• a source of gas, which will have no deleterious effect on the drawn-down polymeric tube, connected to the elongate oven intermediate of its ends;
• means, interconnected between the source of gas and the elongate oven, for heating the gas to a temperature sufficient to effect annealing of the polymeric material of the drawn-down tube;
• and, within the oven, an elongate perforate baffle which extends throughout substantially the whole length of the oven and which will effect turbulence of the heated gas and substantially even distribution of the heated gas around the advancing drawn-down tube.