METHOD FOR PRODUCING A COATING LAYER MADE OF EXPANDABLE AND CROSS-LINKABLE MATERIAL IN A CABLE

摘要

A method is described for producing a cable (1, 101) including: at least one transmissive element (2), such as for example an element transmitting electrical energy or optionally optical signals as well; and an expanded and cross-linked coating layer (5) in a radially outer position with respect to said at least one transmissive element (2), said coating layer (5) comprisin g a composition including an expandable and cross-linkable polymeric material. The method comprises the following steps of: a) extruding the composition; b ) forming a coating layer made of expandable and cross-linkable polymeric material with the composition thus extruded; c) expanding the coating layer made of expandable and cross-linkable polymeric material; and d) cross-linki ng the above-mentioned coating layer made of expandable and cross-linkable polymeric material. The method of the invention provides that the above- mentioned expanding and cross-linking steps c) and d) are carried out by heating the coating layer made of expandable and cross-linkable polymeric material at atmospheric pressure by means of a suitable heating fluid. The method of the invention allows to attain a saving in production time and cos ts with respect to the prior art methods.