Process for in-line inspection of functional film layer containing detectable component

A process for assessing continuity of a functional layer of a web, comprising:

• A. forming the web by extruding a thermoplastic material through an annular die to form an annular tape, quenching the tape, collapsing the tape into lay-flat configuration and orienting the tape to produce an annular film tubing;
• B. forwarding the web at a speed of at least 5 meters per minute, the functional layer comprising a blend of a thermoplastic composition and a detectable component, the detectable component being present in the thermoplastic composition so that the detectable component is present at a detectable level in the functional layer;
• C. detecting the presence of the functional layer and a discontinuity in the functional layer, by inspecting the web with a machine vision system capable of detecting the presence or absence of the detectable component in the functional layer;
• and
• D. generating a signal in response to the discontinuity in the functional layer,
• wherein the inspecting is carried out by scanning the web while the web is in motion and in a lay-flat configuration, the scanning being carried out by a camera positioned downstream of a point at which the tape is quenched and collapsed into the lay-flat configuration.