INSPECTING METHOD FOR FOREIGN MATTER IN POLYMER EXTRUDER

摘要

PURPOSE:To continuously detect the foreign matter in an extruded polymer with high accuracy by providing a light pervious part to the polymer passage of an extruder and allowing parallel light to be incident on the light pervious part from one side thereof and dividing the light into predetermined width on the other side thereof to detect the same. CONSTITUTION:The light pervious part 2 of an extruder 1 is formed from a connection pipeline 3 and the whole of the pipeline 3 or the light projecting window 3a and light detecting window 3b thereof is constituted of a light pervious member such as quartz glass. A light projecting source such as an LD and a lens or optical elements 5, 6 such as diffraction lattices are arranged on the side of the light projecting window 3a to introduce sheet like parallel light into a polymer passage. On the side of the light receiving window 36 light receiver is provided so that light detecting part groups dividing the light detecting width of the sheet like parallel light into 1/1000-1/10000 to detect the same are laterally arranged in one row to arrange a photodetector to detect transmitted light. By this constitution, not only the presence of foreign matter but also the size and position thereof can be detected.