公开(公告)号：CH521168A

公开(公告)日：1972-04-15

申请号：CH963071

申请日：1971-06-30

Applicant: BASF AG

Inventor： HILLER HEINRICH DR ,  STEGE WOLF-DIETER DIPL ING ,  KIRSCHENLOHR WERNER DR ,  JANSEN GERHARD DIPL ING

IPC: B01D35/06 ,  B03C1/032 ,  B03C1/035 ,  B03C1/08

公开(公告)号：DE2158376A1

公开(公告)日：1973-05-30

申请号：DE2158376

申请日：1971-11-25

Applicant: BASF AG

Inventor： NOETZEL WOLFRAM DR ,  DAUR THEODOR DR ,  JANSEN GERHARD DIPL ING

IPC: G01N21/952 ,  G02B27/54 ,  G01N33/44

Abstract: A method for continuously, automatically examining a plastics tube to detect inhomogeneities is as follows: the tube after leaving the cooling ring of the extruder passes without contact perpendicularly to the line through the diaphragms of an optical detector between two symmetrically arranged lenses; the light beam passing through the apparatus is projected onto a screen and converted into electrical signals which are continuously recorded. The method enables point-type faults such as "fish-eyes" to be detected in preference to longitudinal streaks, while the tube is still in its blown state before being flattened into a sheet.