Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
  • G01N21/892—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the flaw, defect or object feature examined
  • G01N21/8922—Periodic flaws

Definitions

• the invention relates to a process for producing a strip-like material avoiding repeated surface defects, in which a feed material is worked using a working means which has at least one periodicity during working, this material being monitored, during the production of the strip-like material, for the occurrence of repeated surface defects, in order to be able to interrupt the working in the event of such surface defects being observed.
• All kinds of surface defects may arise when producing a strip-like material. These defects may be caused by any kind of contamination which is present on the surface of the strip-like material or other external influences. They may also stem from the composition of the strip-like material itself. Most of these surface defects are not due to the influence of the working means used for the production of the striplike material. However, in other cases a surface defect may be caused by the working means used. If such a working means comprises a moving component, the movement of such a component of the working means will often present some form of periodicity. If a surface defect is caused by such a periodically moving component, there is a considerable risk that this will lead to repeated surface defects, in other words surface defects which are repeated at intervals of a fixed strip length.
• the object of the invention is therefore to carry out the process disclosed in the preamble in such a manner that repeated surface defects can be observed with a minimum production of the strip-like material with such repeated surface defects.
• the pictures can be formed in various ways. For example, it is possible for photographic pictures to be visually compared with one another. It is also conceivable for transparent pictures to be superimposed optically onto one another, in which case repeated defects will clearly emerge. However, it is preferable for the pictures to be formed electronically as digital pictures which can then be electronically correlated. In this case, it is also easier to attenuate the representation of non- correlating defects and to intensify that of correlating defects by electronic means. In this way, it is therefore also possible to electronically signal repeated defects.
• strip-like materials may have a wide variety of shapes and chemical compositions
• the novel process has proven to be particularly useful for use on strip-like material which comprises an optionally coated metal strip.
• the working may comprise a rolling operation in which the working means is a rolling mill stand for reducing the thickness of the metal strip.
• the working may also comprise the application of a coating to a metal strip with the aid of an applicator roll. Each revolution of a roller or of an applicator roll then introduces a periodicity into the working, and damage, for example, to such a roll may cause a repeated surface defect.
• the circumference of such a roll can be used to establish the strip length between any repeated surface defects which arise.
• the invention relates not only to the process described but also to a device for use in the novel process, comprising a working means for producing a strip-like material, characterized in that this device furthermore comprises recording equipment for taking successive pictures of any surface defects on the strip-like material, as well as means for correlating successive pictures, it being possible to attenuate the depiction of non-correlating surface defects and to intensify that of correlating surface defects.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Metal Rolling (AREA)
• Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=19766067

Family Applications (1)

Country Status (2)

Cited By (2)

Citations (4)

• 1998
  • 1998-11-27 AU AU13538/99A patent/AU1353899A/en not_active Abandoned
  • 1998-11-27 WO PCT/NL1998/000674 patent/WO1999028730A2/nl active Application Filing

Patent Citations (4)

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