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
  • G01N21/8803—Visual inspection
• • 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
  • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
  • G01N21/952—Inspecting the exterior surface of cylindrical bodies or wires
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/36—Textiles
  • G01N33/362—Material before processing, e.g. bulk cotton or wool

Definitions

• the invention relates to a method for identifying natural fibres .
• the invention relates to a method for identifying natural fibres, in particular wool and cashmere fibres, comprising the steps of: magnifying the fibres, arranged on a support, by means of a microscope; sending the magnified images to a data processor; processing the images sent to the processor so as to determine, for each fibre, at least the characteristic parameters of the scale height and, preferably, also the scale frequency and fibre diameter; comparing the parameters determined with a reference database formed using known fibres .
• an animal keratin fibre has an external structure composed of a multiplicity of scales having a transverse arrangement with respect to the length of the fibre.
• Scale height is understood as referring to the height of the steps which are naturally formed in the boundary zones between one scale and the next.
• Scale frequency is understood as meaning the number of scales per unit of length of the fibre. Background art
• One object of the present invention is to overcome the abovementioned limitations and drawbacks of the known art by providing a method for identifying natural fibres, by means of which it is possible to distinguish with a considerable degree of precision also those fibres which are very similar and can be easily confused with each other, such as, for example, wool and cashmere.
• Another object of the invention is to provide a method by means of which it is possible to determine with a considerable degree of precision and accuracy the quantitative composition of mixed fabrics or yarns made of natural fibres.
• a further object of the invention is to provide a method able to produce reliable and significant results in a relatively short execution time. Disclosure of the invention
• a filter which is able to identify the form of the steps in the scale division zone and use only the steps corresponding to predetermined forms for identification of the fibres.
• at least 1000 fibres should be examined.
• the image provided by the microscope may be divided into regions which are preferably square and which are then examined in succession, following a vertical or horizontal line-by-line path. If the image processing software detects that a region is not occupied by fibres, it passes to the next region. If a fibre occupies several regions, the analysis is performed so as to consider the whole fibre only once. For example, if during the analysis of a region it is detected that a fibre extends beyond the boundary of the region being examined, also occupying an adjacent region, examination of said fibre is momentarily interrupted and resumed during analysis of said adjacent region.
• the method may also be applied by a non-specialised operator since the measurements may be performed automatically.
• identification of the fibres is performed using, in addition to the scale height parameter, also the characteristic parameter for the fibre diameter.
• the contour line of the entire fibre following which the fibre is divided into substantially equidistant sectors.
• the number of division sectors is preferably five.
• Various diameters preferably five are then measured for each sector.
• the median value i.e. the third in order of magnitude
• the median value is then selected for each sector.
• the median value is in turn selected from among the five median values selected (one for each sector) the median value (i.e., in this case also, the third value in order of magnitude) is in turn selected.
• the value thus selected constitutes the characteristic parameter for the fibre diameter.
• the characteristic parameter for the scale frequency namely the number of the scales per unit of length the fibre.
• Identification of the contour lines of the fibres may be performed by various image processing programs of the known type.
• Various types of electron microscopes equipped with software able to perform automatically scanning of the image observed under the microscope are also known.
• the electronic processor after determining the nature of the plurality of fibres which make up the sample analysed, is able to calculate and provide the value relating to the percentage composition of the said fibres.
• Figure 1 shows a magnified image of a fibre sample viewed under an electron microscope
• Figure 2 shows a detail, on a larger scale, of Figure 1;
• Figure 3 shows a detail, on a larger scale, of Figure
• Figure 4 shows a rop plan view of the fibres arrange ⁇ on a suitable support for microscopic analysis
• Figure 5 shows a detail, on a larger scale, of Figure
• Figures 1 and 2 show the external structure of the animal fibres 1.
• the fibres 1 shown may be, for example, cashmere fibres.
• the external structure of each individual fibre 1 is composed of several scales
• the scale heights H may be used m order to distinguish one fibre 1 from another.
• Other characteristic parameters which may be used in order to determine the nature of a fiore may be the diameter D of the fibre and the scale frequency, i.e. the number of scales 2 per unit of length of the fibre.
• the diameter D of each fibre is preferably calculated in the following manner. Five equidistant sectors on the fibre are selected. By means of the image processing program, five diameters D for each sector are measured and the median value diameter thereof is selected. From among the five diameters D selected (one for each sector) the median value diameter is in turn selected, said value being taken as the value of the diameter D F of the fibre 1.
• Figure 3 shows the external profiles of various boundary zones between adjacent scales 2.
• the boundary zones are indicated by A, B, C and D.
• a step 3 which separates a scale 2 from the next one is present in each boundary zone.
• the method in question envisages detecting, for each step 3, by means of the image processing software, the height H and the inclinations S and I of the top and bottom sides, respectively, of the fibre profile, which define the step 3.
• the height H of the various scale steps (H A , H B , H c , etc.) is measured by determining the distance in a substantially radial direction (perpendicular to the longitudinal axis of the fibre) between the top edge and the bottom edge of the step 3.
• a filter of a known type, in order to exclude, when determining the characteristic parameter of the scale height H s of a fibre 1, some of the values detected for the various heights H of the steps.
• the filter acts so as to exclude, with reference to Figure 3, the heights of the steps indicated by B, C and D and so as to consider instead the height of the step indicated by A.
• the side F A of the step extends in a direction almost perpendicular to the longitudinal axis x of the associated fibre.
• S A and I A indicate, respectively, the directions of the sides of the scales which define, at the top and the bottom, the step of the boundary zone A. These directions S A and I A are almost parallel to each other.
• the value H A of the step height falls within a predefined tolerance range.
• the step A satisfies, within certain tolerance limits, predefined criteria (in particular, the perpendicularity of the side F A with respect to the longitudinal axis x of the fibre, the relative parallel arrangement of the top and bottom sides S A and I A , the value of the height H A of the step) and therefore the step itself is considered to be normal and may be therefore used in order to determine the step height parameter H s for that fibre 1.
• the step in the zone B does not satisfy one of the abovementioned criteria: in fact, as can be seen in Figure 3, the directions S B and I B of the top and bottom sides are far from being parallel with each other and exceed the tolerances limits envisaged.
• the step B is anomalous and therefore is not taken into consideration when calculating the scale height H s .
• the step C is also anomalous because it has a height He which is relatively small and lies outside the prechosen tolerance range.
• the step C which probably does not consist in reality of a proper dividing step between the two scales 2, but only of a simple projection of the fibre profile, is therefore excluded from calculation of the scale height parameter H s .
• the abnormal character of the step D and therefore its exclusion, is due to the excessive inclination of the side F D of the step with respect to the direction perpendicular to the longitudinal axis x of the fibre. In other words, the relative inclination of the side F D of the step D with respect to the longitudinal axis x of the fibre 1 exceeds the predefined tolerance range.
• the filter is able to operate so as to exclude scale steps having an inclination which exceeds a predefined range.
• Figure 3 shows, as a broken line, the side F' D of a step which also has an inclination which exceeds the predefined range.
• a filter of the known type which allows one to exclude, for the purpose of determining the scale height H s , scales having a side with a form which does not lie within a certain tolerance range.
• the scale height H s of each individual fibre may be determined, for example, by taking the mathematical mean of the heights H of the scale steps which can be used for that fibre or by selecting a median value from among the heights H of the scale steps which can be used for that fibre.
• Figure 4 shows a sample of fibres.
• the image processing program divides the sample into regions, in particular having a square shape, and analyses them in succession in the direction of the arrows.
• the image processing program may operate so as to consider each fibre no more than once.
• a large number of fibres of the known type is analysed beforehand in order to produce a comparative database.
• Identification of unknown fibres is performed by means of comparison of the characteristic fibre parameters with the comparative database. This comparison is performed using a statistical method, of the known type, preferably of the type which uses a fuzzy logic.
• a device able to implement the method in question comprises an electronic processor which controls a microscope, in particular an electron microscope, and which is designed to store the magnified images provided by the microscope.
• the processor is able to execute an image processing program which determines the characteristic parameters of each fibre and which can be used in accordance with the abovementioned criteria.
• the processor by means of another data processing program, then relates the abovementioned parameters to corresponding predetermined reference values.
• the device is designed to allow automatic analysis, by means of the abovementioned method of analysis, of at least two supports provided with different fibre samples. The analyses of each sample are performed in succession and separately.
• a plurality of supports each containing a fibre sample are conveyed so that the samples are subject to the action of the electron beam emitted by the microscope and are scanned by it in succession, while the data processor controls conveying of the supports.
• the analysis of each fibre should comprise a first step involving detection of the fibre on the support. After this, analysis of the fibre continues with a second step which consists in actual identification of the fibre within its particular group and during which the image processing software determines, using the abovementioned procedures, one or more characteristic parameters of the fibre which are compared with reference values, for example with a predetermined comparative database.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Immunology (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Physics & Mathematics (AREA)
• Pathology (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Food Science & Technology (AREA)
• Medicinal Chemistry (AREA)
• Treatment Of Fiber Materials (AREA)
• Preliminary Treatment Of Fibers (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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Cited By (4)

Citations (1)

• 1999
  • 1999-02-09 IT IT1999RE000017A patent/IT1310944B1/it active
• 2000
  • 2000-02-02 AU AU26885/00A patent/AU2688500A/en not_active Abandoned
  • 2000-02-03 WO PCT/IT2000/000033 patent/WO2000047981A1/en not_active Application Discontinuation
  • 2000-02-03 EP EP00905262A patent/EP1166093A1/en not_active Withdrawn

Patent Citations (1)

Non-Patent Citations (4)

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