• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    In the method according to the invention for measuring the hairiness of a yarn (9), the yarn (9) is moved along its longitudinal axis at a yarn speed (90) through a measuring region (51) where its hairiness is measured. The yarn (9) is acted upon in the measuring region (51) by an air flow (6) whose velocity vectors (61) on the yarn (9) each have a non-vanishing component perpendicular to the longitudinal axis of the yarn (9). This reduces the unwanted influence of air resistance on the measurement results. An apparatus according to the invention comprises a hairiness measuring device with a measuring range and at least one air nozzle arranged next to the measuring range.
    公开号:CH710860A2
    申请号:CH00838/16
    申请日:2016-07-01
    公开日:2016-09-15
    发明作者:Gehrig Stefan；Bodmer Simon；Schmid Peter
    申请人:Uster Technologies Ag；
    IPC主号:
    专利说明:

    AREA OF EXPERTISE
    The present invention is in the field of textile quality control. It relates to a method and a device for measuring the hairiness of a yarn, according to the preambles of the independent claims. Such methods and devices are preferably used in a textile laboratory.
    STATE OF THE ART
    In staple yarns that are spun from many fibers, individual fiber ends are not completely integrated into the actual yarn hull. They partially protrude from the yarn hull, which is called the hairiness of the yarn. The hairiness is an important yarn property, which is why the textile industry has a great interest in their reliable and reproducible measurement.
    Methods and apparatus for measuring the hairiness of yarns are known, e.g. from the documents WO 2011/153 648 A1, WO 2011/153 649 A1 and WO 2011/153 650 A1. According to these documents, the yarn is moved along its longitudinal direction by an optoelectronic yarn sensor device. The optoelectronic yarn sensor device successively takes a plurality of images of the yarn. From the images, a feature concerning the hairiness of the yarn is evaluated by means of image processing.
    In modern devices for testing yarn, the yarn is transported at speeds of several 100 m / min through the yarn sensor device. At such high speeds the air resistance leads to a deformation of the fiber ends. The fiber ends are bent towards the yarn hull - it can be said that "the hair is blown backwards by the wind." This complicates or distorts the measurement of hairiness; the measurement results are undesirably dependent on the yarn speed.
    The CN 101 671 946 A solves the problem by generating a surrounding the yarn, parallel to the yarn longitudinal direction extending air flow. The speed of the air flow is adjusted to the speed of the yarn, so ideally the air flow moves with the yarn and the fiber ends protruding from the yarn hull do not feel air resistance. The air flow is maintained in a cylindrical glass measuring tube along which the yarn passes. The air needed to produce the air flow is injected into the measuring tube through an annular inlet channel, which opens tangentially into the upstream tube end. The structure with the measuring tube and the annular inlet channel is complicated and expensive.
    PRESENTATION OF THE INVENTION
    It is an object of the present invention to provide a method and an apparatus for measuring the hairiness of a yarn, which reduce the undesirable influence of air resistance on the measurement results, but in comparison with the CN 101 671 946 A are simpler and less expensive ,
    These and other objects are achieved by the inventive method and the inventive device, as defined in the independent claims. Advantageous embodiments are given in the dependent claims.
    The invention is based on the idea to blow the yarn laterally in the measuring range. As a result, the fiber ends projecting from the yarn hull experience a force with a non-vanishing component perpendicular to the longitudinal axis of the yarn which sets them up, i.e., the yarn ends. away from the yarn hull.
    Accordingly, in the inventive method for measuring the hairiness of a yarn, the yarn is moved along its longitudinal axis at a yarn speed through a measuring range where its hairiness is measured. The yarn is subjected to an air flow in the measuring range, whose velocity vectors on the yarn each have a non-vanishing component perpendicular to the longitudinal axis of the yarn.
    By the term "non-disappearing component" is meant in this document a component which is not equal to zero.
    In one embodiment, the velocity vectors of the air flow on the yarn each have both a non-vanishing component perpendicular to the longitudinal axis of the yarn and a non-vanishing component parallel to the longitudinal axis of the yarn. The component parallel to the longitudinal axis of the yarn is preferably directed in the same direction as the yarn speed.
    The air flow may include velocity vectors with different directions.
    The air flow is preferably stationary.
    Alternatively, the air flow during the measurement can be changed over time. In particular, the air flow during the measurement - as a special case of temporal change - be turned off at least one time. Hairiness measurements from different times when the yarn was exposed to different air currents in the measuring area can be linked together.
    The amounts and / or the directions of the velocity vectors of the air flow on the yarn can be adapted to the yarn speed.
    The inventive device for measuring the hairiness of a yarn includes a hairiness measuring device with a measuring range through which the yarn along its longitudinal axis with a yarn speed is movable. for measuring the hairiness of the yarn. Furthermore, the device includes at least one air nozzle, which is arranged and formed next to the measuring range, that it discharges air into the measuring range and the ejected air generates an air flow in the measuring range whose velocity vectors on the yarn each have a non-vanishing component perpendicular to the longitudinal axis of the yarn to have.
    In one embodiment, the device has a nozzle body arranged next to the measuring area with a plurality of air nozzles. The nozzle body may have a cavity, the compressed air can be supplied and from which the plurality of air nozzles leads to the outside. Outlet openings of the plurality of air nozzles can be arranged in a planar outer area of the nozzle body facing the measuring area. The plurality of air nozzles may be arranged and formed such that axes of the plurality of air nozzles pass on both sides of a longitudinal axis of the yarn and are spaced therefrom. At least two of the air nozzles may have different angles of inclination with respect to the longitudinal axis of the yarn. In this case, it is advantageous if the at least two of the air nozzles are arranged along the longitudinal axis of the yarn and the amounts of the angle of inclination decrease in the direction of the yarn speed.
    The invention reduces the corruption of the Haarigkeitsmessung by air resistance or eliminates them completely. With a suitable adjustment of the air flow with respect to speed, direction and homogeneity, the hairiness measurement is largely independent of the yarn speed. The inventive method and the inventive device are simple and inexpensive to implement.
    TITLE OF DRAWINGS
    The invention will be explained in detail with reference to the drawings.<Tb> FIG. 1 <SEP> schematically shows a yarn on which the method according to the invention is carried out, in a side view.<Tb> FIG. 2 <SEP> shows force vectors generated by air currents in the method according to the invention.<Tb> FIG. 3 and 4 <SEP> show two different embodiments of a device (a) according to the invention in a frontal view and (b) in a cross section along the line b-b.
    EMBODIMENT OF THE INVENTION
    Fig. 1 shows schematically a yarn 9 in an inventive device for measuring the hairiness of the yarn 9. The yarn 9 consists of a central yarn body 91 and from the yarn body 91 projecting fiber ends 92, which are also called "hair". It is moved along its longitudinal axis at a yarn speed of typically several 100 m / min. The movement is indicated by an arrow 90, which can also be interpreted as a velocity vector of the yarn 9. In this case, in a measuring region 51 of the device, the hairiness of the yarn 9 is measured by one of the methods known per se from the prior art.
    Outside the measuring range 51, in particular in upstream and downstream of the measuring range 51 located further areas 52 and 53, the yarn 9 experiences an air resistance due to its movement. This air resistance deforms the fiber ends 92 projecting from the yarn package 91 and bends them in a direction opposite to the speed vector 90 towards the yarn package 91. This would complicate or distort the measurement of hairiness. If the hairiness is measured by means of a picture of an image and subsequent image processing, there is the danger that fiber ends 92 resting close to the yarn body 91 will not be recognized. If the hairiness is measured by detecting the shading of areas spaced differently from the yarn package 91, too short hair lengths would be measured.
    The invention counteracts the bending of the fiber ends 92 by the yarn 9 is acted upon in the measuring range 51 with an air flow 6, the velocity vectors 61 on the yarn 9 each have a non-vanishing component perpendicular to the longitudinal axis of the yarn 9. In other words, an amount of a velocity vector 61 must be greater than zero, and an angle a that the velocity vector 61 encloses with the yarn 9. must not be equal to 0 ° or 180 °. The velocity component perpendicular to the longitudinal axis of the yarn 9 exerts a force on the fiber ends 92 perpendicular to the longitudinal axis of the yarn 9, thereby re-establishing it, i. at least partially compensates its bending backwards. The airflow is preferably stationary, i. unchanging in time.
    Fig. 2 shows generated by air currents, acting on the fiber ends force vectors in the measuring range. It refers to a location that is so far away from the yarn hull 91 that the frictional co-movement of a boundary layer surrounding the yarn hull 91 is negligible. A first force vector FG is generated by the ambient air, which flows past the yarn 9 due to the yarn movement. The force FG causes in the further regions 52, 53 (see FIG. 1) the bending of the fiber ends 92 described above. A second force vector FL is generated by the air flow 6, with which according to the invention the yarn 9 is acted upon. The two force vectors FG and FL add up to a resultant force vector Fres = FG + FL, which is responsible for setting up the fiber ends 92 in the measuring range 51. In the ideal case, which is shown in Fig. 2, the resulting force vector Fressenkrecht to the longitudinal axis of the yarn 9, but this is not necessary for the functioning of the invention. In any case, the resulting force vector fresher has a non-vanishing component perpendicular to the longitudinal axis of the yarn 9.
    In Fig. 3, an embodiment of an inventive device 1 is shown, namely (a) in a front view and (b) a cross-section along the line b-b. The device 1 has a hairiness measuring device 2 for measuring the hairiness of the yarn 9. The hairiness measuring device 2 includes a camera 21 with a flat image sensor 22, which is mounted in a housing, together with other electronic components, on a printed circuit board 23. The camera 21 also has imaging optics for imaging the yarn 9 onto the image sensor 22, which is not visible in FIG. Furthermore, the hairiness measuring device 2 includes a lighting unit (not shown) for illuminating the yarn 9 in the measuring region 51. In the present exemplary embodiment, the hairiness measuring device 2 measures in the transmitted light, i. the yarn 9 lies between the illumination unit and the camera 21. In the frontal view of Fig. 3a, the camera 21 is on the left, the illumination unit on the right outside the image. An optical axis 24 of the hairiness measuring device 2 is spaced from the longitudinal axis of the yarn 9, as described in WO 2011/153 648 A1.
    The hairiness measuring device 2 includes the measuring region 51, through which the yarn 9 is movable along its longitudinal axis. The term "measuring range" here refers to a slightly wider range than merely that portion of the yarn 9 which is imaged onto the image sensor 22. Rather, the measuring area 51 extends approximately from an upstream yarn guide element 31 to a downstream yarn guide element 32.
    The device 1 includes at least one air nozzle 43, which is arranged and formed in such a way next to the measuring area 51 that it discharges air into the measuring range 51 and the ejected air in the measuring range 51, the air flow 6 (see Fig. 1) generates Velocity vectors 61 on the yarn 9 each have a non-vanishing component perpendicular to the longitudinal axis of the yarn 9.
    In the present embodiment, the device 1 has a arranged next to the measuring range 51 nozzle body 4 with six air nozzles 43. The nozzle body 4 has a cavity 42 to which a compressed air supply line 41 compressed air can be supplied and from which the air nozzles 43 lead to the outside. Axes of the air nozzles 43 are each in a plane which is perpendicular to a flat, the measuring area 51 facing outer surface 44 of the nozzle body 4, and are inclined relative to the longitudinal axis of the yarn 9 by an angle of α ≈ 60 ° (see Fig. 1) , In the embodiment of Fig. 3, the axes of all six air nozzles 43 are parallel to each other. Thus, the velocity vectors 61 of the air flow 6 on the yarn 9 each have both a non-vanishing component perpendicular to the longitudinal axis of the yarn 9 and a non-vanishing component parallel to the longitudinal axis of the yarn 9. The component parallel to the longitudinal axis of the yarn 9 is in the same direction as the speed of the yarn 9 directed.
    Outlet openings of the air nozzles 43 are arranged in the outer surface 44. Each of the air nozzles 43 generates a free jet directed against the measuring area 51. Each three air nozzles 43 are arranged on a straight line parallel to the longitudinal axis of the yarn 9. The two straight lines lie in the frontal view of FIG. 3a on two different sides of a projection of the yarn 9 on the outer surface 44 of the nozzle body 4. Thus, axes of the air nozzles 43 pass on both sides of the longitudinal axis of the yarn 9 without cutting them spaced from her. In addition, the outlet openings are offset on the one and the other side of the longitudinal axis of the yarn 9 in the direction of the longitudinal axis against each other. With this arrangement of the air nozzles 43, the vector field of the resulting air flow 6 on the yarn 9 is relatively homogeneous.
    The embodiment of Fig. 4 has three differences from those of Fig. 3. First, the outlet openings of each two air nozzles 43 are on both sides of the longitudinal axis of the yarn 9 at the same height. Secondly, the three air nozzles 43 each, which are arranged on a straight line parallel to the longitudinal axis of the yarn 9, different inclination angle α (see Fig. 1) relative to the longitudinal axis of the yarn 9. Therefore, the yarn 9 is acted upon by an air flow 6 whose Vector field contains velocity vectors 61 with different directions and is inhomogeneous. The amounts of the inclination angle α decrease in the direction of the yarn speed 90. In the present example, the angle of inclination cc is 90 ° for the uppermost air nozzle 43, 75 ° for the middle air nozzle 43 and 60 ° for the lowermost air nozzle 43. Third, the outlet openings of the air nozzles 43 are closer to one another. Empirical investigations and theoretical considerations have shown that under some circumstances this embodiment provides even better results of the measurement of hairiness than that of FIG. 3.
    In the compressed air supply line 41 (not shown) pressure control valve is preferably used, which regulates the air pressure in the cavity 42 to a predetermined desired value. The pressure control valve can reduce the air pressure in the cavity 42 with respect to a (not shown) compressed air source and compensate for possible pressure fluctuations of the compressed air source.
    The air flow 6 can be varied, i. E. be changed over time. The variation may relate in particular to the amounts and / or directions of the velocity vectors 61 of the vector field of the air flow 6. In the simple embodiment of FIG. 3, the amounts of the velocity vectors 61 can be varied by changing the air pressure in the cavity 42. With appropriate design of the air nozzles 43 and the direction of their axes, i. the drawn in Fig. 1 inclination angle a, and accordingly the direction of the velocity vectors 61 of the air flow 6 are changed. A change in a cross-sectional area of the air nozzles 43 is also conceivable. A further variation of the air flow 6 could be effected by changing the distance between the yarn 9 and the outer surface 44 of the nozzle body 4. The change in the air flow 6 can take place between different measurements and / or during a measurement.
    A variation of the air flow 6 can serve to adapt the air flow 6 to the speed 90 of the yarn 9. In this case, the variation preferably takes place between different measurements. During a measurement, the air flow 6 is then preferably stationary. The adaptation of the air flow 6 to the speed 90 of the yarn 9 can be carried out empirically or on the basis of theoretical calculations, FIG. 2 being able to assist.
    It is possible to vary the air flow 6 during a measurement. In particular, the air flow - as a special case of the variation - can be turned off during the measurement at least one time. Haarigkeitsmessungen from different times, to which the yarn 9 was applied in the measuring range 51 with different air currents 6 are then linked together. Such a combination of hairiness measurements on the same yarn 9, which were carried out under different conditions, may provide more reliable measurement results than with only a specific air flow 6.
    It is not necessary to apply the yarn 9 in the entire measuring range 51 with the air flow 6. For example, it may be sufficient to generate the air flow 6 only in an upstream section of the measuring region 51, that is to say in the vicinity of the upstream yarn guide element 31. The fiber ends 92 set up there remain positioned for a certain time because of their inertia. During this time, they pass through that section of the measuring area 51 which is imaged onto the image sensor 22. In this way, the hairiness of the yarn 9 can be measured without distortion, without the air flow 6 acting in said portion of the measuring range 51.
    Of course, the present invention is not limited to the embodiments discussed above. With knowledge of the invention, the skilled person will be able to derive further variants, which also belong to the subject of the present invention, as defined in the independent patent claims.
    LIST OF REFERENCE NUMBERS
    [0036]<Tb> 1 <September> Device<Tb> 2 <September> Haarigkeitsmesseinrichtung<Tb> 21 <September> Camera<Tb> 22 <September> Image Sensor<Tb> 23 <September> PCB<tb> 24 <SEP> optical axis of the hairiness measuring device<Tb> <September><tb> 31, 32 <SEP> Yarn guide elements<Tb> <September><Tb> 4 <September> nozzle body<Tb> 41 <September> Compressed air supply<Tb> 42 <September> cavity<Tb> 43 <September> air nozzles<tb> 44 <SEP> Outer surface of the nozzle body<Tb> <September><Tb> 51 <September> Range<tb> 52, 53 <SEP> more areas<Tb> <September><Tb> 6 <September> airflow<tb> 61 <SEP> Velocity vector of airflow<Tb> <September><Tb> 9 <September> Yarn<tb> 90 <SEP> Yarn movement, Yarn speed vector<Tb> 91 <September> Garnrumpf<tb> 92 <SEP> Fiber ends, hair
    权利要求:
    Claims (16)
    [1]
    A method (1) for measuring the hairiness of a yarn (9), whereinthe yarn (9) is moved along its longitudinal axis at a yarn speed (90) through a measuring area (51) where its hairiness is measured, characterized in thatthe yarn (9) is subjected to an air flow (6) in the measuring region (51) whose velocity vectors (61) on the yarn (9) each have a non-vanishing component perpendicular to the longitudinal axis of the yarn (9).
    [2]
    2. The method according to claim 1, wherein the velocity vectors (61) of the air flow (6) on the yarn (9) each have both a non-vanishing component perpendicular to the longitudinal axis of the yarn (9) and a non-vanishing component parallel to the longitudinal axis of the yarn ( 9).
    [3]
    A method according to claim 2, wherein the component is directed parallel to the longitudinal axis of the yarn (9) in the same direction as the yarn speed (90).
    [4]
    A method according to any one of the preceding claims, wherein the air flow (6) includes velocity vectors (61) in different directions.
    [5]
    5. The method according to any one of the preceding claims, wherein the air flow (6) is stationary.
    [6]
    6. The method according to any one of claims 1-4, wherein the air flow (6) is changed over time during the measurement.
    [7]
    7. The method of claim 6, wherein the air flow (6) is turned off during the measurement at least one time.
    [8]
    8. The method according to claim 6 or 7, wherein Haarigkeitsmessungen from different times, to which the yarn (9) in the measuring range (51) with different air flows (6) has been applied, are linked together.
    [9]
    A method according to any one of the preceding claims, wherein the amounts and / or directions of the velocity vectors (61) of the air flow (6) on the yarn (9) are adjusted to the yarn speed (90).
    [10]
    10. Device (1) for measuring the hairiness of a yarn (9), comprising a hairiness measuring device (2) with a measuring range (51) through which the yarn (9) along its longitudinal axis with a yarn speed (90) is movable, for the measurement the hairiness of the yarn (9),marked byat least one air nozzle (43), which is arranged and constructed next to the measuring area (51) in such a way that it discharges air into the measuring area (51) and the ejected air generates an air flow (6) in the measuring area (51) whose velocity vectors (61 ) on the yarn (9) each have a non-vanishing component perpendicular to the longitudinal axis of the yarn (9).
    [11]
    11. The device (1) according to claim 10, wherein the device (1) has a nozzle body (4) arranged next to the measuring area (51) with a plurality of air nozzles (43).
    [12]
    12. Device (1) according to claim 11, wherein the nozzle body (4) has a cavity (42), the compressed air can be supplied and from which the plurality of air nozzles (43) leads to the outside.
    [13]
    13. Device (1) according to claim 11 or 12, wherein outlet openings of the plurality of air nozzles (43) in a planar, the measuring area (51) facing the outer surface (44) of the nozzle body (4) are arranged.
    [14]
    The apparatus (1) according to any one of claims 11-13, wherein the plurality of air nozzles (43) are arranged and formed such that axes of the plurality of air nozzles (43) pass on both sides on a longitudinal axis of the yarn (9) and from there are spaced.
    [15]
    15. Device (1) according to any one of claims 11-14, wherein at least two of the air nozzles (43) have different angles of inclination (a) with respect to the longitudinal axis of the yarn (9).
    [16]
    The apparatus (1) according to claim 15, wherein the at least two of the air nozzles (43) are arranged along the longitudinal axis of the yarn (9) and decrease the amounts of the inclination angles (a) in the direction of the yarn speed (90).
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CN105696300A|2016-03-26|2016-06-22|武汉纺织大学|Method for precisely testing selvedge hairiness through yarn hairiness monitor|
    CN108344859A|2018-01-08|2018-07-31|武汉纺织大学|A kind of online test method of circulating friction fabric surface hairiness|
    法律状态:
    2019-10-31| AZW| Rejection (application)|
    优先权:
    申请号 | 申请日 | 专利标题
    CH9712015|2015-07-06|
    CH16172015|2015-11-07|
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