FR2825380A1 - PROCESS FOR MONITORING THE QUALITY OF MANUFACTURE OF TEXTILE FIBER TAPES - Google Patents

Abstract

The present invention relates to a process for controlling the quality of manufacturing textile fiber ribbons. A method characterized in that it consists in comparing the individual measurements made or individual values recorded simultaneously on at least two outgoing ribbons (2a, 2b, 2c ) or on at least two incoming layers of the same drawing machine (1), placed upstream of preparation finishers and provided with a rack (3), of at least one set of food cylinders (4a, 4b , 4c), at least one fiber control zone (5a, 5b, 5c) and at least one set of stretching cylinders (6a, 6b, 6c), by means of measurement sensors (9a, 9b, 9c and / or 10a, 10b, 10c), to an average reference which is itself determined on the basis of these individual measurements. The invention is more particularly applicable in the field of the textile machinery industry, in particular drawing machines. commonly known as Gills.

Description

has an annular light.

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DESCRIPTION

  The present invention relates to the field of textile machinery industry, in particular drawing machines commonly called Gills, and relates to a process for controlling the quality of

  manufacture of textile fiber ribbons.

  Currently, there are many online manufacturing quality control devices on stretching machines. These devices, the measurement principle of which differs depending on the model, are intended to control the variation of the titer in g / m or in Ktex of a fiber tape

  textiles leaving or entering a drawing machine.

  For this purpose, we know, from CH-A-441 067, a measuring device capable of determining the long-term variations of the title of a ribbon by weighing the quantity of ribbon deposited in a jar per unit of length of ribbon . The main drawback of this device is that the measurement is distorted when part of the tape is removed from the jar, either for periodic inspection or because of an incident. In addition, such a device does not

  not allow to control short term variations.

  WO-A-98/18985 and FR-A-2 768 437 respectively describe, moreover, the control of the volume occupied by the fibers which make up the ribbon using a feeler roller or by a feeler. These devices are bulky and of high inertia, so that they are unsuitable for detecting short-term variations, and ill-suited to high speeds when they are placed at the output of the stretching machine where they create windings of fibers. . In addition, the principle of measurement requires compressing the rub an

  output, which deteriorates its quality.

  FR-A-1 473 942 describes a measurement method by elastic deformation, in which the fiber tape passes through a funnel of reduced size, which slows down the passage of the tape and the elastic deformation of a material is controlled using a sensor, which can be a strain gauge, inductive, capacitive or optical. The size of the funnel must correspond exactly to the title of the outgoing tape and it should be changed each time the title of the outgoing tape is changed. In addition, the

  measuring principle deteriorates the quality of the outgoing tape.

  - 2 There is also known a measurement method by radiation, in which the rutan moves in front of a source of beta radiation for example (FR-A-1 209 535). The title of the rub an is proportional to the absorption of Beta particles. This type of device has the disadvantage of irradiating the textile material and poses the problem of recycling.

ray sources.

  There is also an optical measurement method using a device as known, for example, from FR-A-1 375 439 and which consists in circulating the tape in front of a light source emitting on a wavelength of the visible domain and detect light variations using a photoelectric cell. The textile material absorbs part of the electromagnetic waves and the variations in

  light are proportional to the title of the ribbon.

  The devices used for this purpose have the major drawback of being very sensitive to the color of the fibers and of displaying results.

  aberrant when the textile fibers are dyed.

  I1 has also been proposed, by FR-A-2,520,119, a sonic measurement method consisting in moving the tape in a chamber, in which a sound wave is emitted. The textile material absorbs and slows the propagation of the sound wave according to the title of the ribbon. This technology has the disadvantage of being very sensitive to dust and fiber deposits in the measurement chamber, so that one observes

  gradually a drift in the quality of the measurement.

  A pneumatic measurement method has been described in BE-A-873 050 and proposes passing the fiber tape through a funnel, in which the air pressure is measured, the value of which is proportional to the title of the tape. However, this method has the disadvantage of being sensitive to the

linear speed of the ribbon.

  A capacitive measurement method is also known, according to DE-A-1 043 886, which consists in passing the rutan between the electrodes of an electric capacitor, of which it modifies the dielectric capacity. The variations in dielectric capacity depend on the title of the rub an. The sensor used, although it is non-contact, very sensitive and very fast, has the disadvantage of being sensitive to variations in the environment, in particular, the temperature and humidity of the ambient air, so that drift of the measurement is observed. The object of the present invention is to overcome the drawbacks of known devices and methods by proposing a new method for controlling the quality of the manufacture of textile fiber ribbons allowing

an online check.

  To this end, the method is characterized in that it consists in comparing, online, the individual measurements carried out simultaneously on at least two outgoing ribbons or on at least two incoming sheets of the same drawing machine, placed upstream. preparation finishers, at an average reLerence itself determined from these measurements

1 0 individual.

  The invention will be better understood, thanks to the description below

  after, which relates to a preferred embodiment, given by way of nonlimiting example, and explained with reference to the appended schematic drawings, in which: 1S FIG. 1 represents a drawing machine implementing the process in accordance with to the invention, and FIGS. 2a to 2f are graphical representations of the

  individual measurement signals delivered by the device according to FIG. 1.

  Figure 1 of the accompanying drawings shows, for example, a drawing machine intended to produce three ribbons. Such a drawing machine 1, such as a gills, making it possible to simultaneously produce at least two ribbons 2a, 2b, 2c is provided with a rack 3, with at least one set of food cylinders 4a, 4b, 4c, at least one fiber control area Sa, 5b, Sc, at least one set of stretching cylinders 6a, 6b, 6c,

  funnels 7a, 7b, 7c and at least one storage device 8a, 8b, 8c.

  This machine is equipped, in ouke, with measurement sensors 9a, 9b, 9c and / or lOa, lOb, lOc. Thus, measurement sensors 9a, 9b, 9c are advantageously placed between the stretching cylinders 6a, 6b, 6c and the device

8a, 8b, 8c.

  In accordance with the invention, this machine 1 implements a process for controlling the quality of the manufacture of textile fiber ribbons which consists in comparing the individual measurements carried out or individual values recorded simultaneously on at least two outgoing ribbons 2a, 2b, 2c or on at least two wrapping plies of the same stretching machine 1, placed upstream of preparation finishers, at a retention

  average itself determines from these individual measurements.

  - 4 A graphical example of the results obtained is given in FIGS. 2a to 2c, where A is the amplitude of the signal delivered by the sensor 9a, B the amplitude of the signal delivered by the sensor 9b, and C the amplitude of the signal

supplied by sensor 9c.

  According to a characteristic of the invention, the method consists in producing for each sensor 9a, 9b, 9c, etc. a curve A, B. C corresponding to a progressive or sliding average of "m"

  individual values provided by said sensors.

  In accordance with another characteristic of the invention, the method consists in then performing a curve A, B, C of progressive average or sliding average of the arithmetic mean of the individual amplitudes of "n" values A, B and C, so as to smooth the evolution curve. This progressive average forming the curve A, B, C is

shown in Figure 2d.

  The values "n" and "m" are chosen so that very short-term variations are filtered and only the

medium and long term variations.

  Each individual curve A, B. C is compared, according to another characteristic of the invention, with curve A, B, C representing the progressive average and any exceeding of a predetermined difference threshold results in the emission, either of fault information detected, or a signal to stop the machine due to an unacceptable size fault. To this end, the emission of an alert signal will be given in a light or sound manner and supplemented by information in mode

  text describing the type of detect detected.

  The faults are classified according to different types which can be detected as a function of freely chosen thresholds, both in duration and in amplitude, namely thresholds for detection duration of a detachment T4, T5, alert thresholds for size defects different S1 and S2 and a stop threshold S3 for unacceptable size defect. Thus, for example, the duration threshold T4 can be of a relatively short duration, while the threshold T5 is greater than T4. The alert thresholds S1 and S2 can be chosen so as to signal the operator of the different sizes of defects that it is agreed to produce, while the stop threshold S3 is chosen so as to control

  stopping the machine due to a size defect deemed unacceptable.

  Other thresholds can obviously be chosen to replace or complement them. FIG. 2f represents the amplitude of a disturbance Z such as, for example, the increase in the relative humidity of the ambient air. From tl, there is an increase in the relative humidity of the air surrounding the stretching machine 1. This disturbance creates a drift of the signals delivered by the sensors 9a, 9b, 9c, which is represented by an increase in the amplitude of signals A, B and C. From t2 and up to t3 there is the absence of a supply ribbon for the drawing machine 1. This absence is detected by the

sensor 9b.

  By comparison of curve B with curve A, B, C there appears between t2 and t3 a difference which exceeds in hardness and in amplitude at the same time the thresholds of duration T4 or T5, the alert thresholds S1 and S2 and the stop threshold S3. Thus, for example, the alert will be given in a light or sound manner and supplemented by information in text mode describing the type

  fault detected and a machine stop command will be issued.

  Faults can be counted according to their type, as shown, for example, below: De.'fanf fype Durce Amplif ude Characterisf ique 1 T 4 S 2 Short, high amplitude 2 T 5 S 1 Long, low amplitude 3 T 5 S 2 Long, high amplitude Etc According to an alternative embodiment of the invention, it is also possible to determine the curve A, B, C by first performing the progressive average of A, B and C over " m "values so as to obtain the curves A, B and C then by taking the arithmetic mean of A, B and C

  before calculating the progressive average A, B, C. on "n" values.

  Thanks to the invention it becomes possible to overcome the drawbacks associated with indirect contactless measurements of the optical, sonic, pneumatic or capacitive type. Indeed, faced with an external disturbance, the inevitable measurement drifts of these types of sensors are

  supposed to be identical between two sensors of the same principle.

  As a priority, the quality control of the manufacture of textile fiber ribbons is placed on the last stretching machine making up a preparation line, which is located upstream of the supplier, such as the - 6 wiper or the pin bench or upstream. spinning loom, in the case of a

  preparation line for direct spinning without finisher.

  In this case, generally the latter preparation machine simultaneously produces at least two ribbons from the same batch and more commonly four ribbons. This machine feeds the finishers producing wicking coils which are difficult to recycle in the event of a fault. (respectively the spools of thread in the case of direct flotation). Therefore, it is preferable to detect defects at the outlet of the last drawing machine producing ribbons, which are easily

recyclable if necessary.

  L2example according to FIG. 2f represents the evolution of a perturbation Z as a function of time "t", such as, for example, a

  rapid increase in the relative humidity of the air surrounding the machine.

  The amplitude of this variation is relatively greater than its consequence measured by the sensors 9a, 9b, and 9c, which is shown in

Figures 2a, 2b and 2c.

  In the same way, we observe that the appearance of the disturbance Z does not reproduce directly on curves A, B and C. Also, it would be difficult to identify a fault if it were carried out, for example an operation A - Z. According to another alternative embodiment of the invention, measurement sensors lOa, lOb and lOc can be placed between

  the rack 3 and the food cylinders 4a, 4b, and 4c.

  These sensors 10a, 10b and 10c can, in addition, be placed on each individual strip 12 supplying the machine, upstream of the cylinders

food 4a, 4b, and 4c.

  In the case of individual sensors on ribbons, said sensors may, as a variant, be able to control only the presence or absence of a supply ribbon and it will be necessary to ensure that each drawing head of the machine is well fed by the number

adequate ribbons.

  It is also possible to place sensors lla to llf of the

  surrounding environment in addition to sensors 9a, 9b, 9c or 10a, lOb and lOc.

  The sensor 1 1 a is an empty sensor of textile material, of the same type as those, 9 or 10, used on the machine 1, while the sensors 1 lb, 1 lc and 1 ld respectively measure the temperature of the ambient air , the ambient humidity and the speed of the machine and the sensor records the parameters of use of the machine, such as the type of

material, title, etc ...

  By correlating the information from the sensors of the surrounding medium 1 la to 1 lf with the values measured by the sensors 9a, 9b, 9c S or lOa, lOb and lOc, the accuracy of the control process can be improved.

  the quality of manufacture of textile fiber ribbons, object of the invention.

  Of course, the invention is not imitated to the embodiment described and shown in the accompanying drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without leaving

  provided the scope of protection of the invention.

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Claims (10)

  1. Method for controlling the quality of manufacturing textile fiber ribbons, characterized in that it consists in comparing, on line, the individual measurements (A, B. C) made or individual values recorded simultaneously on at least two outgoing ribbons (2a, 2b, 2c) or on at least two incoming plies of the same drawing machine (1), placed upstream of preparation finishers and provided with a rack (3), with at least one set of food cylinders (4a, 4b, 4c), at least one fiber control zone (5a, Sb, 5c) and at least one set of stretching cylinders (6a, 6b, 6c), by means of sensors measurement (9a, 9b, 9c and / or 10a, 10b, 10c), at an average reterence itself determined from these individual measurements.   2. Method according to claim 1, characterized in that measurement sensors (9a, 9b, 9c) are placed between the stretching cylinders (6a,   6b, 6c) and a storage device (8a, 8b, 8c).   3. Method according to any one of claims 1 and 2,   characterized in that it consists in making for each sensor (9a, 9b, 9 c, etc.) a curve (A), (B), (C) corresponding to a progressive or sliding average of "m" individual values provided by said sensors.   4. Method according to any one of claims 1 to 3,   characterized in that it consists in carrying out a curve (A, B, C) of progressive average or sliding average of the arithmetic mean of the individual amplitudes of "n" values (A), (B) and (C), so to smooth the evolution curve.   5. Method according to any one of claims 1 to 4,   characterized in that the values "n" and "m" are chosen in such a way that the very short-term variations are filtered and that only the medium and long term variations.   6. Method according to any one of claims 1 to 4,   characterized in that each individual curve (A), (B), (C) is compared with the curve (A, B, C) representing the progressive average and any exceedance of a predetermined difference threshold begins the emission, that is to say a fault information detected, i.e. a machine stop signal   due to unacceptable size disruption.   7. Method according to claim 6, characterized in that the emission of an alert signal is given in a light or sound manner and supplemented by information in text mode describing the type of fault detected. 8. Method according to claim 6, characterized in that the faults are classified according to different types which can be detected as a function of freely chosen thresholds, both in duration and in amplitude, namely thresholds for detection duration of a detaut (T4, T5), alert thresholds for detours of different sizes (S 1 and S2) and a stop threshold (S3) for fault of unacceptable size.   9. Method according to claim 1, characterized in that it consists in determining a curve (A, B, C) by first carrying out the progressive average of (A), (B) and (C) over "m" values so as to obtain the curves (A, B and C) then by taking the arithmetic mean of (A), (B) and (C) before calculating the progressive average (A, B, C) over "n" values . lO. Method according to claim 1, characterized in that measuring sensors (lOa, lOb and lOc) are placed between the rack 3 and the   food cylinders (4a, 4b, and 4c).   11. Method according to claim 10, characterized in that the sensors (lOa, lOb and lOc) are placed on each individual strip (12)   feeding the machine, upstream of the food cylinders (4a, 4b, and 4c).   12. Method according to any one of claims l, 3,   and 1 1, characterized in that sensors (1 1 a to 1 1 f) of the medium