JPH07102472A - Method of testing yarn evenness for elastic fiber and instrument therefor - Google Patents

Abstract

PURPOSE:To provide a method of testing yarn evenness for elastic fibers independently or continuously, or virtually simultaneously, and to provide an instrument to realize this method. CONSTITUTION:The instrument is made up of (A) an unwinding region to deliver elastic fibers at a constant rate, (B) a sequence of at least two extension regions and (C) a winding region to take up the elastic fibers at a constant rate. The method is characterized by that elastic fibers are made to travel continuously while applying elastic extension thereon, a sensor is set at either of the extension regions, and signals from this sensor are accumulated, controlled and subjected to waveform processing in one signal processor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for continuously measuring and analyzing yarn unevenness such as thickness, outer diameter, elastic modulus, etc. of elastic fibers having a large breaking elongation.

[0002]

2. Description of the Related Art A method for measuring yarn unevenness in the fiber length direction of synthetic fibers such as polyester and nylon filaments is a known technique, and is commercially available as a running yarn elastic modulus measuring device, a Worcester measuring device, or an outer diameter measuring device. ing. These existing yarn unevenness evaluation devices perform tension control using a tensor and supply yarns to a detection unit via a nip roller or a ceramic guide to detect yarn unevenness, but are represented by polyurethane fibers (spandex). In the case of elastic fiber, due to insufficient tension due to low elastic modulus, high peptization resistance due to sticking between fibers, and friction resistance to the yarn-bonded parts, stable plaque is obtained by using the above-mentioned conventional technology as it is, It is impossible to supply the yarn to the detection section, and the yarn unevenness cannot be measured.

In Worcester measurement, the anisotropy of the yarn cross section present in the electrode induces a change in the dielectric constant, which results in poor reproducibility of measured values or inadequate measured values. , The existing Wooster measuring device is equipped with a twisting device with a ceramic guide,
As mentioned above, it cannot be used to measure elastic fibers because of its high friction resistance and low tension.

From the above, Japanese Patent Laid-Open No. 48-136
As disclosed in No. 43, in order to obtain information regarding yarn unevenness of elastic fibers, it is necessary to perform an inefficient operation of repeatedly measuring the elastic modulus in the yarn length direction using a tensilon measuring machine or repeatedly measuring denier. It was the current situation that they were forced.

Further, the commercially available conventional yarn unevenness measuring instruments are based on the mechanical, electrical or optical principle, but since each measurement is carried out by an independent machine base, the It was very difficult to understand the relationship.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have overcome the above-mentioned drawbacks of the prior art and made a method for measuring yarn unevenness of an elastic fiber independently, continuously, or substantially simultaneously, and The inventors of the present invention have conducted intensive research into the apparatus and have reached the present invention.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to measure yarn unevenness in the fiber length direction in consideration of low tension and high frictional resistance of elastic fibers. In a device comprising a ridge region, two or more continuous stretching regions, and a winding region for pulling the elastic fiber at a constant speed, the elastic fiber is continuously run while being elastically stretched to contact and A detector is arranged in any one of the above-mentioned extension regions so that non-contact filament spot measurement can be performed independently, continuously, or substantially simultaneously, and the measurement signal from the detector is processed into one signal. The problem is solved by using a method for measuring yarn unevenness of elastic fiber and a device therefor, which are characterized by accumulating, controlling and corrugating in a section.

The present invention will be described in detail below with reference to the drawings.
FIG. 1 is a schematic diagram showing an example of the yarn unevenness measuring device for elastic fibers of the present invention, but the present invention is not limited to this. The elastic fiber (8) is a roller (R
It is unraveled in the unraveling area consisting of 1) and the roller (R2) that pulls it out. It is also possible to provide a guide for fixing the yarn path between R1 and R2, if necessary. In the peptization zone, the elastic fibers are delivered at a constant speed and stretched at a magnification slightly larger than the peptization resistance.

More specifically, the elongation required for unraveling is 2% or more, more preferably 5% or more and 50% or less. If it is less than 2%, it is detected as yarn unevenness in the extension area where the unraveling fluctuation continues. On the other hand, if it exceeds 50%, the elongation will exceed the elastic deformation range of the elastic fiber, and the measurement will be performed, and appropriate evaluation cannot be performed. As a method for feeding at a constant speed, a surface-driving method as shown in FIG. 1 or a contact-driving method in which elastic fiber cheese rotates is used, but the method is not limited to these. .

The unraveled elastic fibers are stretched in an elastic range in an elongation zone formed subsequent to the unraveling zone. In the apparatus shown in FIG. 1, the extension zone is composed of two or more rollers such as R2-R3, and the extension in the extension zone depends on the composition of the elastic fiber to be measured, denier, etc., but the measured elastic fiber runs stably. Therefore, the elongation rate of 5% or more is required. A more preferable range is 50% or more and 400% or less, but it is important to set it so that the total elongation rate from feeding to winding is 5% or more.

The measurement of yarn unevenness is carried out by R2-R3-R4 (route 1) or R2-R6-R7-R3-R4 (route 2). When the route 1 is used, independent or substantially simultaneous measurement of non-contact yarn unevenness measurement based on the optical principle shown by 4 in the figure and contact yarn unevenness measurement based on the mechanical principle shown by 5 in the figure Is possible. Further, if necessary, online heat treatment by a non-contact heater shown by 3 in the figure becomes possible, and yarn unevenness measurement under heating becomes possible.

When the yarn diameter of the elastic fiber is measured by the route 2, the noncontact yarn spot measurement based on the electrical principle shown by 1 in the figure, the noncontact yarn spot measurement based on the optical principle, and
The contact yarn unevenness measurement based on the mechanical principle can be performed independently or continuously. Further, in performing non-contact yarn unevenness measurement based on the electrical principle, it is necessary to twist with a twist imparting device having two or more self-rotatable guides shown in FIG.

This is especially important for measurements of 70 d or less. Elastic fibers, including polyurethane,
Even when elastically stretched, the tension is lower than that of polyester filaments and the like, and the frictional resistance is high. Therefore, a self-rotating guide is required to stably supply the elastic fiber to the detecting portion.

This guide is usually used as a guide having two or more rotary shafts directly connected to the motor, but is not limited to this. The rotation number of the twisting device is preferably 5 t / m or more, and more preferably 10 t / m or more and 300 t / m or less.

FIG. 2 shows an example of a twisting device for twisting elastic fibers, but the present invention is not limited to this. The twisting device is composed of a frame in which two or more self-rotating guides are arranged in series and which holds them. In this self-rotating guide, a bearing having a rotating shaft fixed to a frame is usually used, but the bearing is not limited to this.

The elastic fibers for which the unevenness measurement has been completed are R4-R.
It is wound up through 5. At this time, either Nelson Tyop or nip type roller may be used as the roller. The elongation rate in the winding area is preferably 10% or less, more preferably 2% or more and 7% or less.

The signal measurements from the contact and non-contact yarn spot detectors are generally controlled in one signal processor (7). The overall control means input of measurement conditions, analysis of measurement results, and output thereof, and statistical processing of contact and / or non-contact measurement signals in the signal processing unit,
Auto and / or cross correlation analysis and frequency analysis can be performed.

EXAMPLE A 40 denier polyurethane urea elastic fiber measured by the yarn unevenness measuring method and apparatus of the present invention,
FIG. 3 shows the measurement result of yarn unevenness based on the electrical principle, and FIG. 4 shows the frequency analysis result.

[0018]

According to the present invention, the yarn unevenness measurement based on the mechanical, electrical and optical principles of the elastic fiber can be performed independently, continuously, or substantially simultaneously.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention.

FIG. 2 shows a twist imparting device used in an embodiment of the present invention.

FIG. 3 is a view showing an example of a result of measuring a yarn unevenness based on an electrical principle in the example.

FIG. 4 shows an example of a frequency analysis result in the example.

[Explanation of symbols]

 1: Non-contact yarn spot detector based on electrical principle 2: Twisting device 3: Non-contact heater 4: Non-contact yarn spot detector based on optical principle 5: Running tension detector 6: Guide 7: Signal processing unit 8: Elastic fiber

Claims (2)

[Claims] 1. A method for continuously measuring yarn unevenness or the like in the fiber length direction of an elastic fiber, comprising a deflocculation region for feeding the elastic fiber at a constant speed, two or more continuous elongation regions, and the elasticity. Using a device comprising a winding area for drawing the fiber at a constant speed, the elastic fiber is continuously run while being elastically stretched, and contact and / or non-contact yarn unevenness measurement is independent or continuous, Further, the elastic fiber is characterized in that the detectors are arranged in any one of the above-mentioned extension regions so that they can be performed substantially simultaneously, and the measurement signals from the detection units are integrated, controlled and waveform-processed in one signal processing unit. Method for measuring yarn unevenness. 2. A device for continuously measuring yarn unevenness or the like in the fiber length direction of an elastic fiber, which comprises an unwinding region for feeding the elastic fiber at a constant speed and two or more continuous stretching regions for the elastic fiber. , And at least a winding area for pulling the elastic fiber at a constant speed, and a detector for measuring yarn unevenness in the contact and / or non-contact area is arranged in the extension area, and a measurement signal from the detector is integrated. An apparatus for measuring yarn unevenness of an elastic fiber, comprising a signal processing unit capable of controlling, waveform processing.