JPH0892828A - Removal of abnormal part in frictional false twisting - Google Patents

Abstract

PURPOSE: To provide a method for detecting and removing abnormal parts developed during conducting a frictional false twisting of a thermoplastic multifilament yarn. CONSTITUTION: In conducting a frictional false twisting of a thermoplastic multifilament yarn, the false twisting zone is equipped with a sensor 7 or 9 for abnormalities in yarn tension and/or yarn morphology zone to detect such abnormal parts. When sensed abnormality signals vanish within a specified time period, a doffer is actuated and a package being in winding operation is doffed and, concurrently, the yarn is transferred to a new package. While, when the abnormality signals do not vanish within the specified time period, a yarn cutter is actuated to cut the yarn. By this method, yarn productivity can be improved while preventing abnormal parts from contaminating into product yarns.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing an abnormal portion that has occurred when friction false twisting a thermoplastic multifilament yarn.

[0002]

2. Description of the Related Art Abnormalities such as untwisting are more likely to occur in friction false twisting than in spindle false twisting. As a method for detecting and removing this abnormal portion, for example, Japanese Patent Laid-Open No. 63-
Japanese Patent No. 112735 discloses a method of detecting yarn thickness unevenness or bulkiness unevenness at a false twisting twisting portion, and at the same time, activating a yarn cutter arranged immediately before a supply roller to cut the yarn being processed. Has been done.

However, the above method is a method for preventing the abnormal portion from being caught by the cutter when the abnormal portion is detected, so that the abnormal portion can be prevented from being wound, but it is cut by the cutter. However, there is a problem that productivity is significantly reduced especially in unmanned operation.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-described problem that productivity is lowered because the yarn is cut every time an abnormal portion is detected in the false false twisting process.
PROBLEM TO BE SOLVED: To provide a method of removing an abnormal portion in a false false twist, which does not involve an abnormal portion generated during processing in an inner layer of a package, and which can reduce the number of times of re-threading by cutting a yarn and improve productivity. This is a technical issue.

[0005]

The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems. That is, the present invention provides a device for detecting an abnormality in the tension or shape of a yarn in the false twisting region when performing the false twisting process on the thermoplastic multifilament yarn, and detects the abnormality during the friction false twisting process. If the detected abnormal signal disappears within a predetermined time, the doffing device is activated to doff the package being wound and the yarn is transferred to a new package. If the problem is not resolved, the gist is to remove the abnormal part in the false false twist, which is characterized by activating the yarn cutter to cut the yarn.

The present invention will be described in detail below.

FIG. 1 is a schematic diagram showing an embodiment of an apparatus for carrying out the present invention. In FIG. 1, the undrawn yarn or highly oriented undrawn yarn Y unwound from the pan 1 is a guide 2,
It reaches the feed roller 5 through the yarn cutter 3 and the guide 4. Next, the feed roller 5 and the first delivery roller
With respect to 10, the yarn Y is twisted by the friction false twisting device 8 and heat-fixed by the first heater 6 to become a false twisted yarn. Further, the false twist textured yarn is wound as a package 14 from the first delivery roller 10 through the second heater 11 and the second delivery roller 12 and by the winding roller 13 with an automatic doffing device.

At this time, a capacitance deviation signal generation detecting device 7 or 9 is provided just above the entrance side or just below the exit side of the false false twisting device 8, in which the yarn Y runs, The thickness unevenness or the bulky unevenness of the strip Y is continuously detected as a capacitance deviation signal. With respect to the detected deviation signal, the frequency signal below a specific frequency is full-wave rectified, and then the full-wave rectified waveform is integrated.

When the voltage of the integrated waveform exceeds a predetermined voltage (detects an abnormal signal) and returns to a predetermined voltage or less in less than 5 seconds (when the abnormal signal disappears), it is detected as an abnormal untwisted yarn. At the same time, the automatic doffing device is activated to doff the package being wound and transfer the yarn to a new package. In this case, since the abnormal untwisted yarn exists in the outermost layer of the doffed package, the outermost layer is unwound to form a product package.

On the other hand, when the voltage of the integrated waveform exceeds a predetermined voltage for 5 seconds or more, it is detected as an abnormal yarn and, at the same time, the yarn cutter 3 arranged immediately before the roller 5 is operated to cut the yarn.

Regarding the time during which the voltage of the integrated waveform exceeds the predetermined voltage, the automatic doffing device operates for less than 5 seconds,
The reason why the yarn cutter is activated for 5 seconds or more is that most of the abnormal untwisted yarns instantly return to normal yarns, and if abnormal yarns continue for 5 seconds or longer, they become abnormal yarns continuously. This is because there are many cases.

The thickness unevenness or the bulky unevenness of the yarn Y is shown in FIG.
As shown in (I), it appears according to the amplitude of the waveform,
When the level changes from the a level to the b level, it is detected as an abnormal untwisted yarn. As for the waveform, the amplitude of the waveform is large as shown in b and the frequency of the waveform is smaller than that of the normal yarn.

In order to reliably detect these abnormal untwisted yarns, the waveform of FIG. 2 (I) is full-wave rectified and further integrated to obtain a waveform of FIG. 2 (II). It is found from this waveform that an abnormal untwisted yarn has occurred when the voltage exceeds a predetermined voltage, and the abnormal untwisted yarn can be easily detected. At this time, when the voltage of the integrated waveform exceeds the predetermined voltage and returns to the predetermined voltage or less in less than 5 seconds, it is detected as an abnormal untwisted yarn and, at the same time, the automatic doffing device is activated and the doffing is automatically performed. At the same time, the yarn is transferred to a new package.

When the voltage of the integrated waveform exceeds a predetermined voltage for 5 seconds or more, it is detected as an abnormal yarn, and at the same time, the yarn cutter arranged immediately before the roller 5 is operated to prevent the abnormal yarn from being wound up. Stop false twisting.

In the above example, the electrostatic capacitance deviation signal generation detecting device 7 or 9 is provided just above the entrance side or just below the exit side of the friction false twisting device 8. Even if a tension measuring device is provided instead, the abnormal untwisted yarn can be detected and removed in the same manner as above.

[0016]

EXAMPLES Next, the present invention will be specifically described by way of examples.

EXAMPLE 1 A disk deviation 1-7-1 friction false twisting machine (manufactured by Teijin Seiki Co., Ltd., SDS-8 type) was used to detect a capacitance deviation signal generation device 7 (manufactured by Sun Electronics Co., Ltd., GQ). The device equipped with a sensor) was equipped with a 120d / 36f polyethylene terephthalate highly oriented undrawn yarn as a feeding yarn, the yarn speed was 760m / min, the draw ratio was 1.563 times, the D / Y (disk peripheral speed / yarn speed) was 1.709, Friction drawing false twisting was performed at a heater temperature of 205 ° C and a second heater temperature of 185 ° C.

At this time, the unevenness of the yarn Y is continuously detected as an electrostatic capacitance signal by using the electrostatic capacitance deviation signal generation / detection device 7 described above, and all waveforms having a frequency of 16 hertz or less are rectified. When this was integrated and this waveform was recorded on a chart, the results shown in FIG. 2 were obtained. At this time,
When the voltage exceeds 3V (dotted line in Fig. 2 (II)) and returns to 3V or less in less than 5 seconds, the above detection device is linked to the automatic doffing device in order to catch it as an abnormal untwisted yarn. When the voltage exceeds 3V and the voltage returns to 3V or less in less than 5 seconds, doffing is automatically performed to unravel the abnormal untwisted yarn existing in the outermost layer of the doffed package. Product packaging.

Further, in FIG. 2, the voltage exceeds 3 V,
When it continues for 5 seconds or more, to catch it as an abnormal thread,
The detection device was linked to the yarn cutter, and the yarn was cut when the voltage exceeded 3 V and 5 seconds or more had elapsed.

Embodiment 2 As a device for detecting an abnormal portion, a yarn tension detecting device (FAG)
Friction drawing false twisting was carried out in the same manner as in Example 1 except that an online tensor system manufactured by the same company was provided. At this time, the above-mentioned yarn tension detecting device is used to continuously detect the tension of the yarn Y, and the yarn tension exceeds 0.15 g / d in less than 5 seconds.
In order to detect abnormal untwisted yarn when it returns to 0.15g / d or less, the above detection device is linked to the automatic doffing device, and the yarn tension exceeds 0.15g / d and is less than 0.15g in less than 5 seconds.
When the temperature returned to below / d, doffing was automatically performed, and the abnormal untwisted yarn existing in the outermost layer of the doffed package was unwound to obtain a product package.

When the yarn tension exceeds 0.15 g / d and continues for 5 seconds or more, the above-mentioned detecting device is linked to the yarn cutter so that the yarn tension is detected as an abnormal yarn.
The yarn was cut when it exceeded 0.15 g / d for 5 seconds or more.

[0022]

According to the present invention, even if an abnormal portion such as untwisting occurs during friction false twisting, if the abnormal portion disappears within a predetermined time, the doffing device is activated. It is necessary to do threading work that involves a large loss of time and risk when reprocessing because the yarn is transferred to a new package while the package being wound up is doffed. There is no.

If the abnormal portion is not eliminated within a predetermined time, the yarn cutter is activated to stop the machining,
Since a large amount of abnormal yarns can be avoided, it is possible to improve the operability while preventing the abnormal parts from being mixed into the product package.

Therefore, the woven or knitted fabric using the obtained textured yarn has good quality, and the number of deficient weights during machining is reduced, so that the operability can be improved.

[Brief description of drawings]

FIG. 1 is a schematic process drawing showing an embodiment of an apparatus for carrying out the present invention.

FIG. 2 (I) is a chart of waveforms before full-wave rectification, (II)
Is a chart of the waveform obtained by full-wave rectification and integration.

[Explanation of symbols]

 Y Undrawn yarn or highly oriented undrawn yarn 3 Yarn cutter 6 First heater 7 Capacitance deviation signal generation detection device 8 Friction false twisting device 9 Capacitance deviation signal generation detection device 11 Second heater 14 Package

Claims (1)

[Claims] 1. When a friction false twisting process is performed on a thermoplastic multifilament yarn, a device is provided in the false twisting region to detect abnormalities in the tension and morphology of the yarn to detect abnormalities during the false false twisting process. When the detected abnormal signal disappears within a predetermined time, the doffing device is activated to doff the package being wound, and the yarn is transferred to a new package.
A method of removing an abnormal portion in friction false twist, which comprises activating a yarn cutter to cut a yarn when the abnormal signal is not eliminated within a predetermined time.