JPS6212328B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for detecting crimp abnormalities in a false-twisted crimped yarn of synthetic fibers, and more specifically, an online method for detecting crimp abnormalities in a false-twisted crimped yarn during its manufacturing process. Regarding detection method. Incidentally, crimping abnormality is an abbreviation for poor yarn quality of false twisted crimped yarn due to an insufficient number of crimps or untwisting.

In general, when synthetic fiber yarn is subjected to draw false twist and crimping processing using a draw false twister, the quality of the resulting processed yarn depends on processing conditions such as the number of false twists and heating temperature, and the fuzz of the raw yarn to be processed.・It is greatly affected by quality abnormalities such as loops, mechanical defects such as damage to the yarn guide of the drawing false twisting machine, and scratches on the disc of the false twisting unit. The quality of such false-twisted crimped yarns is evaluated from various aspects such as fineness, strength, elongation, crimp performance, and others, and crimp performance is particularly important as a differentiating quality of false-twisted yarns.

Therefore, in the past, in order to guarantee this crimp performance, a yarn quality inspection process was set up, and a large number of sample products were taken from the product package and inspected to perform quality control, but the number of samples to be inspected was large. There is a problem in that the inspection work is time-consuming and requires a lot of manpower. Furthermore, there is a problem in that the yarn quality inspection in the inspection process is only a sample inspection of a very small portion of one sample product, and temporary yarn quality abnormalities in the manufacturing process cannot be detected.

The present invention has been made in view of the above problems, and it is possible to immediately detect the above-mentioned abnormality in crimp performance, that is, abnormality in crimp, in the manufacturing process, and also to detect the abnormality in crimp, which can be carried out with a simple configuration of simply providing a tension detector. It provides an online detection method.

That is, the present invention monitors the tension of the yarn in the yarn path of the false twist and crimping process in the process of manufacturing false twisted and crimped yarn, and detects abnormal crimp of the yarn based on the occurrence of pulse-like fluctuations in the tension. It is characterized by:

Hereinafter, the details of the present invention will be explained along with its progress. The present inventors believed that an excellent detection method could be realized if the occurrence of crimp abnormalities could be detected by online measurable variations in processing conditions, and that As a result of examining the relationship between the two, it was found that crimp abnormalities and yarn tension fluctuations in the yarn path downstream of the false twisting means occur simultaneously, and the degree of the correlation was examined as follows.

FIG. 1 is an explanatory diagram of the drawing false twisting machine used in the study, and the false twisted crimped yarn is manufactured as follows. The yarn Y is unwound from the yarn package 1,
The yarn is fed via the yarn guide 2 from the feed roller 3 to the false twisting and crimp processing area S at a constant speed. In the false twisting and crimping processing area S, the yarn Y is given a predetermined twist by the false twisting means 4 (in this example, a friction disk system is used), and at the same time, the twist is traced upstream and twisted by the heater 5. It is heat set, false twisted and crimped. The false-twisted and crimped yarn Y is taken off at a constant speed by a day belt roller 6, passes through a yarn guide 7, and is wound into a predetermined processed yarn package 9 by a winder 8.
is formed. Therefore, the yarn Y is stretched and crimped between the feed roller 3 and the delivery roller 6, and the method for producing such a processed yarn is already known as stretching and simultaneous false twisting.

10 in the figure is a tension detector according to the present invention, which is used to monitor the yarn path directly connected to the false twisting means 4 downstream thereof, specifically the false twist It is provided in the thread path between the applying means 4 and the delivery roller 6. Note that a commercially available thread tension detector can be used as the tension detector 10, so
A detailed explanation thereof will be omitted.

In the drawing false twisting machine having the above configuration, various factors that cause crimp abnormalities are artificially created (abnormal quality of raw yarn, abnormal processing conditions, mechanical defects in processing means, etc.), and crimp abnormalities are caused. The output signal of the tension detector 10 was recorded, and the relationship between the crimp abnormality and the tension of the yarn in the false twist crimp process was investigated.

FIG. 2 is a recording example of the output waveform of the tension detector 10 during abnormal crimp due to ununtwisted yarn. As shown in the same figure,
In the untwisted portion D where crimp abnormality occurs, a pulse-like change is observed in the output waveform of the tension detector 10, in other words, the yarn tension T rapidly rises and slowly returns. If the yarn thickness, processing speed, etc. are changed, the specific waveform of the pulse-like change will change, but as in Figure 2, the yarn tension will vary from the steady tension due to the untwisted portion D to the short-term. A pulse-like change was observed in which the tension changed over time and returned to a steady state. Therefore, although the reason for this is not clear, it is clear that the untwisted portion D of the yarn, that is, the crimp abnormality, can be detected online by monitoring the occurrence of pulse-like fluctuations in the yarn tension T during the false twist crimp process. . As mentioned above, the tension detector 10 for monitoring the thread tension T is commercially available and has already been established as an online measuring device, so the method of the present invention by tension monitoring has the great advantage that it can be immediately put into practical use. have

Figure 3 shows the amount of tension variation from the steady tension value 〒, that is, the wave height value H (see Figure 2) of the pulse-like changes in the untwisted part when changing the brand, processing conditions, weight number, etc., and the manual inspection. This is a diagram showing the relationship between the results of stratification of the degree of untwisting, and each point in the diagram is the measurement result of each sample.
From the figure, it is clear that although the wave height value H does not have a linear relationship with the degree of untwisting, there is a strong correlation. Considering that there is no practical problem when the degree of untwisting is extremely small, the brand This enables a reliable online detection method for untwisted yarn that is not affected by differences in twisting, processing conditions, and weight differences. In this case, as is clear from the figure, extremely small untwisted twists that are not abnormal in practice may be detected in some cases, but this is on the safe side from a quality assurance perspective, and does not pose a problem in practice due to its frequency.

The present invention has been explained above using a stretch false twisting machine as an example.
The present invention is not limited to such examples.

Although the in-draw method is shown as a process, it has been confirmed that it can be applied in exactly the same way to the out-draw method, and it has also been confirmed that the false twisting method can be applied in exactly the same way to other methods. It can be applied to the production process of false twisted crimped yarn in general.

In addition, from the viewpoint of detection sensitivity, it is preferable that the tension is detected downstream of the false twisting means shown in the above example, but it is still possible to detect the tension even after passing through a guide, etc., although the detection sensitivity will decrease somewhat. Therefore, any location where the tension of the yarn during false twisting and crimp processing can be detected, that is, the false twisting and crimping process, may be sufficient, but it is preferably downstream of the false twisting means in view of retroactive twisting.

Further, although the crimp abnormality has been explained using as an example the untwisting caused by untwisting failure during yarn processing, the present invention can also be applied to crimp abnormalities such as a defective number of crimps that exhibits the same situation as untwisting.

As explained above, according to the present invention, it is possible to perform online monitoring of the occurrence of crimp abnormalities in the manufacturing process of false-twisted crimped yarn, which could not be done with the prior art, and the inspection in the inspection process can be omitted. It is possible to rationalize the number of inspection personnel required for inspection. In addition, abnormalities in crimp can be detected early in the production process of false-twisted crimped yarn, and the quality of the yarn is greatly improved, with almost no false-twisted and crimped yarn mixed into the product package. , the effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a stretching false twisting machine according to the present invention;
FIG. 2 is a graph showing an example of yarn tension measurement, and FIG. 3 is a graph showing the relationship between the peak value of tension fluctuation and the degree of untwisting as determined by manual inspection. 1 is a yarn package, 4 is a false twisting means, 5 is a heater, 8 is a winder, and 10 is a tension detector.

Claims (1)

[Scope of Claims] 1. In the process of manufacturing false-twisted crimped yarn, fluctuations in the tension of the yarn are monitored during the false-twisted and crimped process, and abnormal crimp of the yarn is detected by the occurrence of pulse-like fluctuations in the tension. A crimp abnormality detection method characterized by: 2. The crimp abnormality detection method according to claim 1, wherein a crimp abnormality is determined when the peak value of the pulse-like fluctuation is equal to or greater than a predetermined value. 3. The crimp abnormality detection method according to claim 1 or 2, wherein the tension of the yarn is monitored downstream of the false twisting means in the false twisting and crimp processing step. 4. The crimp abnormality detection method according to claim 3, wherein the tension of the yarn is monitored downstream directly connected to the false twisting means.