JPH06166534A - Method for sensing occurrence of defective of chopped strand and sensor - Google Patents

Abstract

(57) [Abstract] [Objective] To provide a method and an apparatus for continuously and accurately measuring the amount of fluff generated from chopped strands to detect the generation of defective products accurately and quickly. [Structure] A fan 15 is provided in the vicinity of the transportation path of the chopped strands 4, and the generated fluff is sucked into the space between the light projecting portion 11 and the light receiving portion 12 of the laser beam a. The change in the intensity of the laser beam with which the light receiving unit 12 is irradiated is measured to determine the number of filaments that cross the beam within a fixed time.

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 measuring the amount of fluff generated in a chopped strand manufacturing process to detect the generation of defective products.

[0002]

As is well known, chopped strands (hereinafter abbreviated as "CS") obtained by cutting a glass fiber bundle into a predetermined length are reinforcing materials such as FRP, FTP (reinforced thermoplastic resin), sheet molding compound and the like. Widely used as.

FIG. 2 shows a general CS manufacturing apparatus. In this manufacturing apparatus, first, the strands 2 are pulled out from a large number of cakes 1 set on a creel table, supplied to a cutting unit 3, and cut into CS4 having a predetermined length. The CS 4 is sent to the drying device 6 by the conveyor 5 and dried. The CS, which has been dried, falls from the take-out port 7 to the conveyor 8 and is provided for sorting and packing.

By the way, since the CS has the use as described above, it is required to have resistance to a mechanical external force, and one having a low resistance is regarded as a defective product. The resistance of CS to external mechanical forces depends on the integrity and integrity of the fibers, so it is necessary to control the manufacturing process so that they are always good.

Generally, the cohesiveness and integrity of CS fibers is
It is controlled by measuring the amount of fluff on the product. Usually, the amount of fluff is obtained by sampling the product regularly, sealing a certain weight of the product in a container, vibrating and mixing the mixture, sieving, and weighing the defibrated fiber remaining on the sieve. Therefore, it is said that the smaller the amount of fluff per unit weight, the better the gathering property and the unity.

[0006]

However, in the above-mentioned conventional fluff amount measuring method, since the sample amount and the number of samplings are limited, it is hard to say that the measurement result definitely represents the whole.

The inventors of the present invention have studied various methods for continuously measuring the amount of fluff of CS. In a working atmosphere immediately before packaging, a high volume sampler for measuring dust in the environment is used. When the number of fluff floating on the surface was measured, it was found that there was a high correlation with the value obtained by the conventional method. However, this method has drawbacks in that it is impossible to continuously measure for a long time due to the clogging of the device and the cost is high.

Accordingly, an object of the present invention is to provide a method and a device for detecting defective CS products, which can continuously measure the amount of fluff of CS, have a high correlation with conventional methods, and are low in cost. is there.

[0009]

In order to achieve the above object, a method of detecting a defective CS product according to the present invention comprises a laser beam projecting portion and a light receiving portion at a predetermined distance in the vicinity of a CS transport path. And a laser beam emitted from the light projecting unit toward the light receiving unit, the change in the intensity of the laser beam irradiated to the light receiving unit is measured, and the filament crosses the beam within a certain time. It is characterized by finding the number of.

In addition, the CS defective product detection apparatus according to the present invention includes a laser beam projecting portion and a light receiving portion, which are opposed to each other at a predetermined interval in the vicinity of the CS transport path, and the light projecting portion. And a measuring unit for measuring the change in the intensity of the laser beam with which the light receiving unit is irradiated to obtain the number of filaments that traverse the beam within a certain period of time.

In a preferred embodiment of the present invention, the above C
A fan is provided in the vicinity of the transport path of S, and the fluff generated by the CS is sucked by this fan and introduced into the space between the light projecting unit and the light receiving unit.

Further, it is more preferable that the fan is provided in the vicinity of a portion where the CS drops in the transport path of the CS. In the above description, the portion where CS falls means, for example, the portion from the take-out port 7 to the conveyor 8 in FIG.

Further, the laser beam has a diameter of 2 m.
It is preferable to use a beam of a semiconductor laser focused to m or less.

[0014]

According to the present invention, the light emitting portion and the light receiving portion of the laser beam are placed in the vicinity of the CS transport path at a predetermined interval, and the laser beam is emitted from the light emitting portion toward the light receiving portion. To do. Some of the fluff generated from the CS is scattered and floating in the space around the CS transport path. When the fluff crosses the laser beam, the amount of light at the light receiving unit changes. Therefore, by changing the amount of change into a count amount, it is possible to measure the number of fluffs that cross the laser beam within a certain period of time.

It was found that the number of fluff thus obtained had a high correlation with the amount of fluff measured using a conventional vibrating screen. That is, according to the method of the present invention, C
It is possible to continuously measure the amount of fluff generated from S,
It becomes possible to more accurately detect the occurrence of defective CS in comparison with the conventional method that can be measured only by batch type sampling.

In a preferred embodiment of the present invention,
Since a fan was installed near the CS transport path to forcibly guide the fluff to the position of the laser beam by the action of the fan, the fluff generated from the CS was effectively collected and the fluff amount was more accurate. It becomes possible to measure.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the CS defective product detection apparatus of the present invention. This defective product detection device is provided with a fan 15 provided in a space above a conveyor 8 that conveys CS4, and a laser beam projecting unit 11 and a light receiving unit 1 that are placed above the fan 15 with a predetermined interval.
2 and a measuring unit 14 connected to the light projecting unit 11 and the light receiving unit 12 by a cable 13.

The fan 15 is a drying device 6 in FIG.
It is provided in the vicinity of the portion where CS4 drops from the take-out port 7 to the conveyor 8, preferably at a height of 20 cm above the conveyor 8 and its diameter is 10 cm. The fan 15 rotates at a speed of 2500 times per minute, sucks the fluff 16 generated from the CS 4 and floating around, and guides the laser beam to a space between the light projecting unit 11 and the light receiving unit 12.

Laser beam projector 11 and laser beam receiver 12
Means a predetermined distance, which is 9 cm in this embodiment, arranged on the air delivery side of the fan 15, and
A laser beam a having a diameter of 0.3 to 5 mm, which is modulated at 0.5 to 50 KHz, is irradiated from 1 toward the light receiving unit 12. The laser beam a has a diameter of 2
More preferably, it is a beam of a semiconductor laser focused to mm or less.

The measuring unit 14 is a laser beam projecting unit 1.
1 and the light receiving unit 12 are electrically connected to measure the intensity of the laser beam a with which the light receiving unit 12 is irradiated, and the change in this intensity is converted into a count amount. That is, when the fluff 16 crosses the laser beam a, the amount of light reaching the light receiving unit 12 changes. Therefore, by measuring how many times the amount of light has changed during a certain period of time, the laser beam a is changed over a certain period of time. The number of fluffs that have been traversed can be determined.

Next, an embodiment of a defective product occurrence detecting method according to the present invention using the defective product occurrence detecting device will be described.
From the outlet 7 of the drying device 6 of FIG. 2 to the conveyor 8,
In the portion where the CS falls, the fluff 16 generated from the CS is scattered and easily floats. These fluffs are sucked by the fan 15 and the laser beam projector 11
And the space between the light receiving unit 12 and the light receiving unit 12.

In this state, the laser beam projection unit 11
Irradiates the laser beam a from the
The intensity of the laser beam a reaching the light receiving unit 12 is detected. At this time, when the fluff 16 crosses the laser beam a, the amount of light in the light receiving unit changes, and the change is transmitted to the measuring unit 14 by an electric signal. The measuring unit 14 changes the change in the amount of received light into a count amount, and calculates, displays, and records the number of fluffs 16 that have crossed the laser beam a during a certain period of time.

According to this method, fluctuations in the amount of fluff can be constantly and continuously monitored, so that a quality abnormality or a process abnormality can be quickly detected.

Experimental Example For CS of the same variety but different fluff amount, the correlation between the fluff amount measured by the conventional method of vibration and sieving and the fluff amount measured by the method of the present invention was investigated. The results are shown in Table 1. Here, the value obtained by the conventional method is 5
It is obtained by vibrating 0 g of the sample, sieving it, and measuring the amount of fluff (g) generated in 1 minute.
Further, the value obtained by the method of the present invention is such that a 2 kg sample is dropped at one time using a vibrating feeder, the apparatus of the present invention is placed in the vicinity thereof, and the fluff that has traversed the laser beam a within 10 minutes is obtained. It is obtained by counting the number of. The above measurement was performed 8 times, and the correlation coefficient was calculated.

[0025]

[Table 1]

The correlation coefficient calculated based on the results in Table 1 was 0.8945, which was a significant value.

[0027]

As described above, according to the present invention,
Near the transportation path of the chopped strand, a laser beam projecting unit and a light receiving unit are placed at a predetermined interval,
Generated from CS by irradiating the laser beam from the light emitting part to the light receiving part, measuring the change in the intensity of the laser beam applied to the light receiving part, and determining the number of filaments that traverse the beam within a fixed time. Since it is possible to constantly and continuously monitor fluctuations in the amount of fluff that occurs, it is possible to quickly detect CS quality abnormalities and process abnormalities, reduce the number of defective CS products, and promote process stabilization. , You can get powerful data. Further, by providing a fan in the vicinity of the CS transport path and forcing the fluff into the space between the laser beam projecting portion and the light receiving portion, the fluff amount can be measured more accurately. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a defective product occurrence detection device according to the present invention.

FIG. 2 is a schematic view showing a general production apparatus for chopped strands.

[Explanation of symbols]

 4 Chopped strands 8 Conveyor 11 Light emitting unit 12 Light receiving unit 14 Measuring unit 15 Fan

Claims (8)

[Claims] 1. A laser beam projecting unit and a light receiving unit are placed in the vicinity of a chopped strand transport path at a predetermined interval, and a laser beam is irradiated from the light projecting unit to the light receiving unit. A method for detecting the occurrence of defective chopped strands, characterized in that the change in the intensity of the laser beam with which the light receiving section is irradiated is measured to determine the number of filaments that traverse the beam within a fixed time. 2. A fan is provided in the vicinity of the transportation path of the chopped strands, and the fluff generated from the chopped strands is sucked by the fan and introduced into the space between the light projecting section and the light receiving section. The method for detecting the occurrence of defective chopped strands according to claim 1. 3. The method for detecting the occurrence of defective chopped strands according to claim 2, wherein the fan is provided near a portion where the chopped strands drop in the chopped strand conveyance path. 4. The laser beam is a beam of a semiconductor laser focused to a diameter of 2 mm or less.
3. The method for detecting the occurrence of defective chopped strands according to any one of 3 above. 5. A laser beam projecting portion and a light receiving portion, which are opposed to each other at a predetermined interval in the vicinity of a chopped strand conveying path, and the intensity of the laser beam emitted from the light projecting portion to the light receiving portion. And a measuring unit for determining the number of filaments that traverse the beam within a fixed time, and a defective product detection device for chopped strands. 6. A fan for sucking fluff generated from the chopped strands and introducing the fluff generated in the chopped strands into a space between the light projecting portion and the light receiving portion is provided in the vicinity of the transportation path of the chopped strands. The defective chopped strand occurrence detection device. 7. The defective product occurrence detecting device for chopped strands according to claim 6, wherein the fan is provided near a portion where the chopped strands fall in the chopped strand conveyance path. 8. The laser beam is a beam of a semiconductor laser focused to a diameter of 2 mm or less.
7. The defective product occurrence detection device for chopped strands according to any one of 7.