阅读说明：本技术 检查方法及检查装置 (Inspection method and inspection apparatus ) 是由 河津祐介 难波谅 野濑诚 藤冈俊文 物部浩之 于 2019-09-05 设计创作，主要内容包括：提供一种检查技术,其能够在脱水/干燥工序之后且成型前检测出过剩水分。一种碎屑状聚合物的检查方法,其特征在于,连续地供给经聚合并脱水干燥后的碎屑状聚合物,并检测出所述碎屑状聚合物内的包含过剩水分的碎屑。(Provided is an inspection technique capable of detecting excess water after a dehydration/drying step and before molding. A method of inspecting a crumb polymer, characterized by continuously supplying a crumb polymer after polymerization and dehydration drying, and detecting a crumb containing excess moisture in the crumb polymer.)

1. An inspection method characterized in that, in the inspection method,

continuously feeding the polymerized and dehydrated dried crumb polymer,

debris including excess moisture within the crumb polymer is detected.

2. The inspection method of claim 1,

the temperature of the polymer in crumb form is measured,

based on the temperature difference, debris containing excess moisture is detected.

3. The inspection method of claim 2,

for the continuously fed polymer in crumb form, the temperature at each measurement point was determined,

the average temperature of more than 2 measurement points is determined,

debris corresponding to measurement points having a temperature below the average temperature is detected.

4. The inspection method of claim 3,

and detecting the chips corresponding to the measurement points with the average temperature difference of more than 9.5 ℃.

5. The inspection method according to any one of claims 1 to 4,

the average temperature of the polymer when the dehydrated and dried crumb-like polymer is supplied is 40 to 70 ℃.

6. The inspection method according to any one of claims 1 to 5,

the crumb containing excess moisture is in the form of a cake.

7. The inspection method according to any one of claims 1 to 6,

the water content of the crumb containing excess water is 1 mass% or more.

8. An inspection apparatus, comprising:

a supply unit continuously supplying the crumb polymer after polymerization and dehydration drying;

a temperature measuring unit for measuring the temperature of the crumb polymer supplied by the supplying unit; and

and a determination unit for calculating a temperature difference from the average temperature by using the temperature measurement unit, and detecting the debris containing the excessive moisture based on the temperature difference.

9. The inspection apparatus of claim 8,

the temperature measuring unit is a thermal imaging camera.

Technical Field

The present invention is a technique for inspecting whether moisture is present in a crumb polymer being supplied and conveyed.

Background

As an example of the process for producing the crumb polymer, a process for producing a synthetic rubber such as butadiene rubber will be briefly described.

A butadiene solution as a raw material is prepared, and a catalyst is added to the butadiene solution to polymerize the butadiene solution to form a polymer solution (polymerization step). The obtained polymer solution was subjected to steam treatment to recover a polymer in the form of a crumb slurry (desolventizing step). The polymer containing moisture is dehydrated by an extruder and dried by hot air or the like to be in a dry crumb state (dehydration/drying step). The polymer in the form of chips is compressed and molded (molding step). Generally, particles having a particle diameter of about 3 to 10mm, which are generated in the production process of synthetic rubber, are referred to as crumb.

The present invention relates to a molding process. The molding step will be described in some detail.

The chip-shaped or powdery semi-finished product is press-formed into a press-formed product (generally referred to as a bale (ベール), hereinafter referred to as a bale) having a regular hexahedral shape by a press-forming machine (generally referred to as a baler, hereinafter referred to as a baler).

At this time, the polymer in the form of chips was automatically measured and adjusted to a predetermined weight range. The rubber packages are wrapped with a film wrapping bag such as a polyethylene film or a polystyrene film, and a plurality of rubber packages are stored in a storage container such as a container and shipped to a user.

The bale is melted or dissolved on the user side, and is vulcanized and processed.

As described above, in the production process of synthetic rubber, water is always used, and therefore water is removed in the dehydration/drying step. However, water that is not completely removed in the dehydration/drying step actually remains. In the case of a package containing excessive moisture, there is a possibility that a defect in appearance may occur or a defect may occur on the user side.

In contrast, in a conventional general forming process, a package containing excessive moisture is detected by visual inspection based on the appearance of a monitor after the package is formed and before the package is carried out. However, the monitoring personnel cannot detect the excess water inside the bale. In addition, the burden on the monitoring personnel is also large.

Patent document 1 proposes the following technique: by using an infrared-transmitting transparent plate having a smooth surface and irradiating infrared rays to the sample rubber through the transparent plate while pressing the rubber, the moisture content of the sample rubber can be measured in a short time and with high accuracy.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2004-020192

Disclosure of Invention

Problems to be solved by the invention

According to the technique of patent document 1, it is estimated that the packaged product does not contain excessive moisture by measuring the moisture content of the sample rubber and confirming that the moisture content is equal to or less than a predetermined value.

However, the present inventors have studied the mechanism of the remaining excess water, and as a result, it is considered that whether the remaining excess water has a low order, is difficult to predict, and it is difficult to determine that the excess water is not contained in the package as a product even when the moisture content of the sample rubber is equal to or less than a predetermined value.

The present invention has been made in view of the above problems, and an object thereof is to provide an inspection technique capable of detecting excessive moisture after a dehydration/drying step and before molding.

Means for solving the problems

The present invention for solving the above problems is an inspection method in which a crumb polymer obtained by polymerization, dehydration and drying is continuously supplied, and a crumb containing excessive moisture in the crumb polymer is detected.

The excess moisture contained in the package, which has not been detected conventionally, can be detected by detecting the chips containing the excess moisture in the chip-like state before the package is formed.

In the above invention, it is preferable that the temperature of the crumb polymer is measured, and the crumb containing excess water is detected based on the temperature difference.

In the above invention, it is preferable that the temperature of each measurement point of the continuously supplied crumb-like polymer is measured, the average temperature of 2 or more measurement points is obtained, and crumb corresponding to the measurement point having a temperature lower than the average temperature is detected.

In the above invention, it is preferable that the chips corresponding to the measurement points in which the temperature difference of the average temperature is 9.5 ℃ or more are detected.

This makes it possible to detect a low-temperature portion that is affected by vaporization of excess water or that is less affected by temperature increase.

In the above invention, it is preferable that the average temperature of the polymer when the dehydrated and dried crumb polymer is supplied is 40 to 70 ℃.

This makes it easy to make the above-described influence by the excessive moisture conspicuous.

In the above invention, it is preferable that the crumb containing excessive moisture is in the form of a lump.

Debris containing excess moisture tends to clump. Further, when the particles are in a lump form, they are easily detected to be vaporized or hardly affected by temperature rise.

In the above invention, it is preferable that the water content of the crumb containing the excessive water is 1 mass% or more.

An inspection device according to the present invention for solving the above-described problems includes: a supply unit continuously supplying the crumb polymer after polymerization and dehydration drying; a temperature measuring unit for measuring the temperature of the crumb polymer supplied by the supplying unit; and a determination unit that calculates a temperature difference from the average temperature using the temperature measurement unit, and detects debris containing excess water based on the temperature difference.

In the above invention, it is preferable that the excess moisture checking means is a thermal imaging camera.

Effects of the invention

The present invention can detect the excessive water content after the dehydration/drying process and before the molding.

Drawings

Fig. 1 is a system configuration diagram of an embodiment of the present invention.

Fig. 2 is a result of a verification test according to the basic concept of the present invention.

Fig. 3 shows an example of detection according to an embodiment of the present invention.

Detailed Description

System constitution ^ E

Fig. 1 is a system configuration diagram of an embodiment of the present invention.

The system includes a continuous supply unit, an excess moisture inspection unit, a package weight measuring unit, a package forming unit, a carrying-out unit, and a control unit, and performs a series of operations.

The continuous supply unit is, for example, a vibratory feeder 1. The vibratory feeder 1 continuously feeds the crumb polymer 2 after polymerization and having passed through the dehydration/drying process 8 to the system.

The excessive moisture checking unit is, for example, a thermal imaging camera 3. The thermal imaging camera 3 is provided on the vibratory feeder 1, and detects excessive moisture by detecting that the temperature does not rise due to insufficiently dried chips (details will be described later).

The bale-equivalent weight measuring unit is, for example, a weighing device 6 having a hopper. The hopper is arranged between the continuous feeding unit and the bale forming unit. The hopper has an upper hopper and a lower hopper. The weight of the crumb polymer accumulated in the hopper is measured by the weighing device 6 by controlling the operation of the upper hopper and the lower hopper, and the weight of the crumb polymer corresponding to the bale is measured.

The bale forming unit is, for example, a press forming machine (baler) 7. The polymer in the form of chips measured by a bale equivalent weight measuring unit is supplied and pressure-molded into a bale.

The carrying-out unit is, for example, a conveyor 14. A weight measuring device 15 is provided midway on the conveyor 14.

The excess moisture check information is input from the excess moisture check unit 3, and the package weight information is input from the weight measuring device 15, so that the control device 30 performs classification control. That is, when the excessive moisture is not detected, the package having a weight within the standard range is carried out as the standard product 12 to the next step (packaging step) 9; the bales detected to have excess water and/or weight outside the standard range are removed as non-standard goods 13 and sent to another step 10 (reprocessing).

The excess water does not have a substantial disadvantage, and the crumb polymer containing the excess water can be reused as a material by reprocessing it.

Basic concept of this application E

The present invention focuses on the temperature difference due to the excess water. Fig. 2 is a result of a verification test according to the basic concept of the present invention. In FIG. 2, the vertical axis represents the water content (% by mass) of the chips, and the horizontal axis represents a value obtained from [ (WP surface temperature) - (average temperature of chips) ]. Here, the WP surface temperature means a measured temperature of a portion assumed to contain excessive moisture in the chips, and the average chip temperature means an average temperature of 2 or more measurement points.

The average temperature of the crumb polymer after polymerization and continuously supplied to the molding step through the dehydration/drying step is 40 to 70 ℃. More specifically, the average temperature of the crumb polymer was 48.8 ℃ in the validation test conducted in winter, while the average temperature of the crumb polymer was 60.7 ℃ in the validation test conducted in summer.

The average outside air temperature in the test site was about 6 ℃ in winter and about 26 ℃ in summer. The average temperature of the crumb polymer after the dehydration/drying process is affected by the outside air temperature.

The temperature of the crumb-like polymer varies from-20 ℃ to +15 ℃ on the average, both in summer and in winter. The water content of the crumb-like polymer at this time was examined.

The following is evident from the results of fig. 2. The moisture content is very low for chips with WP surface temperatures near or above the average chip temperature. On the other hand, the moisture content is high for chips having a lower surface temperature than the average temperature of the WP. Particularly, when the temperature difference between the WP surface temperature and the average crumb temperature is 9.5 ℃ or more, the moisture content of the crumb is very high.

In addition, a tendency was observed that the chips containing excess moisture were likely to clump. The portion of the block containing excess moisture is defined as WET POINT (WP). While the chips after the dehydration/drying step have a relatively high temperature, it is estimated that the chips containing excessive moisture lose heat during vaporization of the moisture or the temperature of the chips is unlikely to increase due to the excessive moisture.

The same trend was observed in both summer and winter. In one example of the test, the chip surface temperature was 48.8 ℃ and the WP was 35.4 ℃ (the difference between the chip surface temperature and the WP was 13.4 ℃); in summer, the chip surface temperature was 60.7 ℃ and the WP was 47.4 ℃ (the difference between the chip surface temperature and the WP was 13.3 ℃).

From the results, it is understood that debris containing excessive moisture can be detected by measuring the temperature of the crumb-like polymer, and in particular, WET POINT can be reliably detected without being affected by the outside air temperature by focusing on the temperature difference. In particular, WET POINT of chips containing excess water of 1 mass% or more can be detected.

Detection of debris containing excess moisture (WET POINT)

The WET POINT is detected based on the temperature difference. More specifically, the WET POINT can be detected by obtaining the average temperature of 2 or more measurement POINTs of the chips and setting the measurement POINT portion having a temperature lower than the average temperature as the WET POINT.

By setting the measurement POINT portion having a difference of 9.5 ℃ or more from the average temperature as the WET POINT, the WET POINT can be detected with higher accuracy.

The average temperature of the chips can be determined by the following method, for example.

Fig. 3 shows an example of temperature measurement. The temperature measuring unit is a thermal imaging camera. It is possible to perform shooting of 30 frames/second. The thermal imaging camera 3 may use, for example, CPA-L25B manufactured by CHINO corporation.

The debris is imaged and imaged by a thermal imaging camera, and the temperature of each image in pixel units in an image range (shown by a dotted line) corresponding to a predetermined range (for example, 600mm × 500mm) is measured. The average temperature of the debris can be determined from the measured temperature of each pixel.

When the average temperature is determined, the measurement point is preferably 100 to 100000, more preferably 1000 to 100000, and particularly preferably 10000 to 100000. The WET POINT can be detected with high accuracy.

Furthermore, the WET POINT is detected by extracting pixels having a low temperature of a predetermined value or less (e.g., 9.5 ℃) of the average temperature.

Estimation of excess moisture Generation mechanism

It is a prerequisite that no chips having excessive moisture are generated by the dehydration/drying process. Nevertheless, debris with excess moisture is actually produced. The mechanism is examined.

In the dehydration/drying process, moisture is discharged to the outside. At this time, the small pieces adhere to the inner wall surface of the discharge portion. The small pieces absorb a part of moisture discharged to the outside.

The chips containing moisture may be peeled off for some reason and mixed into the chips to be supplied to the next step (molding step).

Therefore, it is very difficult to predict the generation of debris with excess moisture.

About piece

As a feature of the chips, it is presumed that the chips have adhesiveness and easily adhere to each other, and a chip mass is easily formed. It is presumed that WET POINT is generated due to the inclusion of the crumb pieces containing excessive moisture.

On the other hand, if excessive water is present in a concentrated manner, the influence of vaporization and the like is easily conspicuous, and the low-temperature portion is easily detected (see fig. 3).

Therefore, the present application is suitable for the detection of WET POINT, but not limited to the debris mass, but can also be applied to debris.

The general crumb particle size is 3 to 10 mm. In the present application, a crumb having a particle size of 20mm or more is referred to as a crumb lump.

Effect E

According to the above, the excessive moisture can be detected after the dehydration/drying step and before the package formation. As a result, the excessive moisture in the package can be detected.

It should be noted that since excess moisture can be detected prior to bale formation, there is a possibility that the crumb polymer containing the excess moisture may be removed, for example, on the drop rail of a baler.

However, the crumb-like polymer has adhesiveness, and particles are easily adhered to each other, and as a result, the particle size becomes non-uniform, and it is difficult to predict behavior. In the case of removing crumb polymer containing excess moisture on the drop rails of a baler, a complex mechanism is required. On the other hand, if the bale containing excessive moisture is removed after the bale is formed, the removal can be easily and reliably performed.

In the above, no other configuration or process is necessary other than the thermal imaging camera and the simple control. The excess water can be detected simply and reliably without adding a new structure or a new process to the existing manufacturing process. The quality of the product is not affected.

In addition, by focusing attention on the temperature difference, it is possible to reliably detect the temperature difference without being affected by the outside air temperature.

Object crumb polymer ℃

Examples of the vulcanizable rubber that is a crumb-like polymer to be packed include Natural Rubber (NR), Isoprene Rubber (IR), Styrene Butadiene Rubber (SBR), Butadiene Rubber (BR), Chloroprene Rubber (CR), butyl rubber (IIR), nitrile rubber (NBR), ethylene-propylene rubber (EPM, EPDM), chlorosulfonated polyethylene rubber (CSM), acrylic rubber (ACM), urethane rubber (U), silicone rubber (VMQ, PVMQ, FVMQ), Fluororubber (FKM), polysulfide rubber (T), and the like. In particular, the present invention is most suitably applied to Butadiene Rubber (BR). Butadiene rubber was used in the validation test.

E

The average temperature of the crumb polymer continuously supplied to the molding step through the dehydration/drying step is 40 to 70 ℃. For example, in the verification test conducted in winter, the average temperature was 48.8 ℃, whereas in the verification test conducted in summer, the average temperature was 60.7 ℃. The water content of the crumb-like polymer at this time was examined. The moisture content is very low near the average or in crumb with a higher temperature than average. On the other hand, when the chips have a lower temperature than the average temperature, particularly when the temperature difference from the average temperature is 9.5 ℃ or more, the water content is remarkably high. For example, when the temperature of the block is measured for the crumb containing excessive moisture, it is 35.4 ℃ in winter (temperature difference 13.4 ℃) and 47.4 ℃ in summer (temperature difference 13.3 ℃). From this result, by measuring the temperature of the crumb polymer and focusing on the temperature difference, the crumb containing excess water can be reliably detected without being affected by the outside air temperature.

Description of the symbols

1 vibration feeder

2 rubber crumb

3 thermal imaging camera

6 metering device with hopper

7 packer (pressure forming machine)

8 dehydration/drying procedure

9 packaging Process

10 reprocessing procedure

11 abnormality detection signal

12 Standard substance (product)

13 non-standard substance

14 conveyer

15 weight measuring device

30 control device