Measuring device and resin block production system

Abstract

To develop a technology to separate a resin containing a foaming material into resin blocks with specified weight.SOLUTION: There is provided a measuring device used in a resin block production system in which a foaming material-containing resin extruded from an extruder is conveyed and cut into resin blocks of a predetermined weight by a cutting device, comprising: a volume measuring unit for measuring a passing volume of the foaming material-containing resin passing through a predetermined measurement position on a transport path of the foaming material-containing resin; and a determination unit that determines whether or not a weight of the foaming material-containing resin that is passed through the measurement position is reached a specified weight based on a density of the foaming material-containing resin and a passing volume, which differ depending on an operating condition of the extruder.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a resin block producing system in which a foam-containing resin is cut to produce a resin block, and a measuring device used therein. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a technique in which a foaming material-containing resin extruded by an extruder is divided into a plurality of resin blocks, and each block is foamed to form a foamed product (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 7-329079 (paragraphs

[0002] ,

[0003] , etc.) Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need to develop technology to separate foam-containing resin into resin blocks of specified weight. [Means for solving the problem]

[0005] One aspect of the invention is a measuring device used in a resin block production system that transports foam-containing resin extruded from an extruder and cuts it into resin blocks of a predetermined specified weight using a cutting device, and is equipped with a volume measuring unit that measures a passing volume, which is the volume of the foam-containing resin passing through a predetermined measurement position on the transport path of the foam-containing resin, and a judgment unit that judges whether the weight of the foam-containing resin that has passed the measurement position has reached the specified weight based on the density of the foam-containing resin and the passing volume, which differ depending on the operating conditions of the extruder. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a side view of a resin block production system including a measurement device according to a first embodiment. [Diagram 2] FIG. 2 is a side view of a resin block made from a foam-containing resin. [Diagram 3] FIG. 3 is a block diagram showing the electrical configuration of the resin block production system. [Figure 4] FIG. 4 is a partially cutaway perspective view of a foam-containing resin being transported by a transport device. [Diagram 5] FIG. 5 is a side view of the resin block production system when the foam-containing resin is detected by a measuring device. [Figure 6] FIG. 6 is a side view of the resin block production system when the weight of the foam-containing resin that has passed the measurement position reaches a specified weight. [Figure 7] FIG. 7 is a side view of the resin block producing system when the cutting position of the foam-containing resin reaches the cutting device. [Figure 8] FIG. 8 is a cross-sectional view of a foam-containing resin molded into a molded portion. [Figure 9] FIG. 9 is a perspective view of a foaming material-containing resin extruded from an extruder. [Figure 10] FIG. 10A is a perspective view of a T-die of an extruder according to another embodiment, and FIG. 10B is a side cross-sectional view of the T-die. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] [First embodiment] A resin block production system 100 according to a first embodiment is shown in Fig. 1. In the resin block production system 100 (hereinafter simply referred to as "system 100" as appropriate), a foaming material-containing resin A extruded from an extruder 11 is cut by a cutting device 12 to produce a resin block B (see Fig. 2). The system 100 is used to divide the foaming material-containing resin A into resin blocks B of a predetermined weight.

[0008] As shown in Fig. 1, in this embodiment, the system 100 includes a conveying device 13 (e.g., a conveyor) in addition to the extruder 11 and the cutting device 12. The conveying device 13 conveys the foam-containing resin A extruded from the extruder 11 to the cutting device 12. For example, a resin block B obtained by cutting the foam-containing resin A by the cutting device 12 is further conveyed downstream by the conveying device 13 and collected. Note that, in the conveying path R of the foam-containing resin A by the conveying device 13, a weight scale for measuring the weight of the resin block B may be provided downstream of the cutting device 12.

[0009] In this embodiment, the foaming material-containing resin A contains a foaming material but is not yet completely foamed, and is extruded in the extruder 11 at a temperature that does not allow foaming of the foaming material-containing resin A. In this embodiment, a post-process is performed to completely foam and expand the resin block B, thereby producing a foamed product.

[0010] In this embodiment, the extruder 11 is configured to receive a predetermined number of resin blocks B worth of raw material as one lot, and repeat the operation of receiving the next lot of raw material after finishing extruding the foam-containing resin A for one lot. In this embodiment, one lot is, for example, four resin blocks B (see FIG. 2).

[0011] In this embodiment, the cutting device 12 cuts the foaming material-containing resin A on the conveying device 13 by lowering a cutter from above.

[0012] The resin block production system 100 of this embodiment is equipped with a measuring device 10. The measuring device 10 measures the volume of the foaming material-containing resin A, and determines whether the weight of the foaming material-containing resin A has reached a specified weight based on the volume and the density of the foaming material-containing resin A.

[0013] In this embodiment, the measuring device 10 includes a volume measuring unit 21 and a determination unit 22 (see FIG. 3). The volume measuring unit 21 measures a passing volume V, which is a volume of the foaming material-containing resin A passing through a predetermined measurement position P (see FIG. 1) on the conveying path R of the foaming material-containing resin A. The measurement position P is provided upstream of a cutting position where the foaming material-containing resin A is cut by the cutting device 12. The determination unit 22 determines whether or not the weight of the foaming material-containing resin A passing through the measurement position P has reached a specified weight based on the density of the foaming material-containing resin A (for example, a density that differs depending on the operating condition of the extruder 11) and the passing volume V. In this embodiment, the measuring device 10 includes a weight calculation unit 25. The weight calculation unit 25 acquires information on the density of the foaming material-containing resin A (for example, a density that differs depending on the order of the resin block B from the top of one lot), and calculates the weight of the foaming material-containing resin A being conveyed based on the density information and the passing volume V. Then, the determination unit 22 determines whether or not the weight calculated by the weight calculation unit 25 has reached the specified weight. Note that the specified weight may be a weight range with a predetermined width.

[0014] For example, the measuring device 10 may be provided with a storage unit 26 that stores information on the density of the foaming material-containing resin A. The storage unit 26 may store a density that varies depending on the operating conditions of the extruder 11 as the density. For example, information on the density of each resin block in one lot may be stored. In such a configuration, the determination unit 22 determines whether the weight of the foaming material-containing resin A that has passed through the measurement position P has reached a specified weight based on the density according to the order of the resin blocks B whose passing volume V is measured by the volume measurement unit 21. The set value of the density of the foaming material-containing resin A may be obtained empirically, for example. For example, in one lot of the foaming material-containing resin A, the density corresponding to the resin block B that is earlier in the order from the top tends to be higher than the density corresponding to the resin block B that is later in the order from the top (for example, this may be due to the fact that back pressure is less likely to be applied to the later part of the lot in the extruder 11). Therefore, the density set in this manner may be used for the determination in the determination unit 22. In this embodiment, for example, of the four resin blocks B (see Figure 2) in one lot, the density corresponding to the first two resin blocks B is set to the highest (e.g., set to the same density), and the density corresponding to the last resin block B is set to the lowest.

[0015] In this embodiment, the volume measuring unit 21 includes a cross-sectional area measuring unit 23 and an integral calculation unit 24 (see FIG. 3). The cross-sectional area measuring unit 23 measures the cross-sectional area S of the cross section D (see FIG. 4) of the foaming material-containing resin A based on an image of at least one side (upper side in this embodiment) of the foaming material-containing resin A transported along the transport path R. The integral calculation unit 24 calculates the passing volume V by integrating the moving volume of the foaming material-containing resin A per unit time passing through the measurement position P based on the cross-sectional area S and the transport speed of the foaming material-containing resin A. In this embodiment, for example, the volume measuring unit 21 includes a 3D sensor 27 that images the foaming material-containing resin A. In this embodiment, the cross-sectional area measuring unit 23 images the foaming material-containing resin A from the upper side, but instead of or in addition to the upper side, the image may be captured from other directions, such as the lower side or at least one side in the width direction of the foaming material-containing resin A.

[0016] The measuring device 10 and the system 100 of this embodiment are controlled, for example, as follows. As shown in FIG. 5, when the foam-containing resin A starts to be extruded from the extruder 11, the volume measuring unit 21 (for example, the 3D sensor 27) checks whether the foam-containing resin A has reached the measurement position P. When the volume measuring unit 21 detects that the foam-containing resin A has reached the measurement position P, the cross-sectional area measuring unit 23 and the integral calculation unit 24 calculate the passing volume V of the foam-containing resin A that has passed the measurement position P. In addition, the weight calculation unit 25 calculates the weight of the foam-containing resin A that has passed the measurement position P from the passing volume V and the set value of the density. Then, when the determination unit 22 determines that the weight has reached the specified weight (see FIG. 6), it transmits a cutting signal to the cutting device 12 to cut the foam-containing resin A. This cutting signal also includes information on the cutting timing that takes into account the conveying speed of the foam-containing resin A. As a result, the cutting device 12 that has received the signal can cut the foam-containing resin A at an appropriate cutting position C (see FIG. 7) so as to obtain a resin block B of a specified weight. In this manner, the first resin block B is produced (see FIG. 1).

[0017] In the measuring device 10, when the determination unit 22 transmits a cutting signal to the cutting device 12, the volume measurement unit 21 checks whether or not there is a subsequent foam-containing resin A. When the volume measurement unit 21 detects the subsequent foam-containing resin A, the volume measurement unit 21, the integral calculation unit 24, the weight calculation unit 25, the determination unit 22, etc. operate in the same manner as described above, and the cutting device 12 cuts the foam-containing resin A based on the cutting signal from the determination unit 22, and the next resin block B of a specified weight is generated. In this manner, the generation of the resin block B is repeated until the volume measurement unit 21 does not detect the subsequent foam-containing resin A. Note that the system 100 may be configured such that the start of extrusion of the foam-containing resin A is cut at a length smaller than the specified weight to form a cross section D, and a resin block B of a specified weight is generated from the subsequent portion.

[0018] As described above, according to the system 100 including the measuring device 10 of this embodiment, it is possible to divide the foaming material-containing resin A into resin blocks B by a specified weight. For example, as a configuration for generating resin blocks B of a specified weight, a configuration is conceivable in which the weight of the foaming material-containing resin A extruded from the extruder 11 is measured by a weighing scale, and when the weight reaches the specified weight, the foaming material-containing resin A is cut. However, in this case, as shown in FIG. 1 and the like, the foaming material-containing resin A is supported by the extruder 11 in a cantilevered state, so that the weight of the resin block B is not accurate. In contrast, in the system 100 including the measuring device 10 of this embodiment, the resin block B is generated based on the volume of the foaming material-containing resin A, so that it is easier to adjust the weight of the resin block B to the specified weight than in the above configuration.

[0019] Furthermore, according to the system 100 including the measuring device 10 of this embodiment, even if the density of the foam-containing resin A is not constant, it is possible to divide the foam-containing resin A into resin blocks B by a specified weight. For example, the extruder 11 may be configured such that the back pressure applied to the foam-containing resin A extruded from the extruder 11 varies depending on the weight of the raw material remaining in the extruder 11. In this case, since the density of the foam-containing resin A is not constant, if the weight of the resin block B is calculated using a predetermined constant density, the weight of the resin block B is not accurate. In contrast, in the system 100 including the measuring device 10 of this embodiment, the resin block B is generated based on the density corresponding to the position of the foam-containing resin A (for example, the position from the front), so that it is possible to more easily adjust the weight of the resin block B to the specified weight than the above configuration.

[0020] As shown in FIG. 1, the system 100 of this embodiment is provided with a molding section 30 that molds the foaming material-containing resin A after it is extruded from the extruder 11 and before it reaches the measurement position P (i.e., before the passing volume V is measured by the volume measuring section 21). Here, in a configuration in which the cross-sectional area measuring section 23 images the foaming material-containing resin A conveyed along the conveying path R from one side (from above in this embodiment), it is desirable that the foaming material-containing resin A has a shape that can be grasped just by looking at it from one side. For this reason, in this embodiment, the molding section 30 is capable of molding the foaming material-containing resin A into such a shape. Specifically, as shown in FIG. 8, for example, the molding section 30 molds the foaming material-containing resin A so that it becomes wider from one side (from one side surface) toward the other side on the opposite side (for example, molds it into a cross-sectional shape that is approximately trapezoidal). In this way, it is possible to arrange a means for imaging the foaming material-containing resin A (for example, a 3D sensor) only on one side of the foaming material-containing resin A. In addition, it is preferable that the molding section 30 is set to a temperature that does not cause the foaming of the foaming material-containing resin A to progress, and is preferably positioned so that it can be molded by preheating the foaming material-containing resin A extruded from the extruder 11.

[0021] In this embodiment, the molding section 30 includes a pair of horizontal pressing sections 31 that sandwich the foam-containing resin A in the width direction, and a pair of vertical pressing sections 32 that sandwich the foam-containing resin A in the vertical direction. The pair of horizontal pressing sections 31 are arranged so that the distance between their opposing surfaces 31M becomes wider from one side (the upper side in this embodiment) to the other side. Therefore, the pair of horizontal pressing sections 31 can mold the foam-containing resin A into the above-mentioned shape. In addition, by crushing the foam-containing resin A with the pair of vertical pressing sections 32, the foam-containing resin A is molded into a flat shape, and the foam-containing resin A is molded into a trapezoidal cross section. In this embodiment, as shown in FIG. 9, the extruder 11 includes a rectangular extrusion outlet 11K (die) and the extruded foam-containing resin A has a rectangular cross section (it is thicker than after molding with the pair of vertical pressing sections 32). Incidentally, by providing the molding section 30, the degree of freedom in designing the shape of the extrusion outlet 11K of the extruder 11 is increased, and even if the same extruder 11 is used, it becomes possible to provide a variety of shapes for the resin block B.

[0022] Here, as described above, the density of the foaming material-containing resin A may vary depending on the operating conditions (e.g., back pressure, etc.) of the extruder 11. In contrast, in the example of this embodiment, the foaming material-containing resin A is pressed by the molding section 30 (particularly the pair of vertical pressing sections 32), so that the density of the foaming material-containing resin A can be made more uniform than when the molding section 30 is not provided. In addition, in the example of this embodiment, each vertical pressing section 32 is configured such that a sleeve belt 34 (e.g., made of metal) is stretched over a pair of rollers 33 whose rotation axes are parallel. The sleeve belts 34 of the pair of vertical pressing sections 32 facing each other (facing each other in the vertical direction in the example of this embodiment) are arranged so that the gap between them narrows toward the downstream side of the conveying path R, so that the foaming material-containing resin A is gradually pressed.

[0023] [Other embodiments] In the above embodiment, the extruder 11 may be provided with a T-die 40 that forms the extrusion outlet 11K (see FIG. 2A). With this configuration, the shape of the foaming material-containing resin A extruded from the extruder 11 can be more uniform, the volume of the foaming material-containing resin A can be calculated more accurately, and the density of the foaming material-containing resin A can be more easily uniformed. Inside the T-die 40, a constricting section 41 that narrows the flow path of the foaming material-containing resin A (for example, narrows the flow path in the thickness direction of the foaming material-containing resin A) may be provided. With this configuration, the density of the foaming material-containing resin A can be more easily uniformed. In addition, in a configuration in which the system 100 is provided with the T-die 40, a molding section 30 may be further provided, or the molding section 30 may not be provided.

[0024] The system 100 may include only one of the pair of horizontal pressing units 31 and the pair of vertical pressing units 32 of the molding unit 30, or may not include the molding unit 30.

[0025] In the above embodiment, the resin extruded from the extruder 11 and cut by the cutting device 12 may be a resin that does not contain a foaming agent.

[0026] In the above embodiment, the extruder 11 may be provided with a pressure measuring unit that measures the back pressure of the extruder 11. According to this configuration, the weight calculation unit 25 can acquire information on the density of the foaming material-containing resin A from the back pressure measuring unit instead of or in addition to the memory unit 26, and can calculate the weight of the foaming material-containing resin A more accurately.

[0027] <Additional Notes> The following describes the feature groups extracted from the above-described embodiments, while indicating their effects, etc., as necessary. Note that, in the following, for ease of understanding, the corresponding configurations in the above-described embodiments are appropriately indicated in parentheses, but these feature groups are not limited to the specific configurations indicated in parentheses.

[0028] For example, the following group of features relate to a "resin block production system in which a foam-containing resin is cut to produce a resin block, and a measuring device used therein," and can be considered to have been conceived in response to the problem that "there is a demand for the development of a technology for dividing a foam-containing resin into resin blocks of a specified weight each," in relation to the background technology that "conventionally, a technology has been known in which a foam-containing resin extruded by an extruder is divided into a plurality of resin blocks, and each of the blocks is foamed to form a foamed product (see, for example, JP-A-7-329079 (paragraphs

[0002] ,

[0003] , etc.))." In addition, there has been a demand for new technologies relating to measuring devices and resin block production systems.

[0029] [Feature 1] A measuring device used in a resin block production system in which a foaming material-containing resin extruded from an extruder is conveyed and cut into resin blocks of a predetermined weight by a cutting device, a volume measuring unit for measuring a passing volume of the foaming material-containing resin passing through a predetermined measurement position on a transport path of the foaming material-containing resin; A measuring device comprising: a judgment unit that judges whether the weight of the foaming material-containing resin that has passed through the measurement position has reached the specified weight based on the density of the foaming material-containing resin and the passing volume, which differ depending on the operating conditions of the extruder.

[0030] [Feature 2] the extruder is configured to receive a predetermined number of raw materials for the resin blocks as one lot, and repeat an operation of receiving the next lot of raw materials after finishing extruding the foam-containing resin for the one lot, the density differs depending on the order of the resin blocks from the top of the one lot of the foam-containing resin, The measuring device described in feature 1, wherein the determination unit determines whether or not the weight of the foam-containing resin that has passed through the measurement position has reached the specified weight based on the density according to the order of the resin blocks in which the volume measuring unit measures the passing volume.

[0031] [Feature 3] The measuring device according to feature 2, wherein in the judgment section, the density used for the resin block that is located earlier in the lot of the foam-containing resin from the front is greater than the density used for the resin block that is located later in the lot.

[0032] [Feature 4] a weight calculation unit that acquires information on the density and calculates a weight of the foaming material-containing resin that has passed through the cutting device based on the information on the density and the passing volume, The measuring device according to any one of features 1 to 3, wherein the determination unit determines whether the weight calculated by the weight calculation unit has reached the specified weight.

[0033] [Feature 5] A resin block production system including the measuring device according to any one of features 1 to 4, A resin block producing system including a T-die forming an extrusion outlet of the extruder.

[0034] [Feature 6] A resin block production system including the measuring device according to any one of features 1 to 4, The volume measuring unit is a cross-sectional area measuring unit that measures a cross-sectional area of ​​the foam-containing resin based on an image of at least one side of the foam-containing resin transported along the transport path; and an integral calculation unit that calculates the passing volume by integrating the moving volume of the foaming material-containing resin per unit time passing through the measurement position based on the cross-sectional area and the conveying speed of the foaming material-containing resin, A resin block producing system comprising a molding section that molds the moving foam-containing resin into an approximately trapezoidal cross-section that becomes wider as it moves from one side to the opposite side before the passing volume is measured by the volume measuring section.

[0035] By using the measuring device or resin block production system described above, it is possible to divide the foam-containing resin A into resin blocks B by a specified weight.

[0036] In addition, although this specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but includes various modifications and variations of the specific examples, as well as parts of the specific examples taken alone. [Explanation of symbols]

[0037] 10. Measurement Equipment 11 Extruder 12 Cutting device 13. Conveyor equipment 21 Volume measurement section 22 Judgment section 23 Cross-sectional area measurement section 24 Integral calculation section 25 Weight calculation section 26 Memory section 27 3D Sensor 30 Molding section 31 Horizontal pressing part 31M Opposite side 32 Vertical pressing part 40 T die 100 System (Resin Block Generation System) A Foam-containing resin B Resin block C Cutting position D cross section P measurement position R Transport route

Claims

1. A measuring device used in a resin block production system in which a foaming material-containing resin extruded from an extruder is conveyed and cut into resin blocks of a predetermined weight by a cutting device, a volume measuring unit for measuring a passing volume of the foaming material-containing resin passing through a predetermined measurement position on a transport path of the foaming material-containing resin; A measuring device comprising: a judgment unit that judges whether the weight of the foaming material-containing resin that has passed through the measurement position has reached the specified weight based on the density of the foaming material-containing resin and the passing volume, which differ depending on the operating conditions of the extruder.

2. the extruder is configured to receive a predetermined number of raw materials equivalent to a plurality of resin blocks as one lot, and repeat an operation of receiving a next lot of raw materials after finishing extruding the foam-containing resin equivalent to the one lot, the density differs depending on the order of the resin blocks from the top of the one lot of the foaming material-containing resin, The measuring device according to claim 1 , wherein the determination unit determines whether or not the weight of the foam-containing resin that has passed through the measurement position has reached the specified weight based on the density according to the order of the resin blocks in which the volume measuring unit measures the passing volume.

3. The measuring device according to claim 2, wherein in the judgment section, the density used for the resin block that is located earlier from the head of the one lot of the foam-containing resin is greater than the density used for the resin block that is located later from the head.

4. A resin block production system comprising the measurement device according to any one of claims 1 to 3, A resin block producing system comprising a T-die forming an extrusion outlet of said extruder.

5. A resin block production system comprising the measurement device according to any one of claims 1 to 3, The volume measuring unit is a cross-sectional area measuring unit that measures a cross-sectional area of ​​the foam-containing resin based on an image of at least one side of the foam-containing resin transported along the transport path; and an integral calculation unit that calculates the passing volume by integrating the moving volume of the foaming material-containing resin per unit time passing through the measurement position based on the cross-sectional area and the conveying speed of the foaming material-containing resin, A resin block producing system comprising a molding section that molds the moving foam-containing resin into an approximately trapezoidal cross-section that becomes wider as it moves from one side to the opposite side before the passing volume is measured by the volume measuring section.

Images