Resin molded product and method for determining degradation of resin molded product

Abstract

To easily determine the degradation of a resin molded product.SOLUTION: The present invention relates to a resin molded product formed of a predetermined resin material, and a beam shape part 20 is formed integrally with a resin molded product 10 so that one end is connected to the resin molded product 10 and the other end is a free end. The presence or the absence of degradation is determined by plastic deformation or the presence or absence of breakage when the other end of the beam shape part 20 is deformed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a resin molded product made of a predetermined resin material, such as a component constituting an apparatus, and a method for determining deterioration thereof. [Background technology]

[0002] 2. Description of the Related Art Conventionally, resin molded products (resin parts) made of a predetermined resin material have been used as components in various devices (industrial products) (see, for example, Patent Documents 1 and 2). Once such resin molded products have completed their useful life in the market and are collected from the market, their degree of deterioration is assessed at recycling plants, etc., and a decision is made as to whether or not they can be reused depending on the degree of deterioration.

[0003] On the other hand, Patent Document 1 discloses a technique for measuring the breaking force when a hole is made in a semiconductor component storage tray using a measuring device, and determining whether or not the tray can be reused based on the measurement results. Furthermore, Patent Document 2 discloses a technology in which the amount of an indicator component is measured when a pin-shaped protrusion on a molded product is separated, and DSC analysis is performed using a calorimeter to evaluate the thermal history and determine the degree of thermal degradation of the molded product. Summary of the Invention [Problem to be solved by the invention]

[0004] In the past, deterioration of resin molded products was determined using measuring instruments, which was a time-consuming process.

[0005] The present invention has been made to solve the above-mentioned problems, and has an object to provide a resin molded product and a method for determining deterioration of a resin molded product, which makes it possible to easily determine deterioration. [Means for solving the problem]

[0006] The resin molded product in this invention is a resin molded product made of a predetermined resin material and has a beam-shaped portion integrally formed with the resin molded product so that one end is connected to the resin molded product and the other end is a free end, and the presence or absence of deterioration is determined based on the presence or absence of plastic deformation or breakage when the other end of the beam-shaped portion is deformed. Effect of the Invention

[0007] According to the present invention, it is possible to provide a resin molded product and a method for determining deterioration of a resin molded product, which allows deterioration to be easily determined. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an apparatus according to an embodiment of the present invention; [Diagram 2] FIG. [Diagram 3] 4 is a perspective view showing the vicinity of a beam-shaped portion in the resin molded product of FIG. 3. FIG. [Figure 4] FIG. 11 is a side cross-sectional view showing a state in which the beam-shaped portion is deformed. [Diagram 5] FIG. 13 is a perspective view showing the vicinity of a beam-shaped portion of a resin molding in a modified example. [Figure 6] 6 is a top view showing the vicinity of the beam-shaped portion in FIG. 5. FIG. [Figure 7] 6 is a side cross-sectional view showing a state in which the beam-shaped portion in FIG. 5 is deformed. [Figure 8] 13 is a graph showing the relationship between strain and stress in a beam-shaped portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and the duplicated description will be appropriately simplified or omitted.

[0010] As shown in FIG. 1, a device 1 is provided with a reusable resin molded product 10. The resin molded product 10 is made of a predetermined resin material (for example, PC resin, PET resin, ABS resin, etc.). Then, when the device 1 reaches the end of its useful life in the market, the device 1 is collected from the market, and the degree of deterioration of the resin molded product 10 disassembled from the device 1 at a recycling plant or the like is judged. Then, depending on the degree of deterioration, it is determined whether or not the resin molded product 10 can be reused.

[0011] In this embodiment, an image forming device such as a printer is used as the device 1, but the device 1 is not limited to this and may be any industrial product. In addition, in this embodiment, a resin exterior cover is used as the reusable resin molded product 10, but the reusable resin molded product 10 is not limited to this, and any resin molded product may be applicable. Furthermore, in this embodiment, the resin molded product 10 is a component part of the device 1 that is distributed on the market, but the resin molded product 10 may also be a product that is distributed on the market by itself.

[0012] Now, referring to Figures 2, 3, etc., the resin molded product 10 in this embodiment has a beam-shaped portion 20 (rib-shaped portion) provided on a part thereof (a part that does not impede the original function of the resin molded product). This beam-shaped portion 20 is integrally formed with the resin molded product 10 so that one end (the base portion at the bottom in Figure 3) is connected to the resin molded product 10 and the other end (the tip portion at the top in Figure 3) is a free end. Specifically, the beam-shaped portion 20 is made of the same resin material as the resin molded product 10, and is formed in the same molding process as the resin molded product 10 as a part of the resin molded product 10. The beam-shaped portion 20 is formed so as to stand up from the bottom portion 11 (see FIG. 4) of the resin molded product 10.

[0013] In particular, the resin molded product 10 in this embodiment is provided with a plurality of beam-shaped portions 20, of which at least the length L and the thickness H are equal to each other among the length L, thickness H, and width D. In detail, four plate-shaped beam-shaped portions 20 having the same shape (length L, thickness H, width D) are arranged side by side with spaces in between in the width direction (a direction intersecting the acting direction of force F described later and parallel to width D).

[0014] In this embodiment, as shown in FIG. 4, a force F is applied to the beam-shaped portion 20 by a human finger or the like to deform the other end side (free end side) of the beam-shaped portion 20, and the presence or absence of deterioration (strength deterioration) is determined based on the presence or absence of plastic deformation or breakage. In other words, at a recycling factory or the like, the beam-shaped portion 20 of the disassembled resin molded product 10 is deformed in the direction of arrow F, and the strength of the resin molded product 10 is evaluated based on whether or not plastic deformation or destruction has occurred. In order to perform stable deterioration judgment, when applying external force F to deform beam-shaped portion 20 in this manner, it is preferable to deform beam-shaped portion 20 to a predetermined position (for example, the position of a mark engraved on resin molded product 10).

[0015] More specifically, in the method for determining deterioration of the resin molded product 10, a deformation step is first performed in which the other end side (free end side) of the beam-shaped portion 20 is deformed. Then, when plastic deformation or breakage occurs in the beam-shaped portion 20 due to the deformation process, a determination process is performed in which it is determined that deterioration has occurred in the resin molded product 10. Specifically, the resin molded product 10 determined to have deteriorated is not reused, and only the resin molded product 10 determined to have not deteriorated is reused. Here, since the resin molded product 10 in this embodiment is provided with a plurality of beam-shaped portions 20, it is possible to perform deterioration determination multiple times.

[0016] In this way, in the present embodiment, the deterioration of the resin molded product 10 can be determined simply by deforming the beam-shaped portion 20 integrated into the resin molded product 10 without using a measuring instrument or the like, making the determination process easy.

[0017] In this embodiment, the deterioration of the resin molded product 10 was determined by deforming the other end side (free end side) of the beam-shaped portion 20, but the deterioration of the resin molded product 10 can also be determined by breaking the other end side (free end side) of the beam-shaped portion 20. In such a case, a breaking process is first performed in which a load F is applied to the beam-shaped portion 20 to deform the other end side of the beam-shaped portion 20 until it breaks. Then, a determination process is performed in which it is determined whether or not deterioration has occurred in the resin molded product 10 based on the magnitude of the load F when the beam-shaped portion 20 breaks in the breaking process. Specifically, if the magnitude of the load F when the beam-shaped portion 20 breaks does not reach the threshold value Fx, the resin molded product 10 is not reused, and if the magnitude of the load F when the beam-shaped portion 20 breaks exceeds the threshold value Fx, the resin molded product 10 is reused. Furthermore, when reusing (attempting to reuse) the resin molded product 10 in this way, the above-mentioned breaking process is performed on one of the beam-shaped portions 20, and the number of times of reuse can be counted based on the number of broken beam-shaped portions 20 among the beam-shaped portions 20. That is, a worker who performs the deterioration determination or a worker who assembles the device 1 using the reused resin molded product 10 can know the number of times that the resin molded product 10 has been reused based on the number of broken beam-shaped portions 20.

[0018] <Modification> 5 to 7, resin molded product 10 in the modified example is provided with a restricting portion 15 that restricts the amount of deformation δ of the other end side (free end side) of beam-shaped portion 20 when the other end side is deformed. This regulating portion 15 is formed in an approximately plate-like shape so as to extend in the direction in which the beam-shaped portion 20 stands up, leaving a gap with respect to the beam-shaped portion 20, when the other end side of the beam-shaped portion 20 is not deformed (when no external force F is applied). More specifically, the restricting portion 15 is made of the same resin material as the resin molded product 10 and is formed in the same molding process as the resin molded product 10 as a part of the resin molded product 10. The restricting portion 15 is formed so as to stand up from the bottom portion 11 (see FIG. 7) of the resin molded product 10. The “deforming step” described above is a step of deforming the beam-shaped portion 20 to a position where the other end side of the beam-shaped portion 20 abuts against the restricting portion 15. By providing such a regulating portion 15, when an external force F (load) is applied to deform the beam-shaped portion 20, the beam-shaped portion 20 is deformed to a predetermined position (a position where it abuts against the regulating portion 15), making it possible to perform stable deterioration judgment.

[0019] As shown in Fig. 6, the restricting portions 15 can be provided on both sides (upper and lower sides in Fig. 6) of the beam-shaped portion 20 so as to sandwich the beam-shaped portion 20. In this case, the beam-shaped portion 20 can be deformed to either side when the deterioration is judged. As shown in FIG. 6, it is preferable that a plurality of restricting portions 15 are provided at intervals in the width direction (the left-right direction in FIG. 6) to ensure a gap for applying a load F to the beam-shaped portion 20.

[0020] 5 to 7, the resin molded product 10 in the modified example is provided with a reinforcing portion 16 that reinforces the base portion at one end of the beam-shaped portion 20 so that elastic deformation of the base portion is restricted. The reinforcing portion 16 is disposed at a position that contacts the base portion, and is a portion that is formed so that its thickness (the thickness in the vertical direction in FIG. 7) is thicker than the surrounding thickness. More specifically, the reinforcing portion 16 is made of the same resin material as the resin molded product 10 and is formed in the same molding process as the resin molded product 10 as a part of the resin molded product 10. The reinforcing portion 16 is formed so as to stand up from the bottom portion 11 (see FIG. 7) of the resin molded product 10. By providing such a reinforcing portion 16, when an external force F is applied to deform the beam-shaped portion 20, the beam-shaped portion 20 will elastically deform in the portion above the reinforcing portion 16 (as there is less variation in the portion that undergoes elastic deformation), making it possible to perform a stable deterioration judgment. As shown in Fig. 7, the reinforcing portion 16 can be provided on both sides (the left and right sides in Fig. 6) of the beam-shaped portion 20 so as to sandwich the beam-shaped portion 20. In this case, the function of the reinforcing portion 16 described above is easily achieved.

[0021] Here, in the “deformation process” in the modified example, the beam-shaped portion 20 is restricted by the restricting portion 15 and deforms by a certain amount δ, and the maximum stress σ acting on the beam-shaped portion 20 can be calculated by the following formula based on the formula for calculating the deflection of a cantilever beam in material mechanics. σ = 3EHδ / (2L 2 ) In the above formula, E is the modulus of longitudinal elasticity of the beam-shaped portion 20, H is the thickness (see FIG. 3), and L is the length (see FIG. 3). Moreover, the above formula can be obtained from the following formula 1 for determining deflection δ, formula 2 for determining maximum bending moment Mmax, and formula 3 for determining maximum stress σmax. δ = FL 3 / (3EI) …(Formula 1) Mmax=FL…(Formula 2) σmax=Mmax / Z …(Equation 3) In (Equation 1) to (Equation 3), F is the load applied to the beam (see Figure 3), I is the second moment of area (=DH 3 / 12), D is the width (see Figure 3), and Z is the section modulus (=DH 2 / 6).

[0022] As can be seen from the above formula, the maximum stress σ applied when the beam-shaped portion 20 is deformed by a certain amount δ is a value determined by the Young's modulus E (a value that changes little even if the material deteriorates over time), the thickness H of the beam-shaped portion 20 (a value that does not change over time), and the length L of the beam-shaped portion 20 (a value that does not change over time). Therefore, since the value of the width D of the beam-shaped portion 20 is not related to the maximum stress σ, even if the multiple beam-shaped portions 20 provided in the resin molded product 10 have different widths D, as long as the thickness H and length L are equivalent, deterioration can be determined with the same accuracy for all of them. Even if deterioration occurs in the resin molded product 10 over time, by deforming the beam-shaped portion 20 by a certain amount δ, the maximum stress σ applied to the beam-shaped portion 20 does not change, and it becomes possible to accurately determine the deterioration by simply applying a certain stress without using a measuring instrument, etc.

[0023] Note that Figure 8 is a graph showing the relationship between strain ? and stress σ in the beam-shaped portion 20, where Figure 8(A) shows the relationship when no deterioration has occurred in the resin molded product 10, and Figure 8(B) shows the relationship when deterioration has occurred in the resin molded product 10. 8(A), there is no strength degradation in the initial state of the resin molded product 10, and when force is applied to the resin molded product 10 (beam-shaped portion 20), it undergoes elastic deformation up to a certain stress (see range X1), and when the stress exceeds this, it undergoes plastic deformation, and when the deformation becomes even larger, it finally breaks (see range X2). The stress at the time of plastic deformation or destruction at this time can be roughly regarded as the strength of the material (resin molded product 10). In contrast, as shown in Fig. 8(B), when the strength of the resin molded product 10 deteriorates over time due to the effects of heat, ultraviolet rays, chemicals, etc., for example, a decrease in the molecular weight of the resin material, its Young's modulus (the slope of the graph within the elastic region) remains almost unchanged, but deterioration that causes sudden destruction with almost no plastic deformation occurs at a smaller stress than in a state without deterioration becomes more likely. The strength of the material (resin molded product 10) at this time becomes smaller than in a state without deterioration (the state in Fig. 8(A)).

[0024] In the present invention, as explained above, the stress when the beam-shaped portion 20 is deformed by applying a force F to the tip thereof until it abuts against the restricting portion 15 does not change before and after deterioration. Therefore, if the shape of the beam-shaped portion 20, such as the thickness H and length L, is set so that the maximum stress σ when the beam-shaped portion 20 is deformed by a certain amount δ becomes a threshold value in determining the material strength of the resin molded product 10, it becomes possible to evaluate the strength deterioration based on the presence or absence of plastic deformation or breakage (fracture) when the same stress F is applied to the beam-shaped portion 20. Therefore, even if the strength of the resin molded product 10 deteriorates over time (due to a decrease in molecular weight due to temperature, humidity, ultraviolet rays, etc.), the strength deterioration can be easily determined by simply observing whether or not there is plastic deformation or breakage when a force F is applied to the tip of the beam-shaped portion 20 until it abuts against the regulating portion 15, without using any measuring instruments or requiring the skill of an operator.

[0025] As described above, the resin molded product 10 in this embodiment is a resin molded product made of a predetermined resin material, and the beam-shaped portion 20 is integrally provided with the resin molded product 10 so that one end is connected to the resin molded product 10 and the other end is a free end. The presence or absence of deterioration is determined based on the presence or absence of plastic deformation or breakage when the other end side of the beam-shaped portion 20 is deformed. This makes it possible to easily determine the deterioration of the resin molded product 10.

[0026] It is clear that the present invention is not limited to the present embodiment, and that the present embodiment may be modified as appropriate within the scope of the technical concept of the present invention in addition to the modifications suggested in the present embodiment. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and may be any number, position, shape, etc. suitable for implementing the present invention. [Explanation of symbols]

[0027] 1 equipment (image forming device), 10 Resin molded products (resin exterior cover), 11 bottom, 15 Regulatory Department, 16 Reinforcement part, 20 Beam shape section.

[0028] The present invention can also be embodied in the following combinations of Supplementary Notes 1 to 10. (Appendix 1) A resin molded product made of a predetermined resin material, a beam-shaped portion that is integrally provided with the resin molded product such that one end is connected to the resin molded product and the other end is a free end; A resin molded product, characterized in that the presence or absence of deterioration is determined based on the presence or absence of plastic deformation or breakage when the other end of the beam-shaped portion is deformed. (Appendix 2) 2. The resin molded product described in claim 1, further comprising a regulating portion that regulates an amount of deformation of the other end side when the other end side of the beam-shaped portion is deformed. (Appendix 3) The resin molded product described in Appendix 2, characterized in that the regulating portion is formed so as to extend in the direction in which the beam-shaped portion stands up, leaving a gap with respect to the beam-shaped portion, without deforming the other end side of the beam-shaped portion. (Appendix 4) 4. The resin molded product according to claim 1, further comprising a reinforcing portion that reinforces the base portion of the one end of the beam-shaped portion so as to restrict elastic deformation of the base portion. (Appendix 5) The resin molded product described in Appendix 4, characterized in that the reinforcing portion is located at a position that contacts the base portion and has a thickness that is thicker than the surrounding area. (Appendix 6) 6. The resin molded product according to any one of claims 1 to 5, comprising a plurality of beam-shaped portions each having at least the same length and thickness. (Appendix 7) A method for determining deterioration of a resin molded product made of a predetermined resin material, comprising: the resin molded product includes a beam-shaped portion that is integrally provided with the resin molded product such that one end of the beam-shaped portion is connected to the resin molded product and the other end of the beam-shaped portion is a free end; a deformation process of deforming the other end side of the beam-shaped portion; a determining step of determining that deterioration has occurred in the resin molding when plastic deformation or breakage has occurred in the beam-shaped portion as a result of the deformation step; A deterioration determination method for a resin molded product, comprising: (Appendix 8) the resin molding includes a restricting portion that restricts a deformation amount of the other end side when the other end side of the beam-shaped portion is deformed, The deterioration determination method for a resin molded product described in Appendix 7, characterized in that the deformation process is a process of deforming the beam-shaped portion to a position where the other end side of the beam-shaped portion abuts the regulating portion. (Appendix 9) A method for determining deterioration of a resin molded product made of a predetermined resin material, comprising: the resin molded product includes a beam-shaped portion that is integrally provided with the resin molded product such that one end of the beam-shaped portion is connected to the resin molded product and the other end of the beam-shaped portion is a free end; a breaking step of applying a load to the beam-shaped portion to deform the other end side of the beam-shaped portion until the other end side of the beam-shaped portion breaks; a determination step of determining whether or not the resin molding has deteriorated based on a magnitude of a load when the beam-shaped portion is broken in the breaking step; A deterioration determination method for a resin molded product, comprising: (Appendix 10) The resin molding is provided with a plurality of beam-shaped portions each having at least the same length and thickness, A deterioration determination method for a resin molded product as described in Appendix 9, characterized in that when reusing the resin molded product, the breaking process is performed on one of the plurality of beam-shaped portions, and the number of times the product is reused is counted based on the number of broken beam-shaped portions among the plurality of beam-shaped portions. [Prior art documents] [Patent documents]

[0029] [Patent Document 1] JP 2001-180782 A [Patent Document 2] JP 2013-29371 A

Claims

1. A resin molded product made of a predetermined resin material, a beam-shaped portion that is integrally provided with the resin molded product such that one end is connected to the resin molded product and the other end is a free end; A resin molded product, characterized in that the presence or absence of deterioration is determined based on the presence or absence of plastic deformation or breakage when the other end of the beam-shaped portion is deformed.

2. 2. The resin molded product according to claim 1, further comprising a restricting portion that restricts an amount of deformation of the other end side of the beam-shaped portion when the other end side of the beam-shaped portion is deformed.

3. The resin molded product according to claim 2, characterized in that the regulating portion is formed so as to extend in a direction in which the beam-shaped portion stands up, leaving a gap with respect to the beam-shaped portion, without deforming the other end side of the beam-shaped portion.

4. 3. The resin molded product according to claim 1, further comprising a reinforcing portion that reinforces the base portion of the one end of the beam-shaped portion so as to restrict elastic deformation of the base portion.

5. 5. The resin molded product according to claim 4, wherein the reinforcing portion is disposed at a position in contact with the base portion and has a thickness greater than that of the surrounding area.

6. 3. The resin molded product according to claim 1, wherein a plurality of the beam-shaped portions are provided, each having at least the same length and thickness.

7. A method for determining deterioration of a resin molded product made of a predetermined resin material, comprising: the resin molded product includes a beam-shaped portion that is integrally provided with the resin molded product such that one end of the beam-shaped portion is connected to the resin molded product and the other end of the beam-shaped portion is a free end; a deformation process of deforming the other end side of the beam-shaped portion; a determining step of determining that deterioration has occurred in the resin molding when plastic deformation or breakage has occurred in the beam-shaped portion as a result of the deformation step; A deterioration determination method for a resin molded product, comprising:

8. the resin molding includes a restricting portion that restricts a deformation amount of the other end side when the other end side of the beam-shaped portion is deformed, 8. The deterioration determining method for a resin molded product according to claim 7, wherein the deformation step is a step of deforming the beam-shaped portion to a position where the other end side of the beam-shaped portion abuts against the restricting portion.

9. A method for determining deterioration of a resin molded product made of a predetermined resin material, comprising: the resin molded product includes a beam-shaped portion that is integrally provided with the resin molded product such that one end of the beam-shaped portion is connected to the resin molded product and the other end of the beam-shaped portion is a free end; a breaking step of applying a load to the beam-shaped portion to deform the other end side of the beam-shaped portion until the other end side of the beam-shaped portion breaks; a determination step of determining whether or not the resin molding has deteriorated based on a magnitude of a load when the beam-shaped portion is broken in the breaking step; A deterioration determination method for a resin molded product, comprising:

10. The resin molding is provided with a plurality of beam-shaped portions each having at least the same length and thickness, The deterioration determination method for a resin molded product according to claim 9, characterized in that, when reusing the resin molded product, the breaking process is performed on one of the plurality of beam-shaped portions, and the number of times the product is reused is counted based on the number of broken beam-shaped portions among the plurality of beam-shaped portions.

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