Resin molded article and method for determining aging of resin molded article

Abstract

The present invention relates to a resin molded article and a method for determining aging of the resin molded article, and aims to facilitate aging determination of the resin molded article. A resin molded article (10) is formed from a predetermined resin material and is provided with a beam-shaped section (20) integrally provided on the resin molded article (10), one end of the beam-shaped section (20) is connected to the resin molded article, the other end of the beam-shaped section (20) is formed as a free end, and the presence or absence of aging of the resin molded article (10) is determined on the basis of the presence or absence of plastic deformation or breakage when the other end of the beam-shaped section (20) is deformed.

Description

Technical Field

[0001] The present invention relates to a resin molded product formed of a predetermined resin material and constituting a machine component or the like, and a method for determining aging of the resin molded product. Background Art

[0002] Conventionally, resin molded products or resin components formed of a predetermined resin material have been used as components of various industrial products such as machines (see, for example, Patent Documents 1 and 2).

[0003] Once such resin molded products have been commercially utilized, they are collected from the market, and the degree of deterioration is determined at a recycling plant or the like, and whether they can be reused (reused) is determined based on the degree of deterioration.

[0004] Patent document 1 discloses a technical solution that uses a measuring instrument to measure the destructive force when a hole is opened on a semiconductor component receiving tray, and determines whether it can be reused based on the measurement result.

[0005] Patent document 2 discloses another technical solution, which uses a calorimeter to measure the amount of an index component when a pin-shaped protrusion provided on a molded product is cut off and performs DSC analysis to evaluate the thermal process and determine the degree of thermal aging of the molded product.

[0006] Patent Document 1: Japanese Patent Publication No. 2001-180782

[0007] Patent Document 2: Japanese Patent Publication No. 2013-29371

[0008] In the past, the degradation of resin molded products was determined using measuring instruments, which took a lot of time. Summary of the invention

[0009] In order to solve the above-mentioned problem, the present invention proposes a technical solution, the purpose of which is to provide a resin molded product that is easy to judge the aging, and a method for judging the aging of the resin molded product.

[0010] The resin molded product of the present invention is formed of a specified resin material, and is characterized in that it has a beam-shaped portion integrally arranged on the resin molded product, one end of the beam-shaped portion is connected to the resin molded product, and the other end is formed as a free end. Whether the resin molded product is aged can be judged based on whether plastic deformation or fracture occurs when the other end of the beam-shaped portion is deformed.

[0011] According to the present invention, a resin molded product that is easy to judge the deterioration, and a method for judging the deterioration of a resin molded product can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view of a device according to an embodiment of the present invention.

[0013] Figure 2 This is a perspective view of a resin molded product.

[0014] Figure 3 yes Figure 2 A perspective view of the vicinity of the beam-shaped portion of the resin molded product shown.

[0015] Figure 4 It is a side cross-sectional view of a state where the beam-shaped portion is deformed.

[0016] Figure 5 It is a perspective view of the vicinity of the beam-shaped portion of the resin molded product in a modified example.

[0017] Figure 6 yes Figure 5 A top view near the beam portion.

[0018] Figure 7 Yes Figure 5 A side sectional view showing a state in which the beam-shaped portion is deformed.

[0019] Figure 8 It is a graph showing the relationship between strain and stress in a beam section.

[0020] Explanation of symbols

[0021] 1 Machine (image forming equipment)

[0022] 10Resin molded products (resin covers)

[0023] 11 Bottom

[0024] 15 Restriction

[0025] 16 Strengthening Department

[0026] 20 beam section DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The same or corresponding parts in each drawing are marked with the same reference numerals, and repeated descriptions are appropriately simplified or omitted.

[0028] like Figure 1 As shown, the machine 1 is provided with a recyclable resin molded product 10 .

[0029] The resin molded product 10 is formed of a predetermined resin material, such as PC resin, PET resin, ABS resin, etc. The machine 1 is collected from the market after commercial use ends, and the degree of aging of the resin molded product 10 removed from the machine 1 is determined at a recycling plant, and whether the resin molded product 10 can be reused is determined based on the degree of aging.

[0030] In this embodiment, an image forming apparatus such as a printer is used as the machine 1 , but the machine 1 is not limited thereto, and all industrial products can be used as the object.

[0031] In this embodiment, the resin cover is used as the reusable resin molded product 10, but the reusable resin molded product 10 is not limited to this, and all resin molded products can be used as the object.

[0032] In this embodiment, the resin molded product 10 is used as a component of the machine 1 distributed on the market, but the resin molded product 10 may be distributed on the market as a separate product.

[0033] In this Figure 2 , Figure 3 As described above, the beam-shaped portion 20 (rib-shaped portion) is provided on a portion (a portion that does not hinder the original function of the resin molded product) of the resin molded product 10 of the present embodiment.

[0034] The beam-shaped portion 20 is integrally provided on the resin molded product 10, one end of which ( Figure 3 The root below) is connected to the resin molded product 10, and the other end ( Figure 3 The front end portion above the free end.

[0035] Specifically, the beam-shaped portion 20 is formed as a part of the resin molded product 10 from the same resin material as the resin molded product 10 and through the same molding process. Figure 4 ) stand upright.

[0036] In particular, the resin molded product 10 of the present embodiment is provided with a plurality of beam-shaped portions 20 of which at least the length L and the thickness H are equal among the length L, the thickness H, and the width D.

[0037] Specifically, four plate-like beam portions 20 of the same shape (length L, thickness H, width D) are provided in the width direction (a direction intersecting the direction of action of the force F described later and also a direction parallel to the width D) with a certain interval therebetween.

[0038] This embodiment is as Figure 4 As shown, a force F is applied to the beam-shaped portion 20 by a person's finger or the like, so that the other end (free end) of the beam-shaped portion 20 is deformed. Whether or not plastic deformation or fracture occurs at this time is used to determine whether the resin molded product 10 is aged (strength aging).

[0039] In other words, the beam-shaped portion 20 of the resin molded product 10 in a disassembled state is deformed in the direction of arrow F at a recycling plant or the like, and the strength of the resin molded product 10 is evaluated based on whether plastic deformation or failure occurs.

[0040] In order to perform stable deterioration judgment, when the external force F is applied to deform the beam portion 20, it is preferable that the beam portion 20 be deformed to a predetermined position (for example, a position where a mark is engraved on the resin molded product 10).

[0041] More specifically, the method for determining the deterioration of the resin molded product 10 first performs a deformation step to deform the other end (free end) of the beam-shaped portion 20 .

[0042] Then, after the beam-shaped portion 20 is plastically deformed or fractured through the deformation process, a determination process is performed to determine whether the resin molded product 10 has deteriorated. Specifically, the resin molded product 10 determined to have deteriorated is not reused, while the resin molded product 10 determined not to have deteriorated is reused.

[0043] Since the resin molded product 10 of the present embodiment is provided with a plurality of beam-shaped portions 20 , multiple deterioration determinations can be performed.

[0044] As described above, the resin molded product 10 of this embodiment can be judged for deterioration simply by deforming the beam-shaped portion 20 formed integrally with the resin molded product 10 without using a measuring instrument, so the judgment operation can be performed simply.

[0045] In this embodiment, the other end (free end) of the beam portion 20 is deformed to determine the deterioration of the resin molded product 10 , but the other end (free end) of the beam portion 20 may be broken to determine the deterioration of the resin molded product 10 .

[0046] In this case, the breaking process is first performed to apply a load F to the beam-shaped portion 20 so that the other end of the beam-shaped portion 20 is deformed until it breaks. Then, a judgment process is performed based on the magnitude of the load F when the beam-shaped portion 20 breaks in the breaking process to judge whether the resin molded product 10 has deteriorated. 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.

[0047] When the resin molded product 10 is reused in this way, the above-mentioned breaking step is performed on one of the plurality of beam-shaped parts 20, and the number of reuses is counted according to the number of broken beam-shaped parts 20 among the plurality of beam-shaped parts 20. That is, an operator who performs deterioration judgment or an operator who assembles the machine 1 using the reused resin molded product 10 can grasp the number of reuses of the resin molded product 10 according to the number of broken beam-shaped parts 20.

[0048] <Modification>

[0049] like Figure 5 to Figure 7As shown, the resin molded product 10 of the modified example is provided with a restriction portion 15 for restricting the deformation amount δ of the other end (free end) of the beam-shaped portion 20 when the other end (free end) is deformed.

[0050] The restricting portion 15 is basically formed in a plate shape, and extends in a direction in which the beam portion 20 stands up with a gap between the restricting portion 15 and the beam portion 20 when the other end of the beam portion 20 is not deformed (when no external force F is applied).

[0051] More specifically, the restricting portion 15 is formed as a part of the resin molded product 10 using the same resin material and in the same molding process as the resin molded product 10. The restricting portion 15 is formed from the bottom 11 (see Figure 7 ) stand up.

[0052] The above-mentioned “deformation process” is to deform the beam-shaped portion 20 to a position where the other end of the beam-shaped portion 20 hits the restriction portion 15.

[0053] By providing such a restriction portion 15 , when the beam portion 20 is deformed by applying an external force F (load), the beam portion 20 deforms to a preset position (ie, a position where it hits the restriction portion 15 ), thereby enabling stable deterioration judgment.

[0054] like Figure 6 As shown, the limiting portion 15 is provided on both sides of the beam-shaped portion 20 ( Figure 6 In this case, when judging aging, the beam-shaped portion 20 can be deformed toward either side.

[0055] In addition, Figure 6 As shown, the limiting portion 15 has a gap for applying a load F to the beam-shaped portion 20, preferably in the width direction ( Figure 6 A plurality of limiting portions 15 are provided in the transverse direction of the device, with certain gaps between them.

[0056] Reference here Figure 5 to Figure 7 The resin molded product 10 of the modified example is provided with a reinforcing portion 16 for reinforcing the elastic deformation of the root of one end of the beam-shaped portion 20 .

[0057] The reinforcing portion 16 is provided at a position in contact with the root thereof and has a thickness ( Figure 7 The longitudinal thickness of the part is greater than the surrounding thickness.

[0058] More specifically, the reinforcing portion 16 is formed as a part of the resin molded product 10 using the same resin material as the resin molded product 10 and in the same molding process. The reinforcing portion 16 is formed from the bottom 11 of the resin molded product 10 (see Figure 7 ) stand up.

[0059] By providing such a reinforcement portion 16, when the beam portion 20 is deformed by applying an external force F, a portion of the beam portion 20 above the reinforcement portion 16 undergoes elastic deformation (the portion undergoing elastic deformation is less likely to vary), thereby enabling stable deterioration judgment.

[0060] In addition, Figure 7 As shown, the reinforcement portion 16 is arranged on both sides of the beam-shaped portion 20 ( Figure 6 In this case, it is easy to function as the reinforcing portion 16.

[0061] In the "deformation step" of the modified example, the beam-shaped portion 20 is restricted by the restriction portion 15 and deforms by a certain amount δ. Based on the cantilever beam deflection calculation formula of material mechanics, the maximum stress σ applied to the beam-shaped portion 20 can be calculated using the following formula.

[0062] σ=3EHδ / (2L 2 )

[0063] In the above formula, E represents the longitudinal elastic coefficient of the beam-shaped portion 20, and H represents the thickness (see Figure 3 ), L represents the length (see Figure 3 ).

[0064] The deflection δ in the above equation is obtained by the following equation 1, the maximum bending moment Mmax is obtained by equation 2, and the maximum stress σmax is obtained by equation 3.

[0065] δ=FL 3 / (3EI) (Formula 1)

[0066] Mmax=FL (Formula 2)

[0067] σmax=Mmax / Z (Formula 3)

[0068] In equations 1 to 3, F represents the load applied to the beam (see Figure 3 ), I represents the 2D momentum of the cross section (=DH 3 / 12), D represents the width (see Figure 3 ), Z represents the cross-sectional modulus (=DH 2 / 6).

[0069] As can be seen from the above formula, the maximum stress σ to which the beam-shaped portion 20 is subjected when a certain amount of deformation δ is deformed depends on the longitudinal elastic coefficient 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 even after a certain period of time), and the length L of the beam-shaped portion 20 (a value that does not change even after a certain period of time). Therefore, since the value of the width D of the beam-shaped portion 20 is irrelevant to the maximum stress σ, even if the width D of a plurality of beam-shaped portions 20 provided on the resin molded article 10 is different from each other, as long as the thickness H and the length L are the same, the deterioration judgment can be performed with the same accuracy.

[0070] Furthermore, even if the resin molded product 10 deteriorates over time, by deforming the beam-shaped portion 20 by a certain amount δ, the maximum stress σ to which the beam-shaped portion 20 is subjected remains unchanged, and a certain stress can be simply applied without using a measuring instrument, thereby making it possible to make a highly accurate aging judgment.

[0071] Figure 8 2 is a graph showing the relationship between the strain and the stress σ of the beam-shaped portion 20 , wherein (A) is a graph showing that the resin molded product 10 has not been degraded, and (B) is a graph showing that the resin molded product 10 has been degraded.

[0072] like Figure 8 As shown in (A), in the initial state where the strength aging of the resin molded product 10 has not yet occurred, when a force is applied to the resin molded product 10 (beam-shaped portion 20), elastic deformation occurs before a certain stress is reached (see range X1), and plastic deformation occurs when the stress exceeds the stress. If the deformation further increases, it will eventually break (see range X2). The stress at the time of plastic deformation or the stress at the time of destruction at this time can basically be regarded as the strength of the material (resin molded product 10).

[0073] And as Figure 8 As shown in (B), after a period of time, the resin molded product 10 will experience strength aging such as a decrease in the molecular weight of the resin material due to the influence of heat, ultraviolet rays, chemicals, etc. Although its longitudinal elastic coefficient (the slope of the curve in the elastic region) remains almost unchanged, it is easy to experience aging such as sudden fracture with a stress lower than that in the unaged state and almost no plastic deformation. The strength of the material (resin molded product 10) at this time is lower than that in the unaged state ( Figure 8 The strength of (A) state).

[0074] In this regard, the present invention applies a force F to the front end of the beam-shaped portion 20 to deform it until the beam-shaped portion 20 hits the limiting portion 15 as described above, and the stress at this time does not change before and after aging. Therefore, if the thickness H and the length L are set so that the maximum stress σ when the beam-shaped portion 20 is deformed by a certain amount δ becomes the threshold value for judging the material strength of the resin molded article 10, the strength aging can be evaluated by whether there is plastic deformation and fracture (destruction) when the same stress F is applied to the beam-shaped portion 20.

[0075] Therefore, even if the strength of the resin molded product 10 deteriorates over time (due to a decrease in molecular weight caused by temperature, humidity, ultraviolet rays, etc.), it is only necessary to observe whether there is plastic deformation or fracture when a force F is applied to the front end of the beam-shaped portion 20 to deform it until it hits the limiting portion 15, without the need to use a measuring instrument or the like, and without requiring the operator's proficiency, etc., and the strength aging can be easily judged.

[0076] As described above, the resin molded article 10 of the present embodiment is a resin molded article formed of a predetermined resin material, and the beam-shaped portion 20 is integrally provided on the resin molded article 10, one end of which is connected to the resin molded article 10 and the other end is a free end. The presence or absence of deterioration is determined by whether plastic deformation or fracture occurs when the other end of the beam-shaped portion 20 is deformed.

[0077] Therefore, the deterioration of the resin molded product 10 can be easily determined.

[0078] The present invention is not limited to this embodiment. Obviously, in addition to the contents of this embodiment, this embodiment can be further changed as long as it is within the technical concept of the present invention. The number, position, shape, etc. of the above-mentioned components are not limited to this embodiment, and can be set to a suitable number, position, shape, etc. according to the needs of implementing the present invention.

[0079] The embodiment of the present invention may be, for example, as follows <1> ~ <10> combination.

[0080] <1> A resin molded product, formed of a predetermined resin material, characterized in that:

[0081] A beam-shaped portion is integrally provided on the resin molded product, one end of the beam-shaped portion is connected to the resin molded product, and the other end is formed as a free end,

[0082] Whether the resin molded product has deteriorated is determined based on whether plastic deformation or fracture occurs when the other end of the beam-shaped portion is deformed.

[0083] <2> according to <1> The resin molded product is characterized by further comprising a restricting portion for restricting the amount of deformation of the other end when the other end of the beam-shaped portion is deformed.

[0084] <3> according to <2> The resin molded product is characterized in that the restricting portion is formed to be spaced apart from the beam-shaped portion and to extend in a direction in which the beam-shaped portion stands upright when the other end of the beam-shaped portion is not deformed.

[0085] <4> <1> ~ <3> The resin molded product according to any one of the above is characterized by comprising a reinforcing portion for reinforcing and restricting elastic deformation of a root portion of the one end of the beam-shaped portion.

[0086] <5> according to <4> The resin molded product is characterized in that the reinforcing portion is provided at a position in contact with the root portion and is a portion having a thickness greater than that of the surrounding portion.

[0087] <6> according to <1> ~ <5> The resin molded product described in any one of the above is characterized in that at least a plurality of the beam-shaped parts are provided, and the length and thickness of the beam-shaped parts are the same.

[0088] <7> A method for determining aging of a resin molded product, wherein the resin molded product is formed of a predetermined resin material and has a beam-shaped portion integrally provided on the resin molded product, wherein one end of the beam-shaped portion is connected to the resin molded product and the other end is a free end, wherein the method for determining aging is characterized by:

[0089] a deformation step of deforming the other end of the beam-shaped portion; and

[0090] A judging step of judging that the resin molded product has deteriorated when plastic deformation or fracture occurs in the beam-shaped portion after the deformation step.

[0091] <8> according to <7> The method for determining aging of a resin molded product is characterized in that:

[0092] The resin molded product includes a restriction portion for restricting the amount of deformation of the other end when the other end of the beam-shaped portion is deformed.

[0093] In the deformation step, the beam-shaped portion is deformed to a position where the other end of the beam-shaped portion hits the restriction portion.

[0094] <9> A method for determining aging of a resin molded product, wherein the resin molded product is formed of a predetermined resin material and has a beam-shaped portion integrally provided on the resin molded product, wherein one end of the beam-shaped portion is connected to the resin molded product and the other end is a free end, wherein the method for determining aging is characterized by:

[0095] a breaking step of applying a load to the beam-shaped portion to deform the other end of the beam-shaped portion until the beam-shaped portion breaks; and

[0096] A judging step of judging whether the resin molded product has deteriorated based on the magnitude of the load when the beam-shaped portion is broken in the breaking step.

[0097] <10> according to <9> The method for determining aging of a resin molded product is characterized in that:

[0098] The resin molded product is provided with a plurality of beam-shaped portions having at least the same length and thickness,

[0099] When the resin molded product is reused, the breaking step is performed on one of the plurality of beam-shaped portions, and the number of reuses is counted based on the number of broken beam-shaped portions among the plurality of beam-shaped portions.

Claims

1. A resin molded product, formed of a predetermined resin material, characterized in that: A beam-shaped portion is integrally provided on the resin molded product, one end of the beam-shaped portion is connected to the resin molded product, and the other end is formed as a free end, Whether the resin molded product has deteriorated is determined based on whether plastic deformation or fracture occurs when the other end of the beam-shaped portion is deformed.

2. The resin molded product according to claim 1, characterized in that A limiting portion is further provided for limiting the amount of deformation of the other end when the other end of the beam-shaped portion is deformed.

3. The resin molded product according to claim 2, characterized in that The restricting portion is formed to be spaced apart from the beam-shaped portion and to extend in a direction in which the beam-shaped portion stands upright when the other end of the beam-shaped portion is not deformed.

4. The resin molded article according to claim 1 or 2, characterized in that: A reinforcing portion is provided for reinforcing and restricting elastic deformation of a root portion of the one end of the beam-shaped portion.

5. The resin molded article according to claim 4, characterized in that The reinforcing portion is a portion provided at a position in contact with the root portion and having a thickness greater than that of the surrounding portion.

6. The resin molded article according to claim 1 or 2, characterized in that: At least a plurality of beam-shaped portions are provided, and the length and thickness of the beam-shaped portions are the same.

7. A method for determining aging of a resin molded product, wherein the resin molded product is formed of a predetermined resin material and has a beam-shaped portion integrally provided on the resin molded product, wherein one end of the beam-shaped portion is connected to the resin molded product and the other end is a free end, wherein the method for determining aging is characterized by: a deformation step of deforming the other end of the beam-shaped portion; and A judging step of judging that the resin molded product has deteriorated when plastic deformation or fracture occurs in the beam-shaped portion after the deformation step.

8. The method for determining deterioration of a resin molded product according to claim 7, wherein: The resin molded product includes a restriction portion for restricting the amount of deformation of the other end when the other end of the beam-shaped portion is deformed. In the deformation step, the beam-shaped portion is deformed to a position where the other end of the beam-shaped portion hits the restriction portion.

9. A method for determining aging of a resin molded product, wherein the resin molded product is formed of a predetermined resin material and has a beam-shaped portion integrally provided on the resin molded product, wherein one end of the beam-shaped portion is connected to the resin molded product and the other end is a free end, wherein the method for determining aging is characterized by comprising: a breaking step of applying a load to the beam-shaped portion to deform the other end of the beam-shaped portion until the beam-shaped portion breaks; and A judging step of judging whether the resin molded product has deteriorated based on the magnitude of the load when the beam-shaped portion is broken in the breaking step.

10. The method for determining deterioration of a resin molded product according to claim 9, wherein: The resin molded product is provided with a plurality of beam-shaped portions having at least the same length and thickness, When the resin molded product is reused, the breaking step is performed on one of the plurality of beam-shaped portions, and the number of reuses is counted based on the number of broken beam-shaped portions among the plurality of beam-shaped portions.

Images