Testing jig for environmental stress cracking resistance of plastic

Abstract

The utility model relates to the technical field of testing tools, in particular to a plastic environmental stress cracking resistance testing jig which comprises a box body and a testing device arranged in the box body, the testing device comprises a first base, a second base and a bending assembly, a first containing cavity used for containing chemical reagents is arranged between the first base and the second base, and a second containing cavity used for containing chemical reagents is arranged between the first base and the second base. The two ends of the bending assembly are connected with the upper end of the first base and the upper end of the second base correspondingly. The bending assembly comprises a bending part and two supporting blocks, the bending part is provided with a second containing cavity communicating with the first containing cavity, the bending part is lower than the top ends of the supporting blocks, the second containing cavity is used for allowing the external plastic plate to penetrate through, and the two supporting blocks are located on the two sides of the bending part correspondingly and used for supporting the two ends of the external plastic plate. The testing jig can be used for carrying out a contact test and a non-contact test on a plastic plate and a volatile solvent, so that the experimental requirements can be better met; the testing process is carried out in a closed box body, so that the result stability is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of testing tooling, in particular to a plastic environmental stress cracking resistance testing tool. Background Art

[0002] Environmental stress cracking refers to the degradation of plastic resins under the action of chemicals in the presence of internal stress, which eventually leads to damage to the plastic components. Environmental stress cracking is a solvent-induced damage, which is a cracking caused by the synergistic action of chemicals and mechanical stress. In fact, the chemical penetrates into the molecular structure and damages the internal molecular force of the polymer chain. In the common failure classification of plastic parts, environmental stress cracking accounts for 31% and is called the killer of plastic parts. When testing ISO 22088-3-2006 "Determination of Environmental Stress Crack Resistance of Plastics", the test standard spline will be bent into a certain arc to generate bending stress in the spline itself. In the bent state, it will come into contact with other potential materials or chemical reagents that may be in contact. After a certain period of time, the compatibility of the two will be evaluated. At the same time, this test is also used to prove the effects of various chemicals on resins.

[0003] The prior art discloses a test device for environmental stress cracking test of plastic materials with application number 202021052616.0, which includes a device base, a mandrel, a lifting chuck and a fixed clamp seat; the mandrel is placed flat in the middle of the upper side of the device base, and the upper convex top surface of the middle part of the mandrel has a curved arc surface, and the fixed clamp seat is installed on the upper side of the device base outside the mandrel, and there is a slot between the edge of the fixed clamp seat and the surface of the mandrel, and the lifting chuck is installed on the other side of the mandrel. The structure is simple and reasonable, the operation is simple and practical, and it is convenient to further strengthen and enrich the functional improvement, and the provisions in the standard can be strictly implemented to accurately control the bending amount of the spline.

[0004] However, if the above test device is used to evaluate the environmental strain resistance of plastic materials under different bending stresses, it is necessary to prepare many mandrels with different bending radii, which is time-consuming and laborious. At the same time, the bent specimens need to be in contact with volatile chemical reagents for a period of time during the test, and the above test device placed in an open-air environment will cause the chemical reagents to evaporate too quickly, resulting in errors in the test results. Moreover, the above test device can only be used for contact testing of plastic materials and chemical reagents, but cannot be used for non-contact testing of plastic materials and chemical reagents. Summary of the invention

[0005] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the utility model is to provide a plastic environmental stress cracking resistance test jig, which is easy to use, highly practical, and can better meet experimental requirements.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0007] A plastic environmental stress cracking resistance test jig comprises a box body and a test device arranged in the box body, the test device comprises a first base, a second base and a bending assembly, a first accommodating cavity for placing chemical reagents is provided between the first base and the second base, and two ends of the bending assembly are respectively connected to the upper end of the first base and the upper end of the second base; the bending assembly comprises a bending piece and two support blocks, the bending piece is provided with a second accommodating cavity connected to the first accommodating cavity, the height of the bending piece is lower than the height of the support block, the second accommodating cavity is used for an external plastic sheet to pass through, and the two support blocks are respectively located on both sides of the bending piece and are used to support the two ends of the external plastic sheet.

[0008] Furthermore, the first base and the second base are both provided with a plurality of movable grooves, wherein the movable grooves are long hole structures and extend along the connecting direction of the two support blocks. One end of the support block is detachably connected to the movable groove corresponding to the first base, and the other end of the support block is detachably connected to the movable groove corresponding to the second base.

[0009] Furthermore, the support block and the movable groove are detachably connected via a first fastener.

[0010] Furthermore, the plurality of movable grooves are arranged in a matrix on the first base and the second base respectively.

[0011] Furthermore, the bending part includes a pressing block and two connecting rods, the two ends of the pressing block are slidably connected to the upper ends of the two connecting rods, the lower ends of the two connecting rods are connected to the first base and the second base respectively, the second accommodating cavity is surrounded by the pressing block and the two connecting rods, and the bottom of the pressing block is used for passing the external plastic sheet.

[0012] Furthermore, the bending part also includes an elastic part sleeved on the connecting rod, the upper end of the elastic part abuts against the pressing block, the lower end of the elastic part abuts against the first base or the second base, and the upper end of the connecting rod is provided with a second fastener located at the upper end of the pressing block.

[0013] Furthermore, the box body includes a shell and a cover body detachably connected to the shell.

[0014] Furthermore, the test fixture is made of stainless steel.

[0015] Furthermore, the height of the connecting rod is 7-9 cm, and the height of the supporting block is 5-7 cm.

[0016] Furthermore, the longitudinal section of the pressed block is circular or semicircular, and the diameter of the pressed block is 1-3 cm.

[0017] The beneficial effects of the utility model: the plastic environmental stress cracking resistance test jig of the utility model has a simple structure, is easy to use, saves time and effort, when in use, one end of the plastic sheet is placed on the upper end of a support block, and the other end extends along the cavity wall of the second accommodating cavity toward another support block until it abuts against the upper end of the other support block, so that the plastic sheet is bent and deformed to generate bending stress, the chemical reagent can be placed in a first accommodating cavity that is connected to the second accommodating cavity, and the volatile solvent in the chemical reagent evaporates into the second accommodating cavity, so that the plastic sheet and the volatile solvent in the chemical reagent are subjected to non-contact testing, or the chemical reagent is directly applied to the curved surface of the plastic sheet, so that the plastic sheet and the volatile solvent in the chemical reagent are subjected to contact testing, and a variety of tests can be performed to better meet experimental requirements and have a wide range of applications. At the same time, the test device is placed in a box, so that the test process of the test device is placed in a closed space, which can avoid the excessive volatilization of the volatile solvent in the chemical reagent and ensure the stability of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional structural diagram of the box;

[0019] Figure 2 It is a top view of the interior of the box;

[0020] Figure 3 This is a bottom view of a jig for testing the environmental stress cracking resistance of plastics;

[0021] Figure 4 This is a side view of the plastic environmental stress cracking test fixture.

[0022] Figure 5 For along Figure 4 Partial cross-sectional view along line AA.

[0023] Reference numerals include:

[0024] 1. Box body; 11. Shell; 12. Cover body; 3. First base; 4. Second base; 5. Movable groove; 6. First accommodating cavity; 7. Bending member; 71. Press block; 72. Connecting rod; 73. Elastic member; 74. Second fastener; 75. Second accommodating cavity; 8. Support block; 9. First fastener; 10. External plastic. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0026] like Figure 1-5As shown, a plastic environmental stress cracking resistance test jig includes a box body 1 and a test device arranged in the box body 1, the test device includes a first base 3, a second base 4 and a bending assembly, a first accommodating cavity 6 for placing chemical reagents is provided between the first base 3 and the second base 4, and two ends of the bending assembly are respectively connected to the upper end of the first base 3 and the upper end of the second base 4; the bending assembly includes a bending piece 7 and two support blocks 8, the bending piece 7 is provided with a second accommodating cavity 75 connected to the first accommodating cavity 6, the height of the bending piece 7 is lower than the height of the top of the support block 8 relative to the first base 3 and the second base 4, the second accommodating cavity 75 is used for allowing an external plastic sheet 10 to pass through, and the two support blocks 8 are respectively located on both sides of the bending piece 7 and are used to support the two ends of the external plastic sheet 10.

[0027] The plastic environmental stress cracking resistance test fixture of the utility model has a simple structure, is easy to use, and saves time and effort. When in use, the plastic plate 10 is inserted into the second accommodating chamber 75, and the two ends of the plastic plate 10 are respectively located at the upper ends of the support blocks 8, that is, one end of the plastic plate 10 is placed on the upper end of one support block 8, and the other end passes through the second accommodating chamber 75 and extends to the other support block 8 until it abuts against the upper end of the other support block 8, so that the plastic plate 10 is bent and deformed to generate bending stress. The chemical reagent can be placed in the first accommodating chamber 6 communicated with the second accommodating chamber 75, and the volatile solvent in the chemical reagent evaporates into the second accommodating chamber 75, so that the plastic plate 10 and the volatile solvent in the chemical reagent are subjected to non-contact testing, or the chemical reagent is directly applied to the curved surface of the plastic plate 10, so that the plastic plate 10 and the volatile solvent in the chemical reagent are subjected to contact testing. A variety of tests can be performed to better meet experimental requirements and have a wide range of applications. At the same time, the testing device is placed in the box 1, so that the testing process of the testing device is placed in a closed space, which can avoid the volatile solvent in the chemical reagent from volatilizing too quickly and ensure the stability of the test results.

[0028] Furthermore, the first base 3 and the second base 4 are both provided with a plurality of movable grooves 5, the support block 8 is arranged corresponding to the movable grooves 5, the movable grooves 5 are long strip hole structures, the movable grooves 5 extend along the connecting line direction of the two support blocks 8, one end of the support block 8 is detachably connected to the movable groove 5 corresponding to the first base (3), and the other end of the support block 8 is detachably connected to the movable groove 5 corresponding to the second base 4. The support block 8 can be adjusted to any position of the movable groove 5 of the long strip hole structure as required to adjust the distance between the support block 8 and the bending member 7, thereby flexibly adapting to plastic plates 10 of various sizes.

[0029] Further, the support block 8 is detachably connected to the movable groove 5 via a first fastener 9, and the first fastener 9 is used to firmly connect the two ends of the support block 8 to the first base 3 and the second base 4. Specifically, the upper end of the first fastener 9 is passed through the movable groove 5 and the support block 8 in sequence, and the first fastener 9 is threadedly connected to the support block 8, so that the two support blocks 8 can be detachably connected to the first base 3 and the second base 4 respectively in a simple and effective manner, wherein the first fastener 9 can be a screw, a bolt, etc.

[0030] Further, the plurality of movable grooves 5 are respectively arranged in a matrix on the first base 3 and the second base 4. In the present embodiment, the number of movable grooves 5 of the first base 3 and the second base 4 are both four, and the four movable grooves 5 are arranged in a matrix, that is, one end of the support block 8 is sequentially connected to the two movable grooves 5 of the first base 3 through the corresponding first fasteners 9, and the other end of the support block 8 is sequentially connected to the two movable grooves 5 of the second base 4 through the corresponding first fasteners 9, so that the two ends of the support block 8 are respectively and firmly connected to the first base 3 and the second base 4, avoiding displacement of the support block 8, and having a simple structure.

[0031] Furthermore, the bending member 7 includes a pressing block 71 and two connecting rods 72, the two ends of the pressing block 71 are slidably connected to the upper ends of the two connecting rods 72, and the lower ends of the two connecting rods 72 are connected to the first base 3 and the second base 4 respectively. The second accommodating cavity 75 is surrounded by the pressing block 71 and the two connecting rods 72. The lower part of the pressing block 71 is used for the external plastic sheet 10 to pass through, that is, one end of the external plastic sheet 10 abuts against the upper end of a support block 8, and the other end passes through the lower part of the pressing block 71 and extends to the other support block 8 until it abuts against the upper end of the other support block 8. At the same time, the two ends of the pressing block 71 are slidably connected to the upper ends of the two connecting rods 72 respectively, and the height of the pressing block 71 relative to the first base 3 and the second base 4 can be adjusted to control the curvature of the bending deformation of the plastic sheet 10, thereby causing the plastic sheet 10 to produce different strains, thereby realizing the quantitative inspection of the environmental stress cracking resistance of the plastic sheet 10. The overall fixture has a simple structure and is easy to operate.

[0032] Furthermore, the bending member 7 also includes an elastic member 73 sleeved on the connecting rod 72, the upper end of the elastic member 73 abuts against the pressing block 71, and the lower end of the elastic member 73 abuts against the first base 3 or the second base 4. The upper end of the connecting rod 72 is provided with a second fastener 74 located at the upper end of the pressing block 71, that is, the upper end of the connecting rod 72 passes through the pressing block 71 and the second fastener 74 in sequence. The second fastener 74 is used to adjust the height of the pressing block 71 relative to the first base 3 and the second base 4, and the elastic member 73 is used to support the pressing block 71 when the test fixture does not test the stress of the plastic, and the structure is simple. In this embodiment, the connecting rod 72 is threadedly connected to the second fastener 74, wherein the second fastener 74 can be a nut or the like, and the connecting rod 72 can be a screw.

[0033] Furthermore, the box 1 includes a shell 11 and a cover 12 detachably connected to the shell 11. The cover 12 and the shell 11 cooperate with each other, which is convenient for placing the test fixture and simple to operate.

[0034] Furthermore, the test fixture is made of stainless steel. Stainless steel can withstand the corrosion of chemical media, improve the service life of the fixture, and avoid the problem of failure of the bending part 7 or the support block 8 after a long time. Preferably, the test fixture is made of 304 stainless steel.

[0035] Further, the height of the connecting rod 72 is 7-9 cm, and the height of the supporting block 8 is 5-7 cm. Such a size can better play the role of deforming the plastic sheet 10. Preferably, the height of the connecting rod 72 is 8 cm, and the height of the supporting block 8 is 6 cm.

[0036] Furthermore, the pressing block 71 is a cylinder or a semi-cylinder, the longitudinal section of the pressing block 71 is circular or semi-circular, and the diameter of the pressing block 71 is 1-3 cm. Such a size can better play the role of deforming the plastic sheet 10, and also prevent the plastic sheet 10 from being affected by other external forces at the bend. Preferably, the diameter of the pressing block 71 is 2 cm.

[0037] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there will be changes in the specific implementation methods and application scopes. The contents of this specification should not be understood as limiting the present invention.

Claims

1. A plastic environmental stress cracking test jig, characterized in that: The invention comprises a box (1) and a testing device arranged in the box (1), wherein the testing device comprises a first base (3), a second base (4) and a bending assembly, wherein a first accommodating cavity (6) for placing chemical reagents is arranged between the first base (3) and the second base (4), and two ends of the bending assembly are respectively connected to the upper end of the first base (3) and the upper end of the second base (4); the bending assembly comprises a bending piece (7) and two supporting blocks (8), wherein the bending piece (7) is provided with a second accommodating cavity (75) connected to the first accommodating cavity (6), wherein the height of the bending piece (7) is lower than the height of the supporting blocks (8), and the second accommodating cavity (75) is used for allowing an external plastic sheet (10) to pass through, and the two supporting blocks (8) are respectively located on both sides of the bending piece (7) and are used for supporting the two ends of the external plastic sheet (10).

2. The plastic environmental stress cracking resistance test jig according to claim 1, characterized in that: The first base (3) and the second base (4) are both provided with a plurality of movable grooves (5), the movable grooves (5) being of a long hole structure, the movable grooves (5) extending along the connecting direction of the two support blocks (8), one end of the support block (8) being detachably connected to the movable groove (5) corresponding to the first base (3), and the other end of the support block (8) being detachably connected to the movable groove (5) corresponding to the second base (4).

3. The plastic environmental stress cracking resistance test jig according to claim 2, characterized in that: The support block (8) and the movable groove (5) are detachably connected via a first fastener (9).

4. The plastic environmental stress cracking resistance test jig according to claim 2, characterized in that: The plurality of movable grooves (5) are arranged in a matrix on the first base (3) and the second base (4).

5. The plastic environmental stress cracking resistance test jig according to claim 1, characterized in that: The bending member (7) comprises a pressing block (71) and two connecting rods (72), the two ends of the pressing block (71) are respectively slidably connected to the upper ends of the two connecting rods (72), the lower ends of the two connecting rods (72) are respectively connected to the first base (3) and the second base (4), the second accommodating cavity (75) is surrounded by the pressing block (71) and the two connecting rods (72), and the lower part of the pressing block (71) is used for the external plastic plate (10) to pass through.

6. The plastic environmental stress cracking resistance test jig according to claim 5, characterized in that: The bending member (7) further comprises an elastic member (73) sleeved on the connecting rod (72), the upper end of the elastic member (73) abuts against the pressing block (71), the lower end of the elastic member (73) abuts against the first base (3) or the second base (4), and the upper end of the connecting rod (72) is provided with a second fastener (74) located at the upper end of the pressing block (71).

7. The plastic environmental stress cracking resistance test jig according to claim 1, characterized in that: The box body (1) comprises a shell body (11) and a cover body (12) detachably connected to the shell body (11).

8. The plastic environmental stress cracking resistance test jig according to claim 1, characterized in that: The plastic environmental stress cracking resistance test jig is made of stainless steel.

9. The plastic environmental stress cracking resistance test jig according to claim 5, characterized in that: The height of the connecting rod (72) is 7-9 cm, and the height of the supporting block (8) is 5-7 cm.

10. The plastic environmental stress cracking resistance test jig according to claim 5, characterized in that: The longitudinal section of the pressing block (71) is circular or semicircular, and the diameter of the pressing block (71) is 1-3 cm.

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