A mold for epoxy resin tensile specimen casting suitable for μts

Abstract

The utility model provides a mould is suitable for epoxy resin tensile test piece pouring of mu TS, including metal frame and silica gel inner bag, the top opening of metal frame, the silica gel inner bag is placed in metal frame, the metal frame includes the first frame body and the second frame body of detachable connection, a plurality of independent forming cavities are seted up on the silica gel inner bag, a plurality of the forming cavity is used for pouring forming epoxy resin test piece in, the inner wall of a plurality of forming cavities all has the non - stick coating that coats. The utility model can realize easy stripping and guarantee the size accuracy of test piece simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of casting mold technology, and in particular to a mold suitable for casting epoxy resin tensile specimens of μTS. Background Technology

[0002] The micro-Tensile System (μTS) is suitable for testing the mechanical properties of various materials. It is a unique micro-universal material testing system that lies between nanoindenters and macroscopic universal loading systems. It can acquire local strain field data through non-contact measurement using a combination of digital image correlation software (DIC) and microscopy.

[0003] Epoxy resins possess excellent mechanical, dielectric, and adhesive properties, as well as good process adaptability, making them widely used in various fields. In experiments, they are often made into standard specimens to test their tensile properties. However, traditional molds are difficult to demold, easily damage the samples, and cleaning residual resin is time-consuming and laborious.

[0004] Traditional metal molds offer advantages such as good dimensional stability, excellent thermal conductivity, and high durability. However, metal molds have long manufacturing cycles, high costs, and heavy weight. Most importantly, they are difficult to demold, requiring strong release agents, and the demolding process can easily damage the edges or surfaces of the specimen. In recent years, silicone rubber molds have developed with excellent flexibility, making demolding easier. They also offer strong detail replication capabilities and are less likely to damage the specimen. However, the molds themselves have poor dimensional stability and are prone to deformation under curing pressure or resin shrinkage stress, affecting the dimensional accuracy of the specimen. Furthermore, compared to metal molds, silicone molds are more susceptible to wear and tear, resulting in a shorter service life.

[0005] The invention disclosed in CN106896010A is a mold for making epoxy asphalt specimens and a method for making the mold. The mold is made of silicone and is prepared by curing liquid silicone with a silicone curing agent. Its cavity is dumbbell-shaped, and the effective length A, end width B, length C, width D, outer transition edge radius E, and inner transition edge radius F of the cavity conform to a certain proportional relationship. Although this silicone resin mold does not cause demolding difficulties when making epoxy asphalt specimens, the mold itself has poor dimensional stability and is prone to deformation under curing pressure and resin shrinkage stress, affecting the dimensional accuracy of the specimens. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a mold suitable for casting epoxy resin tensile specimens for μTS, which achieves easy demolding while ensuring the dimensional accuracy of the specimens.

[0007] To achieve the above objectives, this utility model provides a mold suitable for casting epoxy resin tensile specimens for μTS, comprising a metal frame and a silicone inner liner. The top of the metal frame is open, and the silicone inner liner is placed inside the metal frame. The metal frame includes a first frame and a second frame that are detachably connected. The silicone inner liner has multiple independent molding cavities, which are used for casting epoxy resin specimens. The inner walls of the multiple molding cavities are coated with a non-stick coating.

[0008] In this invention, a detachable metal frame is provided outside the silicone inner liner to form a rigid constraint on the silicone inner liner, preventing deformation caused by external forces during the curing process of the specimen, reducing mold wear, and extending the service life of the mold. By opening a molding cavity in the silicone inner liner, due to the high flexibility of the silicone inner liner, after the specimen is molded, the silicone inner liner can be easily removed after the first frame and the second frame are separated. Furthermore, by squeezing the silicone inner liner, the elasticity of the silicone can be used to expand the molding cavity to facilitate the removal of the specimen. The non-stick coating on the inner wall of the molding cavity can prevent the specimen from remaining in the molding cavity, ensuring the integrity of the specimen.

[0009] Optionally, each of the molding cavities includes an intermediate cavity, two transition cavities, and two end cavities. The two transition cavities are connected between the intermediate cavity and the two end cavities, and the transition cavities are designed to gradually expand from the intermediate cavity to the end cavities. The dimensions of the two ends of the transition cavities are the same as the dimensions of the intermediate cavity and the end cavities, respectively.

[0010] In this invention, by setting the structure of the molding cavity, the molded specimen is made into a dumbbell shape with a smaller middle and larger ends. The tensile test fixture clamps the two ends of the specimen to perform a tensile test on the specimen.

[0011] Optionally, each of the end cavities is provided with a scratch groove at intervals on the bottom wall, and the scratch groove forms a 30° angle with the length direction of the molding cavity.

[0012] In this invention, since the end of the specimen needs to be clamped during tensile testing, a scratch groove is set on the bottom wall of the end cavity, so that the end of the formed specimen forms a scratch protrusion, and the tensile test fixture can provide a more stable clamping and biting effect.

[0013] Optionally, each of the end cavities is designed to be lengthened along the length direction of the corresponding molding cavity, and the length of the lengthened end cavity is 8-12mm.

[0014] In this invention, when the length of the end cavity is increased, the length of both ends of the molded specimen is increased simultaneously. When the tensile test fixture clamps the specimen, it can reduce the stress concentration of the specimen, avoid specimen instability, and improve the reliability of the test.

[0015] Optionally, both the first frame and the second frame are magnetic metal frames, and can be closed by magnetic attraction or separated by external force.

[0016] In this invention, the first and second frames made of magnetic material do not require additional design to fix them together, which not only simplifies the structure of the metal frame, but also makes the disassembly and assembly operations simple and convenient.

[0017] Optionally, both the first frame and the second frame are designed with SPCC low carbon steel plate with nickel plating and N35 neodymium iron boron magnets embedded at the edges and corners.

[0018] In this invention, SPCC refers to general-purpose cold-rolled carbon steel sheet and strip, which has good mechanical and processing properties. N35 grade neodymium iron boron magnets have good magnetic properties, which can ensure the relative stability of the first frame and the second frame, and the cost is low.

[0019] Optionally, the plurality of molding cavities are arranged side by side at uniform intervals on the silicone inner liner.

[0020] In this invention, multiple molding cavities arranged side by side at even intervals make the casting and demolding processes more convenient.

[0021] Beneficial effects:

[0022] 1. A detachable metal frame is installed outside the silicone inner liner to provide rigid constraint on the silicone inner liner, preventing deformation caused by external forces during the curing process of the specimen, reducing mold wear, and extending the service life of the mold.

[0023] 2. By creating a molding cavity in the silicone inner liner, the silicone inner liner is highly flexible. After the specimen is molded, the silicone inner liner can be easily removed after the first frame and the second frame are separated. The molding cavity can be expanded by squeezing the silicone inner liner, which utilizes the elasticity of the silicone to facilitate the removal of the specimen. The non-stick coating on the inner wall of the molding cavity can prevent the specimen from remaining in the molding cavity, thus ensuring the integrity of the specimen. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1This is a three-dimensional structural diagram of a mold for casting epoxy resin tensile specimens suitable for μTS, as disclosed in this utility model.

[0026] Figure 2 This is a front view of a mold for casting epoxy resin tensile specimens suitable for μTS, as disclosed in this utility model.

[0027] Figure label:

[0028] 1. Metal frame; 11. First frame; 12. Second frame; 2. Silicone inner liner; 21. Molding cavity; 211. Intermediate cavity; 212. Transition cavity; 213. End cavity; 22. Non-stick coating; 23. Scratching groove.

[0029] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0032] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0033] See Figure 1 and Figure 2According to an embodiment of the present invention, a mold for casting epoxy resin tensile specimens suitable for μTS includes a metal frame 1 and a silicone inner liner 2. The top of the metal frame 1 is open, and the silicone inner liner 2 is placed inside the metal frame 1. The metal frame 1 includes a first frame 11 and a second frame 12 that are detachably connected. The silicone inner liner 2 has a plurality of independent molding cavities 21. The plurality of molding cavities 21 are used for casting epoxy resin specimens. The inner walls of the plurality of molding cavities 21 are coated with a non-stick coating 22.

[0034] In this invention, a detachable metal frame 1 is provided outside the silicone inner liner 2 to form a rigid constraint on the silicone inner liner 2, preventing deformation caused by external forces during the curing process of the specimen, reducing mold wear, and extending the service life of the mold. By opening a molding cavity 21 on the silicone inner liner 2, due to the high flexibility of the silicone inner liner 2, after the specimen is molded, the silicone inner liner 2 can be easily removed after the first frame 11 and the second frame 12 are separated. Furthermore, by squeezing the silicone inner liner 2, the elasticity of the silicone can be used to expand the molding cavity 21 to facilitate the removal of the specimen. The non-stick coating 22 coated on the inner wall of the molding cavity 21 can prevent the specimen from remaining in the molding cavity 21, thus ensuring the integrity of the specimen.

[0035] Specifically, the depth of the molding cavity 21 is set to 4mm, and the non-stick coating 22 is made of PTFE, i.e., polytetrafluoroethylene. Since the coefficient of friction of the PTFE coating is very low, it can significantly reduce the resistance between the molded specimen and the silicone inner liner 2, so that the molded specimen can be easily removed. In addition, it also has excellent anti-adhesion and environmental safety, which can meet the usage requirements.

[0036] See Figure 1 In some embodiments of this utility model, each of the molding cavities 21 includes an intermediate cavity 211, two transition cavities 212 and two end cavities 213. The two transition cavities 212 are connected between the intermediate cavity 211 and the two end cavities 213. The transition cavities 212 are designed to gradually expand from the intermediate cavity 211 to the end cavities 213. The dimensions of the two ends of the transition cavity 212 are the same as the dimensions of the intermediate cavity 211 and the end cavities 213, respectively.

[0037] In this invention, by setting the structure of the forming cavity 21, the formed specimen is dumbbell-shaped with a smaller middle and larger ends. The tensile test fixture clamps the two ends of the specimen to perform a tensile test on the specimen.

[0038] See Figure 1 In some embodiments of this utility model, each end cavity 213 is provided with a scratch groove 23 at intervals on its bottom wall, and the scratch groove 23 forms a 30° angle with the length direction of the molding cavity 21.

[0039] In the present utility model, since the ends of the test piece need to be clamped during the tensile test, by providing a scratch groove 23 on the bottom wall of the end cavity 213, a scratch protrusion is formed at the end of the formed test piece, and the tensile test fixture can provide a more stable clamping and biting effect.

[0040] Specifically, the depth of the scratch groove 23 is 0.2 mm, the width is 0.5 mm, and the spacing between adjacent scratch grooves 23 is 1 mm, so as to increase the friction between the formed test piece and the tensile test fixture.

[0041] See Figure 1 In some embodiments of the present utility model, each of the end cavities 213 is designed to be lengthened along the length direction of the corresponding forming cavity 21, and the length of the lengthened end cavity 213 is 8 - 12 mm.

[0042] In the present utility model, when the length of the end cavity 213 is lengthened, the lengths of both ends of the formed test piece are synchronously lengthened. When the tensile test fixture clamps the test piece, the stress concentration of the test piece can be reduced, the instability of the test piece can be avoided, and the reliability of the test can be improved.

[0043] Specifically, the length of the end cavity 213 is preferably 10 mm. Compared with the traditional scheme where only a 4 - mm - long end of the test piece is used, the preferred scheme of the present utility model can ensure the reduction of the stress concentration of the test piece while reducing the waste of epoxy resin material and controlling the overall size length of the test piece.

[0044] See Figure 1 In some embodiments of the present utility model, both the first frame 11 and the second frame 12 are magnetic metal frames and can be closed by magnetic attraction or separated by an external force.

[0045] In the present utility model, the first frame 11 and the second frame 12 made of magnetic - attracting materials do not require an additional structure for fixing the two, which not only simplifies the structure of the metal frame 1 but also makes the disassembly and assembly operations simple and convenient.

[0046] Specifically, the first frame 11 has a bottomed "匚" - shaped structure, and the second frame 12 has an "I" - shaped structure. After the silica gel inner liner 2 is placed in the "匚" - shaped first frame 11, the "I" - shaped second frame 12 is adsorbed and fixed to the first frame 11 to achieve rigid constraint on the silica gel inner liner 2. Of course, the present utility model is not limited to this, and other structures that can achieve the closing and separation of the metal frame 1 are also possible.

[0047] See Figure 1 In some embodiments of the present utility model, both the first frame 11 and the second frame 12 adopt the design of SPCC low - carbon steel plates plated with nickel and embedded with N35 neodymium iron boron magnets at the corners.

[0048] In this invention, SPCC refers to general-purpose cold-rolled carbon steel sheet and strip, which has good mechanical and processing properties. N35 grade neodymium iron boron magnets have good magnetic properties, which can ensure the relative stability of the first frame 11 and the second frame 12, and the cost is low.

[0049] See Figure 1 In some embodiments of this utility model, the plurality of molding cavities 21 are arranged side by side at uniform intervals on the silicone inner liner 2.

[0050] In this invention, the multiple molding cavities 21 arranged side by side at even intervals make the casting and demolding processes more convenient.

[0051] In use, the silicone inner liner 2 is placed inside the first frame 11, and the second frame 12 is attached to the first frame 11, forming a square frame structure with an open top and closed bottom and sides. The first and second frames 11 and 12 provide rigid constraints on the silicone inner liner 2. Epoxy resin and curing agent are mixed in proportion and stirred evenly before being injected into the molding cavity 21. The mixture is left to cure. Once the cured specimen is formed, the first and second frames 11 and 12 are manually pulled apart to release the magnetic attraction and remove the silicone inner liner 2. By gently pinching both ends of the inner liner, the elasticity of the silicone expands the molding cavity 21. During testing, the PTFE coating automatically peels off without residue. The demolded specimen ends have oblique raised textures, which increases the stability of the tensile test fixture's gripping. Simultaneously, the lengthened ends of the specimen reduce stress concentration during the tensile process, ensuring more stable and reliable tensile testing.

[0052] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A mold suitable for epoxy resin tensile specimen casting for μTS, characterized by, The device includes a metal frame (1) and a silicone inner liner (2). The top of the metal frame (1) is open, and the silicone inner liner (2) is placed inside the metal frame (1). The metal frame (1) includes a first frame (11) and a second frame (12) that are detachably connected. The silicone inner liner (2) has multiple independent molding cavities (21) for casting epoxy resin specimens. The inner walls of the multiple molding cavities (21) are coated with a non-stick coating (22).

2. The mold for casting epoxy resin tensile specimens suitable for μTS according to claim 1, characterized in that, Each of the molding cavities (21) includes an intermediate cavity (211), two transition cavities (212) and two end cavities (213). The two transition cavities (212) are connected between the intermediate cavity (211) and the two end cavities (213). The transition cavity (212) is designed to gradually expand from the intermediate cavity (211) to the end cavity (213). The dimensions of the two ends of the transition cavity (212) are the same as the dimensions of the intermediate cavity (211) and the end cavity (213), respectively.

3. The mold for casting epoxy resin tensile specimens suitable for μTS according to claim 2, characterized in that, Each of the end cavities (213) has a scratch groove (23) spaced apart on its bottom wall, and the scratch groove (23) forms a 30° angle with the length direction of the molding cavity (21).

4. The mold for casting epoxy resin tensile specimens suitable for μTS according to claim 2, characterized in that, Each of the end cavities (213) is designed to be elongated along the length direction of the corresponding molding cavity (21), and the length of the elongated end cavity (213) is 8-12mm.

5. The mold for casting epoxy resin tensile specimens suitable for μTS according to claim 1, characterized in that, Both the first frame (11) and the second frame (12) are magnetic metal frames and can be closed by magnetic attraction or separated by external force.

6. A mold for casting epoxy resin tensile specimens suitable for μTS according to claim 5, characterized in that, Both the first frame (11) and the second frame (12) are designed with SPCC low carbon steel plate with nickel plating and N35 neodymium iron boron magnets embedded at the edges and corners.

7. A mold for casting epoxy resin tensile specimens suitable for μTS according to any one of claims 1 to 6, characterized in that, The plurality of molding cavities (21) are evenly spaced and arranged side by side on the silicone inner liner (2).

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