A mold for testing the magnitude of a demolding force

Abstract

The experiment relates to a mold for testing demolding force, which comprises an upper base, a cylinder, a pull rod and a lower base. The mold is made of metal, and the upper base and the lower base of the mold contain inner threads, which play a role in fixed connection of the cylinder. The inner wall of the cylinder of the mold is provided with uniformly distributed tooth structure, which aims to increase the contact area, increase the friction force, enlarge the demolding effect and the like. The pull rod of the mold does not contact with the upper base, the lower base and the cylinder, and the pull rod, the accessory fixed disc and the demolding object are fixed together, and the demolding object is separated from the mold by pulling the pull rod. The other end of the pull rod is connected with a tension machine device, so that the demolding force process and the maximum force of the demolding object when the demolding object is separated from the mold are tested. The experimental device has the advantages of simple structure, convenient operation, application to various polymer demolding objects, multiple disassembly and cleaning, repeated use, and greatly improved experimental efficiency and measurement accuracy.

Description

Technical Field

[0001] This utility model relates to the field of mold technology, and in particular to a mold for testing the magnitude of demolding force. Background Technology

[0002] With the improvement of living standards, the plastic and other products needed in daily life have become more diverse and complex. During the production of these products, a release agent is often applied to the mold surface to improve production efficiency and quality. The release agent has the functions of lubrication, anti-sticking, isolation, and reducing demolding force. The magnitude of the demolding force is an important dimension for judging the ease of demolding. Currently, there are few molds on the market for testing demolding force, and their application is limited, only able to test the demolding force of a certain type of adhesive at a certain temperature. However, the mold involved in this utility model can test the demolding force of rubber, polyurethane, epoxy resin, unsaturated resin, and other adhesives at different temperatures, and has the advantages of convenient operation, high precision, and good repeatability, greatly improving the research efficiency of demolding force analysis. Utility Model Content

[0003] Since the molds for testing demolding force have limited applications in the market, this utility model discloses a mold for testing the magnitude of demolding force. It can test the demolding force of rubber, polyurethane, epoxy resin, unsaturated resin and other types of adhesives at different temperatures. It also has the advantages of convenient operation, high precision and good repeatability, which greatly improves the research and development efficiency of demolding force.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A mold for testing demolding force includes an upper base 1, a lower base 2, a tube 3, and a pull rod 4. The tube 3 is fixed together by the upper base 1 and the lower base 2. The pull rod 4 does not contact the upper base 1, the lower base 2, or the tube 3. The pull rod 4 is fixed together with the object to be demolded, and pulling the pull rod 4 causes the object to be demolded from the mold. The base 1 and the lower base 2 contain internal threads 7, each with an inner diameter of 6 cm, and four corner holes 5 with an inner diameter of 0.3 cm for fixing. The upper base 1 is hollow, and the lower base 2 is half hollow. The tube 3 has external threads 8 at both ends, with an outer diameter of 6 cm and a length of 20 cm. The tube 3 is divided into an upper mold 3-1 and a lower mold 3-2, which are fixed together by the internal threads 7 of the upper base 1 and the lower base 2. The inner wall of the tube 3 has a uniformly distributed toothed structure 9. The pull rod 4 is 25 cm long and contains an accessory fixing plate 6 with a diameter of 3 cm. The fixing plate 6 enhances the resistance of the pull rod 4 and the object to be demolded to damage, thus allowing the object to be demolded smoothly from the mold. Before the experiment, the inside of the mold was cleaned with mold cleaning solution. The upper mold 3-1 and lower mold 3-2 of the tube 3 were fixed by rotation via the upper base 1 and lower base 2. A certain mass of release agent was taken and applied evenly to the inside of the mold using a clean wool brush. After the solvent in the release agent evaporated, an appropriate amount of polymer was weighed, quickly mixed and stirred, and then poured into the mold. The pull rod 4 was quickly placed into the mold, and its position was adjusted so that it did not touch the inner wall of the mold and was placed vertically. The polymer was allowed to react and cure completely at a certain temperature. The top of the pull rod 4 was connected to a tensile testing machine and fixed in a suitable position through the hole 5 in the mold. The tensile testing machine was started, and the polymer was slowly released from the mold by the pull rod 4. The entire demolding force process of the polymer being released from the mold could be recorded by the tensile testing machine. At this time, the maximum force F1 of the polymer being released from the mold for the first time was recorded. Since there was residual release agent, continuous demolding was possible. An equal mass of polymer was taken again, and other conditions were kept consistent. The maximum force F2 of the polymer being released from the mold for the second time was recorded. As mentioned above, the maximum force F3 of the polyurethane during the third demolding is recorded. Generally, the demolding force is relatively large after three consecutive demoldings of the polymer, or there may be localized sticking to the mold. Therefore, to minimize errors, only the maximum demolding force F for the first three demoldings is recorded. Following the same steps and conditions, two more parallel experiments are performed, and the maximum demolding force F of the polymer when it leaves the mold is recorded. Attached Figure Description

[0006] Figure 1 An exploded view of a mold for testing the magnitude of demolding force, provided in Embodiment 1 of this utility model;

[0007] Figure 2 An assembly drawing of a mold for testing the magnitude of demolding force, provided for Embodiment 1 of this utility model;

[0008] Figure 3 This is a structural diagram of the pull rod provided in Embodiment 1 of this utility model;

[0009] Figure 4 This is a structural diagram of the tube provided in Embodiment 1 of this utility model;

[0010] Figure 5 A part drawing of the tube provided in Embodiment 1 of this utility model;

[0011] Figure 6 A top view of the tube provided in Embodiment 1 of this utility model;

[0012] Figure 7 This is a structural diagram of the upper base provided in Embodiment 1 of the present utility model;

[0013] Figure 8 This is a structural diagram of the lower base provided in Embodiment 1 of this utility model;

[0014] In the diagram: 1-Upper base; 2-Lower base; 3-1-Upper mold of the tube; 3-2-Lower mold of the tube; 4-Pull rod; 5-Hole; 6-Fixing plate; 7-Internal thread; 8-External thread; 9-Gear-like structure inside the tube. Detailed Implementation

[0015] The present invention will now be further described with reference to the accompanying drawings.

[0016] Example 1

[0017] In this first embodiment, polyurethane was used as the material to be released, and the stability of the release force of the same release agent was tested at around 25°C.

[0018] A mold for testing the release force includes an upper base 1, a lower base 2, a tube 3, and a pull rod 4. Before the experiment, the inside of the mold is cleaned with mold cleaning solution. The upper mold 3-1 and lower mold 3-2 of the tube 3 are fixed by rotation via the upper base 1 and lower base 2. 100 grams of release agent No. 1 is taken and evenly applied to the inside of the mold using a clean wool brush. After the solvent in the release agent evaporates at 25°C for 3 minutes, 20 grams of polyurethane component A and 5 grams of component B are weighed, quickly mixed and stirred until evenly mixed, and then poured into the mold. The pull rod 4 is quickly placed into the mold, adjusted to a suitable position so that it does not touch the inner wall of the mold and is placed vertically. The polyurethane is completely cured at 25°C for 10 minutes. The top of the pull rod 4 is connected to a tensile testing machine and fixed in a suitable position through a hole 5 in the mold. The tensile testing machine was started, and the polyurethane slowly detached from the mold under the action of pull rod 4. The entire demolding force process of the polyurethane detaching from the mold was recorded using the tensile testing machine. At this point, the maximum force of the polyurethane during the first detachment process was recorded as 23.43 N. Due to the residue of the release agent, continuous demolding was possible. An equal mass of polyurethane material was taken again, and other conditions were kept consistent. The maximum force of the polyurethane during the second detachment process was 33.12 N. As above, the maximum force of the polyurethane during the third detachment process was 53.22 N. Following the same steps and conditions, two more parallel experiments were conducted, and the maximum demolding force of the polyurethane during detachment from the mold was recorded. Table 1. Maximum demolding force of polyurethane when it leaves the mold at 25°C First Model 23.43 23.36 23.29 23.36 0.003 Second Model 33.12 33.09 33.18 33.13 0.001 Third Model 53.24 53.27 53.33 53.28 0.001

[0019] Under the same process conditions, the release agent was used to conduct three release force tests on polyurethane. Each test involved removing the first three molds, and the data were recorded in Table 1. According to Table 1, the maximum force F measured in the parallel tests on each mold of polyurethane showed small fluctuations and strong data repeatability. Therefore, the test results obtained by this method are stable and reliable.

[0020] Example 2

[0021] In this second embodiment, epoxy resin was used as the release agent, and the stability of the release force of the same release agent was tested at around 150°C.

[0022] A mold for testing the release force includes an upper base 1, a lower base 2, a tube 3, and a pull rod 4. Before the experiment, the inside of the mold is cleaned with mold cleaning solution. The upper mold 3-1 and lower mold 3-2 of the tube 3 are fixed by the upper base 1 and lower base 2. Take 100 grams of No. 2 release agent, and use a clean wool brush to apply the release agent evenly inside the mold. After the solvent of the release agent evaporates at 60℃ for 3 minutes, weigh 80 grams of epoxy resin and 40 grams of curing agent, quickly mix and stir, and pour the mixture into the mold. Quickly place the pull rod 4 into the mold, adjust its position so that the pull rod 4 does not touch the inner wall of the mold and is placed vertically. Finally, place the entire mold in an oven at 150℃ and bake for 20 minutes. After the epoxy resin has completely reacted and cured, connect the top of the pull rod 4 to a tensile testing machine and fix it in a suitable position through the hole 5 of the mold. The tensile testing machine was started, and the epoxy resin slowly detached from the mold under the action of pull rod 4. The tensile testing machine recorded the entire demolding force process of the epoxy resin detaching from the mold. At this point, the maximum force of the epoxy resin during the first demolding process was recorded as 43.22 N. Due to the residue of the release agent, continuous demolding was possible. Equal masses of epoxy resin and curing agent were taken again, and other conditions were kept consistent. The maximum force of the epoxy resin during the second demolding process was 66.89 N. Similarly, the maximum force of the epoxy resin during the third demolding process was 94.55 N. Following the same steps and conditions, two more parallel experiments were performed, and the maximum demolding force of the epoxy resin during demolding was recorded. Table 2 Maximum release force of epoxy resin when it leaves the mold at 150°C First Model 43.22 43.98 44.02 43.74 0.135 Second Model 66.89 67.25 66.47 66.87 0.102 Third Model 94.55 95.22 94.88 94.88 0.075

[0023] Under the same process conditions, the release agent was used to conduct three release force tests on epoxy resin. Each test involved removing the first three molds, and the data are recorded in Table 2. According to Table 2, the maximum force F measured in the parallel tests for each mold of epoxy resin showed relatively small fluctuations, indicating strong data repeatability. Therefore, the results of this method are reliable.

[0024] The above embodiments are merely examples to illustrate the present utility model. Their purpose is to enable those skilled in the art to understand the content of the present utility model and implement it. They should not be used to limit the scope of protection of the present utility model. All equivalent changes or modifications made in accordance with the spirit and essence of the present utility model should be covered within the scope of protection of the present utility model.

Claims

1. A mold for testing the magnitude of demolding force, comprising an upper base (1), a lower base (2), a cylindrical tube (3), and a pull rod (4), characterized in that: The tube (3) is fixed together by the upper base (1) and the lower base (2). The pull rod (4) does not contact the upper base (1), the lower base (2), or the tube (3). The pull rod (4) is fixed together with the object to be removed. The object to be removed is removed from the mold by pulling the pull rod (4).

2. A mold for testing the magnitude of demolding force according to claim 1, characterized in that: The upper base (1) and the lower base (2) contain inner wires (7), both with an inner diameter of 6cm. There are holes (5) at the four corners for fixing, with an inner diameter of 0.3cm. The upper base (1) is hollow, and the lower base (2) is half hollow.

3. A mold for testing the magnitude of demolding force according to claim 1, characterized in that: The two ends of the tube (3) are external threads (8), the outer diameter is 6cm, and the length is 20cm. The tube (3) is divided into an upper mold (3-1) and a lower mold (3-2), which are fixed together by the internal threads (7) of the upper base (1) and the lower base (2). At the same time, the tube (3) The inner wall has a uniformly distributed tooth-like structure (9).

4. A mold for testing the magnitude of demolding force according to claim 1, characterized in that: The pull rod (4) is 25cm long and contains an accessory fixing plate (6) with a diameter of 3cm. The fixing plate (6) enhances the resistance of the pull rod (4) and the object to be removed, thereby allowing the object to be removed to be smoothly removed from the mold.

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