Bonding joint for testing bonding strength of liquid glue and testing device

Abstract

The utility model relates to a bonding joint and a testing device for testing the bonding strength of liquid glue, the bonding joint comprises a first sample piece and a second sample piece which are arranged in parallel, the center of the first sample piece is provided with a pushing hole for a pushing column to pass through, the size of the second sample piece is smaller than that of the first sample piece, and the first sample piece and the second sample piece are arranged in parallel. The center of the second sample piece is right opposite to the center of the pushing hole. The release film is arranged between the first sample wafer and the second sample wafer along the edge of the second sample wafer, a through hole is formed in the center of the release film, the diameter of the through hole is larger than that of the pushing hole, and an annular groove is defined by a gap between the first sample wafer and the second sample wafer through the release film; and the to-be-tested liquid glue is filled in the annular groove so as to bond the first sample piece and the second sample piece into a whole. According to the utility model, a test can be carried out in a manner of pushing away the bonding joint, a grabbing lug does not need to be arranged on the bonding joint, tension equipment can be simplified, the shape, the thickness and the area of the liquid glue in a bonding state can be restrained through the design of the release film, and meanwhile, even if redundant liquid glue overflows, a test result cannot be influenced.

Description

Technical Field

[0001] The utility model relates to the technical field of bonding strength testing, in particular to a bonding joint and a testing device for testing the bonding strength of liquid glue. Background Art

[0002] In the industrial adhesive material industry, such as adhesives and tapes, bonding strength is one of the basic technical indicators of the product. Manufacturers usually use "T"-shaped bonded samples to make bonding joints, and then use a tensile test machine to test the bonding strength of the adhesive products. Figure 1 As shown, a "T"-shaped bonded specimen 1 has a flat surface 11 on the bonding surface and tabs 12 extending from the non-bonding surface. These tabs are used for tensile testing after clamping to a tensile testing machine. Because these tests are destructive, test specimens are rarely reusable and require high quantities of consumables. Furthermore, the T-shaped bonded specimens require machining of both the flat surface and tabs, requiring the use of precision tensile testing machine fixtures, which can be costly. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a bonding joint and a testing device for testing the bonding strength of liquid glue. The test can be performed by pushing the bonding joint open. There is no need to set a grab ear on the bonding joint, which can simplify the tensile equipment. Moreover, through the design of the release film, the shape, thickness and area of ​​the liquid glue bonding state can be constrained. At the same time, the overflow of excess liquid glue will not affect the test results.

[0004] The utility model is realized by the following scheme: a bonding joint for testing the bonding strength of liquid glue, comprising:

[0005] A first sample and a second sample are arranged in parallel, wherein the first sample has a center having a push hole for a push pin to pass through, the second sample is smaller than the first sample, and the center of the second sample is aligned with the center of the push hole;

[0006] a release film, arranged between the first sample sheet and the second sample sheet along the edge of the second sample sheet, the release film having a through hole in the center thereof, the diameter of the through hole being larger than the diameter of the push hole, and the gap between the first sample sheet and the second sample sheet being enclosed by the release film to form an annular groove;

[0007] The liquid glue to be tested is filled in the annular groove to bond the first sample piece and the second sample piece into a whole.

[0008] A further improvement of the adhesive joint for liquid adhesive bonding strength testing of the present invention is that a single side of the release film is provided with adhesive backing for being adhered to the surface of the first sample sheet, and the surface of the release film except the adhesive backing surface is coated with a release agent.

[0009] A further improvement of the adhesive joint for liquid adhesive bonding strength testing of the present invention is that the surface of the release film except for the adhesive backing surface is made of low surface energy material.

[0010] A further improvement of the adhesive joint for liquid adhesive bonding strength testing of the utility model is that the low surface energy material is selected from PET, PE, PP, and OPP.

[0011] A further improvement of the adhesive joint for testing the bonding strength of liquid glue according to the present invention lies in that the release agent is selected from a silicon release agent and a fluorine release agent.

[0012] A further improvement of the adhesive joint for liquid adhesive bonding strength testing of the present invention is that the first sample piece is a circular or rectangular flat plate, and the second sample piece is a circular or rectangular flat plate.

[0013] The present invention also provides a liquid adhesive bonding strength testing device, comprising a bonding joint as described in any of the above items, a push column for applying a thrust from the push hole to the second sample piece, and a reaction force bracket for providing a return force to the first sample piece when the push column applies a thrust to the second sample piece.

[0014] A further improvement of the liquid adhesive bonding strength testing device of the present invention is that the cross-section of the reaction bracket is U-shaped, the edge of the first sample extends out of the second sample, and the reaction bracket accommodates the second sample and is supported on the edge of the first sample.

[0015] A further improvement of the liquid adhesive bonding strength testing device of the present invention is that the distal end of the push pin is formed into a spherical surface.

[0016] A further improvement of the liquid adhesive bonding strength testing device of the present invention is that it also includes an environmental box for covering the outside of the bonding joint and the reaction force bracket, and the environmental box has a temperature control function to facilitate maintaining the specified temperature in the box during the test.

[0017] This utility model can be used to test adhesive joints by pushing them apart, eliminating the need for gripping ears on the joints and simplifying the tensioning equipment. Furthermore, this utility model is suitable for testing the bonding strength of liquid adhesives. The design of the release film can constrain the shape, thickness, and area of ​​the liquid adhesive bond. Even if excess liquid adhesive overflows, the release film will not be able to form a bond, thus not affecting the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A three-dimensional schematic diagram of a traditional "T"-shaped bonded sample is shown.

[0019] Figure 2A schematic elevation view of the adhesive joint of the present invention is shown.

[0020] Figure 3 A schematic elevation view of the adhesive joint of the utility model filled with liquid glue to be tested is shown.

[0021] Figure 4 Shown is a planar schematic diagram of the release film of the present invention.

[0022] Figure 5 Shown is a schematic elevation view of the testing device of the present invention. DETAILED DESCRIPTION

[0023] To address the complex processes, high consumables consumption, and high requirements for tensile testing equipment associated with traditional adhesive joints, the present invention provides an adhesive joint and testing device for testing the bonding strength of liquid adhesives. This device allows for testing by pushing the adhesive joint apart, eliminating the need for gripping tabs on the joint and simplifying the tensile testing equipment. Furthermore, the design of the release film constrains the shape, thickness, and area of ​​the liquid adhesive bond. Furthermore, even if excess liquid adhesive overflows, the test results will not be affected. The following describes the adhesive joint and testing device for testing the bonding strength of liquid adhesives, using specific embodiments and accompanying drawings.

[0024] See Figures 2 to 5 As shown, a bonding joint for liquid adhesive bonding strength testing comprises:

[0025] The first and second samples 2 and 3 are arranged in parallel. The first sample 2 has a central ejection hole 21 for the ejection column 6 to pass through. The second sample 3 is smaller than the first sample 2, and the center of the second sample 3 is aligned with the center of the ejection hole 21. Both the first and second samples 2 and 3 are made of simple plate materials, such as circular or rectangular plates, which easily achieve high flatness. Furthermore, the plates can be made of a variety of materials, including various metal and non-metal materials.

[0026] The release film 4 is padded between the first sample 2 and the second sample 3 along the edge of the second sample 3. A through hole 41 is provided in the center of the release film 4. The diameter of the through hole 41 is larger than the diameter of the push hole 21. The gap between the first sample 2 and the second sample 3 is enclosed by the release film 4 to form an annular groove 5. Specifically, a single side of the release film 4 is provided with a backing adhesive 42 for adhering to the surface of the first sample 2. The surface of the release film 4 except the backing adhesive 42 is made of low surface energy materials, such as PET, PE, PP, OPP, etc. The outside of the low surface energy material (i.e., the non-backing adhesive surface of the release film 4) should be surface treated, including coating with a release agent such as a silicone release agent and a fluorine release agent, so that it has an extremely light and stable release force on the liquid glue to be tested. Release film is a common material on the market and can be purchased at a low cost. The outer contour of the release film can be processed into a rectangle or a circle according to the shape of the second sample 3, and the outer contour size is slightly smaller than the outer contour size of the second sample, and the difference is, for example, 1mm to 5mm. The through hole 41 in the center of the release film 4 is circular, and the radius size is larger than the radius size of the push hole 21 of the first sample 2, and the difference is equal to the width required for the liquid glue to be tested. The thickness of the release film 4 is selected according to the required thickness of the liquid glue to be tested, and the values ​​should be equal. If the release film cannot reach the test thickness, multiple layers can be stacked. In other words, the size of the annular groove formed by the setting of the release film 4 should be consistent with the size required for the liquid glue to be tested;

[0027] The liquid glue to be tested is filled in the annular groove 5 to bond the first sample piece 2 and the second sample piece 3 into a whole.

[0028] When making the above-mentioned adhesive joint, the typical process sequence is: attach the release film 4 to the first sample 2, and ensure that the through hole 41 on the release film 4 is aligned with the center of the push hole 21 on the first sample 2; Figure 3 The liquid glue to be tested is applied to the position of the annular groove 5 shown; then the second sample 3 is assembled, and usually pressure is required to make the liquid glue to be tested fill the annular groove 5; then the pressure is maintained and the liquid glue to be tested is waited for to solidify to reach the final bonding strength. Through the above process, the first sample 2, the second sample 3, the release film 4 and the liquid glue to be tested together form a bonding joint for the bonding strength test of the liquid glue to be tested. In summary, the shape, thickness and area of ​​the bonding state of the liquid glue can be constrained by the release film 4, but the amount of glue applied should be guaranteed so that the glue can fill the annular groove 5 area. Even if excess liquid glue overflows, it will not affect the test results because the release film cannot form bonding strength.

[0029] A liquid adhesive bonding strength testing device, see Figure 5As shown, it includes a bonding joint as described in any of the above items, a push column 6 for applying a push force from the push hole 21 to the second sample 3, and a reaction bracket 7 for providing a return force to the first sample 2 when the push column 6 applies a push force to the second sample 3. Specifically, the push column 6 is installed on a tensile testing machine, which can be a tensile testing machine used for traditional bonding strength testing. It is only necessary to set a push fixture on the tensile testing machine to install the push column 6. The push fixture has a significant simplification effect compared to the traditional gripping clamp. The edge 22 of the first sample 2 extends out of the second sample 3. The reaction bracket 7 has a U-shaped cross-section and a size comparable to that of the first sample 2. The inner diameter of the reaction bracket 7 is slightly larger than the outer diameter of the second sample 3, so that the reaction bracket 7 can accommodate the second sample 3 and support the edge 22 of the first sample 2.

[0030] During testing, a push pin 6 passes through the push hole 21 of the first sample 2 in the bonded joint and pushes the second sample 3, thereby achieving a tensile test. Connecting the tensile testing machine to this push pin 6 allows the bond strength at break to be measured. The end of the push pin 6 is machined into a spherical shape to ensure that the push force is always perpendicular to the bonding surface, thus mitigating low test strengths caused by manufacturing precision issues in the bonded joint.

[0031] As a preferred embodiment, the testing apparatus also includes an environmental chamber positioned over the bonded joint and reaction bracket. This chamber features temperature control to maintain a specified temperature during testing, making it suitable for testing under various environmental conditions, such as high and low temperatures. Because the bonded joint, ejector column, and reaction bracket are extremely compact and do not occupy excessive space, they can be fitted with a standard-sized environmental chamber, eliminating the need for a custom-built large chamber and reducing testing costs.

[0032] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. A person skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention. The scope of protection of the present invention shall be determined by the scope defined in the appended claims.

Claims

1. A bonding joint for testing the bonding strength of liquid glue, characterized in that: include: A first sample and a second sample are arranged in parallel, wherein the first sample has a center having a push hole for a push pin to pass through, the second sample is smaller than the first sample, and the center of the second sample is aligned with the center of the push hole; a release film, arranged between the first sample sheet and the second sample sheet along the edge of the second sample sheet, the release film having a through hole in the center thereof, the diameter of the through hole being larger than the diameter of the push hole, and the gap between the first sample sheet and the second sample sheet being enclosed by the release film to form an annular groove; The liquid glue to be tested is filled in the annular groove to bond the first sample piece and the second sample piece into a whole.

2. The adhesive joint for liquid adhesive bonding strength testing according to claim 1, characterized in that: One side of the release film is provided with adhesive backing for being adhered to the surface of the first sample sheet. The surface of the release film except the adhesive backing surface is coated with a release agent.

3. The adhesive joint for liquid adhesive bonding strength testing according to claim 2, characterized in that: The surface of the release film except the adhesive backing surface is made of low surface energy material.

4. The adhesive joint for liquid adhesive bonding strength testing according to claim 3, characterized in that: The low surface energy material is selected from PET, PE, PP, and OPP.

5. The adhesive joint for liquid adhesive bonding strength testing according to claim 2, characterized in that: The release agent is selected from silicone release agent and fluorine release agent.

6. The adhesive joint for liquid adhesive bonding strength testing according to claim 1, wherein: The first sample piece is a circular or rectangular flat plate, and the second sample piece is a circular or rectangular flat plate.

7. A liquid adhesive bonding strength testing device, characterized in that: include: The adhesive joint according to any one of claims 1 to 6; A pulling device for applying a thrust, wherein the pulling device applies a thrust from the pushing hole to the second sample piece via a pushing column; and A reaction force bracket is used to provide a return force to the first sample when the push column applies a thrust to the second sample.

8. The liquid adhesive bonding strength testing device according to claim 7, characterized in that: The reaction bracket has a U-shaped cross section, the edge of the first sample extends beyond the second sample, and the reaction bracket accommodates the second sample and is supported on the edge of the first sample.

9. The liquid adhesive bonding strength testing device according to claim 7, wherein: The end of the push pin is formed into a spherical surface.

10. The liquid adhesive bonding strength testing device according to claim 7, wherein: It also includes an environmental box for covering the outside of the bonding joint and the reaction bracket. The environmental box has a temperature control function so that the temperature inside the box can be maintained at a specified temperature during the test.

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