Drop hammer testing device

Abstract

According to one embodiment of the utility model, the drop hammer testing device comprises glass; the clamp is arranged on the glass; the drop hammer ball impacts the upper surface of the glass; and an impact plate including an impact surface adjacent to a lower surface opposite to the upper surface and on which the glass is placed, the weight of the drop weight ball being 0.5 g or more and 1 g or less, and the jig applying a pressure of 8.6 kPa or more and 21.6 kPa or less to the glass in the thickness direction to improve dispersion of strength evaluation data of the glass.

Description

Technical Field

[0001] The utility model relates to a drop hammer test device, and more particularly to a drop hammer test device capable of improving the reliability of glass strength evaluation. Background Art

[0002] Various display devices are being developed for multimedia devices such as televisions, mobile phones, tablet computers, navigation systems, and game consoles. In particular, recent developments are underway for display devices that have flexible display components that can be folded or rolled to enhance portability and user convenience.

[0003] Ultra-Thin Glass (UTG) can be used in foldable or rollable displays. Ultra-Thin Glass is not only thinner than 100 μm, making it flexible and foldable, but also has the properties of a scratch-resistant glass material.

[0004] Ultra-thin film tempered glass plays a role in protecting display devices from external foreign matter and impacts, but in order to select an appropriate material, reliable strength evaluation is required. Utility Model Content

[0005] The purpose of the utility model is to provide a reliable drop hammer test device which can adjust the weight of a drop hammer ball and the pressure applied by a fixture to glass within a certain range.

[0006] Another object of the present invention is to provide a reliable drop hammer test method that can adjust the weight of the drop hammer ball and the pressure applied to the glass by the fixture within a certain range.

[0007] According to one embodiment of the present invention, a drop hammer test device includes: glass; a fixture configured on the glass; a drop hammer ball that strikes the upper surface of the glass; and an impact plate including an impact surface adjacent to a lower surface opposite to the upper surface and on which the glass is placed, wherein the weight of the drop hammer ball is greater than 0.5g and less than 1g, and the fixture applies a pressure of greater than 8.6kPa and less than 21.6kPa to the glass in the thickness direction.

[0008] In one embodiment, the clamp may include a groove, and the shape of the groove on a plane defined by a first direction intersecting the thickness direction of the clamp and a second direction intersecting the first direction has a quadrilateral shape with one side being greater than 7 mm and less than 9 mm.

[0009] In one embodiment, the area of ​​the groove on the plane is 49 mm. 2 Above and 81mm 2 the following.

[0010] In one embodiment, the weight of the clamp may be greater than or equal to 0.8 kg and less than or equal to 2 kg.

[0011] In one embodiment, the clamp may be directly disposed on the glass.

[0012] In one embodiment, the contact area between the clamp and the glass may be 850 mm 2 Above and 950mm 2 the following.

[0013] In one embodiment, the glass may be directly disposed on the impact surface.

[0014] In one embodiment, the impact plate may be formed of sandpaper.

[0015] In one embodiment, the surface roughness of the sandpaper may be 180 Grit.

[0016] In one embodiment, the drop weight testing apparatus may further include a support base plate disposed below the impact plate.

[0017] In one embodiment, the support substrate may be formed of granite.

[0018] In one embodiment, the diameter of the drop hammer ball may be greater than or equal to 5 mm and less than or equal to 7 mm.

[0019] In one embodiment, the drop weight ball may be formed of at least one of iron and aluminum.

[0020] In one embodiment, the drop weight test device may further include a drop weight adjustment portion for positioning the drop weight ball at a predetermined height from the upper surface of the glass in the groove.

[0021] According to one embodiment of the present invention, the drop hammer test method includes: a step of placing the glass on an impact plate; a step of directly disposing a fixture including a groove on the glass; a step of making the fixture close to the glass so as to apply a pressure of 8.6 kPa or more and 21.6 kPa or less to the glass in the thickness direction; a step of positioning the drop hammer ball at a predetermined height from the top of the glass in the groove; and a step of dropping the drop hammer ball to collide with the top of the glass, wherein the weight of the drop hammer ball is 0.5 g or more and 1 g or less.

[0022] In one embodiment, the groove may have a quadrilateral shape with a side being not less than 7 mm and not more than 9 mm in a plane defined by a first direction intersecting the thickness direction of the jig and a second direction intersecting the first direction.

[0023] In one embodiment, the area of ​​the groove on the plane is 49 mm. 2 Above and 81mm 2 the following.

[0024] In one embodiment, the impact plate may include sandpaper, and the surface roughness of the sandpaper may be 180 Grit.

[0025] In one embodiment, the drop weight test method may further include the step of disposing the impact plate on a support substrate before the step of placing the glass on the impact plate.

[0026] In one embodiment, the diameter of the drop hammer ball may be greater than or equal to 5 mm and less than or equal to 7 mm.

[0027] The drop hammer test device of the utility model can adjust the weight of the drop hammer ball and the pressure applied to the glass by the clamp within a certain range, thereby improving the dispersion of data in the evaluation of glass strength.

[0028] In addition, the drop hammer test method of the present invention can adjust the weight of the drop hammer ball and the pressure applied to the glass by the fixture within a certain range, thereby providing a reliable glass strength evaluation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a three-dimensional diagram of a drop weight test device according to one embodiment of the present invention.

[0030] Figure 2 It is a three-dimensional diagram of a drop weight test device according to one embodiment of the present invention.

[0031] Figure 3 It is an exploded perspective view of a drop weight test device according to one embodiment of the present invention.

[0032] Figure 4 It is along Figure 1 A cross-sectional view taken along line II'.

[0033] Figure 5 4 is a flow chart of a drop weight test method according to an embodiment of the present invention.

[0034] Figure 6 FIG. 1 is a diagram showing a portion of a drop weight test method according to an embodiment of the present invention.

[0035] Figure 7 FIG. 1 is a diagram showing a portion of a drop weight test method according to an embodiment of the present invention.

[0036] Figures 8a to 8cFIG. 1 is a diagram showing a portion of a drop weight test method according to an embodiment of the present invention.

[0037] (Explanation of Reference Numerals)

[0038] DTD: Drop Test Device JG: Grip

[0039] FB: Falling Hammer GL: Glass

[0040] GS: Top IP: Impact Plate

[0041] IPS: Impact Surface HM: Grooved DETAILED DESCRIPTION

[0042] In this specification, when it is mentioned that a certain component (or region, layer, part, etc.) is "on" other components, "connected to" or "combined with" other components, it means that the certain component can be directly configured / connected / combined with other components or a third component can be configured between them.

[0043] The same reference numerals refer to the same components. In the accompanying drawings, the thickness, proportions, and dimensions of the components are exaggerated for the purpose of effectively illustrating the technical content. "And / or" includes all possible combinations of the associated components.

[0044] Terms such as "first" and "second" may be used to describe various constituent elements, but the constituent elements are not limited by these terms. These terms are used solely to distinguish one constituent element from other constituent elements. For example, without departing from the scope of the present invention, the first constituent element may be named the second constituent element, and similarly, the second constituent element may be named the first constituent element. Unless otherwise expressly indicated in the context, a singular expression encompasses a plural expression.

[0045] In addition, terms such as “below,” “lower side,” “above,” and “upper side” are used to describe the relationship between components shown in the drawings. These terms are relative concepts and are described based on the directions shown in the drawings.

[0046] Terms such as "including" or "having" should be understood as being used to specify the existence of features, numbers, steps, tasks, constituent elements, parts or their combinations recorded in the specification, and do not preclude the existence or additional possibilities of one or more other features or numbers, steps, tasks, constituent elements, parts or their combinations.

[0047] In this specification, "directly configured" may mean that there is no additional layer, film, region, disk, component, etc. between a structure such as a layer, film, region, disk, component, etc. and another member. For example, "directly configured" may mean that two layers or two components are configured without using an additional component such as a bonding component between them.

[0048] Unless otherwise defined, all terms (including technical and scientific terms) used in this specification have the same meanings as those commonly understood by those skilled in the art to which this utility model belongs. In addition, terms such as terms defined in commonly used dictionaries should be interpreted as having the same meanings as those in the context of the relevant technology, and unless otherwise explicitly defined, should not be interpreted as having overly idealized or formalized meanings.

[0049] In this specification, the third direction DR3 is defined as a thickness direction. The first direction DR1 intersects with the third direction DR3, and the second direction DR2 intersects with the first direction DR1.

[0050] In this specification, “on a plane” means on a plane defined by the first direction DR1 and the second direction DR2 .

[0051] Hereinafter, a drop weight test device DTD and a drop weight test method according to an embodiment of the present invention will be described.

[0052] Figure 1 It is a three-dimensional diagram of a drop weight test device according to one embodiment of the present invention. Figure 2 It is a three-dimensional diagram of a drop weight test device according to one embodiment of the present invention. Figure 3 It is an exploded perspective view of a drop weight test device according to one embodiment of the present invention. Figure 4 It is along Figure 1 A cross-sectional view taken along line II'. Figure 2 It shows that Figure 1 This is a situation in which the drop weight adjustment portion FC moves in the first direction DR1 and the drop weight ball FB falls in the third direction DR3 by gravity.

[0053] Refer to it together Figures 1 to 4 According to an embodiment, a drop weight test device DTD includes a glass GL, a fixture JG, a drop weight ball FB, and an impact plate IP.

[0054] The jig JG is placed on the glass GL. The falling ball FB strikes the upper surface GS of the glass GL. The impact plate IP includes an impact surface IPS adjacent to the lower surface opposite to the upper surface GS and on which the glass GL is placed.

[0055] The drop weight test device DTD is a device for measuring the strength of glass GL, which can be used as a display device window. Glass GL can be used as a window for large display devices such as televisions and monitors, as well as small and medium-sized display devices such as smart phones, tablets, car navigation systems, and game consoles. Glass GL can be a material part for display cover windows as ultra-thin film strengthened glass (UTG, Ultra thinglass). The thickness of glass GL can be more than 1 micrometer and less than 200 micrometers. With the trend of related industries that the thickness of the window is gradually becoming thinner, chemical strengthening can be performed to increase the strength of the thinned window. In order to use a window that is thin and high in strength, it is necessary to select glass with appropriate strength. The glass GL is arranged between the fixture JG and the impact plate IP. The glass GL can be directly arranged on the impact surface IPS. As shown in FIG. Figure 1 As shown, the area of ​​the glass GL on the plane may be the same as the area of ​​the impact plate IP on the plane. However, the present invention is not limited thereto, and the area of ​​the glass GL on the plane may be smaller than the area of ​​the impact plate IP on the plane.

[0056] The weight of the clamp JG can be greater than 0.8 kg and less than 2 kg. For example, the weight of the clamp JG can be 0.8 kg. The clamp JG is directly placed on the upper surface GS of the glass GL and applies a pressure of greater than 8.6 kPa and less than 21.6 kPa to the glass GL in the thickness direction. For example, the clamp JG can be directly placed on the upper surface GS of the glass GL and apply a pressure of 8.6 kPa to the glass GL in the thickness direction, that is, in the third direction DR3. The clamp JG can apply a pressure of 8.6 kPa to the glass GL in the downward direction. If the clamp JG applies pressure to the glass GL in the downward direction, the glass GL and the impact plate IP can be in close contact. The pressure applied by the clamp JG to the glass GL in the thickness direction is proportional to the weight of the clamp JG. Therefore, the weight of the clamp JG can be adjusted to adjust the pressure applied by the clamp JG to the glass GL in the thickness direction within a certain range. If the pressure applied by the clamp JG to the glass GL in the thickness direction is less than 8.6 kPa, the clamp JG and the glass GL are not in sufficient close contact and the dispersion of the data is not improved. In the case where the pressure applied by the jig JG to the glass GL in the thickness direction exceeds 21.6 kPa, a crack CK may be generated on the lower surface of the glass GL before the drop weight test is performed by the pressure applied by the jig JG to the glass GL (see Figure 8c ).

[0057] The fixture JG may include a groove HM. The shape of the groove HM on the plane defined by the first direction DR1 and the second direction DR2 may have a quadrilateral shape with a side being greater than 7 mm and less than 9 mm. For example, the groove HM may include a regular quadrilateral shape with a side being 8 mm. The groove HM may be an empty space including a quadrangular prism shape. The groove HM may be in the form of one side being connected to the outside, and the remaining side surfaces being surrounded by the fixture JG. In the case where the shape of the groove HM on the plane is a circular shape, the energy loss may become greater in the process of converting the potential energy of the drop ball FB into kinetic energy through friction when the area of ​​contact between the drop ball FB and the fixture JG becomes wider. The fixture JG may play a role in accommodating the drop ball FB in the groove HM so that the drop ball FB can be guided in a manner that it can fall in the third direction DR3 by gravity. That is, the groove HM may be a space in which the drop ball FB can fall in the third direction DR3. The area of ​​the groove HM on the plane may be 49 mm 2 Above and 81mm 2 For example, the area of ​​the groove HM on the plane may be 64 mm 2 If the area of ​​the groove HM on the plane is less than 49mm 2 If the area of ​​the groove HM on the plane exceeds 81mm, the groove HM cannot accommodate the falling ball FB and cannot guide the falling ball FB. 2 , the jig JG and the glass GL are not in close contact with each other and the data dispersion may become larger.

[0058] The fixture JG can be directly placed on the glass GL. The area of ​​the glass GL on the plane can be larger than the contact area between the glass GL and the fixture JG. The contact area between the glass GL and the fixture JG can be 850mm 2 Above and 950mm 2 For example, the contact area between the glass GL and the fixture JG can be 911mm 2 The contact area between the glass GL and the fixture JG is less than 850mm 2 In the case of , it is difficult to form sufficient supporting force and the clamp JG may be easily detached. When the contact area between the glass GL and the clamp JG is more than 950mm 2 In this case, in order to achieve the pressure range that the jig JG applies to the glass GL in the thickness direction, the weight of the jig JG needs to be unnecessarily increased, which may increase the cost required to provide the jig JG.

[0059] The drop ball FB is received in the groove HM of the jig JG and falls in the third direction DR3 to strike the top surface GS of the glass GL. The weight of the drop ball FB is not less than 0.5g and not more than 1g. For example, the weight of the drop ball FB can be 0.88g. When the weight of the drop ball FB is less than 0.5g, the crack CK for generating the glass GL (see Figure 8c ) is too high and the manufacturing of the fixture JG may become difficult. In the case where the weight of the drop ball FB exceeds 1g, when the drop ball FB hits the upper surface GS of the glass GL, the upper surface GS of the glass GL may be damaged. The diameter of the drop ball FB can be greater than 5mm and less than 7mm. For example, the diameter of the drop ball FB can be 6mm. If the diameter of the drop ball FB is less than 5mm, the contact area between the drop ball FB and the upper surface GS of the glass GL is small, and as a result, the possibility of damage to the upper surface GS increases. If the diameter of the drop ball FB exceeds 7mm, there is a problem that it is difficult to accommodate the groove HM of the fixture JG. The drop ball FB can include at least one of iron and aluminum. For example, the drop ball FB can include aluminum.

[0060] The impact plate IP can be arranged under the glass GL. It can be that the impact plate IP is directly arranged under the glass GL, and the glass GL is directly arranged on the impact surface IPS of the impact plate IP. The impact surface IPS of the impact plate IP may include concavo-convex. If the falling hammer ball FB falls in the third direction DR3 and hits the upper surface GS of the glass GL, the kinetic energy of the falling hammer ball FB is transferred from the upper surface GS of the glass GL to the lower surface, and the glass GL applies pressure to the impact plate IP. Through the reaction equivalent to the pressure applied from the glass GL to the impact plate IP, the concavo-convex formed on the impact surface IPS of the impact plate IP can apply pressure to the lower surface GS of the glass GL. That is, the lower surface of the glass GL can be in contact with the impact surface IPS of the impact plate IP. If the impact surface IPS includes concavo-convex, a crack CK may be generated on the lower surface of the glass GL (refer to Figure 8c ).

[0061] The impact plate IP may include sandpaper. The impact plate IP may include sandpaper, and the upper surface of the sandpaper may provide an impact surface IPS for the glass GL. The surface roughness of the sandpaper may be 180 grit. If the surface roughness of the sandpaper is less than 180 grit and is coarser, the likelihood of the glass GL being broken by the falling ball FB at a very low height increases, hindering data analysis. If the surface roughness of the sandpaper is greater than 180 grit and is softer, the range of heights at which the falling ball FB can break the glass GL becomes excessively wide, failing to improve data dispersion.

[0062] The drop weight test device DTD of one embodiment may further include a support substrate SP disposed below the impact plate IP. When the drop weight ball FB falls in the third direction DR3 and strikes the upper surface GS of the glass GL, the support substrate SP can minimize energy dispersion and prevent fluctuations in the fixture JG, the glass GL, and the impact plate IP. The support substrate SP may have a larger surface area than the impact plate IP. If the support substrate SP has a larger surface area than the impact plate IP, it can provide a more stable support. The support substrate SP may include rock. For example, the support substrate SP may include granite.

[0063] The drop weight test device DTD of one embodiment may further include a drop weight adjustment portion FC. The drop weight adjustment portion FC can be used to position the drop weight ball FB at a predetermined height from the upper surface GS of the glass GL within the slot HM. A user can position a portion of the drop weight adjustment portion FC within the slot HM and place the drop weight ball FB on the drop weight adjustment portion FC. The user can then quickly move the drop weight adjustment portion FC in the first direction DR1, causing the drop weight ball FB to drop in the third direction DR3.

[0064] Figure 5 4 is a flow chart of a drop weight test method according to an embodiment of the present invention. Figure 6 FIG. 1 is a diagram showing a portion of a drop weight test method according to an embodiment of the present invention. Figure 7 FIG. 1 is a diagram showing a portion of a drop weight test method according to an embodiment of the present invention. Figures 8a to 8c FIG is a diagram showing a portion of a drop weight test method according to an embodiment of the present invention. Figure 6 Shown in Figure 5 The step (S100) of placing the glass GL on the impact plate IP. Figure 7 Shown in Figure 5 The step of placing the jig JG directly on the glass GL GS (S110). Figures 8a to 8c Shown in Figure 5 The dropping hammer ball FB is accommodated in the groove HM and arranged on the dropping hammer adjustment part FC so as to be at a predetermined height from the upper surface GS of the glass GL, and then the dropping hammer adjustment part FC is removed so that the dropping hammer ball FB hits the upper surface GS of the glass GL and generates a crack CK on the lower side of the glass GL (S120, S130, S140).

[0065] Reference Figure 5According to one embodiment, the drop hammer test method includes the steps of placing glass on an impact plate (S100), directly disposing a fixture including a groove on the glass (S110), pressing the fixture against the glass so as to apply a pressure of 8.6 kPa or more and 21.6 kPa or less to the glass in a thickness direction (S120), positioning a drop hammer ball at a predetermined height from the top of the glass in the groove (S130), and dropping the drop hammer ball to collide with the top of the glass (S140).

[0066] Refer to it together Figure 5 and Figure 6 In the step of placing the glass on the impact plate ( S100 ), the impact plate IP includes an impact surface IPS adjacent to the lower surface opposite to the upper surface GS of the glass GL and on which the glass GL is placed. That is, the lower surface of the glass GL may be in direct contact with the impact surface IPS.

[0067] Refer to it together Figure 5 and Figure 7 In the step (S110) of placing the jig including the groove directly on the glass and in the step (S120) of bringing the jig into close contact with the glass so as to apply a pressure of 8.6 kPa or more and 21.6 kPa or less to the glass in the thickness direction, after aligning the bottom of the jig JG to be parallel to the top GS of the glass GL, the jig JG can be arranged so as to slowly approach the glass GL. When placing the jig JG on the top GS of the glass GL, if the jig JG is placed too quickly, the glass GL may be broken by the jig JG. The jig JG may have the same Figures 1 to 4 Same weight as in the description.

[0068] Reference Figure 8a In the step of positioning the drop weight ball FB at a predetermined height from the top surface of the glass within the groove (S130), the user can utilize the drop weight adjustment portion FC to position the drop weight ball FB at a predetermined height from the top surface GS of the glass GL. The width of the drop weight adjustment portion FC in the second direction DR2 can be less than the width of the groove HM in the second direction DR2. For example, the width of the drop weight adjustment portion FC in the second direction DR2 can be greater than 4 mm and less than 8 mm. If the width of the drop weight adjustment portion FC in the second direction DR2 is less than 4 mm, it may be difficult for the drop weight ball FB to be stably positioned on the drop weight adjustment portion FC, and the scatter of the drop weight test data may not be improved.

[0069] Reference Figure 8b and Figure 8cIf, in the step (S140) of dropping the ball hammer to collide with the top surface of the glass (GL), the ball hammer FB falls and collides with the top surface GS of the glass (GL), the impact energy of the ball hammer FB is transferred from the top surface GS of the glass (GL) to the bottom surface. The impact energy transferred to the bottom surface of the glass (GL) causes the bottom surface of the glass (GL) to collide with the impact surface IP of the impact plate IP, and the resulting reaction may generate a crack CK. Due to the collision of the ball hammer FB, no crack CK is generated on the top surface GS of the glass (GL), but a crack CK may be generated on the bottom surface of the glass (GS). The strength of various types of glass can be evaluated by determining whether cracks CK are generated on the bottom surface of the glass (GS) that is not the top surface GS of the glass (GL) due to the collision of the ball hammer FB. This can also improve data dispersion and classify glasses with similar strength. In the drop hammer test apparatus used in the drop hammer test method of one embodiment, the weight of the ball hammer FB is adjusted to be greater than 0.5g and less than 1g. When the ball hammer FB strikes the top surface GS of the glass (GL), no crack CK is generated on the top surface GS of the glass (GL), but cracks CK are generated on the bottom surface of the glass (GL), thereby achieving the purpose of improving data dispersion.

[0070] Hereinafter, the results of evaluating the strength of various types of glass will be specifically described through a drop weight test method using a drop weight test apparatus according to an embodiment of the present invention.

[0071] The drop weight test apparatus used in the drop weight test method of the embodiment includes Figure 1 The fixture, test object glass, drop hammer ball, impact plate, drop hammer adjustment part and supporting substrate are shown. The test object glass is a product of the company listed in Tables 1, 2 and 3 below. The impact plate is a 272L product of 3M Company, and sandpaper with a roughness of 180Grit is used to place the test object glass on the impact plate. The fixture is a BDT JIG product of MASTEK Company, and a module with a weight of 0.8kg is used and is configured on the test object glass in a manner that applies a pressure of 8.6kPa to the test object glass. The contact area between the fixture and the test object glass is set to 911mm 2 The drop weight ball used was an aluminum sphere with a diameter of 6 mm and a weight of 0.88 g. The support substrate used was a flat granite substrate so that the impact plate, the test object glass, and the fixture placed on the support substrate were placed in a flat environment.

[0072] In the drop hammer test method of the embodiment, after the drop hammer ball is positioned at a predetermined height from the top of the test object glass in the groove, the drop hammer ball is lifted and fixed on the drop hammer adjustment part, the drop hammer adjustment part is removed and the drop hammer ball is dropped so that the drop hammer ball collides with the top of the test object glass. After the drop hammer ball collides, the fixture is removed and it is observed whether cracks are generated on the bottom of the glass. If cracks are not generated, the fixture is reset and the drop hammer test method of an embodiment is performed again. If cracks are generated, the drop hammer test method is performed at a height lower than the drop height of the drop hammer ball in the drop hammer test method. The drop hammer test method of an embodiment is repeated several times by adjusting the drop height of the drop hammer ball to analyze the drop height of the drop hammer ball that generates cracks on the bottom of the test object glass and is shown in the following Tables 1 to 3.

[0073] Tables 1, 2, and 3 below show the crack height (B10) and standard deviation (STD) of each embodiment of the drop hammer test method performed N times on various types of test glass. The results are shown as the minimum drop height (MIN), the maximum drop height (MAX), the average drop height (AVG), and the 10% frequency. When performing the drop hammer test method of the embodiment N times, the drop height can be different for each drop hammer test method and is set within a range from the minimum height (MIN) to the maximum height (MAX). A large B10 value indicates strong glass strength. The standard deviation indicates the degree of data dispersion; a large standard deviation indicates high data dispersion.

[0074]

Table 1

[0075]

[0076]

[0077]

Table 2

[0078]

[0079]

Table 3

[0080]

[0081] The test glass in Table 1 has a lower B10 value than the test glasses in Tables 2 and 3. This suggests that the test glass in Table 1 is weaker than the test glasses in Tables 2 and 3. Looking at different products manufactured by the same company, it is suggested that Corning's GG3, GG5, and GG7 have B10 values ​​of 66.7 cm, 89.8 cm, and 113.9 cm, respectively. This suggests that GG5 is stronger than GG3, and GG7 is stronger than GG5. Similarly, the DT-Pro and DT-Star manufactured by AGC (Asahi Glass Company) have B10 values ​​of 57.4 cm and 106.6 cm, respectively; the T2X-1 and T2X-7 manufactured by NEG (Nippon Electric Glass Company) have B10 values ​​of 75.5 cm and 102.6 cm, respectively; and the Wonder 5 and Wonder 7 manufactured by SDC (Samsung Display Company) have B10 values ​​of 96.5 cm and 135.3 cm, respectively. The drop weight test method according to one embodiment of the present invention can be used to explain the differences in strength between glass types manufactured by the same company. Furthermore, in the examples measured using the drop weight test method according to one embodiment of the present invention, it was confirmed that the standard deviation was small, the dispersion of the data was reduced, and the reproducibility was excellent. In particular, the larger the numbers of Corning's GG3, GG5, and GG7 sizes, the higher the strength. This tendency can be accurately confirmed in the drop weight test method of the present invention.

[0082] According to one embodiment of the present invention, a drop weight test device has a structure in which a fixture applies a pressure within a range of 8.6 kPa to 21.6 kPa to the test object glass. When the drop weight ball strikes the top of the test object glass, the impact energy is effectively transferred to the bottom of the glass, thereby enabling adjustment so that cracks are primarily generated on the bottom of the glass rather than on the top. If the fixture does not press the test object glass to a pressure of 8.6 kPa to 21.6 kPa, warping may occur, increasing the dispersion of the data. In addition, the user can adjust the weight of the drop weight ball of the drop weight test device according to one embodiment within a range of 0.5 g to 1 g, thereby adjusting the weight so that the drop weight ball does not generate cracks on the top of the test object glass. If the drop weight ball is not within the range of 0.5 g to 1 g, the drop weight ball generates cracks on the top of the test object glass, resulting in increased dispersion of the data and making it impossible to accurately classify glasses with different strengths. The user can adjust the pressure range of the glass pressurized by the fixture and the weight of the drop weight ball in the drop weight test apparatus according to one embodiment of the present invention to a predetermined range, so that cracks primarily occur on the underside of the target glass, thereby obtaining consistent test data over repeated tests. Furthermore, the drop weight test method according to one embodiment of the drop weight test apparatus enables the strength of glass to be evaluated and classified under consistent standards. Therefore, the drop weight test apparatus and drop weight test method according to one embodiment of the present invention enable reliable glass strength evaluation with reduced data dispersion.

[0083] While the present invention has been described above with reference to preferred embodiments, those skilled in the art or those with ordinary knowledge in the art will appreciate that various modifications and variations may be made to the present invention without departing from the scope of the present invention and the technical scope as set forth in the appended claims. Therefore, the technical scope of the present invention is not limited to the details set forth in the specification but is determined by the claims.

Claims

1. A drop weight test device, characterized in that: include: Glass; a fixture, disposed on the glass; A falling hammer ball hits the top of the glass; as well as an impact plate including an impact surface adjacent to a lower side opposite to the upper side and on which the glass is placed, The weight of the falling hammer ball is not less than 0.5g and not more than 1g, The jig applies a pressure of 8.6 kPa or more and 21.6 kPa or less to the glass in a thickness direction.

2. The drop weight test device according to claim 1, characterized in that: The fixture includes a slot, The groove has a quadrilateral shape with one side being 7 mm or more and 9 mm or less in a plane defined by a first direction intersecting the thickness direction of the jig and a second direction intersecting the first direction.

3. The drop weight test device according to claim 2, characterized in that: The area of ​​the groove on the plane is 49 mm 2 Above and 81mm 2 the following.

4. The drop weight test device according to claim 1, characterized in that: The weight of the clamp is greater than or equal to 0.8 kg and less than or equal to 2 kg.

5. The drop weight test device according to claim 1, characterized in that: The clamp is directly disposed on the glass.

6. The drop weight test device according to claim 5, characterized in that: The contact area between the fixture and the glass is 850 mm 2 Above and 950mm 2 the following.

7. The drop weight test device according to claim 1, characterized in that: The glass is disposed directly on the impact surface.

8. The drop weight test device according to claim 1, characterized in that: The impact plate is formed from sandpaper.

9. The drop weight test device according to claim 8, characterized in that: The surface roughness of the sandpaper is 180 Grit.

10. The drop weight test device according to claim 1, characterized in that: The drop weight test apparatus further includes a support base plate disposed below the impact plate.

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